/* =============================================
   SATTIMD.COM — Design Tokens & Global Styles
   Medical · Clean · Modern
   ============================================= */

/* --- MEDICAL COLOR PALETTE ---
   Inspired by clinical precision: deep navy,
   clean white, teal accent (echoes medical equipment
   and health data visualization standards)
*/

:root, [data-theme="light"] {
  /* Surfaces */
  --color-bg:             #f4f6f9;
  --color-surface:        #ffffff;
  --color-surface-2:      #f8fafc;
  --color-surface-offset: #edf1f5;
  --color-surface-offset-2: #e4eaf0;
  --color-surface-dynamic: #dce4ed;
  --color-divider:        #dae1ea;
  --color-border:         #ccd4de;

  /* Text */
  --color-text:           #1a2332;
  --color-text-muted:     #5a6a7e;
  --color-text-faint:     #a0b0c0;
  --color-text-inverse:   #f4f6f9;

  /* Primary — Medical Teal */
  --color-primary:        #0a7b8c;
  --color-primary-hover:  #086475;
  --color-primary-active: #064e5c;
  --color-primary-highlight: #cde8ec;

  /* Secondary — Navy */
  --color-navy:           #1e3a5f;
  --color-navy-hover:     #162d4a;

  /* Success */
  --color-success:        #1a7c4f;
  --color-success-hover:  #145f3c;
  --color-success-highlight: #cce8db;

  /* Warning */
  --color-warning:        #b56309;
  --color-warning-highlight: #fde8c8;

  /* Error */
  --color-error:          #c0392b;
  --color-error-hover:    #922b21;
  --color-error-highlight: #fce8e6;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(26, 35, 50, 0.06), 0 1px 2px rgba(26, 35, 50, 0.04);
  --shadow-md: 0 4px 12px rgba(26, 35, 50, 0.08), 0 2px 6px rgba(26, 35, 50, 0.05);
  --shadow-lg: 0 12px 32px rgba(26, 35, 50, 0.10), 0 4px 12px rgba(26, 35, 50, 0.06);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;

  /* Type scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-hero: clamp(2.5rem,   1rem    + 5vw,    4.5rem);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;

  /* Fonts */
  --font-body: 'Inter', 'Helvetica Neue', system-ui, sans-serif;
  --font-display: 'DM Sans', 'Inter', 'Helvetica Neue', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

[data-theme="dark"] {
  --color-bg:             #0e1520;
  --color-surface:        #141d2b;
  --color-surface-2:      #1a2435;
  --color-surface-offset: #1e2a3a;
  --color-surface-offset-2: #243040;
  --color-surface-dynamic: #2a3848;
  --color-divider:        #2e3e54;
  --color-border:         #3a4d64;
  --color-text:           #d8e4f0;
  --color-text-muted:     #7a90a8;
  --color-text-faint:     #4a5e74;
  --color-text-inverse:   #0e1520;
  --color-primary:        #3eb5c8;
  --color-primary-hover:  #2ca0b4;
  --color-primary-active: #1a8da0;
  --color-primary-highlight: #1a3840;
  --color-navy:           #4a7ab5;
  --color-navy-hover:     #3a6a9f;
  --color-success:        #4dbb88;
  --color-success-hover:  #3a9f72;
  --color-success-highlight: #1a3028;
  --color-warning:        #f0a832;
  --color-warning-highlight: #382808;
  --color-error:          #e85555;
  --color-error-hover:    #d44040;
  --color-error-highlight: #3a1010;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.4);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:             #0e1520;
    --color-surface:        #141d2b;
    --color-surface-2:      #1a2435;
    --color-surface-offset: #1e2a3a;
    --color-surface-offset-2: #243040;
    --color-surface-dynamic: #2a3848;
    --color-divider:        #2e3e54;
    --color-border:         #3a4d64;
    --color-text:           #d8e4f0;
    --color-text-muted:     #7a90a8;
    --color-text-faint:     #4a5e74;
    --color-text-inverse:   #0e1520;
    --color-primary:        #3eb5c8;
    --color-primary-hover:  #2ca0b4;
    --color-primary-active: #1a8da0;
    --color-primary-highlight: #1a3840;
    --color-navy:           #4a7ab5;
    --color-navy-hover:     #3a6a9f;
    --color-success:        #4dbb88;
    --color-success-hover:  #3a9f72;
    --color-success-highlight: #1a3028;
    --color-warning:        #f0a832;
    --color-warning-highlight: #382808;
    --color-error:          #e85555;
    --color-error-hover:    #d44040;
    --color-error-highlight: #3a1010;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.4);
  }
}

/* =============================================
   BASE RESET
   ============================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-16);
  overflow-x: hidden;
  width: 100%;
  position: relative;
}

body {
  min-height: 100dvh;
  line-height: 1.6;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  display: flex;
  flex-direction: column;
}

img, picture, video, canvas, svg { display: block; max-width: 100%; height: auto; }
ul[role="list"], ol[role="list"] { list-style: none; }
input, button, textarea, select { font: inherit; color: inherit; }
h1, h2, h3, h4, h5, h6 { text-wrap: balance; line-height: 1.15; font-family: var(--font-display); }
p, li, figcaption { text-wrap: pretty; }

button { cursor: pointer; background: none; border: none; }
table { border-collapse: collapse; width: 100%; }

a, button, [role="button"], input, textarea, select {
  transition: color var(--transition-interactive),
              background var(--transition-interactive),
              border-color var(--transition-interactive),
              box-shadow var(--transition-interactive),
              opacity var(--transition-interactive);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border-width: 0;
}

/* =============================================
   HEADER / NAVIGATION
   ============================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}

.logo-mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-name {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.logo-credential {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 400;
}

/* Nav */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-link {
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  position: relative;
}

.nav-link:hover {
  color: var(--color-text);
  background: var(--color-surface-offset);
}

.nav-link.active {
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: var(--space-4);
  right: var(--space-4);
  height: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transition: transform var(--transition-interactive);
  border-radius: var(--radius-full);
}

.nav-link.active::after {
  transform: scaleX(1);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* Theme toggle */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  flex-shrink: 0;
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-dynamic);
}

/* Mobile menu */
.menu-toggle {
  display: none;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
}

@media (max-width: 640px) {
  .menu-toggle { display: flex; }
  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4) var(--space-6);
    gap: var(--space-2);
    box-shadow: var(--shadow-md);
  }
  .site-nav.open { display: flex; }
  .nav-link { padding: var(--space-3) var(--space-4); }
  .nav-link::after { display: none; }
  .header-inner { position: relative; padding: var(--space-3) var(--space-4); }
}

/* =============================================
   MAIN CONTENT
   ============================================= */
main {
  flex: 1;
}

/* =============================================
   HERO SECTION
   ============================================= */
.hero {
  background: #0a0f1a;
  padding: 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-image {
  display: block;
  width: 100%;
  height: auto;
}

.hero::before {
  display: none;
}

.hero-inner {
  max-width: var(--content-default);
  margin: 0 auto;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-full);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--space-6);
  backdrop-filter: blur(8px);
}

.hero h1 {
  font-size: var(--text-hero);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: white;
  margin-bottom: var(--space-3);
  line-height: 1.05;
}

.hero-credentials {
  font-size: var(--text-base);
  color: rgba(255,255,255,0.75);
  margin-bottom: var(--space-8);
  font-weight: 400;
  letter-spacing: 0.02em;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
  margin-bottom: var(--space-8);
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 500;
  color: rgba(255,255,255,0.88);
  letter-spacing: 0.02em;
}

.hero-tag + .hero-tag::before {
  content: '·';
  margin-right: var(--space-2);
  font-size: var(--text-lg);
  color: rgba(255,255,255,0.4);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-4);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: white;
  color: var(--color-navy);
}

.btn-primary:hover {
  background: rgba(255,255,255,0.9);
  color: var(--color-primary-active);
}

.btn-outline {
  background: rgba(255,255,255,0.1);
  border: 1.5px solid rgba(255,255,255,0.35);
  color: white;
  backdrop-filter: blur(4px);
}

.btn-outline:hover {
  background: rgba(255,255,255,0.2);
}

/* =============================================
   SECTION LAYOUT
   ============================================= */
.section {
  padding: clamp(var(--space-12), 6vw, var(--space-20)) var(--space-6);
}

.section-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
}

.section-inner--narrow {
  max-width: var(--content-default);
}

.section-header {
  margin-bottom: var(--space-10);
  text-align: center;
}

.section-tag {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.section-title {
  font-size: var(--text-xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.section-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 60ch;
  margin: 0 auto;
  line-height: 1.7;
}

/* =============================================
   FEATURE CARDS (Homepage)
   ============================================= */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  text-decoration: none;
  color: var(--color-text);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-interactive), box-shadow var(--transition-interactive), border-color var(--transition-interactive);
}

.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.feature-icon {
  width: 52px;
  height: 52px;
  background: var(--color-primary-highlight);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  flex-shrink: 0;
}

.feature-card h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.feature-card p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
}

.feature-cta {
  margin-top: auto;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* =============================================
   BIO / ABOUT SECTION
   ============================================= */
.bio-section {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.bio-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-12);
  align-items: center;
}

@media (max-width: 768px) {
  .bio-grid { grid-template-columns: 1fr; text-align: center; }
}

.bio-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
}

.bio-avatar {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-navy), var(--color-primary));
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.bio-stats {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  width: 100%;
}

.stat-item {
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  text-align: center;
}

.stat-value {
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
}

.bio-content h2 {
  font-size: var(--text-xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}

.bio-content p {
  color: var(--color-text-muted);
  line-height: 1.75;
  margin-bottom: var(--space-4);
  max-width: 65ch;
}

.credential-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

.credential-list li {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.credential-dot {
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border-radius: 50%;
  flex-shrink: 0;
}

/* =============================================
   CLINICAL RESOURCES PAGE
   ============================================= */
.page-header {
  background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-primary-active) 100%);
  color: white;
  padding: clamp(var(--space-10), 6vw, var(--space-16)) var(--space-6);
}

.page-header-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  text-align: center;
}

.page-breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.6);
  margin-bottom: var(--space-4);
}

.page-breadcrumb a {
  color: rgba(255,255,255,0.7);
  text-decoration: none;
}
.page-breadcrumb a:hover { color: white; }

.page-header h1 {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: white;
  margin-bottom: var(--space-3);
}

.page-header p {
  font-size: var(--text-base);
  color: rgba(255,255,255,0.75);
  max-width: 55ch;
  margin: 0 auto;
}

/* Calculator category sections */
.calc-category {
  margin-bottom: var(--space-12);
}

.category-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 2px solid var(--color-border);
}

.category-icon {
  width: 44px;
  height: 44px;
  background: var(--color-primary-highlight);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  flex-shrink: 0;
}

.category-header h2 {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
}

.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-5);
}

.calc-card {
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  text-decoration: none;
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-interactive), box-shadow var(--transition-interactive), border-color var(--transition-interactive);
}

.calc-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.calc-card-icon {
  width: 40px;
  height: 40px;
  background: var(--color-surface-offset);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
  font-size: var(--text-lg);
  font-weight: 800;
  font-family: var(--font-mono);
  flex-shrink: 0;
}

.calc-card h3 {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.calc-card p {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  line-height: 1.55;
  flex: 1;
}

.calc-card-arrow {
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.disclaimer-box {
  background: var(--color-warning-highlight);
  border: 1px solid var(--color-warning);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  margin-top: var(--space-8);
  display: flex;
  gap: var(--space-4);
  align-items: flex-start;
}

.disclaimer-icon {
  color: var(--color-warning);
  flex-shrink: 0;
  margin-top: 2px;
}

.disclaimer-box p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* =============================================
   CALCULATOR PAGES (Individual)
   ============================================= */
.calc-page {
  max-width: 680px;
  margin: 0 auto;
  padding: var(--space-8) var(--space-6);
}

.calc-back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  margin-bottom: var(--space-6);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.calc-back-link:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.calc-card-header {
  margin-bottom: var(--space-8);
}

.calc-card-header h1 {
  font-size: var(--text-xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.calc-subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* Form elements */
.calc-form {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--space-6);
}

.form-group {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--color-divider);
}

.form-group:last-of-type {
  border-bottom: none;
}

.form-label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  flex: 1;
}

.form-label small {
  display: block;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 400;
  margin-top: var(--space-1);
}

.form-control {
  background: var(--color-surface-offset);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text);
  min-width: 0;
  transition: border-color var(--transition-interactive), box-shadow var(--transition-interactive);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-highlight);
}

.form-control-sm {
  width: 100px;
}

.form-control-md {
  width: 140px;
}

.form-input-group {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* Input field classes (used by newer calculators) */
.input-group {
  margin-bottom: var(--space-4);
}

.input-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.input-field {
  width: 100%;
  background: var(--color-surface-offset);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text);
  min-width: 0;
  transition: border-color var(--transition-interactive), box-shadow var(--transition-interactive);
}

.input-field:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-highlight);
}

.radio-row {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.radio-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  cursor: pointer;
  font-size: var(--text-sm);
  color: var(--color-text);
}

.radio-item input[type="radio"] {
  accent-color: var(--color-primary);
  cursor: pointer;
}

/* Checkbox groups */
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.checkbox-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition-interactive), border-color var(--transition-interactive);
}

.checkbox-item:hover {
  background: var(--color-surface-offset);
  border-color: var(--color-primary);
}

.checkbox-item input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--color-primary);
  flex-shrink: 0;
  margin-top: 1px;
  cursor: pointer;
}

.checkbox-label {
  font-size: var(--text-sm);
  color: var(--color-text);
}

.checkbox-label small {
  display: block;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: 2px;
}

/* Score/checkpoint value badge */
.score-badge {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-primary);
  background: var(--color-primary-highlight);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  white-space: nowrap;
  font-family: var(--font-mono);
}

/* Calculate button */
.btn-calculate {
  width: 100%;
  padding: var(--space-4);
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-lg);
  font-size: var(--text-base);
  font-weight: 700;
  cursor: pointer;
  margin-top: var(--space-6);
  letter-spacing: 0.01em;
}

.btn-calculate:hover {
  background: var(--color-primary-hover);
}

.btn-reset {
  width: 100%;
  padding: var(--space-3);
  background: var(--color-surface-offset);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  margin-top: var(--space-3);
}

.btn-reset:hover {
  background: var(--color-surface-dynamic);
  color: var(--color-text);
}

/* Result box */
.result-box {
  background: var(--color-surface);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-xl);
  padding: var(--space-6) var(--space-8);
  margin-bottom: var(--space-6);
  display: none;
  box-shadow: var(--shadow-md);
}

.result-box.visible {
  display: block;
  animation: slideIn 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.result-box h3 {
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-5);
}

.result-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-divider);
}

.result-item:last-child {
  border-bottom: none;
}

.result-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.result-value {
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-text);
  font-family: var(--font-mono);
}

.result-value.highlight {
  color: var(--color-primary);
  font-size: var(--text-xl);
}

.result-value.warning { color: var(--color-warning); }
.result-value.success { color: var(--color-success); }
.result-value.error   { color: var(--color-error);   }

.result-recommendation {
  margin-top: var(--space-4);
  padding: var(--space-4);
  background: var(--color-primary-highlight);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--color-primary);
  font-weight: 500;
}

/* Notes / Reference section */
.calc-notes {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6) var(--space-8);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.calc-notes h4 {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.calc-notes ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.calc-notes ul li {
  padding-left: var(--space-4);
  position: relative;
  line-height: 1.65;
}

.calc-notes ul li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

.ref-link {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
}

.ref-link:hover { text-decoration: underline; }

/* Algorithm step-flow (for AT localization, Brugada, WPW, idiopathicVT, VT mapping) */
.algo-step {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6) var(--space-8);
  margin-bottom: var(--space-4);
  box-shadow: var(--shadow-sm);
}

.algo-step.hidden { display: none; }

.algo-question {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-5);
  line-height: 1.5;
}

.algo-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.algo-option-btn {
  text-align: left;
  padding: var(--space-4) var(--space-5);
  background: var(--color-surface-offset);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.algo-option-btn:hover {
  background: var(--color-primary-highlight);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.algo-option-btn.selected {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.algo-option-btn.faded {
  opacity: 0.4;
}

.algo-result {
  background: linear-gradient(135deg, var(--color-primary), var(--color-navy));
  color: white;
  border-radius: var(--radius-xl);
  padding: var(--space-6) var(--space-8);
  text-align: center;
  margin-bottom: var(--space-4);
  box-shadow: var(--shadow-md);
}

.algo-result-label {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.75;
  margin-bottom: var(--space-2);
}

.algo-result-value {
  font-size: var(--text-lg);
  font-weight: 800;
  text-transform: capitalize;
}

.algo-history-step {
  opacity: 0.65;
}

.algo-history-step .algo-question {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* Brugada two-col buttons */
.algo-options.two-col {
  flex-direction: row;
  gap: var(--space-4);
}
.algo-options.two-col .algo-option-btn {
  flex: 1;
  text-align: center;
}

.step-indicator {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
}

/* =============================================
   AI PAGE
   ============================================= */
.ai-hero {
  background: linear-gradient(135deg, #0a0f1a 0%, #0a2a3a 50%, #0a4a5a 100%);
  color: white;
  padding: clamp(var(--space-12), 8vw, var(--space-20)) var(--space-6);
  position: relative;
  overflow: hidden;
}

.ai-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 80%, rgba(62, 181, 200, 0.15) 0%, transparent 70%);
}

.ai-hero-inner {
  max-width: var(--content-default);
  margin: 0 auto;
  position: relative;
  text-align: center;
}

.ai-hero h1 {
  font-size: var(--text-hero);
  font-weight: 800;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, white, rgba(62, 181, 200, 0.9));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-4);
}

.ai-hero h2 {
  font-size: var(--text-lg);
  color: rgba(255,255,255,0.65);
  font-weight: 400;
  max-width: 55ch;
  margin: 0 auto;
  line-height: 1.6;
}

/* Article content */
.article-body {
  max-width: var(--content-narrow);
  margin: 0 auto;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-5) var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  margin-bottom: var(--space-8);
}

.article-meta-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-navy), var(--color-primary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: var(--text-base);
  flex-shrink: 0;
  overflow: hidden;
}

.article-meta-info h4 {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
}

.article-meta-info p {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.article-section {
  margin-bottom: var(--space-10);
}

.article-section h2 {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}

.article-section p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.8;
  margin-bottom: var(--space-4);
  max-width: 70ch;
}

.article-section .formula-box {
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-6);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text);
  margin: var(--space-4) 0;
}

.result-highlight-box {
  background: linear-gradient(135deg, var(--color-primary-highlight), var(--color-surface-offset));
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-xl);
  padding: var(--space-6) var(--space-8);
  text-align: center;
  margin: var(--space-6) 0;
}

.result-highlight-box .big-number {
  font-size: var(--text-2xl);
  font-weight: 900;
  color: var(--color-primary);
  font-family: var(--font-mono);
  letter-spacing: -0.03em;
}

.result-highlight-box p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-2);
}

.video-embed {
  border-radius: var(--radius-xl);
  overflow: hidden;
  aspect-ratio: 16/9;
  background: #000;
  margin-bottom: var(--space-8);
  box-shadow: var(--shadow-lg);
}

.video-embed iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* =============================================
   FOOTER
   ============================================= */
.site-footer {
  background: var(--color-navy);
  color: rgba(255,255,255,0.7);
  padding: var(--space-10) var(--space-6);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-8);
  flex-wrap: wrap;
}

.footer-brand h3 {
  font-size: var(--text-base);
  font-weight: 700;
  color: white;
  margin-bottom: var(--space-2);
}

.footer-brand p {
  font-size: var(--text-xs);
  line-height: 1.6;
  max-width: 42ch;
}

.footer-links {
  display: flex;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.footer-link {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.6);
  text-decoration: none;
  transition: color var(--transition-interactive);
}

.footer-link:hover {
  color: white;
}

.footer-bottom {
  padding-top: var(--space-6);
  border-top: 1px solid rgba(255,255,255,0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.footer-bottom p {
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.4);
}

.footer-bottom a {
  color: rgba(255,255,255,0.5);
  text-decoration: none;
  font-size: var(--text-xs);
}

.footer-bottom a:hover {
  color: rgba(255,255,255,0.9);
}

/* ECG Caliper tool (Smart_Caliper2) */
.caliper-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
}

.upload-area {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-10) var(--space-6);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-interactive);
  background: var(--color-surface-2);
}

.upload-area:hover,
.upload-area.dragover {
  border-color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.upload-area svg {
  color: var(--color-text-faint);
  margin: 0 auto var(--space-4);
}

.upload-area p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.upload-area .upload-cta {
  color: var(--color-primary);
  font-weight: 600;
}

#ecg-canvas {
  border-radius: var(--radius-lg);
  cursor: crosshair;
  touch-action: none;
}

.caliper-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.caliper-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
}

.caliper-btn:hover,
.caliper-btn.active {
  background: var(--color-primary-highlight);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.zoom-control {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.zoom-control input[type="range"] {
  width: 120px;
  accent-color: var(--color-primary);
}

/* Measurement display */
.measurements-panel {
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  margin-top: var(--space-4);
}

.measurement-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--color-divider);
  font-size: var(--text-sm);
}

.measurement-row:last-child { border-bottom: none; }
.measurement-row-label { color: var(--color-text-muted); }
.measurement-row-value {
  font-weight: 700;
  color: var(--color-text);
  font-family: var(--font-mono);
}


/* =============================================
   EP LEARNING LIBRARY — Article & Topic Styles
   ============================================= */

/* --- Library Hub Page --- */
/* ============================================================
   EP LEARNING LIBRARY — FULL UI SYSTEM
   ============================================================ */

/* ---- Hub Hero ---- */
.library-hero {
  background: linear-gradient(135deg, var(--color-navy) 0%, color-mix(in srgb, var(--color-primary) 80%, #1e3a5f) 100%);
  padding: var(--space-20) var(--space-6) var(--space-16);
  text-align: center;
  color: #fff;
  position: relative;
  overflow: hidden;
}
.library-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 110%, rgba(10,123,140,0.35) 0%, transparent 70%);
  pointer-events: none;
}
.library-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  color: #fff;
  margin-bottom: var(--space-4);
  position: relative;
}
.library-hero p {
  font-size: var(--text-base);
  color: rgba(255,255,255,0.78);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.7;
  position: relative;
}
.library-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.22);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-4);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.88);
  margin-bottom: var(--space-5);
  position: relative;
}

/* ---- Hub section wrapper ---- */
.library-section {
  max-width: 1160px;
  margin: 0 auto;
  padding: var(--space-14) var(--space-6) var(--space-16);
}
.library-section-header {
  margin-bottom: var(--space-10);
}
.library-section-label {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}
.library-section-header h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}
.library-section-header p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 560px;
  line-height: 1.65;
}

/* ---- Topic card grid ---- */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-5);
}
.topic-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  position: relative;
}
.topic-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 8px 28px rgba(10,123,140,0.15), var(--shadow-md);
  transform: translateY(-3px);
}
/* Colored top accent bar */
.topic-card-accent {
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), color-mix(in srgb, var(--color-primary) 60%, var(--color-navy)));
  flex-shrink: 0;
}
.topic-card-body {
  padding: var(--space-5) var(--space-6) var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  flex: 1;
}
.topic-card-icon-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-1);
}
.topic-card-icon {
  width: 42px; height: 42px;
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--color-primary) 10%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-primary) 20%, var(--color-border));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  flex-shrink: 0;
}
.topic-card-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-text-muted);
  opacity: 0.55;
}
.topic-card h3 {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin: 0;
  line-height: 1.25;
}
.topic-card p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin: 0;
  flex: 1;
  line-height: 1.65;
}
/* Card footer with pills + arrow */
.topic-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-6) var(--space-5);
  border-top: 1px solid var(--color-border);
  margin-top: auto;
}
.topic-card-pills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.topic-pill {
  display: inline-flex;
  align-items: center;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 9%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-primary) 18%, var(--color-border));
  border-radius: var(--radius-full);
  padding: 2px 9px;
  line-height: 1.6;
}
.topic-arrow {
  color: var(--color-text-muted);
  transition: color 0.18s, transform 0.18s;
  flex-shrink: 0;
  margin-left: var(--space-3);
}
.topic-card:hover .topic-arrow {
  color: var(--color-primary);
  transform: translateX(4px);
}

/* Library disclaimer notice */
.library-notice {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-5) var(--space-6);
  display: flex;
  gap: var(--space-4);
  align-items: flex-start;
  margin-top: var(--space-10);
}
.library-notice-icon {
  width: 36px; height: 36px;
  border-radius: var(--radius-full);
  background: color-mix(in srgb, var(--color-primary) 10%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-primary) 20%, var(--color-border));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  flex-shrink: 0;
}
.library-notice h4 {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}
.library-notice p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
  margin: 0;
}
.library-notice a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
}
.library-notice a:hover { text-decoration: underline; }

/* ============================================================
   EP ARTICLE / TOPIC PAGE LAYOUT
   ============================================================ */

/* Hero banner */
.ep-article-hero {
  background: linear-gradient(135deg, var(--color-navy) 0%, color-mix(in srgb, var(--color-primary) 75%, #1e3a5f) 100%);
  padding: var(--space-14) var(--space-6) var(--space-12);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.ep-article-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 80% at 80% 50%, rgba(10,123,140,0.25) 0%, transparent 65%);
  pointer-events: none;
}
.ep-article-hero-inner {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
}
.ep-topic-category {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.6);
  margin-bottom: var(--space-4);
}
.ep-article-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  font-weight: 800;
  color: #fff;
  margin-bottom: var(--space-4);
  line-height: 1.12;
  max-width: 760px;
}
.ep-article-hero .ep-subtitle {
  font-size: var(--text-base);
  color: rgba(255,255,255,0.75);
  margin: 0 0 var(--space-5);
  max-width: 640px;
  line-height: 1.65;
}
.ep-article-hero .ep-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-2);
}
.ep-meta-pill {
  display: inline-flex;
  align-items: center;
  font-size: var(--text-xs);
  font-weight: 600;
  color: rgba(255,255,255,0.88);
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-full);
  padding: 4px 12px;
}

/* Updated date stamp */
.ep-updated {
  font-size: var(--text-xs);
  font-weight: 500;
  color: rgba(255,255,255,0.55);
  margin-top: var(--space-3);
  font-family: var(--font-mono);
  letter-spacing: 0.03em;
}

/* Back link */
.ep-back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  color: rgba(255,255,255,0.55);
  text-decoration: none;
  margin-bottom: var(--space-6);
  transition: color 0.18s;
}
.ep-back-link:hover { color: rgba(255,255,255,0.9); }

/* ---- Two-column article layout ---- */
.ep-article-outer {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-10) var(--space-6) var(--space-16);
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: var(--space-10);
  align-items: start;
}

/* Sticky sidebar TOC */
.ep-sidebar {
  position: sticky;
  top: 80px;
}
.ep-toc {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}
.ep-toc h4 {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}
.ep-toc ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.ep-toc li a {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  transition: background 0.15s, color 0.15s;
  line-height: 1.35;
}
.ep-toc li a:hover {
  background: color-mix(in srgb, var(--color-primary) 8%, var(--color-surface));
  color: var(--color-primary);
}
.ep-toc li a::before {
  content: attr(data-num);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--color-primary) 12%, var(--color-surface));
  color: var(--color-primary);
  font-size: 10px;
  font-weight: 800;
  flex-shrink: 0;
  font-family: var(--font-mono);
}

/* Main article column */
.ep-article {
  min-width: 0;
}

/* ---- Sections ---- */
.ep-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8) var(--space-8);
  margin-bottom: var(--space-6);
  box-shadow: var(--shadow-sm);
  scroll-margin-top: 90px;
  overflow: visible;
}
.ep-section-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 2px solid color-mix(in srgb, var(--color-primary) 20%, var(--color-border));
}
.ep-section-number {
  width: 34px; height: 34px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 800;
  flex-shrink: 0;
  font-family: var(--font-mono);
  box-shadow: 0 2px 8px rgba(10,123,140,0.3);
}
.ep-section h2 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin: 0;
  line-height: 1.2;
}
.ep-section p {
  font-size: var(--text-base);
  line-height: 1.8;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}
.ep-section p:last-child { margin-bottom: 0; }
.ep-section ul, .ep-section ol {
  margin: var(--space-3) 0 var(--space-5) var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.ep-section li {
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-text);
}

/* ---- Callout boxes ---- */
.ep-callout {
  background: color-mix(in srgb, var(--color-primary) 6%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-primary) 18%, var(--color-border));
  border-left: 4px solid var(--color-primary);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  padding: var(--space-4) var(--space-5);
  margin: var(--space-5) 0;
}
.ep-callout-label {
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.ep-callout p {
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-text);
  margin: 0;
  font-weight: 500;
}
.ep-callout ul {
  margin: var(--space-2) 0 0 var(--space-4);
  gap: var(--space-1);
}
.ep-callout li {
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-text);
  font-weight: 500;
}

/* ---- Clinical Pearl (amber) ---- */
.ep-pearl {
  background: color-mix(in srgb, var(--color-warning) 7%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-warning) 22%, var(--color-border));
  border-left: 4px solid var(--color-warning);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  padding: var(--space-4) var(--space-5);
  margin: var(--space-5) 0;
}
.ep-pearl .ep-callout-label { color: var(--color-warning); }
.ep-pearl p, .ep-pearl li { font-size: var(--text-sm); line-height: 1.65; color: var(--color-text); font-weight: 500; }

/* ---- Data table ---- */
.ep-table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: var(--space-5) 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}
.ep-table {
  width: 100%;
  min-width: 600px;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.ep-table th,
.ep-table td {
  white-space: normal;
  word-break: normal;
}
.ep-table th {
  background: color-mix(in srgb, var(--color-primary) 6%, var(--color-surface));
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}
.ep-table td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
  line-height: 1.55;
  vertical-align: top;
}
.ep-table tr:last-child td { border-bottom: none; }
.ep-table tr:hover td { background: color-mix(in srgb, var(--color-primary) 4%, var(--color-surface)); }

/* ---- References box ---- */
.ep-references {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-7) var(--space-8);
  margin-bottom: var(--space-6);
  box-shadow: var(--shadow-sm);
  scroll-margin-top: 90px;
}
.ep-references h4 {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}
.ep-references ol {
  margin: 0;
  padding-left: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.ep-references li {
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-text-muted);
}
.ep-references a {
  color: var(--color-primary);
  text-decoration: none;
}
.ep-references a:hover { text-decoration: underline; }

/* Nav highlight */
body[data-page="library"] .nav-link[href*="ep-library"] {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .ep-article-outer {
    grid-template-columns: 1fr;
    padding: var(--space-6) var(--space-4) var(--space-12);
  }
  .ep-sidebar {
    position: static;
  }
  .ep-toc ol {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-2);
  }
  .ep-toc li a {
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
  }
  .ep-section {
    padding: var(--space-6) var(--space-5);
  }
}
@media (max-width: 600px) {
  .topic-grid { grid-template-columns: 1fr; }
  .ep-article-hero { padding: var(--space-10) var(--space-4) var(--space-8); }
  .ep-article-hero h1 { font-size: clamp(1.4rem, 6vw, 2rem); }
  .library-hero { padding: var(--space-14) var(--space-4) var(--space-10); }
  .library-section { padding: var(--space-10) var(--space-4) var(--space-12); }
  .ep-section { padding: var(--space-5) var(--space-4); }
  .ep-references { padding: var(--space-5) var(--space-4); }
}

/* ═══════════════════════════════════════════════════════
   GUIDELINE PAGES — shared table & container overrides
   Keep viewport fixed; only tables scroll horizontally
   ═══════════════════════════════════════════════════════ */

/* ═══════════════════════════════════════════════════════
   GUIDELINE PAGES — PHASE 1: absolute viewport lock
   Goal: NOTHING scrolls horizontally. Tables clip. Fix tables later.
   ═══════════════════════════════════════════════════════

   IMPORTANT — iOS Safari fix:
   iOS Safari ignores overflow-x:hidden on html/body and expands
   the viewport to fit wide content. This external CSS alone does
   NOT fix horizontal scrolling on iOS.

   The real fix is an inline <style> block inside EVERY guideline
   HTML file (added at the end, before </style>). The inline block
   overrides the same selectors with !important so it wins in
   source-order. Search for "iOS VIEWPORT LOCK" in any guideline
   HTML to see the block.

   When creating a NEW guideline HTML page, copy the
   "iOS VIEWPORT LOCK" CSS block from any existing guideline
   into the new file's <style> section before </style>.

   Phase 2 TODO: Re-enable independent horizontal table scrolling
   within the locked viewport (overflow-x:auto on .table-scroll-wrapper
   while keeping the page body locked).
   ═══════════════════════════════════════════════════════ */

/* Every element everywhere — hard clamp to viewport */
.guideline-container,
.guideline-container * {
  max-width: 100vw !important;
  overflow-x: hidden !important;
}

/* Container */
.guideline-container {
  width: 100%;
  margin: 0 auto;
  padding: 0 1rem;
  box-sizing: border-box;
}

/* All children must shrink, never expand beyond parent */
.guideline-container *,
.guideline-container *::before,
.guideline-container *::after {
  min-width: 0;
  box-sizing: border-box;
}

/* Tables: squish to fit, no min-width, clip anything that overflows */
.guideline-table,
.table-scroll-wrapper > table,
.table-scroll-wrapper {
  width: 100% !important;
  max-width: 100% !important;
  overflow-x: hidden !important;
  table-layout: fixed;
}

/* Word-break everything */
.guideline-container * {
  overflow-wrap: break-word;
  word-wrap: break-word;
  word-break: break-word;
}

@media (max-width: 768px) {
  .guideline-container {
    padding: 0 0.75rem;
  }
}

@media (max-width: 480px) {
  .guideline-container {
    padding: 0 0.5rem;
  }
}

/* ═══════════════════════════════════════════════════════
   GUIDELINE PAGE — TEXT, LINK, AND CONTRAST STYLES
   Applied globally so every guideline page inherits them.
   These supplement the inline <style> in each HTML file.
   ═══════════════════════════════════════════════════════ */

/* --- Base text & link colors inside guideline pages --- */
.guideline-container {
  color: var(--color-text);
}

.guideline-container a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-thickness: 1px;
}

.guideline-container a:hover {
  color: var(--color-primary-hover);
  text-decoration-thickness: 2px;
}

/* Links inside the green hero banner MUST stay white — !important
   overrides .guideline-container a and any dark-mode link rules */
.guideline-detail-hero a {
  color: #ffffff !important;
  text-decoration-color: rgba(255, 255, 255, 0.6) !important;
}

.guideline-detail-hero a:hover {
  color: #e0f2fe !important;
}

/* Jump nav links: no underline, pill style */
.guideline-jump-nav a {
  text-decoration: none;
}

/* Calculator cards: no underline on the whole card */
.calculator-card {
  text-decoration: none;
}

.calculator-card:hover {
  text-decoration: none;
}

/* Back link */
.guideline-container > .back-link {
  text-decoration: none;
}

.guideline-container > .back-link:hover {
  text-decoration: underline;
}

/* --- Section content text --- */
.guideline-section {
  color: var(--color-text);
}

.guideline-section h2,
.guideline-section h3 {
  color: var(--color-text);
}

.guideline-section p,
.guideline-section li,
.guideline-section td,
.guideline-section th {
  color: var(--color-text);
}

/* --- Table header text (white on primary bg) --- */
.guideline-table thead {
  background: var(--color-primary);
}

.guideline-table thead th {
  color: #ffffff;
}

/* Table links — ensure they pop against white/dark row bg */
.guideline-table a {
  color: var(--color-primary);
  font-weight: 500;
}

/* --- Guideline box (blue callout) --- */
.guideline-box {
  color: var(--color-text);
}

.guideline-box a {
  color: var(--color-primary);
  font-weight: 500;
}

/* --- Algorithm boxes --- */
.algorithm-box {
  color: var(--color-text);
}

.algorithm-step {
  color: var(--color-text);
}

.algorithm-step a {
  color: var(--color-primary);
  font-weight: 600;
}

/* --- Pearl & Pitfall boxes --- */
.pearl-box {
  color: var(--color-text);
}

.pitfall-box {
  color: var(--color-text);
}

/* --- Do / Don't cards --- */
.do-card {
  color: var(--color-text);
}

.do-card li {
  color: var(--color-text);
}

.dont-card {
  color: var(--color-text);
}

.dont-card li {
  color: var(--color-text);
}

/* --- Calculator cards text --- */
.calculator-card h4 {
  color: var(--color-primary);
}

.calculator-card p {
  color: var(--color-text-muted);
}

/* --- COR/LOE Recommendation Badges --- */
.recommendation-badge {
  color: #ffffff;
  font-weight: 700;
}

/* --- Framework items --- */
.framework-item {
  color: var(--color-text);
}

.framework-item h3 {
  color: var(--color-primary);
}

/* ═══════════════════════════════════════════════════════
   GUIDELINE PAGE — DARK MODE OVERRIDES (OS dark, no JS toggle)
   Uses :root:not([data-theme]) to avoid conflicting with
   the JS toggle (data-theme="light" / "dark").
   ═══════════════════════════════════════════════════════ */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) .guideline-container a {
    color: #7dd3fc;                               /* sky-300: bright & readable on dark bg */
  }

  :root:not([data-theme]) .guideline-container a:hover {
    color: #bae6fd;                               /* sky-200: lighter on hover */
  }

  :root:not([data-theme]) .guideline-section {
    background: var(--color-surface);
    color: var(--color-text);
  }

  :root:not([data-theme]) .guideline-section h2,
  :root:not([data-theme]) .guideline-section h3 {
    color: var(--color-text);
  }

  :root:not([data-theme]) .guideline-section p,
  :root:not([data-theme]) .guideline-section li,
  :root:not([data-theme]) .guideline-section td {
    color: var(--color-text);
  }

  :root:not([data-theme]) .guideline-table thead {
    background: var(--color-primary);
  }

  :root:not([data-theme]) .guideline-table thead th {
    color: #ffffff;
  }

  :root:not([data-theme]) .guideline-table td {
    border-bottom-color: var(--color-border);
  }

  :root:not([data-theme]) .guideline-table tbody tr:hover {
    background: rgba(62, 181, 200, 0.08);
  }

  :root:not([data-theme]) .guideline-table a {
    color: #7dd3fc;
  }

  :root:not([data-theme]) .guideline-box {
    background: rgba(62, 181, 200, 0.08);
    border-left-color: var(--color-primary);
    color: var(--color-text);
  }

  :root:not([data-theme]) .guideline-box a {
    color: #7dd3fc;
  }

  :root:not([data-theme]) .algorithm-box {
    background: rgba(62, 181, 200, 0.05);
    border-color: var(--color-border);
    color: var(--color-text);
  }

  :root:not([data-theme]) .algorithm-step {
    background: var(--color-surface-offset);
    color: var(--color-text);
  }

  :root:not([data-theme]) .algorithm-step a {
    color: #7dd3fc;
  }

  :root:not([data-theme]) .pearl-box {
    background: rgba(59, 130, 246, 0.1);
    border-left-color: #60a5fa;
    color: var(--color-text);
  }

  :root:not([data-theme]) .pitfall-box {
    background: rgba(239, 68, 68, 0.1);
    border-left-color: #f87171;
    color: var(--color-text);
  }

  :root:not([data-theme]) .do-card {
    background: rgba(16, 185, 129, 0.1);
    border-left-color: #34d399;
    color: var(--color-text);
  }

  :root:not([data-theme]) .do-card h4 {
    color: #34d399;
  }

  :root:not([data-theme]) .do-card li {
    color: var(--color-text);
  }

  :root:not([data-theme]) .dont-card {
    background: rgba(239, 68, 68, 0.1);
    border-left-color: #f87171;
    color: var(--color-text);
  }

  :root:not([data-theme]) .dont-card h4 {
    color: #f87171;
  }

  :root:not([data-theme]) .dont-card li {
    color: var(--color-text);
  }

  :root:not([data-theme]) .guideline-jump-nav {
    background: var(--color-surface);
    border-color: var(--color-border);
  }

  :root:not([data-theme]) .guideline-jump-nav a {
    background: var(--color-surface-offset);
    color: var(--color-text);
  }

  :root:not([data-theme]) .guideline-jump-nav a:hover,
  :root:not([data-theme]) .guideline-jump-nav a.active {
    background: var(--color-primary);
    color: #ffffff;
  }

  :root:not([data-theme]) .calculator-card {
    background: var(--color-surface);
    border-color: var(--color-border);
    color: var(--color-text);
  }

  :root:not([data-theme]) .calculator-card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 4px 12px rgba(62, 181, 200, 0.2);
  }

  :root:not([data-theme]) .calculator-card h4 {
    color: var(--color-primary);
  }

  :root:not([data-theme]) .calculator-card p {
    color: var(--color-text-muted);
  }

  :root:not([data-theme]) .framework-item {
    background: var(--color-surface);
    border-color: var(--color-border);
    color: var(--color-text);
  }

  :root:not([data-theme]) .framework-item h3 {
    color: var(--color-primary);
  }

  :root:not([data-theme]) .guideline-detail-hero {
    background: linear-gradient(135deg, #065f46 0%, #047857 100%);
  }

  :root:not([data-theme]) .guideline-detail-hero a {
    color: #ffffff;
  }

  :root:not([data-theme]) .guideline-detail-hero a:hover {
    color: #e0f2fe;
  }
}

/* Dark mode via data-theme attribute (for JS toggle) */
[data-theme="dark"] .guideline-container a { color: #7dd3fc; }
[data-theme="dark"] .guideline-container a:hover { color: #bae6fd; }
[data-theme="dark"] .guideline-section { background: var(--color-surface); color: var(--color-text); }
[data-theme="dark"] .guideline-section h2,
[data-theme="dark"] .guideline-section h3 { color: var(--color-text); }
[data-theme="dark"] .guideline-section p,
[data-theme="dark"] .guideline-section li,
[data-theme="dark"] .guideline-section td { color: var(--color-text); }
[data-theme="dark"] .guideline-table thead { background: var(--color-primary); }
[data-theme="dark"] .guideline-table thead th { color: #ffffff; }
[data-theme="dark"] .guideline-table td { border-bottom-color: var(--color-border); }
[data-theme="dark"] .guideline-table a { color: #7dd3fc; }
[data-theme="dark"] .guideline-box { background: rgba(62, 181, 200, 0.08); border-left-color: var(--color-primary); color: var(--color-text); }
[data-theme="dark"] .guideline-box a { color: #7dd3fc; }
[data-theme="dark"] .algorithm-box { background: rgba(62, 181, 200, 0.05); border-color: var(--color-border); color: var(--color-text); }
[data-theme="dark"] .algorithm-step { background: var(--color-surface-offset); color: var(--color-text); }
[data-theme="dark"] .algorithm-step a { color: #7dd3fc; }
[data-theme="dark"] .pearl-box { background: rgba(59, 130, 246, 0.1); border-left-color: #60a5fa; color: var(--color-text); }
[data-theme="dark"] .pitfall-box { background: rgba(239, 68, 68, 0.1); border-left-color: #f87171; color: var(--color-text); }
[data-theme="dark"] .do-card { background: rgba(16, 185, 129, 0.1); border-left-color: #34d399; color: var(--color-text); }
[data-theme="dark"] .do-card h4 { color: #34d399; }
[data-theme="dark"] .do-card li { color: var(--color-text); }
[data-theme="dark"] .dont-card { background: rgba(239, 68, 68, 0.1); border-left-color: #f87171; color: var(--color-text); }
[data-theme="dark"] .dont-card h4 { color: #f87171; }
[data-theme="dark"] .dont-card li { color: var(--color-text); }
[data-theme="dark"] .guideline-jump-nav { background: var(--color-surface); border-color: var(--color-border); }
[data-theme="dark"] .guideline-jump-nav a { background: var(--color-surface-offset); color: var(--color-text); }
[data-theme="dark"] .guideline-jump-nav a:hover,
[data-theme="dark"] .guideline-jump-nav a.active { background: var(--color-primary); color: #ffffff; }
[data-theme="dark"] .calculator-card { background: var(--color-surface); border-color: var(--color-border); }
[data-theme="dark"] .calculator-card:hover { border-color: var(--color-primary); }
[data-theme="dark"] .calculator-card h4 { color: var(--color-primary); }
[data-theme="dark"] .calculator-card p { color: var(--color-text-muted); }
[data-theme="dark"] .framework-item { background: var(--color-surface); border-color: var(--color-border); }
[data-theme="dark"] .framework-item h3 { color: var(--color-primary); }
[data-theme="dark"] .guideline-detail-hero { background: linear-gradient(135deg, #065f46 0%, #047857 100%); }
[data-theme="dark"] .guideline-detail-hero a { color: #ffffff; }
[data-theme="dark"] .guideline-detail-hero a:hover { color: #e0f2fe; }

/* ── SCROLL-TO-TOP BUTTON (guideline pages) ────────────── */
.scroll-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: none;
    background: var(--color-primary, #0a7b8c);
    color: #ffffff;
    font-size: 1.25rem;
    line-height: 1;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.25s ease, background 0.2s ease;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}
.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.scroll-to-top:hover {
    background: var(--color-primary-hover, #065f46);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
    transform: translateY(-2px);
}
.scroll-to-top:active {
    transform: translateY(0);
}
/* Arrow icon via CSS — no external font needed */
.scroll-to-top::before {
    content: "↑";
    font-weight: 700;
    font-size: 1.3rem;
}
.scroll-to-top-label {
    position: absolute;
    bottom: -1.4rem;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.6rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary, #0a7b8c);
    white-space: nowrap;
}

/* Dark mode overrides */
[data-theme="dark"] .scroll-to-top {
    background: var(--color-primary, #3eb5c8);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}
[data-theme="dark"] .scroll-to-top:hover {
    background: #5cc8d8;
}
[data-theme="dark"] .scroll-to-top-label {
    color: var(--color-primary, #3eb5c8);
}

:root:not([data-theme]) .scroll-to-top-label {
    color: var(--color-primary, #0a7b8c);
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .scroll-to-top {
        background: var(--color-primary, #3eb5c8);
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
    }
    :root:not([data-theme]) .scroll-to-top:hover {
        background: #5cc8d8;
    }
    :root:not([data-theme]) .scroll-to-top-label {
        color: var(--color-primary, #3eb5c8);
    }
}

/* Mobile: slightly smaller, tighter to edge */
@media (max-width: 768px) {
    .scroll-to-top {
        bottom: 1.25rem;
        right: 1.25rem;
        width: 40px;
        height: 40px;
        font-size: 1.1rem;
    }
    .scroll-to-top::before {
        font-size: 1.15rem;
    }
    .scroll-to-top-label {
        font-size: 0.55rem;
    }
}

/* Print: hide */
@media print {
    .scroll-to-top { display: none !important; }
}