/* ============================================================
   MDT 泌尿病例教学库 — Design System
   Arknights-inspired medical education theme (light mode)
   ============================================================ */

/* --- CSS Variables --- */
:root {
  /* Colors */
  --bg-primary: #F5F7FA;
  --bg-card: #FFFFFF;
  --color-primary: #1E88E5;
  --color-primary-dark: #1565C0;
  --color-primary-light: #E3F2FD;
  --color-accent: #00B4D8;
  --color-accent-light: #E0F7FA;
  --color-warning: #FF6B6B;
  --color-warning-light: #FFEBEE;
  --color-dark: #2C3E50;
  --color-border: #E2E8F0;
  --color-text: #263238;
  --color-text-secondary: #546E7A;
  --color-text-muted: #78909C;
  --color-success: #4CAF50;
  --color-success-light: #E8F5E9;

  /* Typography */
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;

  /* 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;

  /* Layout */
  --max-width: 1280px;
  --nav-height: 64px;
  --toc-width: 56px;

  /* Effects */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.10);
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;

  /* Arknights-inspired decorations */
  --cut-size: 8px;
  --border-thin: 1px solid var(--color-border);

  /* Safe area insets (iPhone notch / home indicator) */
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
}

/* --- Reset & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-primary-dark); }

img { max-width: 100%; display: block; }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-mono);
  color: var(--color-dark);
  line-height: 1.35;
  letter-spacing: -0.02em;
}

h1 { font-size: var(--font-size-3xl); font-weight: 700; }
h2 { font-size: var(--font-size-2xl); font-weight: 700; }
h3 { font-size: var(--font-size-xl); font-weight: 600; }
h4 { font-size: var(--font-size-lg); font-weight: 600; }

p { margin-bottom: var(--space-4); }

code, .code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-primary);
  padding: 0.15em 0.4em;
  border: 1px solid var(--color-border);
}

/* --- Navigation --- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
}

.nav-inner {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-dark);
  text-decoration: none;
}

.nav-logo-icon {
  width: 36px;
  height: 36px;
  background: var(--color-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1em;
  position: relative;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
}

.nav-links a {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-primary);
}

.nav-links a.active {
  border-bottom-color: var(--color-primary);
}

/* Language toggle button */
.nav-lang-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-1) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  font-weight: 700;
  background: var(--color-primary-light);
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  clip-path: polygon(0 0, calc(100% - 4px) 0, 100% 4px, 100% 100%, 4px 100%, 0 calc(100% - 4px));
  min-width: 44px;
  min-height: 32px;
  margin-left: var(--space-3);
  line-height: 1;
}

.nav-lang-toggle:hover {
  background: var(--color-primary);
  color: #fff;
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-dark);
  transition: transform var(--transition-normal);
}

/* --- Layout Containers --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Case detail layout: sidebar + main */
.case-layout {
  display: flex;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
  gap: 0;
  position: relative;
}

.case-layout .case-main {
  flex: 1;
  min-width: 0;
  padding-right: calc(var(--toc-width) + var(--space-8));
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  position: relative;
  clip-path: polygon(0 0, calc(100% - 6px) 0, 100% 6px, 100% 100%, 6px 100%, 0 calc(100% - 6px));
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn-outline:hover {
  background: var(--color-primary);
  color: #fff;
}

.btn-accent {
  background: var(--color-warning);
  color: #fff;
  border-color: var(--color-warning);
}
.btn-accent:hover {
  background: #E55A5A;
  color: #fff;
}

.btn-sm {
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
  clip-path: polygon(0 0, calc(100% - 4px) 0, 100% 4px, 100% 100%, 4px 100%, 0 calc(100% - 4px));
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-base);
}

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: 0;
}

/* --- Cards --- */
.card {
  background: var(--bg-card);
  border: var(--border-thin);
  padding: var(--space-6);
  transition: all var(--transition-normal);
  position: relative;
}

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

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-4);
}

@media (min-width: 1100px) {
  .card-grid { grid-template-columns: repeat(4, 1fr); }
}

/* --- Filter Chips --- */
.chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.chip {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  font-weight: 600;
  border: 1px solid var(--color-border);
  background: var(--bg-card);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  clip-path: polygon(0 0, calc(100% - 4px) 0, 100% 4px, 100% 100%, 4px 100%, 0 calc(100% - 4px));
}

.chip:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.chip.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

/* --- Badges / Tags --- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  font-weight: 600;
  border: 1px solid;
}

.badge-primary {
  background: var(--color-primary-light);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.badge-accent {
  background: var(--color-accent-light);
  border-color: var(--color-accent);
  color: #007B9E;
}

.badge-warning {
  background: var(--color-warning-light);
  border-color: var(--color-warning);
  color: var(--color-warning);
}

.badge-dark {
  background: #ECEFF1;
  border-color: var(--color-dark);
  color: var(--color-dark);
}

.star-rating {
  color: #FFB300;
  font-size: var(--font-size-xs);
  letter-spacing: 1px;
}

/* --- Section Headers --- */
.section-header {
  position: relative;
  padding-left: var(--space-4);
  margin-bottom: var(--space-6);
  border-left: 3px solid var(--color-primary);
}

.section-header::before {
  content: '';
  position: absolute;
  left: -1px;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-accent);
  clip-path: polygon(0 0, 100% 4px, 100% 100%, 0 calc(100% - 4px));
  opacity: 0;
}

.section-number {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  display: block;
  margin-bottom: var(--space-1);
}

/* --- Diagonal Banner --- */
.banner-diagonal {
  position: relative;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff;
  padding: var(--space-8) var(--space-6);
  overflow: hidden;
}

.banner-diagonal::after {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 300px;
  height: 300px;
  border: 20px solid rgba(255,255,255,0.08);
  transform: rotate(15deg);
}

.banner-diagonal h2 {
  color: #fff;
  margin-bottom: var(--space-2);
}

.banner-diagonal p {
  color: rgba(255,255,255,0.85);
  margin-bottom: var(--space-4);
}

/* --- Tabs --- */
.tabs {
  display: flex;
  border-bottom: 1px solid var(--color-border);
  gap: 0;
  margin-bottom: var(--space-6);
}

.tab-btn {
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  font-weight: 600;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-bottom: -1px;
}

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

.tab-btn.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

/* --- Accordion / Collapsible --- */
.collapsible-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  font-weight: 600;
  background: var(--bg-primary);
  border: var(--border-thin);
  cursor: pointer;
  color: var(--color-dark);
  transition: all var(--transition-fast);
}

.collapsible-toggle:hover {
  background: var(--color-primary-light);
  border-color: var(--color-primary);
}

.collapsible-toggle::after {
  content: '▸';
  font-size: 0.8em;
  transition: transform var(--transition-normal);
}

.collapsible-toggle.open::after {
  transform: rotate(90deg);
}

.collapsible-content {
  display: none;
  padding: var(--space-4);
  border: var(--border-thin);
  border-top: none;
}

.collapsible-content.open {
  display: block;
}

/* --- Table of Contents (Floating Nav) --- */
.toc {
  position: fixed;
  right: calc((100vw - var(--max-width)) / 2 + var(--space-6));
  top: 50%;
  transform: translateY(-50%);
  z-index: 50;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.toc-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  cursor: pointer;
  position: relative;
}

.toc-dot {
  width: 12px;
  height: 12px;
  border: 1px solid var(--color-text-muted);
  background: #B0BEC5;
  transition: all var(--transition-fast);
  flex-shrink: 0;
  clip-path: polygon(0 0, calc(100% - 3px) 0, 100% 3px, 100% 100%, 3px 100%, 0 calc(100% - 3px));
}

.toc-item:hover .toc-dot,
.toc-item.active .toc-dot {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.toc-label {
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
  transition: all var(--transition-normal);
}

.toc-item:hover .toc-label,
.toc-item.active .toc-label {
  color: var(--color-primary);
}

.toc-item.active .toc-label {
  font-weight: 700;
}

/* Mobile TOC FAB */
.toc-fab {
  display: none;
  position: fixed;
  bottom: calc(var(--space-6) + var(--safe-bottom));
  right: calc(var(--space-6) + var(--safe-right));
  z-index: 60;
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 1.2em;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
  box-shadow: var(--shadow-lg);
  align-items: center;
  justify-content: center;
}

/* Mobile TOC Drawer */
.toc-drawer-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 70;
}

.toc-drawer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--bg-card);
  border-top: 2px solid var(--color-primary);
  z-index: 71;
  padding: var(--space-6);
  padding-bottom: calc(var(--space-6) + var(--safe-bottom));
  transform: translateY(100%);
  transition: transform var(--transition-normal);
}

.toc-drawer.open {
  transform: translateY(0);
}

.toc-drawer-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.toc-drawer-list a {
  display: block;
  padding: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
  text-decoration: none;
}

.toc-drawer-list a:hover {
  color: var(--color-primary);
  background: var(--color-primary-light);
}

/* --- Live Banner Section --- */
.live-section {
  margin: var(--space-8) auto;
  padding: 0;
}

/* --- Case Card --- */
.case-card {
  background: var(--bg-card);
  border: var(--border-thin);
  padding: var(--space-5);
  transition: all var(--transition-normal);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  text-decoration: none;
  color: inherit;
}

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

.case-card-number {
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

.case-card-title {
  font-family: var(--font-mono);
  font-size: var(--font-size-base);
  font-weight: 700;
  color: var(--color-dark);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.case-card-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.case-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
}

.case-card-tags {
  display: flex;
  gap: var(--space-1);
}

.case-card-heat {
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* --- Resource Cards --- */
.resource-card {
  background: var(--bg-card);
  border: 1px solid var(--color-accent);
  padding: var(--space-5);
  transition: all var(--transition-normal);
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
}

.resource-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.resource-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-size: 1.3em;
  flex-shrink: 0;
  clip-path: polygon(0 0, calc(100% - 6px) 0, 100% 6px, 100% 100%, 6px 100%, 0 calc(100% - 6px));
}

/* --- Process Steps --- */
.process-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-4);
  counter-reset: step;
}

.process-step {
  position: relative;
  background: var(--bg-card);
  border: var(--border-thin);
  padding: var(--space-6);
  padding-top: var(--space-10);
  counter-increment: step;
}

.process-step::before {
  content: '0' counter(step);
  position: absolute;
  top: var(--space-4);
  left: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-primary);
  opacity: 0.15;
}

.process-step h4 {
  margin-bottom: var(--space-2);
}

/* --- Search Tool Widget --- */
.search-tool {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: 55;
  display: none;
}

.search-tool-trigger {
  width: 48px;
  height: 48px;
  background: var(--color-dark);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 1.2em;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.search-tool-panel {
  position: fixed;
  bottom: calc(var(--space-6) + 56px + var(--safe-bottom));
  right: calc(var(--space-6) + var(--safe-right));
  width: 400px;
  max-width: calc(100vw - 48px - var(--safe-left) - var(--safe-right));
  background: var(--bg-card);
  border: 1px solid var(--color-dark);
  padding: var(--space-5);
  z-index: 56;
  display: none;
  box-shadow: var(--shadow-lg);
}

.search-tool-panel.open {
  display: block;
}

.search-tool input {
  width: 100%;
  padding: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  border: var(--border-thin);
  background: var(--bg-primary);
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.search-tool input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.search-result {
  background: var(--color-dark);
  color: #E0E0E0;
  padding: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  line-height: 1.6;
  margin-bottom: var(--space-3);
  position: relative;
}

.search-result .copy-btn {
  position: absolute;
  top: var(--space-2);
  right: var(--space-2);
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: #fff;
  padding: 2px var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  cursor: pointer;
}

.search-result .copy-btn:hover {
  background: rgba(255,255,255,0.2);
}

/* --- Footer --- */
.footer {
  margin-top: var(--space-20);
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-border);
  background: var(--bg-card);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.footer p {
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

/* --- Attribution Box --- */
.attribution {
  margin-top: var(--space-8);
  padding: var(--space-4);
  background: var(--bg-primary);
  border: var(--border-thin);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.attribution a {
  font-family: var(--font-mono);
}

/* --- Decision Flow Diagram --- */
.flow-diagram {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin: var(--space-6) 0;
}

.flow-node {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--bg-card);
  border: var(--border-thin);
  border-left: 3px solid var(--color-primary);
  position: relative;
}

.flow-node::after {
  content: '';
  position: absolute;
  bottom: -13px;
  left: 24px;
  width: 1px;
  height: 12px;
  background: var(--color-border);
}

.flow-node:last-child::after {
  display: none;
}

.flow-node-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--font-size-sm);
  flex-shrink: 0;
}

.flow-node-content h4 {
  font-size: var(--font-size-sm);
  margin-bottom: 2px;
}

.flow-node-content p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

/* --- Evidence Tag --- */
.evidence-tag {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 1px var(--space-2);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  background: #FFF8E1;
  border: 1px solid #FFD54F;
  color: #F57F17;
}

/* --- Question Block --- */
.question-block {
  background: var(--bg-primary);
  border: var(--border-thin);
  padding: var(--space-5);
  margin-bottom: var(--space-4);
}

.question-block h4 {
  margin-bottom: var(--space-3);
  color: var(--color-primary);
}

.question-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.question-option {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border: var(--border-thin);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.question-option:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.question-option.selected {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.question-option.correct {
  border-color: var(--color-success);
  background: var(--color-success-light);
}

.question-option.incorrect {
  border-color: var(--color-warning);
  background: var(--color-warning-light);
}

.question-option input { display: none; }

/* --- Concept Cards --- */
.concept-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-3);
}

.concept-card {
  padding: var(--space-4);
  border: var(--border-thin);
  border-top: 3px solid var(--color-accent);
  background: var(--bg-card);
}

.concept-card h5 {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-accent);
  margin-bottom: var(--space-2);
}

.concept-card p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

/* --- Reflection Prompts --- */
.reflection-prompt {
  counter-increment: reflection;
  padding: var(--space-4);
  margin-bottom: var(--space-3);
  border: var(--border-thin);
  border-left: 3px solid var(--color-warning);
  background: var(--bg-card);
}

.reflection-prompt::before {
  content: 'Q' counter(reflection);
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  color: var(--color-warning);
  display: block;
  margin-bottom: var(--space-1);
}

.reflection-prompt h4 {
  font-size: var(--font-size-base);
  margin-bottom: var(--space-2);
}

.reflection-prompt p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

/* --- Download Button --- */
.download-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4);
  background: var(--bg-card);
  border: var(--border-thin);
  transition: all var(--transition-fast);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.download-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(30,136,229,0.12);
}

.download-card.has-link:hover {
  border-color: var(--color-primary);
  box-shadow: 0 2px 12px rgba(30,136,229,0.18);
  background: #FAFDFF;
}

/* --- Highlight Box --- */
.highlight-box {
  padding: var(--space-4);
  border: var(--border-thin);
  background: #FAFBFC;
  border-left: 3px solid var(--color-accent);
  margin: var(--space-4) 0;
}

.highlight-box.warning {
  border-left-color: var(--color-warning);
  background: #FFFAFA;
}

/* --- Dispute Box --- */
.dispute-box {
  margin: var(--space-4) 0;
  border: var(--border-thin);
}

.dispute-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-primary-light);
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.dispute-body {
  padding: var(--space-4);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.dispute-side {
  padding: var(--space-3);
  border: var(--border-thin);
}

.dispute-side h5 {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-2);
}

.dispute-side p {
  font-size: var(--font-size-sm);
  margin-bottom: 0;
}

/* --- Learning Path --- */
.learning-path {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  counter-reset: week;
}

.path-step {
  display: flex;
  gap: var(--space-4);
  padding: var(--space-4);
  border: var(--border-thin);
  counter-increment: week;
}

.path-step::before {
  content: counter(week) '.';
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--color-primary);
  white-space: nowrap;
  min-width: 28px;
}

/* --- Section Divider --- */
.section-divider {
  height: 1px;
  background: var(--color-border);
  margin: var(--space-12) 0;
  position: relative;
}

.section-divider::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 60px;
  height: 1px;
  background: var(--color-primary);
}

/* --- Empty State --- */
.empty-state {
  text-align: center;
  padding: var(--space-12);
  color: var(--color-text-muted);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: var(--space-4);
  opacity: 0.3;
}

/* --- Toast --- */
.toast {
  position: fixed;
  top: var(--space-4);
  right: var(--space-4);
  z-index: 200;
  padding: var(--space-3) var(--space-5);
  background: var(--color-dark);
  color: #fff;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  opacity: 0;
  transform: translateY(-8px);
  transition: all var(--transition-normal);
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

/* --- Utility --- */
.text-mono { font-family: var(--font-mono); }
.text-sm { font-size: var(--font-size-sm); }
.text-xs { font-size: var(--font-size-xs); }
.text-muted { color: var(--color-text-muted); }
.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.flex { display: flex; }
.items-center { align-items: center; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }

/* --- Responsive --- */
@media (max-width: 1024px) {
  .case-layout .case-main {
    padding-right: 0;
  }

  .toc {
    display: none;
  }

  .toc-fab {
    display: flex;
  }

  .dispute-body {
    grid-template-columns: 1fr;
  }

  /* Stack FABs vertically — search tool above TOC FAB */
  .search-tool {
    right: calc(var(--space-6) + var(--safe-right));
    bottom: calc(var(--space-6) + 56px + var(--safe-bottom));
  }

  .search-tool-trigger {
    box-shadow: var(--shadow-md);
  }

  :root {
    --max-width: 100%;
  }
}

@media (max-width: 768px) {
  .mobile-back-home {
    display: block !important;
  }

  .nav {
    padding: 0 var(--safe-left) 0 var(--safe-right);
  }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    flex-direction: column;
    padding: var(--space-4);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    max-height: 70vh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: var(--space-3) var(--space-4);
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-lang-toggle {
    margin-left: 0;
    margin-top: var(--space-2);
    width: 100%;
    min-height: 44px;
  }

  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .banner-diagonal {
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 30px) 100%, 0 100%);
    padding: var(--space-6) var(--space-4);
  }

  .search-tool-panel {
    width: calc(100vw - 32px - var(--safe-left) - var(--safe-right));
    right: calc(var(--space-4) + var(--safe-right));
    left: calc(var(--space-4) + var(--safe-left));
  }

  .concept-list {
    grid-template-columns: 1fr;
  }

  .process-steps {
    grid-template-columns: 1fr;
  }

  /* Touch target enlargements */
  .chip {
    min-height: 36px;
    display: inline-flex;
    align-items: center;
  }

  .tab-btn {
    min-height: 44px;
    padding: var(--space-3) var(--space-4);
  }

  .question-option {
    min-height: 44px;
    padding: var(--space-3);
  }

  .toc-drawer-list a {
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .btn {
    min-height: 44px;
  }

  .download-card {
    flex-wrap: wrap;
    gap: var(--space-3);
  }
}

@media (max-width: 480px) {
  .card-grid {
    grid-template-columns: 1fr;
  }

  h1 { font-size: var(--font-size-2xl); }
  h2 { font-size: var(--font-size-xl); }
  h3 { font-size: var(--font-size-lg); }

  .banner-diagonal::after {
    display: none;
  }

  .overview-grid {
    grid-template-columns: 1fr !important;
  }
}

/* --- Accessibility --- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *, *::before, *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }
}