/* ============================================================
   糖尿病知识中心 — Diabetes Knowledge Hub
   Design System (Modern Clinical Style)
   ============================================================ */

:root {
  /* Color palette — clinical, calm, modern */
  --color-bg: #fafbfc;
  --color-bg-alt: #ffffff;
  --color-surface: #ffffff;
  --color-border: #e5e7eb;
  --color-border-light: #f0f2f5;

  --color-text: #111827;
  --color-text-secondary: #4b5563;
  --color-text-muted: #6b7280;

  --color-primary: #0369a1;        /* clinical blue */
  --color-primary-dark: #075985;
  --color-primary-light: #e0f2fe;
  --color-accent: #0891b2;         /* teal accent */
  --color-success: #059669;
  --color-warning: #d97706;
  --color-danger: #dc2626;

  --color-research: #7c3aed;       /* purple for research */
  --color-research-light: #f3e8ff;

  --color-drug: #db2777;           /* pink for drug-dev */
  --color-drug-light: #fce7f3;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --font-mono: "SF Mono", "Monaco", "Inconsolata", "Roboto Mono", monospace;

  /* Spacing */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08);
}

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

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

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover { color: var(--color-primary-dark); text-decoration: underline; }

/* ============================================================
   Layout
   ============================================================ */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-wide {
  max-width: 1300px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============================================================
   Navigation
   ============================================================ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--color-border-light);
}

.nav-inner {
  max-width: 1300px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
  color: var(--color-text);
}
.nav-brand:hover { text-decoration: none; }

.nav-logo {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 16px;
}

.nav-brand-sub {
  font-size: 11px;
  font-weight: 400;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-link {
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: 14px;
  font-weight: 500;
  transition: all 0.15s ease;
}
.nav-link:hover { background: var(--color-border-light); color: var(--color-text); text-decoration: none; }
.nav-link.active { background: var(--color-primary-light); color: var(--color-primary-dark); }

/* Mobile nav */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--color-text);
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 12px;
    border-bottom: 1px solid var(--color-border);
    gap: 4px;
  }
  .nav-links.open { display: flex; }
  .nav-link { width: 100%; }
  .nav-toggle { display: block; }
}

/* ============================================================
   Hero
   ============================================================ */
.hero {
  padding: 96px 0 72px;
  background: linear-gradient(180deg, #fafbfc 0%, #ffffff 100%);
  border-bottom: 1px solid var(--color-border-light);
}

.hero-eyebrow {
  display: inline-block;
  padding: 4px 12px;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-size: 12px;
  font-weight: 600;
  border-radius: 999px;
  letter-spacing: 0.04em;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: 20px;
}

.hero-sub-en {
  font-size: clamp(18px, 2.5vw, 24px);
  font-weight: 400;
  color: var(--color-text-secondary);
  margin-bottom: 28px;
}

.hero-lede {
  font-size: 17px;
  color: var(--color-text-secondary);
  max-width: 720px;
  line-height: 1.7;
}

/* ============================================================
   Sections / Typography
   ============================================================ */
section { padding: 64px 0; }
section.compact { padding: 40px 0; }

.section-header {
  margin-bottom: 40px;
  max-width: 760px;
}

.section-eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

h2 {
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-text);
  margin-bottom: 12px;
  line-height: 1.25;
}

h2 .en {
  display: block;
  font-size: 0.55em;
  font-weight: 400;
  color: var(--color-text-muted);
  margin-top: 4px;
  letter-spacing: 0.02em;
}

h3 {
  font-size: 20px;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 12px;
  color: var(--color-text);
}
h3 .en {
  font-weight: 400;
  font-size: 0.8em;
  color: var(--color-text-muted);
  margin-left: 8px;
}

h4 {
  font-size: 16px;
  font-weight: 600;
  margin-top: 20px;
  margin-bottom: 8px;
  color: var(--color-text);
}

p { margin-bottom: 14px; color: var(--color-text-secondary); }
p strong { color: var(--color-text); font-weight: 600; }

.section-intro {
  font-size: 17px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ============================================================
   Card grid
   ============================================================ */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.card-grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all 0.2s ease;
}
.card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-link {
  display: block;
  color: inherit;
}
.card-link:hover { text-decoration: none; color: inherit; }

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 18px;
  font-weight: 700;
}

.card-icon.research { background: var(--color-research-light); color: var(--color-research); }
.card-icon.drug { background: var(--color-drug-light); color: var(--color-drug); }
.card-icon.success { background: #d1fae5; color: var(--color-success); }
.card-icon.warning { background: #fed7aa; color: var(--color-warning); }

.card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}
.card-title-en {
  font-size: 13px;
  font-weight: 400;
  color: var(--color-text-muted);
  margin-bottom: 12px;
}

.card-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.card-arrow {
  display: inline-flex;
  align-items: center;
  margin-top: 14px;
  color: var(--color-primary);
  font-size: 14px;
  font-weight: 500;
}

/* ============================================================
   Content blocks
   ============================================================ */
.content {
  max-width: 820px;
}

.content p, .content li {
  font-size: 15.5px;
  line-height: 1.75;
}

.content ul, .content ol {
  margin: 14px 0 20px 22px;
  color: var(--color-text-secondary);
}
.content li { margin-bottom: 8px; }

.callout {
  background: var(--color-primary-light);
  border-left: 3px solid var(--color-primary);
  padding: 18px 22px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 24px 0;
}
.callout.research { background: var(--color-research-light); border-left-color: var(--color-research); }
.callout.drug { background: var(--color-drug-light); border-left-color: var(--color-drug); }
.callout.warning { background: #fef3c7; border-left-color: var(--color-warning); }
.callout.danger { background: #fee2e2; border-left-color: var(--color-danger); }

.callout-title {
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
  font-size: 14px;
}

/* ============================================================
   Tables
   ============================================================ */
.table-wrap {
  overflow-x: auto;
  margin: 24px 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  background: white;
}

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border-light);
  vertical-align: top;
}

th {
  background: #f8fafc;
  font-weight: 600;
  color: var(--color-text);
  font-size: 13px;
  letter-spacing: 0.02em;
}

tbody tr:hover { background: #fafbfc; }
tbody tr:last-child td { border-bottom: none; }

/* ============================================================
   Source citations
   ============================================================ */
.source {
  font-size: 13px;
  color: var(--color-text-muted);
  border-left: 2px solid var(--color-border);
  padding: 10px 14px;
  margin: 18px 0;
  background: #fafbfc;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.source strong { color: var(--color-text-secondary); }
.source a { font-weight: 500; }

.source-list {
  list-style: none;
  padding: 0;
}
.source-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border-light);
  font-size: 14px;
}
.source-list li:last-child { border-bottom: none; }
.source-list .source-meta {
  display: block;
  font-size: 12px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* In-text citation [n] */
.cite {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 1px 6px;
  border-radius: 4px;
  margin: 0 2px;
  vertical-align: super;
  line-height: 1.4;
  text-decoration: none;
}
.cite:hover { background: var(--color-primary); color: white; text-decoration: none; }

/* ============================================================
   Stats
   ============================================================ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin: 32px 0;
}

.stat {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
}

.stat-value {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.1;
}

.stat-label {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-top: 6px;
}

.stat-source {
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 8px;
}

/* ============================================================
   Tags / pills
   ============================================================ */
.tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 4px;
  background: var(--color-border-light);
  color: var(--color-text-secondary);
  letter-spacing: 0.02em;
  margin-right: 4px;
}
.tag.phase3 { background: #fef3c7; color: #92400e; }
.tag.phase2 { background: #dbeafe; color: #1e40af; }
.tag.phase1 { background: #f3e8ff; color: #6b21a8; }
.tag.approved { background: #d1fae5; color: #065f46; }
.tag.t1d { background: #fce7f3; color: #9f1239; }
.tag.t2d { background: #cffafe; color: #155e75; }
.tag.gdm { background: #fed7aa; color: #9a3412; }

/* ============================================================
   Two-column layout
   ============================================================ */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  margin: 24px 0;
}
@media (max-width: 760px) {
  .two-col { grid-template-columns: 1fr; }
}

/* ============================================================
   Page header
   ============================================================ */
.page-header {
  padding: 64px 0 32px;
  border-bottom: 1px solid var(--color-border-light);
  background: var(--color-bg-alt);
}

.page-header h1 {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}
.page-header .en {
  font-size: 0.45em;
  font-weight: 400;
  color: var(--color-text-muted);
  display: block;
  margin-top: 4px;
  letter-spacing: 0.02em;
}

.page-header .lede {
  font-size: 17px;
  color: var(--color-text-secondary);
  max-width: 720px;
  margin-top: 16px;
}

.breadcrumb {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}
.breadcrumb a { color: var(--color-text-muted); }

/* ============================================================
   TOC (Table of Contents)
   ============================================================ */
.layout-with-toc {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 60px;
  padding: 48px 0;
}
@media (max-width: 960px) {
  .layout-with-toc { grid-template-columns: 1fr; gap: 24px; }
}

.toc {
  position: sticky;
  top: 80px;
  align-self: start;
  font-size: 13px;
  border-left: 2px solid var(--color-border);
  padding-left: 16px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}
.toc-title {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 10px;
}
.toc ul { list-style: none; padding: 0; }
.toc li { margin-bottom: 8px; }
.toc a {
  color: var(--color-text-secondary);
  font-weight: 500;
  display: block;
  line-height: 1.4;
}
.toc a:hover { color: var(--color-primary); text-decoration: none; }
.toc .sub { padding-left: 14px; font-size: 12px; }

@media (max-width: 960px) {
  .toc { display: none; }
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: #111827;
  color: #9ca3af;
  padding: 56px 0 32px;
  margin-top: 80px;
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}
@media (max-width: 760px) {
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
}

.footer h4 {
  color: #f3f4f6;
  font-size: 14px;
  margin-bottom: 12px;
}

.footer a { color: #9ca3af; }
.footer a:hover { color: #f3f4f6; }

.footer-bottom {
  border-top: 1px solid #1f2937;
  padding-top: 24px;
  font-size: 12px;
  color: #6b7280;
}

.disclaimer {
  background: #1f2937;
  padding: 14px 18px;
  border-radius: var(--radius-md);
  margin-bottom: 28px;
  border-left: 3px solid var(--color-warning);
  font-size: 13px;
}

/* ============================================================
   Utility
   ============================================================ */
.mt-0 { margin-top: 0 !important; }
.mb-0 { margin-bottom: 0 !important; }
.text-center { text-align: center; }
.muted { color: var(--color-text-muted); }
.small { font-size: 13px; }
.mono { font-family: var(--font-mono); }

.divider { height: 1px; background: var(--color-border-light); margin: 40px 0; }

/* ============================================================
   i18n — language toggle (single-language display)
   <html data-lang="zh"> or "en" controls visibility.
   ============================================================ */
html[data-lang="zh"] .i18n-en { display: none !important; }
html[data-lang="en"] .i18n-zh { display: none !important; }

/* Language switcher button in nav */
.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  margin-left: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  flex-shrink: 0;
}
.lang-switch button {
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px 10px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-secondary);
  transition: all 0.15s ease;
}
.lang-switch button:hover { background: var(--color-border-light); }
html[data-lang="zh"] .lang-switch button[data-set-lang="zh"],
html[data-lang="en"] .lang-switch button[data-set-lang="en"] {
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
}

@media (max-width: 860px) {
  .lang-switch { margin-left: auto; margin-right: 8px; }
}