/* PathBridge 启桥教育 — Design System */
:root {
  /* Light theme — 学术权威 */
  --pb-navy-900: #0B1F3A;
  --pb-navy-800: #112B4F;
  --pb-navy-700: #1B3A66;
  --pb-navy-600: #2A4D7E;
  --pb-navy-100: #E8EDF5;
  --pb-navy-50: #F2F5FA;

  --pb-gold-700: #9C7E3D;
  --pb-gold-600: #B89352;
  --pb-gold-500: #C9A968;
  --pb-gold-400: #D9BE85;
  --pb-gold-100: #F4ECDA;

  --pb-ivory: #F6F2EA;
  --pb-paper: #FBF9F4;
  --pb-white: #FFFFFF;

  --pb-ink-900: #0E1320;
  --pb-ink-700: #2B3142;
  --pb-ink-500: #5A6172;
  --pb-ink-400: #7E8597;
  --pb-ink-300: #A8AEBD;
  --pb-ink-200: #D4D8E0;
  --pb-ink-100: #ECEEF2;

  --pb-success: #2F7D5B;
  --pb-warn: #C28B3A;
  --pb-danger: #B0463E;

  --pb-bg: var(--pb-paper);
  --pb-surface: var(--pb-white);
  --pb-surface-alt: var(--pb-ivory);
  --pb-fg: var(--pb-ink-900);
  --pb-fg-muted: var(--pb-ink-500);
  --pb-border: var(--pb-ink-200);
  --pb-border-strong: var(--pb-ink-300);

  --pb-serif: 'Cormorant Garamond', 'Noto Serif SC', 'Source Han Serif SC', Georgia, serif;
  --pb-sans: 'Inter', 'Noto Sans SC', -apple-system, system-ui, 'Helvetica Neue', sans-serif;
  --pb-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', monospace;

  --pb-radius-sm: 2px;
  --pb-radius: 4px;
  --pb-radius-lg: 6px;

  --pb-shadow-sm: 0 1px 2px rgba(11, 31, 58, 0.04);
  --pb-shadow: 0 1px 3px rgba(11, 31, 58, 0.06), 0 8px 24px -10px rgba(11, 31, 58, 0.10);
  --pb-shadow-lg: 0 1px 3px rgba(11, 31, 58, 0.06), 0 32px 64px -24px rgba(11, 31, 58, 0.22);

  /* Subtle paper-grain texture for surfaces */
  --pb-grain: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.04  0 0 0 0 0.06  0 0 0 0 0.10  0 0 0 0.025 0'/></filter><rect width='240' height='240' filter='url(%23n)'/></svg>");
}

[data-theme="dark"] {
  --pb-navy-900: #050913;
  --pb-navy-800: #0A1426;
  --pb-navy-700: #122036;
  --pb-navy-600: #1B2C46;
  --pb-navy-100: #1E2A40;
  --pb-navy-50: #141B2B;

  --pb-ivory: #0F1626;
  --pb-paper: #070D1A;
  --pb-white: #0F1626;

  --pb-ink-900: #ECEEF2;
  --pb-ink-700: #C9CDD8;
  --pb-ink-500: #8B92A4;
  --pb-ink-400: #6B7286;
  --pb-ink-300: #4D5365;
  --pb-ink-200: #2C3346;
  --pb-ink-100: #1A2032;

  --pb-bg: #070D1A;
  --pb-surface: #0F1626;
  --pb-surface-alt: #141B2B;
  --pb-fg: #ECEEF2;
  --pb-fg-muted: #8B92A4;
  --pb-border: #2C3346;
  --pb-border-strong: #3A4259;
}

* { box-sizing: border-box; }

.pb-frame {
  width: 100%;
  height: 100%;
  background: var(--pb-bg);
  color: var(--pb-fg);
  font-family: var(--pb-sans);
  font-size: 14px;
  line-height: 1.55;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  letter-spacing: 0.005em;
}

.pb-scroll {
  width: 100%;
  height: 100%;
  overflow-y: auto;
  background: var(--pb-bg);
  color: var(--pb-fg);
  font-family: var(--pb-sans);
  font-size: 14px;
  line-height: 1.55;
  position: relative;
}
.pb-scroll::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: var(--pb-grain);
  opacity: 0.5;
  pointer-events: none;
  z-index: 999;
  mix-blend-mode: multiply;
}
[data-theme="dark"] .pb-scroll::before { mix-blend-mode: screen; opacity: 0.35; }

/* ===== Top nav ===== */
.pb-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 56px;
  background: rgba(251, 249, 244, 0.88);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid var(--pb-border);
  position: sticky;
  top: 0;
  z-index: 10;
}
[data-theme="dark"] .pb-nav { background: rgba(7, 13, 26, 0.82); }
.pb-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--pb-serif);
  font-weight: 600;
  font-size: 22px;
  letter-spacing: 0.01em;
  color: var(--pb-fg);
}
.pb-logo-mark {
  width: 36px; height: 36px;
  border-radius: 0;
  background: var(--pb-navy-900);
  display: grid; place-items: center;
  color: var(--pb-gold-500);
  font-family: var(--pb-serif);
  font-weight: 600;
  font-size: 18px;
  flex-shrink: 0;
  position: relative;
  box-shadow: inset 0 0 0 1px rgba(201,169,104,0.35);
}
.pb-logo-mark::after {
  content: '';
  position: absolute;
  inset: 3px;
  border: 0.5px solid rgba(201,169,104,0.25);
  pointer-events: none;
}
.pb-logo-en { color: var(--pb-fg-muted); font-family: var(--pb-sans); font-size: 13px; font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase; margin-left: 2px; }
.pb-logo-divider { width: 1px; height: 18px; background: var(--pb-border); margin: 0 4px; }

.pb-nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
  font-size: 14px;
}
.pb-nav-link {
  color: var(--pb-fg);
  cursor: pointer;
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.pb-nav-link:hover { color: var(--pb-navy-700); border-bottom-color: var(--pb-gold-500); }
.pb-nav-link.active { color: var(--pb-navy-900); border-bottom-color: var(--pb-gold-500); font-weight: 500; }
[data-theme="dark"] .pb-nav-link:hover { color: var(--pb-gold-400); }
[data-theme="dark"] .pb-nav-link.active { color: var(--pb-gold-500); }

.pb-nav-actions { display: flex; align-items: center; gap: 12px; }

/* ===== Buttons ===== */
.pb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 22px;
  border-radius: var(--pb-radius);
  font-family: var(--pb-sans);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.22s cubic-bezier(0.2, 0.7, 0.2, 1);
  text-decoration: none;
  white-space: nowrap;
  position: relative;
}
.pb-btn-primary {
  background: var(--pb-navy-900);
  color: var(--pb-gold-500);
  border-color: var(--pb-navy-900);
  box-shadow: inset 0 0 0 1px rgba(201,169,104,0.18);
}
.pb-btn-primary:hover { background: var(--pb-navy-800); box-shadow: inset 0 0 0 1px rgba(201,169,104,0.4), 0 8px 20px -8px rgba(11,31,58,0.4); }
.pb-btn-gold {
  background: var(--pb-gold-500);
  color: var(--pb-navy-900);
  border-color: var(--pb-gold-500);
  box-shadow: inset 0 -1px 0 rgba(0,0,0,0.08);
}
.pb-btn-gold:hover { background: var(--pb-gold-400); box-shadow: inset 0 -1px 0 rgba(0,0,0,0.08), 0 8px 20px -8px rgba(201,169,104,0.5); }
.pb-btn-ghost {
  background: transparent;
  color: var(--pb-fg);
  border-color: var(--pb-border-strong);
}
.pb-btn-ghost:hover { border-color: var(--pb-navy-900); color: var(--pb-navy-900); }
[data-theme="dark"] .pb-btn-ghost:hover { border-color: var(--pb-gold-500); color: var(--pb-gold-500); }
.pb-btn-link {
  background: transparent;
  border: none;
  color: var(--pb-navy-700);
  padding: 4px 0;
  font-weight: 500;
}

/* ===== Decorative ornaments ===== */
.pb-ornament {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--pb-serif);
  color: var(--pb-gold-600);
  font-size: 14px;
}
.pb-ornament::before, .pb-ornament::after {
  content: '';
  width: 24px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--pb-gold-600), transparent);
}

/* Drop cap for editorial paragraphs */
.pb-dropcap::first-letter {
  font-family: var(--pb-serif);
  font-weight: 500;
  font-size: 4.2em;
  line-height: 0.9;
  float: left;
  padding: 6px 12px 0 0;
  color: var(--pb-navy-900);
}
[data-theme="dark"] .pb-dropcap::first-letter { color: var(--pb-gold-500); }

/* Pull quote */
.pb-pullquote {
  font-family: var(--pb-serif);
  font-style: italic;
  font-size: 28px;
  line-height: 1.35;
  letter-spacing: -0.005em;
  color: var(--pb-fg);
  border-left: 2px solid var(--pb-gold-500);
  padding: 6px 0 6px 24px;
}

/* Section number badge */
.pb-section-num {
  font-family: var(--pb-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--pb-gold-700);
  font-weight: 500;
}
[data-theme="dark"] .pb-section-num { color: var(--pb-gold-500); }

/* Hairline rule with center mark */
.pb-hairline {
  height: 1px;
  background: var(--pb-border);
  position: relative;
}
.pb-hairline::after {
  content: '';
  position: absolute;
  top: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 5px; height: 5px;
  background: var(--pb-gold-500);
  transform: translateX(-50%) rotate(45deg);
}

/* Marquee/serif heading underline accent */
.pb-accent-underline {
  position: relative;
  display: inline-block;
}
.pb-accent-underline::after {
  content: '';
  position: absolute;
  left: 0; right: 0;
  bottom: -8px;
  height: 1px;
  background: var(--pb-gold-500);
  transform-origin: left;
}
[data-theme="dark"] .pb-btn-link { color: var(--pb-gold-500); }
.pb-btn-sm { padding: 6px 12px; font-size: 13px; }
.pb-btn-lg { padding: 14px 28px; font-size: 15px; }

/* ===== Cards ===== */
.pb-card {
  background: var(--pb-surface);
  border: 1px solid var(--pb-border);
  border-radius: var(--pb-radius-lg);
  padding: 24px;
  position: relative;
}
.pb-card-flat { background: var(--pb-surface-alt); border: 1px solid transparent; }

.pb-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: var(--pb-navy-50);
  color: var(--pb-navy-700);
  border-radius: 100px;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.02em;
}
.pb-tag-gold { background: var(--pb-gold-100); color: var(--pb-gold-700); }
[data-theme="dark"] .pb-tag-gold { background: rgba(201,169,104,0.15); color: var(--pb-gold-500); }
[data-theme="dark"] .pb-tag { background: var(--pb-navy-100); color: var(--pb-gold-400); }

/* ===== Headings ===== */
.pb-h1 {
  font-family: var(--pb-serif);
  font-weight: 400;
  font-size: 56px;
  line-height: 1.04;
  letter-spacing: -0.018em;
  color: var(--pb-fg);
  margin: 0;
  text-wrap: balance;
}
.pb-h2 {
  font-family: var(--pb-serif);
  font-weight: 400;
  font-size: 42px;
  line-height: 1.1;
  letter-spacing: -0.012em;
  color: var(--pb-fg);
  margin: 0;
  text-wrap: balance;
}
.pb-h3 {
  font-family: var(--pb-serif);
  font-weight: 500;
  font-size: 26px;
  line-height: 1.18;
  letter-spacing: -0.006em;
  color: var(--pb-fg);
  margin: 0;
}
.pb-eyebrow {
  font-family: var(--pb-sans);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.24em;
  color: var(--pb-gold-700);
  display: inline-flex;
  align-items: center;
  gap: 12px;
}
.pb-eyebrow::before {
  content: '';
  width: 28px;
  height: 1px;
  background: var(--pb-gold-600);
}
[data-theme="dark"] .pb-eyebrow { color: var(--pb-gold-500); }
.pb-mono { font-family: var(--pb-mono); }

/* ===== Form ===== */
.pb-input, .pb-select {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--pb-border-strong);
  border-radius: var(--pb-radius);
  background: var(--pb-surface);
  color: var(--pb-fg);
  font-family: var(--pb-sans);
  font-size: 14px;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.pb-input:focus, .pb-select:focus {
  outline: none;
  border-color: var(--pb-navy-700);
  box-shadow: 0 0 0 3px rgba(43, 77, 126, 0.12);
}
.pb-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--pb-fg-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

/* ===== Divider ===== */
.pb-divider { height: 1px; background: var(--pb-border); width: 100%; }
.pb-rule {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--pb-fg-muted);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.2em;
}
.pb-rule::before, .pb-rule::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--pb-border);
}

/* ===== Image placeholder ===== */
.pb-img-placeholder {
  background:
    repeating-linear-gradient(135deg, var(--pb-ink-100) 0 8px, var(--pb-ink-200) 8px 9px),
    var(--pb-surface-alt);
  border: 1px solid var(--pb-border);
  border-radius: var(--pb-radius);
  display: grid;
  place-items: center;
  font-family: var(--pb-mono);
  font-size: 11px;
  color: var(--pb-fg-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* ===== Footer ===== */
.pb-footer {
  background: var(--pb-navy-900);
  color: var(--pb-ink-200);
  padding: 56px 48px 28px;
  font-size: 13px;
}
[data-theme="dark"] .pb-footer { background: #03070F; border-top: 1px solid var(--pb-border); }
.pb-footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr 1fr;
  gap: 40px;
  max-width: 1280px;
  margin: 0 auto;
}
.pb-footer h4 { color: var(--pb-gold-500); font-family: var(--pb-sans); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.14em; margin: 0 0 14px; }
.pb-footer ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 9px; }
.pb-footer a, .pb-footer li { color: rgba(236,238,242,0.72); cursor: pointer; }
.pb-footer a:hover, .pb-footer li:hover { color: var(--pb-gold-500); }
.pb-footer-bottom {
  max-width: 1280px;
  margin: 36px auto 0;
  padding-top: 22px;
  border-top: 1px solid rgba(255,255,255,0.08);
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: rgba(236,238,242,0.5);
}

/* ===== Progress ===== */
.pb-progress-track {
  height: 6px;
  background: var(--pb-ink-100);
  border-radius: 100px;
  overflow: hidden;
}
.pb-progress-fill {
  height: 100%;
  background: var(--pb-navy-700);
  border-radius: 100px;
  transition: width 0.3s ease;
}
.pb-progress-fill.gold { background: var(--pb-gold-500); }

/* ===== Stat ===== */
.pb-stat-num {
  font-family: var(--pb-serif);
  font-weight: 400;
  font-size: 48px;
  line-height: 1;
  color: var(--pb-navy-900);
  letter-spacing: -0.02em;
  font-feature-settings: 'lnum';
}
[data-theme="dark"] .pb-stat-num { color: var(--pb-gold-500); }
.pb-stat-label { font-size: 12px; color: var(--pb-fg-muted); text-transform: uppercase; letter-spacing: 0.1em; margin-top: 6px; }

/* Probability bars */
.pb-prob-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--pb-mono);
  font-size: 12px;
}
.pb-prob-track {
  flex: 1;
  height: 8px;
  background: var(--pb-ink-100);
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}
.pb-prob-fill {
  position: absolute; left: 0; top: 0; height: 100%;
  border-radius: 4px;
}
.pb-prob-fill.reach { background: linear-gradient(90deg, #B0463E, #D9BE85); }
.pb-prob-fill.match { background: linear-gradient(90deg, var(--pb-navy-600), var(--pb-gold-500)); }
.pb-prob-fill.safety { background: linear-gradient(90deg, var(--pb-success), #76B89B); }

/* utility */
.pb-row { display: flex; align-items: center; }
.pb-col { display: flex; flex-direction: column; }
.pb-gap-4 { gap: 4px; }
.pb-gap-8 { gap: 8px; }
.pb-gap-12 { gap: 12px; }
.pb-gap-16 { gap: 16px; }
.pb-gap-24 { gap: 24px; }
.pb-gap-32 { gap: 32px; }
.pb-mt-8 { margin-top: 8px; }
.pb-mt-16 { margin-top: 16px; }
.pb-mt-24 { margin-top: 24px; }
.pb-mt-40 { margin-top: 40px; }

/* Locked / paywall */
.pb-locked {
  position: relative;
  overflow: hidden;
}
.pb-locked::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 0%, var(--pb-surface) 85%);
  pointer-events: none;
  z-index: 1;
}
.pb-locked-blur { filter: blur(4px); user-select: none; }

/* Star rating */
.pb-stars { color: var(--pb-gold-500); letter-spacing: 2px; font-size: 13px; }