/* ===========================
   超师学堂官网样式
   =========================== */

:root {
  --color-ink: #0a1628;
  --color-ink-light: #143d66;
  --color-blue: #1e5a94;
  --color-gold: #c9a86c;
  --color-gold-light: #e3d0a6;
  --color-paper: #f7f9fc;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #5a6a7f;
  --color-border: rgba(20, 61, 102, 0.12);
  --shadow-sm: 0 2px 8px rgba(10, 22, 40, 0.06);
  --shadow-md: 0 12px 32px rgba(10, 22, 40, 0.1);
  --shadow-lg: 0 24px 64px rgba(10, 22, 40, 0.14);
  --radius: 16px;
  --radius-sm: 8px;
  --transition: 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --font-serif: 'Noto Serif SC', 'Songti SC', serif;
  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-brush: 'Ma Shan Zheng', cursive;
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.85;
  color: var(--color-text);
  background: var(--color-paper);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  transition: background var(--transition), box-shadow var(--transition), backdrop-filter var(--transition);
}

.site-header.scrolled {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
  color: #fff;
  transition: color var(--transition);
}

.site-header.scrolled .logo,
.site-header.nav-open .logo {
  color: var(--color-ink);
}

.logo-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--color-gold);
  color: #fff;
  font-family: var(--font-brush);
  font-size: 22px;
  line-height: 1;
}

.logo-text {
  font-family: var(--font-serif);
  letter-spacing: 0.04em;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.main-nav a {
  font-size: 17px;
  color: rgba(255,255,255,0.85);
  position: relative;
  padding: 6px 0;
  transition: color var(--transition);
}

.site-header.scrolled .main-nav a,
.site-header.nav-open .main-nav a {
  color: var(--color-text);
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-gold);
  transition: width var(--transition);
}

.main-nav a:hover::after,
.main-nav a:focus::after {
  width: 100%;
}

.main-nav a:hover,
.main-nav a:focus {
  color: #fff;
}

.site-header.scrolled .main-nav a:hover,
.site-header.scrolled .main-nav a:focus,
.site-header.nav-open .main-nav a:hover,
.site-header.nav-open .main-nav a:focus {
  color: var(--color-ink);
}

.nav-cta {
  padding: 8px 20px !important;
  border: 1px solid currentColor;
  border-radius: 999px;
}

.nav-cta::after { display: none; }

.nav-cta:hover,
.nav-cta:focus {
  background: var(--color-gold);
  border-color: var(--color-gold);
  color: #fff !important;
}

.menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 6px;
  z-index: 1001;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  transition: transform 0.3s ease, opacity 0.3s ease, background 0.3s ease;
}

.site-header.scrolled .menu-toggle span,
.site-header.nav-open .menu-toggle span {
  background: var(--color-ink);
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
  overflow: hidden;
  padding: 120px 0 80px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.05);
  animation: heroZoom 20s ease-in-out infinite alternate;
}

@keyframes heroZoom {
  to { transform: scale(1.12); }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(10,22,40,0.82) 0%, rgba(20,61,102,0.68) 60%, rgba(10,22,40,0.5) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 900px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 8px 18px 8px 8px;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 999px;
  font-size: 15px;
  margin-bottom: 28px;
  backdrop-filter: blur(4px);
}

.hero-badge .seal {
  display: inline-block;
  padding: 4px 12px;
  background: var(--color-gold);
  border-radius: 999px;
  font-weight: 700;
  color: var(--color-ink);
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(42px, 7vw, 78px);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 24px;
  letter-spacing: 0.06em;
}

.hero-title .sub {
  display: block;
  font-size: clamp(20px, 3vw, 32px);
  font-weight: 400;
  letter-spacing: 0.08em;
  margin-top: 14px;
  opacity: 0.95;
}

.hero-lead {
  font-size: clamp(16px, 2vw, 20px);
  line-height: 1.9;
  margin: 0 auto 36px;
  max-width: 720px;
  opacity: 0.92;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: 999px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.04em;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition);
  border: 1px solid transparent;
}

.btn:hover { transform: translateY(-2px); }
.btn:focus-visible { outline: 3px solid var(--color-gold); outline-offset: 3px; }

.btn-primary {
  background: var(--color-gold);
  color: var(--color-ink);
  box-shadow: 0 8px 24px rgba(201,168,108,0.35);
}

.btn-primary:hover {
  background: var(--color-gold-light);
  box-shadow: 0 12px 32px rgba(201,168,108,0.45);
}

.btn-ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.5);
}

.btn-ghost:hover {
  background: rgba(255,255,255,0.12);
  border-color: #fff;
}

.btn-block { width: 100%; }

.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255,255,255,0.8);
  font-size: 15px;
  letter-spacing: 0.1em;
  z-index: 2;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-8px); }
  60% { transform: translateX(-50%) translateY(-4px); }
}

.mouse {
  width: 22px;
  height: 36px;
  border: 2px solid rgba(255,255,255,0.7);
  border-radius: 12px;
  position: relative;
}

.mouse span {
  position: absolute;
  top: 7px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 6px;
  background: #fff;
  border-radius: 2px;
  animation: scrollWheel 1.5s infinite;
}

@keyframes scrollWheel {
  0% { opacity: 1; transform: translateX(-50%) translateY(0); }
  100% { opacity: 0; transform: translateX(-50%) translateY(10px); }
}

/* Sections */
.section {
  padding: 110px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 64px;
}

.section-kicker {
  display: inline-block;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-blue);
  margin-bottom: 14px;
  padding-left: 0.18em;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(30px, 4.5vw, 44px);
  font-weight: 700;
  line-height: 1.3;
  margin: 0 0 18px;
  color: var(--color-ink);
}

.section-title .brush {
  font-family: var(--font-brush);
  color: var(--color-gold);
  font-weight: 400;
  padding: 0 6px;
}

.section-subtitle {
  font-size: 17px;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin: 0;
}

.lead {
  font-size: 18px;
  line-height: 1.9;
  color: var(--color-text);
}

/* About */
.era-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 32px;
  margin-bottom: 80px;
}

.era-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 36px 30px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

.era-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

.era-icon {
  font-family: var(--font-serif);
  font-size: 36px;
  font-weight: 700;
  color: var(--color-gold);
  margin-bottom: 16px;
  line-height: 1;
}

.era-card h3 {
  font-family: var(--font-serif);
  font-size: 22px;
  margin: 0 0 12px;
  color: var(--color-ink);
}

.era-card p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 17px;
  line-height: 1.85;
}

.mission-statement {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
  background: var(--color-surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.mission-media {
  height: 100%;
  min-height: 420px;
}

.mission-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.mission-body {
  padding: 48px 48px 48px 0;
}

.mission-body h3 {
  font-family: var(--font-serif);
  font-size: clamp(30px, 3.6vw, 38px);
  margin: 0 0 18px;
  color: var(--color-ink);
}

.mission-body h3 .founder-title-en {
  display: block;
  font-size: 17px;
  font-weight: 400;
  color: var(--color-text-secondary);
  letter-spacing: 0.08em;
  margin-top: 6px;
}

.mission-body p {
  margin: 0 0 16px;
  color: var(--color-text-secondary);
}

.mission-footnote {
  margin-top: 20px;
  padding: 14px 20px;
  border-left: 3px solid var(--color-gold);
  background: rgba(201,168,108,0.08);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-family: var(--font-serif);
  font-size: 17px;
  color: var(--color-ink-light);
}

.mission-values {
  display: flex;
  gap: 24px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.value {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.value-num {
  font-family: var(--font-brush);
  font-size: 32px;
  color: var(--color-gold);
  line-height: 1;
}

.value span:last-child {
  font-size: 17px;
  color: var(--color-text-secondary);
  letter-spacing: 0.05em;
}

/* Founder */
.founder {
  background: linear-gradient(180deg, var(--color-paper) 0%, #eef2f7 100%);
}

.founder-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 64px;
  align-items: center;
}

.founder-portrait {
  position: relative;
}

.founder-portrait img {
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  position: relative;
  z-index: 2;
}

.portrait-frame {
  position: absolute;
  inset: 24px -24px -24px 24px;
  border: 2px solid var(--color-gold);
  border-radius: var(--radius);
  z-index: 1;
}

.founder-body .section-kicker {
  margin-bottom: 10px;
}

.founder-body h2 {
  font-family: var(--font-serif);
  font-size: clamp(30px, 4vw, 42px);
  margin: 0 0 20px;
  color: var(--color-ink);
}

.founder-title-en {
  display: block;
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 400;
  color: var(--color-text-secondary);
  letter-spacing: 0.04em;
  margin-top: 6px;
}

.founder-body blockquote {
  margin: 24px 0;
  padding: 18px 24px;
  border-left: 4px solid var(--color-gold);
  background: rgba(201,168,108,0.08);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.founder-body blockquote p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 17px;
  color: var(--color-ink-light);
}

.founder-body p {
  color: var(--color-text-secondary);
}

/* Theory */
.books-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 64px;
}

.book-card {
  position: relative;
  background: var(--color-surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}

.book-card:hover,
.book-card:focus {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  outline: none;
}

.book-spine {
  height: 140px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--color-ink-light) 0%, var(--color-blue) 100%);
  color: #fff;
  font-family: var(--font-brush);
  font-size: 48px;
  letter-spacing: 0.1em;
}

.book-content {
  padding: 28px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.book-content h3 {
  font-family: var(--font-serif);
  font-size: 22px;
  margin: 0 0 6px;
  color: var(--color-ink);
}

.book-sub {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-gold);
  margin: 0 0 14px;
  letter-spacing: 0.04em;
}

.book-content p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 17px;
  line-height: 1.85;
}

.framework {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 20px;
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.framework-item {
  flex: 1;
  text-align: center;
  padding: 24px;
}

.framework-num {
  display: inline-block;
  width: 44px;
  height: 44px;
  line-height: 44px;
  border-radius: 50%;
  background: var(--color-gold);
  color: #fff;
  font-weight: 700;
  font-family: var(--font-serif);
  margin-bottom: 14px;
}

.framework-item h4 {
  font-family: var(--font-serif);
  font-size: 20px;
  margin: 0 0 10px;
  color: var(--color-ink);
}

.framework-item p {
  margin: 0;
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.framework-arrow {
  display: grid;
  place-items: center;
  font-size: 32px;
  color: var(--color-gold);
  align-self: center;
}

/* Layers */
.layers {
  background: var(--color-surface);
}

.layers-tabs {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.layer-tab {
  flex: 1;
  min-width: 220px;
  max-width: 320px;
  padding: 24px 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-paper);
  text-align: left;
  transition: border-color var(--transition), background var(--transition), box-shadow var(--transition);
}

.layer-tab:hover { background: #fff; }

.layer-tab.active {
  border-color: var(--color-gold);
  background: #fff;
  box-shadow: var(--shadow-md);
}

.layer-tab .tab-name {
  display: block;
  font-family: var(--font-brush);
  font-size: 34px;
  color: var(--color-ink);
  line-height: 1;
  margin-bottom: 10px;
}

.layer-tab.active .tab-name { color: var(--color-gold); }

.layer-tab .tab-desc {
  display: block;
  font-size: 15px;
  color: var(--color-text-secondary);
}

.layer-panels {
  position: relative;
}

.layer-panel {
  display: none;
  animation: fadeIn 0.45s ease;
}

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

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.panel-intro {
  max-width: 760px;
  margin: 0 auto 36px;
  text-align: center;
}

.panel-intro h3 {
  font-family: var(--font-serif);
  font-size: 28px;
  color: var(--color-ink);
  margin: 0 0 14px;
}

.panel-intro h3 span {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-gold);
  border: 1px solid var(--color-gold);
  padding: 4px 12px;
  border-radius: 999px;
  margin-left: 12px;
  vertical-align: middle;
}

.panel-intro p {
  color: var(--color-text-secondary);
  margin: 0;
  font-size: 17px;
}

.modules-accordion {
  max-width: 860px;
  margin: 0 auto 36px;
}

.module-item {
  background: var(--color-paper);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
}

.module-item summary {
  padding: 20px 24px;
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  color: var(--color-ink);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background var(--transition);
}

.module-item summary::-webkit-details-marker { display: none; }

.module-item summary::after {
  content: '+';
  font-size: 22px;
  color: var(--color-gold);
  transition: transform var(--transition);
}

.module-item[open] summary { background: rgba(201,168,108,0.06); }
.module-item[open] summary::after { transform: rotate(45deg); }

.module-item p {
  padding: 0 24px 20px;
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 17px;
  line-height: 1.85;
}

.panel-features {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.chip {
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  border-radius: 999px;
  background: rgba(20,61,102,0.06);
  color: var(--color-ink-light);
  font-size: 15px;
  font-weight: 500;
}

/* Coach dimensions */
.coach-dimensions {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.coach-card {
  background: var(--color-paper);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.coach-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.coach-num {
  font-family: var(--font-serif);
  font-size: 32px;
  font-weight: 700;
  color: var(--color-gold);
  line-height: 1;
  margin-bottom: 14px;
}

.coach-card h4 {
  font-family: var(--font-serif);
  font-size: 20px;
  margin: 0 0 10px;
  color: var(--color-ink);
}

.coach-card p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 15px;
  line-height: 1.8;
}

.panel-media {
  max-width: 900px;
  margin: 0 auto;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.panel-media img {
  width: 100%;
  height: auto;
}

/* Master list */
.master-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 900px;
  margin: 0 auto 40px;
}

.master-item {
  background: var(--color-paper);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: box-shadow var(--transition);
}

.master-item:hover { box-shadow: var(--shadow-md); }

.master-tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--color-ink-light);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.master-item h4 {
  font-family: var(--font-serif);
  font-size: 20px;
  margin: 0 0 8px;
  color: var(--color-ink);
}

.master-item p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 15px;
  line-height: 1.8;
}

.master-circle {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
  padding: 40px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--color-ink-light) 0%, var(--color-blue) 100%);
  color: #fff;
}

.master-circle p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.8;
}

/* Roadmap */
.roadmap {
  background: linear-gradient(180deg, #eef2f7 0%, var(--color-paper) 100%);
}

.roadmap-timeline {
  position: relative;
  max-width: 880px;
  margin: 0 auto;
  padding-left: 40px;
}

.roadmap-timeline::before {
  content: '';
  position: absolute;
  top: 8px;
  bottom: 8px;
  left: 16px;
  width: 2px;
  background: linear-gradient(180deg, var(--color-gold) 0%, var(--color-ink-light) 100%);
}

.roadmap-item {
  position: relative;
  margin-bottom: 36px;
}

.roadmap-item:last-child { margin-bottom: 0; }

.roadmap-marker {
  position: absolute;
  left: -32px;
  top: 4px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 2px solid var(--color-gold);
  display: grid;
  place-items: center;
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 700;
  color: var(--color-gold);
  box-shadow: 0 0 0 6px rgba(201,168,108,0.12);
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.roadmap-item.active .roadmap-marker {
  background: var(--color-gold);
  color: #fff;
  transform: scale(1.1);
}

.roadmap-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 30px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), border-color var(--transition);
}

.roadmap-item.active .roadmap-card {
  border-color: var(--color-gold);
  box-shadow: var(--shadow-md);
}

.roadmap-meta {
  display: inline-block;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-blue);
  margin-bottom: 8px;
}

.roadmap-card h3 {
  font-family: var(--font-serif);
  font-size: 22px;
  margin: 0 0 10px;
  color: var(--color-ink);
}

.roadmap-card p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 17px;
  line-height: 1.85;
}

/* Letter section */
.letter-section {
  background: var(--color-surface);
}

.letter-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.letter-visual {
  position: relative;
}

.letter-visual .zoom-media {
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.letter-highlight {
  margin: 28px 0 24px;
  padding: 20px 24px;
  background: rgba(201,168,108,0.08);
  border-left: 3px solid var(--color-gold);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.75;
  color: var(--color-ink);
}

.letter-body .section-kicker { margin-bottom: 10px; }
.letter-body h2 {
  font-family: var(--font-serif);
  font-size: clamp(30px, 4vw, 40px);
  margin: 0 0 20px;
  color: var(--color-ink);
}

.letter-body p {
  color: var(--color-text-secondary);
  margin: 0 0 16px;
}

.letter-body .btn { margin-top: 12px; }

/* Contact */
.contact {
  background: linear-gradient(135deg, var(--color-ink) 0%, var(--color-ink-light) 100%);
  color: #fff;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact-info .section-kicker {
  color: var(--color-gold);
}

.contact-info h2 {
  font-family: var(--font-serif);
  font-size: clamp(30px, 4vw, 40px);
  margin: 0 0 20px;
}

.contact-info > p {
  opacity: 0.85;
  margin: 0 0 32px;
  line-height: 1.9;
}

.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 18px;
}

.contact-list li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.contact-label {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-gold);
  text-transform: uppercase;
}

.contact-form {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: var(--radius);
  padding: 36px;
  backdrop-filter: blur(8px);
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 15px;
  margin-bottom: 8px;
  opacity: 0.9;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.08);
  color: #fff;
  font-size: 17px;
  transition: border-color var(--transition), background var(--transition);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: rgba(255,255,255,0.45);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-gold);
  background: rgba(255,255,255,0.12);
}

.form-note {
  font-size: 15px;
  opacity: 0.7;
  margin: 14px 0 0;
  text-align: center;
}

/* Footer */
.site-footer {
  background: #060d18;
  color: rgba(255,255,255,0.65);
  padding: 56px 0 28px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 24px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #fff;
}

.footer-brand strong {
  display: block;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 700;
}

.footer-brand span {
  display: block;
  font-size: 15px;
  opacity: 0.7;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 24px;
}

.footer-nav a {
  font-size: 15px;
  transition: color var(--transition);
}

.footer-nav a:hover { color: var(--color-gold); }

.copyright {
  font-size: 15px;
  opacity: 0.55;
  margin: 12px 0 0;
}

/* Back to top */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  background: var(--color-gold);
  color: var(--color-ink);
  font-size: 20px;
  font-weight: 700;
  box-shadow: var(--shadow-md);
  z-index: 999;
  transition: transform var(--transition), opacity var(--transition);
}

.back-to-top:hover { transform: translateY(-3px); }
.back-to-top[hidden] { opacity: 0; pointer-events: none; }

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal[hidden] { display: none; }

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10,22,40,0.78);
  backdrop-filter: blur(4px);
}

.modal-content {
  position: relative;
  width: 100%;
  max-width: 720px;
  max-height: 85vh;
  background: var(--color-surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  animation: modalIn 0.35s ease;
}

@keyframes modalIn {
  from { opacity: 0; transform: translateY(30px) scale(0.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 40px;
  height: 40px;
  border: none;
  background: rgba(10,22,40,0.06);
  border-radius: 50%;
  font-size: 24px;
  line-height: 1;
  color: var(--color-ink);
  z-index: 2;
  transition: background var(--transition);
}

.modal-close:hover { background: rgba(10,22,40,0.12); }

.modal-body {
  padding: 48px;
  overflow-y: auto;
  max-height: 85vh;
}

.modal-body h2 {
  font-family: var(--font-serif);
  font-size: 32px;
  margin: 0 0 24px;
  color: var(--color-ink);
}

.modal-body p {
  color: var(--color-text-secondary);
  margin: 0 0 16px;
  line-height: 1.9;
}

.modal-sign {
  margin-top: 28px !important;
  font-family: var(--font-serif);
  color: var(--color-ink) !important;
  font-weight: 600;
}

/* Reveal animations */
.reveal-up {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
  transition-delay: var(--delay, 0s);
}

.reveal-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .reveal-up { opacity: 1; transform: none; transition: none; }
  .hero-bg img { animation: none; }
  .scroll-indicator { animation: none; }
}

/* Responsive */
@media (max-width: 1024px) {
  .era-grid,
  .books-grid,
  .coach-dimensions {
    grid-template-columns: repeat(2, 1fr);
  }

  .framework { flex-wrap: wrap; }
  .framework-item { flex: 1 1 45%; }
  .framework-arrow { display: none; }

  .mission-statement,
  .founder-grid,
  .letter-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .mission-media { min-height: 280px; }
  .mission-body { padding: 36px; }
  .letter-highlight { padding: 16px 18px; font-size: 17px; }
}

@media (max-width: 768px) {
  .main-nav {
    position: fixed;
    inset: 0;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
    background: #fff;
    transform: translateY(-100%);
    opacity: 0;
    transition: transform 0.4s ease, opacity 0.4s ease;
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
  }

  .main-nav a {
    font-size: 20px;
    color: var(--color-ink) !important;
  }

  .menu-toggle { display: flex; }

  .hero-actions { flex-direction: column; align-items: center; }
  .hero-actions .btn { width: min(100%, 260px); }

  .era-grid,
  .books-grid,
  .coach-dimensions,
  .master-list {
    grid-template-columns: 1fr;
  }

  .framework-item { flex: 1 1 100%; }

  .layer-tab { min-width: 100%; max-width: 100%; }

  .roadmap-timeline { padding-left: 32px; }
  .roadmap-card { padding: 22px; }

  .section { padding: 76px 0; }
  .section-header { margin-bottom: 44px; }

  .modal-body { padding: 28px; }
}

/* ===========================
   增强交互样式
   =========================== */

/* 顶部阅读进度条 */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-gold) 0%, var(--color-gold-light) 100%);
  z-index: 1100;
  transition: width 0.1s linear;
}

/* 图片悬浮放大 */
.zoom-media {
  overflow: hidden;
}

.zoom-media img {
  transition: transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  will-change: transform;
}

.zoom-media:hover img {
  transform: scale(1.06);
}

/* Hero 背景视差 */
.hero-bg img {
  transition: transform 0.4s ease-out;
  will-change: transform;
}

/* 卡片 3D 微倾斜 */
[data-tilt] {
  transform-style: preserve-3d;
  transition: transform 0.2s ease-out, box-shadow var(--transition);
  will-change: transform;
}

/* Hero 滚动提示呼吸增强 */
.hero-badge-pulse {
  animation: badgePulse 2.4s ease-in-out infinite;
}

@keyframes badgePulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(201, 168, 108, 0.4); }
  50% { box-shadow: 0 0 0 10px rgba(201, 168, 108, 0); }
}

@media (hover: none) {
  .zoom-media:hover img { transform: none; }
  [data-tilt] { transition: box-shadow var(--transition); }
}