/* ========================================
   电工电子与智慧能源实验教学示范中心
   Apple-Inspired Light Design System
   ======================================== */

/* ---------- CSS Variables ---------- */
:root {
  --bg-white: #ffffff;
  --bg-light: #f5f5f7;
  --bg-footer: #f5f5f7;
  --text-primary: #1d1d1f;
  --text-secondary: #86868b;
  --text-tertiary: #6e6e73;
  --accent: #2997ff;
  --accent-hover: #0071e3;
  --accent-glow: rgba(41, 151, 255, 0.12);
  --card-bg: #ffffff;
  --card-border: rgba(0, 0, 0, 0.06);
  --card-hover-shadow: 0 8px 40px rgba(0, 0, 0, 0.06);
  --nav-blur: rgba(255, 255, 255, 0.88);
  --glass-border: rgba(255, 255, 255, 0.4);
  --glass-bg: rgba(255, 255, 255, 0.18);
  --glass-bg-hover: rgba(255, 255, 255, 0.28);
  --nav-height: 52px;
  --max-width: 1200px;
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --transition-fast: 0.2s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-smooth: 0.4s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-spring: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
               "PingFang SC", "Helvetica Neue", "Microsoft YaHei", sans-serif;
  color: var(--text-primary);
  background: var(--bg-white);
  line-height: 1.5;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Typography ---------- */
.section-title {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.1;
  margin-bottom: 12px;
}
.section-subtitle {
  font-size: clamp(17px, 2.5vw, 21px);
  font-weight: 400;
  color: var(--text-secondary);
  letter-spacing: 0.01em;
}

.block-title {
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 20px;
  color: var(--text-primary);
}
.block-text {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-primary);
  opacity: 0.85;
}
.block-desc {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-secondary);
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

/* Module Badge */
.module-badge {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 20px;
  padding: 4px 14px;
  margin-bottom: 16px;
}

/* ---------- Section Backgrounds ---------- */
.section-light { background: var(--bg-light); }
.section-white { background: var(--bg-white); }

/* Module Section */
.module {
  padding: 100px 0;
}

/* Content Block */
.content-block { margin-bottom: 64px; }

/* Two Column */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 64px;
}

/* ========================================
   Navigation (浅色毛玻璃)
   ======================================== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: var(--nav-blur);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  transition: background var(--transition-fast);
}
.nav.scrolled {
  background: rgba(255, 255, 255, 0.97);
  border-bottom-color: rgba(0, 0, 0, 0.12);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex; align-items: center; gap: 8px;
  color: var(--text-primary);
  font-size: 14px; font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.nav-logo-img {
  height: 28px;
  width: auto;
}
.nav-logo-text {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
}

.nav-links {
  display: flex; align-items: center; gap: 2px;
}
.nav-link {
  padding: 6px 12px;
  font-size: 12px; font-weight: 400;
  color: var(--text-secondary);
  border-radius: 16px;
  border: 1px solid transparent;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
  white-space: nowrap;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
}
.nav-link:hover {
  color: var(--text-primary);
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: var(--glass-border);
  box-shadow: 0 2px 12px rgba(0,0,0,0.04), inset 0 1px 0 rgba(255,255,255,0.6);
}
.nav-link.active {
  color: var(--accent);
  background: rgba(41,151,255,0.08);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: rgba(41,151,255,0.18);
  box-shadow: 0 2px 12px rgba(41,151,255,0.06), inset 0 1px 0 rgba(255,255,255,0.5);
}

.nav-cta {
  padding: 6px 16px;
  font-size: 12px; font-weight: 500;
  color: #fff; background: var(--accent);
  border: 1px solid transparent;
  border-radius: 20px; cursor: pointer;
  transition: all var(--transition-smooth);
  white-space: nowrap;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
}
.nav-cta:hover {
  background: var(--accent-hover);
  transform: scale(1.03);
  border-color: rgba(255,255,255,0.25);
  box-shadow: 0 4px 16px var(--accent-glow), inset 0 1px 0 rgba(255,255,255,0.25);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

/* ========================================
   Hero Section (浅色)
   ======================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-white); overflow: hidden;
}
.hero-glow {
  position: absolute; border-radius: 50%;
  filter: blur(140px); pointer-events: none;
}
.hero-glow-1 {
  width: 700px; height: 700px;
  background: radial-gradient(circle, rgba(41,151,255,0.06), transparent 70%);
  top: -250px; right: -150px;
  animation: glowPulse 8s ease-in-out infinite;
}
.hero-glow-2 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(245,166,35,0.04), transparent 70%);
  bottom: -200px; left: -150px;
  animation: glowPulse 10s ease-in-out infinite reverse;
}
.hero-glow-3 {
  width: 350px; height: 350px;
  background: radial-gradient(circle, rgba(41,151,255,0.05), transparent 70%);
  top: 45%; left: 50%; transform: translate(-50%, -50%);
  animation: glowPulse 6s ease-in-out infinite;
}
@keyframes glowPulse {
  0%, 100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.15); }
}

.hero-content {
  position: relative; z-index: 1;
  text-align: center; padding: 0 24px;
  max-width: 900px;
}
.hero-eyebrow {
  font-size: 15px; font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.08em; text-transform: uppercase;
  margin-bottom: 24px;
}
.hero-title {
  font-size: clamp(36px, 7vw, 64px);
  font-weight: 700; letter-spacing: -0.025em;
  line-height: 1.08; color: var(--text-primary);
  margin-bottom: 16px;
}
.title-line { display: block; }
.title-accent {
  background: linear-gradient(135deg, #0071e3 0%, #2997ff 50%, #5e9eff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: clamp(18px, 2.5vw, 24px);
  font-weight: 500; color: var(--text-secondary);
  letter-spacing: 0.02em; margin-bottom: 16px;
}
.hero-desc {
  font-size: 17px; color: var(--text-secondary);
  margin-bottom: 40px; max-width: 520px;
  margin-left: auto; margin-right: auto; line-height: 1.6;
}
.hero-cta-group {
  display: flex; align-items: center; justify-content: center;
  gap: 20px; flex-wrap: wrap;
}
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 12px 28px; font-size: 16px; font-weight: 500;
  border-radius: 28px;
  transition: all var(--transition-smooth); cursor: pointer;
}
.btn-primary {
  background: var(--accent); color: #fff;
  border: 1px solid transparent;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
}
.btn-primary:hover {
  background: var(--accent-hover);
  transform: scale(1.03);
  border-color: rgba(255,255,255,0.25);
  box-shadow: 0 4px 24px var(--accent-glow), inset 0 1px 0 rgba(255,255,255,0.3);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.btn-outline {
  background: transparent; color: var(--accent);
  border: 1px solid var(--accent);
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
}
.btn-outline:hover {
  background: rgba(41,151,255,0.08);
  color: var(--accent);
  transform: scale(1.03);
  border-color: rgba(41,151,255,0.5);
  box-shadow: 0 4px 20px rgba(41,151,255,0.08), inset 0 1px 0 rgba(255,255,255,0.5);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.hero-scroll-indicator {
  position: absolute; bottom: 40px; left: 50%;
  transform: translateX(-50%);
  color: var(--text-secondary);
  animation: bounce 2s ease-in-out infinite; opacity: 0.5;
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(10px); }
}

/* ========================================
   Info Card
   ======================================== */
.info-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.info-card-title {
  font-size: 19px; font-weight: 600; margin-bottom: 12px;
}
.info-card p {
  font-size: 15px; line-height: 1.7; color: var(--text-secondary);
}

/* ========================================
   Timeline (发展历程)
   ======================================== */
.timeline {
  position: relative;
  padding-left: 32px;
}
.timeline::before {
  content: '';
  position: absolute; left: 7px; top: 8px; bottom: 8px;
  width: 1.5px;
  background: linear-gradient(to bottom, var(--accent), rgba(41,151,255,0.15));
}
.timeline-item { position: relative; margin-bottom: 32px; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot {
  position: absolute; left: -28px; top: 6px;
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--bg-white);
  border: 2px solid var(--accent);
  box-shadow: 0 0 0 3px var(--bg-light);
}
.timeline-dot-accent {
  background: var(--accent);
  box-shadow: 0 0 16px var(--accent-glow);
}
.timeline-content h4 {
  font-size: 18px; font-weight: 600; margin-bottom: 6px;
}
.timeline-content p {
  font-size: 15px; line-height: 1.7; color: var(--text-secondary);
}
.timeline-year {
  display: inline-block;
  font-size: 13px; font-weight: 600;
  color: var(--accent); letter-spacing: 0.04em;
  margin-bottom: 6px;
}

/* ========================================
   Org Cards (机构设置)
   ======================================== */
.org-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.org-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  transition: all var(--transition-spring);
}
.org-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}
.org-icon { margin-bottom: 16px; }
.org-card h4 {
  font-size: 18px; font-weight: 600; margin-bottom: 8px;
}
.org-card p {
  font-size: 14px; color: var(--text-secondary);
}

/* ========================================
   Lab Overview Grid
   ======================================== */
.lab-overview-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 20px;
}
.lab-overview-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 20px;
  text-align: center;
  font-size: 15px; font-weight: 500;
  transition: all var(--transition-fast);
}
.lab-overview-item:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 12px rgba(41,151,255,0.08);
}
.lab-count {
  display: block;
  font-size: 28px; font-weight: 700; color: var(--accent);
  margin-bottom: 4px;
}

/* ========================================
   Method Cards
   ======================================== */
.method-cards {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.method-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  position: relative;
  overflow: hidden;
}
.method-num {
  font-size: 48px; font-weight: 700;
  color: rgba(41,151,255,0.08);
  position: absolute; top: 16px; right: 24px;
  letter-spacing: -0.03em; line-height: 1;
}
.method-card h4 {
  font-size: 19px; font-weight: 600; margin-bottom: 12px;
}
.method-card p {
  font-size: 14px; line-height: 1.7; color: var(--text-secondary);
}

/* ========================================
   Feature Cards
   ======================================== */
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: all var(--transition-spring);
  cursor: pointer;
  display: flex; flex-direction: column; gap: 14px;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}
.feature-icon { margin-bottom: 4px; }
.feature-title {
  font-size: 18px; font-weight: 600; letter-spacing: -0.01em;
}
.feature-desc {
  font-size: 14px; line-height: 1.6; color: var(--text-secondary);
  flex: 1;
}
.feature-link {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 14px; font-weight: 500; color: var(--accent);
  margin-top: auto; transition: gap var(--transition-fast);
}
.feature-link:hover { gap: 8px; }

/* ========================================
   Accordion (折叠面板)
   ======================================== */
.accordion {
  display: flex; flex-direction: column; gap: 1px;
}
.accordion-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.accordion-header {
  width: 100%;
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px;
  font-size: 15px; font-weight: 500;
  background: none; border: 1px solid transparent; cursor: pointer;
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-smooth);
}
.accordion-header:hover {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: var(--glass-border);
  box-shadow: 0 2px 12px rgba(0,0,0,0.03), inset 0 1px 0 rgba(255,255,255,0.5);
}
.accordion-arrow {
  transition: transform var(--transition-smooth);
  flex-shrink: 0;
}
.accordion-item.open .accordion-arrow {
  transform: rotate(180deg);
}
.accordion-item.open .accordion-header {
  background: rgba(41,151,255,0.04);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: rgba(41,151,255,0.12);
  box-shadow: 0 2px 12px rgba(41,151,255,0.04), inset 0 1px 0 rgba(255,255,255,0.4);
}
.accordion-body {
  max-height: 0; overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}
.accordion-item.open .accordion-body {
  max-height: 2000px;
}

/* Course List */
.course-list {
  padding: 8px 20px 20px;
}
.course-list li {
  padding: 8px 0;
  font-size: 14px;
  color: var(--text-secondary);
  border-bottom: 1px solid rgba(0,0,0,0.04);
  display: flex; align-items: center; gap: 8px;
}
.course-list li::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
}

/* ========================================
   Director Cards
   ======================================== */
.director-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.director-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all var(--transition-spring);
}
.director-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}
.director-avatar {
  width: 72px; height: 72px;
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: 16px;
  border: 2px solid var(--card-border);
  flex-shrink: 0;
}
.director-avatar img {
  width: 100%; height: 100%;
  object-fit: cover;
  display: block;
}
.director-avatar-placeholder {
  width: 72px; height: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(41,151,255,0.1), rgba(41,151,255,0.2));
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px;
  border: 2px solid var(--card-border);
  flex-shrink: 0;
}
.director-avatar-placeholder span {
  font-size: 24px; font-weight: 600;
  color: var(--accent);
}
.director-info h4 {
  font-size: 20px; font-weight: 600; margin-bottom: 4px;
}
.director-role {
  display: inline-block;
  font-size: 12px; font-weight: 600; color: var(--accent);
  border: 1px solid var(--accent); border-radius: 12px;
  padding: 2px 10px; margin-bottom: 4px;
}
.director-title {
  display: block;
  font-size: 14px; color: var(--text-secondary);
  margin-bottom: 10px;
}
.director-info p {
  font-size: 14px; line-height: 1.6; color: var(--text-secondary);
  margin-bottom: 8px;
}
.director-email {
  font-size: 13px; color: var(--accent);
  transition: opacity var(--transition-fast);
}
.director-email:hover { opacity: 0.7; }

/* ========================================
   Teacher Cards
   ======================================== */
.teacher-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.teacher-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: all var(--transition-spring);
}
.teacher-card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 20px rgba(41,151,255,0.08);
}
.teacher-photo {
  width: 64px; height: 64px;
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: 16px;
  border: 2px solid var(--card-border);
  flex-shrink: 0;
}
.teacher-photo img {
  width: 100%; height: 100%;
  object-fit: cover;
  display: block;
}
.teacher-header {
  display: flex; align-items: baseline; gap: 10px;
  margin-bottom: 12px;
}
.teacher-header h4 {
  font-size: 20px; font-weight: 600;
}
.teacher-badge {
  font-size: 12px; font-weight: 500; color: var(--accent);
}
.teacher-tags {
  display: flex; flex-wrap: wrap; gap: 6px;
  margin-bottom: 12px;
}
.teacher-tags span {
  font-size: 11px;
  padding: 3px 10px;
  background: rgba(41,151,255,0.06);
  color: var(--accent);
  border-radius: 10px;
}
.teacher-field {
  font-size: 13px; color: var(--text-secondary);
  margin-bottom: 6px; line-height: 1.5;
}
.teacher-courses {
  font-size: 13px; color: var(--text-secondary);
  opacity: 0.8;
}

/* Teacher Table */
.teacher-table-wrap {
  overflow-x: auto;
  padding: 8px 20px 20px;
}
.teacher-table {
  width: 100%; border-collapse: collapse;
  font-size: 13px;
}
.teacher-table th {
  text-align: left; padding: 12px 10px;
  font-weight: 600; color: var(--text-primary);
  border-bottom: 1px solid var(--card-border);
  background: rgba(0,0,0,0.02); white-space: nowrap;
}
.teacher-table td {
  padding: 10px; border-bottom: 1px solid rgba(0,0,0,0.04);
  line-height: 1.5; vertical-align: top; color: var(--text-secondary);
}
.teacher-table tr:hover td {
  background: rgba(41,151,255,0.03);
}
.teacher-table-photo {
  width: 36px; height: 36px;
  border-radius: 50%;
  object-fit: cover;
  display: block;
}
.teacher-table-initials {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: rgba(41,151,255,0.08);
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 600;
  color: var(--accent);
}

/* ========================================
   Environment Overview
   ======================================== */
.env-overview {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.env-stat {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 28px;
  text-align: center;
}
.env-num {
  display: block;
  font-size: 36px; font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em; line-height: 1.1;
}
.env-unit {
  font-size: 16px; font-weight: 500;
  color: var(--text-secondary);
}
.env-label {
  display: block;
  font-size: 13px; color: var(--text-secondary);
  margin-top: 8px;
}

/* ========================================
   Lab Detail Cards
   ======================================== */
.lab-detail-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.lab-detail-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: all var(--transition-spring);
}
.lab-detail-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}
.lab-detail-card h4 {
  font-size: 18px; font-weight: 600; margin-bottom: 12px;
}
.lab-meta {
  display: flex; flex-wrap: wrap; gap: 8px;
  margin-bottom: 12px;
}
.lab-meta span {
  font-size: 12px; color: var(--text-secondary);
  background: rgba(0,0,0,0.03);
  padding: 3px 10px; border-radius: 6px;
}
.lab-detail-card p {
  font-size: 14px; line-height: 1.6; color: var(--text-secondary);
}

/* ========================================
   Stats
   ======================================== */
.stats-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 32px; text-align: center;
}
.stat-item { padding: 40px 20px; }
.stat-number {
  font-size: clamp(42px, 7vw, 64px);
  font-weight: 700; letter-spacing: -0.03em;
  line-height: 1; font-variant-numeric: tabular-nums;
  color: var(--text-primary);
}
.stat-unit {
  font-size: 24px; font-weight: 600; color: var(--accent);
}
.stat-label {
  display: block; font-size: 16px; color: var(--text-secondary);
  margin-top: 12px;
}

/* ========================================
   Resource Cards
   ======================================== */
.resource-cards {
  display: flex; flex-direction: column; gap: 16px;
}
.resource-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  display: flex; align-items: center; gap: 20px;
  transition: all var(--transition-spring);
}
.resource-card:hover {
  transform: translateX(4px);
  border-color: var(--accent);
  box-shadow: 0 2px 16px rgba(41,151,255,0.06);
}
.resource-icon { flex-shrink: 0; }
.resource-content { flex: 1; }
.resource-content h4 {
  font-size: 17px; font-weight: 600; margin-bottom: 4px;
  color: var(--text-primary);
}
.resource-platform {
  font-size: 13px; color: var(--accent);
  margin-bottom: 4px; display: block;
}
.resource-content p {
  font-size: 14px; color: var(--text-secondary);
}
.resource-arrow { flex-shrink: 0; opacity: 0; transition: opacity var(--transition-fast); }
.resource-card:hover .resource-arrow { opacity: 1; }

/* Book Cards */
.book-cards {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.book-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: all var(--transition-spring);
}
.book-card:hover { transform: translateY(-3px); box-shadow: var(--card-hover-shadow); }
.book-cover { margin-bottom: 16px; }
.book-tag {
  display: inline-block;
  font-size: 12px; font-weight: 600;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 4px 12px;
}
.book-card h4 {
  font-size: 18px; font-weight: 600; margin-bottom: 8px;
  color: var(--text-primary);
}
.book-author {
  font-size: 14px; color: var(--text-secondary); margin-bottom: 4px;
}
.book-pub {
  font-size: 13px; color: var(--text-tertiary); margin-bottom: 10px;
}
.book-desc {
  font-size: 13px; line-height: 1.6; color: var(--text-secondary);
}

/* Ref Book List */
.ref-book-list {
  padding: 8px 20px 20px;
}
.ref-book {
  padding: 10px 0;
  font-size: 14px; line-height: 1.6;
  color: var(--text-secondary);
  border-bottom: 1px solid rgba(0,0,0,0.04);
}
.ref-book strong { color: var(--text-primary); }

/* ========================================
   Achievements
   ======================================== */
.achieve-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.achieve-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: all var(--transition-spring);
}
.achieve-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}
.achieve-icon { margin-bottom: 14px; }
.achieve-card h4 {
  font-size: 18px; font-weight: 600; margin-bottom: 8px;
}
.achieve-card p {
  font-size: 14px; line-height: 1.6; color: var(--text-secondary);
}

/* Student Achievements */
.student-achieve-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 20px; text-align: center;
}
.student-achieve {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 32px 20px;
}
.sa-num {
  display: block;
  font-size: 48px; font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.03em; line-height: 1;
}
.sa-label {
  display: block;
  font-size: 14px; color: var(--text-secondary);
  margin-top: 8px;
}

/* ========================================
   Contact Section
   ======================================== */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 48px;
}
.contact-list {
  display: flex; flex-direction: column; gap: 20px;
}
.contact-item {
  display: flex; gap: 14px; align-items: flex-start;
}
.contact-icon { flex-shrink: 0; margin-top: 2px; }
.contact-label {
  font-size: 12px; color: var(--text-secondary);
  opacity: 0.6; display: block;
}
.contact-value {
  font-size: 15px; font-weight: 500; color: var(--text-primary);
  display: block;
}
.contact-email {
  font-size: 13px; color: var(--accent);
  display: block; margin-top: 2px;
}

/* Contact Form */
.contact-form {
  display: flex; flex-direction: column; gap: 16px;
}
.form-group { width: 100%; }
.form-input {
  width: 100%;
  padding: 14px 18px;
  font-size: 15px;
  font-family: inherit;
  background: var(--bg-light);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  outline: none;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}
.form-input::placeholder { color: var(--text-secondary); }
.form-input:focus { border-color: var(--accent); background: var(--card-bg); }
select.form-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none'%3E%3Cpath d='M1.5 2L6 6.5L10.5 2' stroke='%232997ff' stroke-width='1.75' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
}
textarea.form-input { resize: vertical; min-height: 100px; }

/* ========================================
   Footer (浅色)
   ======================================== */
.footer {
  background: var(--bg-footer);
  color: var(--text-secondary);
  padding: 80px 0 32px;
}
.footer-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 40px; margin-bottom: 48px;
}
.footer-col-title {
  font-size: 14px; font-weight: 600;
  color: var(--text-primary); margin-bottom: 16px;
}
.footer-col ul {
  display: flex; flex-direction: column; gap: 10px;
}
.footer-col li { font-size: 13px; line-height: 1.6; }
.footer-col a {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}
.footer-col a:hover { color: var(--text-primary); }
.footer-label {
  display: block; font-size: 11px;
  color: var(--text-secondary); opacity: 0.6;
  margin-bottom: 2px;
}
.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid rgba(0,0,0,0.06);
  display: flex; justify-content: space-between;
  align-items: center; flex-wrap: wrap; gap: 16px;
}
.footer-legal p { font-size: 12px; }
.footer-links {
  display: flex; align-items: center; gap: 8px;
  font-size: 12px;
}
.footer-links a {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}
.footer-links a:hover { color: var(--text-primary); }
.footer-divider { color: rgba(0,0,0,0.12); }

/* ========================================
   Scroll Reveal
   ======================================== */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.revealed { opacity: 1; transform: translateY(0); }

.animate-on-load {
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}
.animate-on-load:nth-child(1) { animation-delay: 0.1s; }
.animate-on-load:nth-child(2) { animation-delay: 0.2s; }
.animate-on-load:nth-child(3) { animation-delay: 0.35s; }
.animate-on-load:nth-child(4) { animation-delay: 0.45s; }
.animate-on-load:nth-child(5) { animation-delay: 0.55s; }

@keyframes fadeInUp {
  to { opacity: 1; transform: translateY(0); }
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1024px) {
  .features-grid, .method-cards, .achieve-grid, .lab-detail-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .teacher-grid { grid-template-columns: 1fr; }
  .director-grid { grid-template-columns: repeat(2, 1fr); }
  .director-grid .director-card:last-child { grid-column: span 2; }
  .org-grid { grid-template-columns: 1fr; }
  .two-col { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .env-overview, .student-achieve-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .book-cards { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }

  .module { padding: 72px 0; }
  .section-header { margin-bottom: 40px; }

  .features-grid, .method-cards, .achieve-grid, .lab-detail-grid {
    grid-template-columns: 1fr;
  }
  .lab-overview-grid { grid-template-columns: repeat(2, 1fr); }
  .director-grid { grid-template-columns: 1fr; }
  .director-grid .director-card:last-child { grid-column: auto; }
  .env-overview { grid-template-columns: repeat(2, 1fr); }
  .student-achieve-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }

  .hero-title { font-size: clamp(28px, 8vw, 42px); }
  .hero-cta-group { flex-direction: column; }
  .content-block { margin-bottom: 40px; }
}

@media (max-width: 480px) {
  .env-overview, .student-achieve-grid, .stats-grid,
  .lab-overview-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}