/* ============================================
   广东哈理工校友会 — 官网设计系统
   Guangdong HUST Alumni Association
   域名：hustgd.com.cn
   参考：公众号 hustgd365
   ============================================ */

/* ——— Design Tokens ——— */
:root {
  /* HUST 品牌色 — 科技蓝 */
  --hust-blue-deep: #0a2d5c;
  --hust-blue: #0f3d7a;
  --hust-blue-mid: #1855a3;
  --hust-blue-bright: #2175d9;
  --hust-blue-soft: #4a90d9;
  --hust-blue-subtle: #93bced;
  --hust-blue-ghost: #d6e8fa;
  --hust-blue-wash: #eef5fc;

  /* Accent — 金色/红色，校友会温暖感 */
  --gold: #c8923a;
  --gold-hover: #d4a54e;
  --gold-light: #f5e6cc;
  --gold-wash: #fdf7ed;

  --red-accent: #c43a3a;
  --red-light: #fce8e8;

  /* Neutrals */
  --white: #ffffff;
  --bg: #f7f8fa;
  --bg-alt: #eef1f5;
  --border: #dde2e8;
  --border-light: #eaeef3;
  --text-primary: #1a1d23;
  --text-secondary: #4a5568;
  --text-tertiary: #8896a6;
  --text-placeholder: #b0bec5;

  /* Typography - 思源黑体 Noto Sans SC */
  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", system-ui, -apple-system, sans-serif;
  --font-en: "Inter", "Helvetica Neue", Arial, sans-serif;

  --fs-hero: clamp(2.2rem, 4.5vw, 3.5rem);
  --fs-h1: clamp(1.7rem, 3vw, 2.4rem);
  --fs-h2: clamp(1.3rem, 2.2vw, 1.7rem);
  --fs-h3: clamp(1.1rem, 1.8vw, 1.3rem);
  --fs-h4: 1.1rem;
  --fs-body: clamp(0.95rem, 1.4vw, 1.05rem);
  --fs-sm: 0.875rem;
  --fs-xs: 0.75rem;

  --lh-tight: 1.2;
  --lh-snug: 1.4;
  --lh-normal: 1.65;
  --lh-relaxed: 1.8;

  --fw-regular: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;
  --fw-black: 900;

  /* Spacing (4px base) */
  --s-1: 0.25rem; --s-2: 0.5rem; --s-3: 0.75rem;
  --s-4: 1rem; --s-5: 1.25rem; --s-6: 1.5rem;
  --s-8: 2rem; --s-10: 2.5rem; --s-12: 3rem;
  --s-16: 4rem; --s-20: 5rem; --s-24: 6rem;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(10, 45, 92, 0.04);
  --shadow-sm: 0 2px 8px rgba(10, 45, 92, 0.06);
  --shadow-md: 0 6px 20px rgba(10, 45, 92, 0.08);
  --shadow-lg: 0 12px 36px rgba(10, 45, 92, 0.12);
  --shadow-card: 0 2px 12px rgba(10, 45, 92, 0.05), 0 1px 2px rgba(10, 45, 92, 0.04);

  /* Radii */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;
  --radius-full: 9999px;

  /* Layout */
  --content-max: 1180px;
  --nav-height: 100px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 150ms;
  --duration: 250ms;
  --duration-slow: 400ms;
}

/* ——— Reset ——— */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-normal);
  color: var(--text-primary);
  background: var(--bg);
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font: inherit; cursor: pointer; border: none; background: none; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* ——— Utility ——— */
.container { width: 100%; max-width: var(--content-max); margin: 0 auto; padding: 0 var(--s-6); }
.section { padding: var(--s-20) 0; }
.section-pad { padding: var(--s-16) 0; }

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--hust-blue-bright);
  margin-bottom: var(--s-4);
  padding: 4px 12px;
  background: var(--hust-blue-wash);
  border-radius: var(--radius-full);
}

.section-heading {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: var(--fw-bold);
  color: var(--hust-blue-deep);
  margin-bottom: var(--s-4);
  line-height: var(--lh-tight);
  letter-spacing: -0.01em;
}

.section-sub {
  font-size: var(--fs-body);
  color: var(--text-secondary);
  max-width: 52ch;
  line-height: var(--lh-relaxed);
}

.section-header {
  margin-bottom: var(--s-10);
}

.section-header.center { text-align: center; }
.section-header.center .section-sub { margin: 0 auto; }

/* ——— Top Bar ——— */
.topbar {
  background: var(--hust-blue-deep);
  color: rgba(255,255,255,0.7);
  font-size: var(--fs-xs);
  padding: var(--s-1) 0;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--s-6);
}
.topbar-links { display: flex; gap: var(--s-4); }
.topbar-links a { color: rgba(255,255,255,0.6); transition: color var(--duration-fast); }
.topbar-links a:hover { color: white; }

/* ——— Navigation ——— */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-light);
  height: var(--nav-height);
}
.nav.scrolled { box-shadow: var(--shadow-xs); }
.nav-inner {
  display: flex;
  flex-direction: column;
  justify-content: center;
  height: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: var(--s-2) var(--s-6);
}
.nav-row-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-4);
}
.nav-row-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--s-1);
}
.nav-links-left { display: flex; align-items: center; gap: 2px; }
.nav-links-right { display: flex; align-items: center; gap: var(--s-2); margin-left: auto; }
.nav-search {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 24px;
  overflow: hidden;
  transition: border-color 0.2s;
  flex: 1;
  max-width: 360px;
}
.nav-search:focus-within { border-color: var(--hust-blue-mid); }
.nav-search input {
  flex: 1;
  border: none;
  padding: 8px 16px;
  font-size: var(--fs-sm);
  background: transparent;
  outline: none;
  color: var(--text-primary);
}
.nav-search input::placeholder { color: var(--text-placeholder); }
.nav-search button {
  border: none;
  background: none;
  padding: 8px 14px;
  cursor: pointer;
  font-size: var(--fs-sm);
  color: var(--text-tertiary);
  transition: color 0.2s;
}
.nav-search button:hover { color: var(--hust-blue); }
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}
.nav-logo {
  width: 42px; height: 42px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
  flex-shrink: 0;
}
.nav-logo img { width: 100%; height: 100%; object-fit: cover; }
.nav-brand-text {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: var(--fw-bold);
  color: var(--hust-blue-deep);
  line-height: 1.2;
}
.nav-brand-text small {
  display: block;
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: var(--fw-medium);
  color: var(--text-tertiary);
  letter-spacing: 0.03em;
}
.nav-links { display: flex; align-items: center; gap: 2px; }
.nav-link {
  padding: 8px 14px;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  transition: all var(--duration-fast);
}
.nav-link:hover, .nav-link.active { color: var(--hust-blue); background: var(--hust-blue-wash); }
.nav-cta {
  margin-left: var(--s-3);
  padding: 8px 20px;
  background: var(--hust-blue);
  color: white;
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  transition: all var(--duration-fast);
}
.nav-cta:hover { background: var(--hust-blue-mid); transform: translateY(-1px); box-shadow: var(--shadow-sm); }

.nav-toggle { display: none; flex-direction: column; gap: 5px; padding: 8px; }
.nav-toggle span {
  display: block; width: 22px; height: 2px;
  background: var(--hust-blue-deep); border-radius: var(--radius-full);
  transition: all var(--duration-fast);
}

/* ——— Hero ——— */
.hero {
  position: relative;
  background: linear-gradient(160deg, var(--hust-blue-deep) 0%, var(--hust-blue) 50%, var(--hust-blue-mid) 100%);
  color: white;
  height: 560px;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 40%, rgba(201, 162, 70, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 75% 20%, rgba(255,255,255,0.04) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 80%, rgba(33, 117, 217, 0.15) 0%, transparent 60%);
  pointer-events: none;
}
.hero-pattern {
  position: absolute;
  right: -80px; top: -80px;
  width: 500px; height: 500px;
  border: 1px solid rgba(255,255,255,0.05);
  border-radius: 50%;
  pointer-events: none;
}
.hero-pattern:nth-child(3) {
  right: 60px; top: -160px;
  width: 320px; height: 320px;
}
.hero-pattern:nth-child(4) {
  right: 200px; top: 80px;
  width: 180px; height: 180px;
}
.hero-content {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--s-12);
  align-items: center;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(255,255,255,0.12);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  margin-bottom: var(--s-6);
  border: 1px solid rgba(255,255,255,0.1);
}
.hero-badge::before {
  content: ""; display: inline-block; width: 8px; height: 8px;
  background: #4ade80; border-radius: 50%; box-shadow: 0 0 8px rgba(74,222,128,0.4);
}
.hero-title {
  font-family: var(--font-display);
  font-size: var(--fs-hero);
  font-weight: var(--fw-black);
  line-height: var(--lh-tight);
  margin-bottom: var(--s-4);
  letter-spacing: -0.02em;
}
.hero-title .highlight {
  background: linear-gradient(180deg, transparent 60%, var(--gold) 60%);
  padding: 0 4px;
  color: white;
}
.hero-desc {
  font-size: var(--fs-body);
  color: rgba(255,255,255,0.75);
  line-height: var(--lh-relaxed);
  max-width: 44ch;
  margin-bottom: var(--s-8);
}
.hero-actions { display: flex; gap: var(--s-4); flex-wrap: wrap; }
.hero-stats {
  display: flex;
  gap: var(--s-8);
  margin-bottom: var(--s-8);
  padding-top: var(--s-6);
  border-top: 1px solid rgba(255,255,255,0.1);
}
.hero-stat-num {
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  font-weight: var(--fw-black);
  line-height: 1;
}
.hero-stat-label {
  font-size: var(--fs-xs);
  color: rgba(255,255,255,0.55);
  margin-top: var(--s-1);
}

/* Hero visual — news cards */
.hero-visual {
  display: flex;
  flex-direction: column;
  gap: var(--s-4);
}
.hero-news-card {
  background: rgba(255,255,255,0.08);
  border-radius: var(--radius-lg);
  padding: var(--s-5);
  border: 1px solid rgba(255,255,255,0.1);
  transition: all var(--duration);
  cursor: pointer;
}
.hero-news-card:hover {
  background: rgba(255,255,255,0.14);
  transform: translateX(4px);
}
.hero-news-card .hn-date {
  font-size: var(--fs-xs);
  color: var(--gold);
  font-weight: var(--fw-semibold);
  margin-bottom: 4px;
}
.hero-news-card .hn-title {
  font-family: var(--font-display);
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  line-height: var(--lh-snug);
  color: white;
  margin-bottom: 4px;
}
.hero-news-card .hn-tag {
  font-size: 11px;
  color: rgba(255,255,255,0.4);
}

/* ——— Button System ——— */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  font-size: var(--fs-sm); font-weight: var(--fw-semibold);
  border-radius: var(--radius-full); padding: 10px 24px;
  transition: all var(--duration-fast); white-space: nowrap; user-select: none;
}
.btn:focus-visible { outline: 2px solid var(--hust-blue-bright); outline-offset: 3px; }
.btn-primary { background: var(--hust-blue); color: white; }
.btn-primary:hover { background: var(--hust-blue-mid); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-outline { border: 1.5px solid rgba(255,255,255,0.3); color: white; background: transparent; }
.btn-outline:hover { border-color: rgba(255,255,255,0.6); background: rgba(255,255,255,0.08); }
.btn-white { background: white; color: var(--hust-blue); }
.btn-white:hover { background: var(--bg); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-gold { background: var(--gold); color: white; }
.btn-gold:hover { background: var(--gold-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-sm { padding: 6px 16px; font-size: var(--fs-xs); }
.btn-lg { padding: 12px 32px; font-size: var(--fs-body); }

/* ——— Section: News ——— */
.news-layout {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: var(--s-8);
}
.news-featured {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--hust-blue);
  min-height: 380px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: var(--s-8);
  transition: transform var(--duration);
  cursor: pointer;
}
.news-featured:hover { transform: scale(1.01); }
.news-featured::before {
  content: "";
  position: absolute; inset: 0;
  background: linear-gradient(180deg, transparent 30%, rgba(10,45,92,0.9) 100%);
  z-index: 1;
}
.news-featured .nf-content { position: relative; z-index: 2; }
.news-featured .nf-tag {
  display: inline-block; padding: 4px 12px;
  background: var(--gold); color: white;
  font-size: var(--fs-xs); font-weight: var(--fw-semibold);
  border-radius: var(--radius-full); margin-bottom: var(--s-3);
}
.news-featured .nf-title {
  font-family: var(--font-display);
  font-size: var(--fs-h2); font-weight: var(--fw-bold);
  color: white; line-height: var(--lh-snug); margin-bottom: var(--s-2);
}
.news-featured .nf-meta { font-size: var(--fs-xs); color: rgba(255,255,255,0.65); }

.news-list {
  display: flex; flex-direction: column;
  background: white; border-radius: var(--radius-xl);
  padding: var(--s-6); border: 1px solid var(--border-light);
}
.news-list-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: var(--s-4); padding-bottom: var(--s-4);
  border-bottom: 1px solid var(--border-light);
}
.news-list-header h3 {
  font-family: var(--font-display); font-size: var(--fs-h3); font-weight: var(--fw-bold); color: var(--hust-blue-deep);
}
.news-list-header .more {
  font-size: var(--fs-xs); color: var(--text-tertiary); transition: color var(--duration-fast);
}
.news-list-header .more:hover { color: var(--hust-blue); }
.news-item {
  display: grid; grid-template-columns: 52px 1fr; gap: var(--s-3);
  padding: var(--s-3) 0; cursor: pointer;
  border-bottom: 1px solid var(--border-light);
  transition: background var(--duration-fast);
}
.news-item:last-child { border-bottom: none; }
.news-item:hover { background: var(--hust-blue-wash); margin: 0 calc(-1 * var(--s-3)); padding-left: var(--s-3); padding-right: var(--s-3); border-radius: var(--radius-md); }
.news-item-date {
  font-family: var(--font-en); font-size: 11px; font-weight: var(--fw-semibold);
  color: var(--text-tertiary); text-align: center; line-height: 1.3;
  padding: 4px; background: var(--bg); border-radius: var(--radius-sm);
}
.news-item-date .nd-day { font-size: 18px; color: var(--hust-blue); display: block; }
.news-item-title {
  font-size: var(--fs-sm); font-weight: var(--fw-medium); color: var(--text-primary);
  line-height: var(--lh-snug);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.news-item-tag {
  font-size: 11px; color: var(--hust-blue-soft); margin-top: 2px;
}

/* ——— Section: About / Intro ——— */
.about-section {
  background: linear-gradient(180deg, var(--bg) 0%, white 50%);
}
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s-12);
  align-items: center;
}
.about-visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: linear-gradient(135deg, var(--hust-blue-deep) 0%, var(--hust-blue) 40%, var(--hust-blue-mid) 100%);
  display: flex; align-items: center; justify-content: center;
}
.about-visual-content {
  text-align: center;
  padding: var(--s-8);
}
.about-visual-content .av-school {
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  font-weight: var(--fw-black);
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--s-2);
}
.about-visual-content .av-subtitle {
  font-size: var(--fs-sm);
  color: rgba(255,255,255,0.5);
  letter-spacing: 0.05em;
}
.about-backdrop {
  position: absolute; right: -40px; bottom: -40px;
  width: 200px; height: 200px;
  border: 2px solid rgba(255,255,255,0.08);
  border-radius: 50%;
  pointer-events: none;
}
.about-values {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-4);
  margin-top: var(--s-8);
}
.about-value {
  text-align: center;
  padding: var(--s-5) var(--s-3);
  background: var(--bg);
  border-radius: var(--radius-lg);
  transition: all var(--duration-fast);
}
.about-value:hover { background: var(--hust-blue-wash); }
.about-value-icon {
  width: 40px; height: 40px; margin: 0 auto var(--s-2);
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
}
.about-value-icon.connect { background: #dbeafe; color: #2563eb; }
.about-value-icon.events { background: #fef3c7; color: #d97706; }
.about-value-icon.service { background: #d1fae5; color: #059669; }
.about-value h4 {
  font-size: var(--fs-sm); font-weight: var(--fw-semibold); color: var(--text-primary); margin-bottom: 2px;
}
.about-value p {
  font-size: var(--fs-xs); color: var(--text-tertiary); line-height: var(--lh-snug);
}

/* ——— Section: Events ——— */
.events-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-6);
}
.event-card {
  background: white;
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--border-light);
  transition: all var(--duration);
  cursor: pointer;
}
.event-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.event-card-image {
  height: 180px;
  background: linear-gradient(135deg, var(--hust-blue) 0%, var(--hust-blue-mid) 100%);
  display: flex; align-items: center; justify-content: center;
  position: relative;
}
.event-card-image .eci-date {
  position: absolute; top: 12px; left: 12px;
  background: white; color: var(--hust-blue);
  padding: 6px 12px; border-radius: var(--radius-md);
  font-family: var(--font-en); font-size: 11px; font-weight: var(--fw-bold);
  box-shadow: var(--shadow-sm);
}
.event-card-body { padding: var(--s-5); }
.event-card-body h3 {
  font-family: var(--font-display);
  font-size: var(--fs-h3); font-weight: var(--fw-bold);
  color: var(--text-primary); margin-bottom: var(--s-2); line-height: var(--lh-snug);
}
.event-card-body p {
  font-size: var(--fs-sm); color: var(--text-secondary);
  line-height: var(--lh-snug); margin-bottom: var(--s-3);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.event-card-meta {
  display: flex; gap: var(--s-4);
  font-size: var(--fs-xs); color: var(--text-tertiary);
}

/* ——— Section: Alumni Spotlight ——— */
.alumni-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--s-5);
}
.alumni-card {
  background: white;
  border-radius: var(--radius-xl);
  padding: var(--s-6) var(--s-5);
  text-align: center;
  border: 1px solid var(--border-light);
  transition: all var(--duration);
  cursor: pointer;
}
.alumni-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.alumni-avatar {
  width: 72px; height: 72px; margin: 0 auto var(--s-4);
  border-radius: 50%;
  background: linear-gradient(135deg, var(--hust-blue-soft) 0%, var(--hust-blue) 100%);
  display: flex; align-items: center; justify-content: center;
  color: white; font-family: var(--font-display);
  font-size: 28px; font-weight: var(--fw-bold);
}
.alumni-card h4 {
  font-family: var(--font-display);
  font-size: var(--fs-h4); font-weight: var(--fw-bold); color: var(--text-primary); margin-bottom: 2px;
}
.alumni-card .alumni-title {
  font-size: var(--fs-xs); color: var(--hust-blue-soft); margin-bottom: var(--s-2);
}
.alumni-card .alumni-company {
  font-size: var(--fs-xs); color: var(--text-tertiary);
}

/* ——— Section: Membership ——— */
.membership-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-6);
}
.membership-card {
  background: white;
  border-radius: var(--radius-xl);
  padding: var(--s-8) var(--s-6);
  border: 1px solid var(--border-light);
  text-align: center;
  transition: all var(--duration);
  position: relative;
}
.membership-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.membership-card.featured {
  border-color: var(--gold);
  box-shadow: 0 0 0 1px var(--gold), var(--shadow-md);
}
.membership-card.featured::before {
  content: "推荐";
  position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: var(--gold); color: white;
  padding: 4px 16px; border-radius: var(--radius-full);
  font-size: 11px; font-weight: var(--fw-bold);
}
.membership-icon {
  width: 56px; height: 56px; margin: 0 auto var(--s-5);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 28px;
}
.membership-card h3 {
  font-family: var(--font-display);
  font-size: var(--fs-h3); font-weight: var(--fw-bold); margin-bottom: var(--s-3);
}
.membership-card p {
  font-size: var(--fs-sm); color: var(--text-secondary);
  line-height: var(--lh-normal); margin-bottom: var(--s-5);
}
.membership-features {
  text-align: left;
  margin-bottom: var(--s-5);
}
.membership-features li {
  padding: var(--s-1) 0; font-size: var(--fs-sm); color: var(--text-secondary);
  display: flex; align-items: center; gap: 6px;
}
.membership-features li::before {
  content: "✓"; color: var(--hust-blue-bright); font-weight: var(--fw-bold);
}

/* ——— Section: Gallery ——— */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--s-4);
}
.gallery-item {
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: linear-gradient(135deg, var(--hust-blue-soft) 0%, var(--hust-blue-deep) 100%);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: all var(--duration);
  position: relative;
}
.gallery-item:hover { transform: scale(1.03); box-shadow: var(--shadow-lg); }
.gallery-item::after {
  content: "";
  position: absolute; inset: 0;
  background: rgba(10,45,92,0.15);
  opacity: 0; transition: opacity var(--duration);
}
.gallery-item:hover::after { opacity: 1; }
.gallery-label {
  color: rgba(255,255,255,0.7);
  font-size: var(--fs-xs);
  z-index: 1;
}

/* ——— Section: CTA ——— */
.cta-section {
  background: linear-gradient(160deg, var(--hust-blue-deep) 0%, var(--hust-blue) 100%);
  color: white;
  padding: var(--s-20) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-section::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 30% 60%, rgba(200,146,58,0.1) 0%, transparent 60%);
  pointer-events: none;
}
.cta-section > * { position: relative; z-index: 1; }
.cta-section .section-tag {
  background: rgba(255,255,255,0.12);
  color: var(--gold);
  border: 1px solid rgba(255,255,255,0.1);
}
.cta-section .section-heading { color: white; }
.cta-section .section-sub { color: rgba(255,255,255,0.7); margin: 0 auto var(--s-8); }
.cta-qr {
  display: flex; align-items: center; justify-content: center; gap: var(--s-8);
  margin-top: var(--s-8);
}
.cta-qr-box {
  width: 120px; height: 120px;
  background: white; border-radius: var(--radius-lg);
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; color: var(--text-tertiary);
  box-shadow: var(--shadow-lg);
}
.cta-qr-text {
  text-align: left;
  font-size: var(--fs-sm); color: rgba(255,255,255,0.7); line-height: var(--lh-relaxed);
}
.cta-qr-text strong { color: white; display: block; font-size: var(--fs-h3); margin-bottom: 4px; }

/* ——— Partners ——— */
.partners-row {
  display: flex; align-items: center; justify-content: center;
  gap: var(--s-10); flex-wrap: wrap;
  padding: var(--s-8) 0;
}
.partner-item {
  padding: var(--s-3) var(--s-6);
  font-size: var(--fs-sm); color: var(--text-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  transition: all var(--duration-fast);
}
.partner-item:hover { color: var(--hust-blue); border-color: var(--hust-blue-ghost); }

/* ——— Footer ——— */
.footer {
  background: var(--hust-blue-deep);
  color: rgba(255,255,255,0.55);
  padding: var(--s-16) 0 var(--s-8);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.2fr;
  gap: var(--s-10);
  margin-bottom: var(--s-10);
}
.footer-brand .nav-brand-text { color: white; }
.footer-brand .nav-brand-text small { color: rgba(255,255,255,0.4); }
.footer-brand p {
  font-size: var(--fs-sm); line-height: var(--lh-relaxed);
  max-width: 36ch; margin-top: var(--s-4);
}
.footer-col h4 {
  font-size: var(--fs-xs); font-weight: var(--fw-semibold);
  text-transform: uppercase; letter-spacing: 0.06em;
  color: rgba(255,255,255,0.35); margin-bottom: var(--s-4);
}
.footer-col a {
  display: block; font-size: var(--fs-sm);
  padding: 4px 0; transition: color var(--duration-fast);
}
.footer-col a:hover { color: white; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: var(--s-8);
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: var(--s-4); font-size: var(--fs-xs);
}
.footer-contact { display: flex; gap: var(--s-6); }

/* ——— Scroll reveal ——— */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out); }
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-d1 { transition-delay: 0.1s; }
.reveal-d2 { transition-delay: 0.2s; }
.reveal-d3 { transition-delay: 0.3s; }
.reveal-d4 { transition-delay: 0.4s; }

/* ——— Responsive ——— */
@media (max-width: 1024px) {
  .hero-content { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .news-layout { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  .alumni-grid { grid-template-columns: repeat(2, 1fr); }
  .events-grid { grid-template-columns: repeat(2, 1fr); }
  .membership-cards { grid-template-columns: repeat(2, 1fr); }
  .membership-card.featured { grid-column: span 2; }
  .gallery-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .topbar { display: none; }
  .nav-toggle { display: flex; }
  .nav-links {
    display: none;
    position: absolute; top: var(--nav-height); left: 0; right: 0;
    background: white; flex-direction: column;
    padding: var(--s-4); gap: 2px;
    border-bottom: 1px solid var(--border-light);
    box-shadow: var(--shadow-md);
  }
  .nav-links.open { display: flex; }
  .nav-cta { margin-left: 0; }

  .hero { min-height: 380px; height: auto; padding: var(--s-10) 0; }
  .hero-stats { gap: var(--s-4); }
  .hero-stat-num { font-size: 1.3rem; }

  .alumni-grid { grid-template-columns: repeat(2, 1fr); }
  .events-grid { grid-template-columns: 1fr; }
  .membership-cards { grid-template-columns: 1fr; }
  .membership-card.featured { grid-column: span 1; }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); }
  .about-values { grid-template-columns: repeat(3, 1fr); gap: var(--s-2); }

  .section { padding: var(--s-12) 0; }
  .cta-section { padding: var(--s-12) 0; }
}

@media (max-width: 480px) {
  .container { padding: 0 var(--s-4); }
  .alumni-grid { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); }
  .partners-row { gap: var(--s-4); }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ——— Join section toggle ——— */
body.join-hidden #join { display: none; }