/* ============================================================
   每日大赛校园创意赛平台 - 青春校园插画卡片风
   设计哲学：现代扁平插画卡片主义
   核心原则：大面积留白+精致卡片、圆润友好、插画驱动、清晰层级
   ============================================================ */

:root {
  --primary: #1D4ED8;
  --primary-light: #3B82F6;
  --primary-dark: #1E40AF;
  --secondary: #22C55E;
  --secondary-light: #4ADE80;
  --secondary-dark: #16A34A;
  --bg: #F0F9FF;
  --card: #FFFFFF;
  --accent: #F59E0B;
  --accent-light: #FCD34D;
  --text: #0F172A;
  --text-light: #475569;
  --text-muted: #94A3B8;
  --border: #E2E8F0;
  --radius: 14px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  --shadow: 0 10px 30px rgba(0,0,0,0.08);
  --shadow-sm: 0 4px 12px rgba(0,0,0,0.05);
  --shadow-lg: 0 20px 50px rgba(0,0,0,0.12);
  --ease-out: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-in-out: cubic-bezier(0.77, 0, 0.175, 1);
  --font-title: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Courier New", monospace;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--text);
  background-color: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s var(--ease-out);
}

a:hover {
  color: var(--primary-dark);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-title);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: 1rem;
  color: var(--text-light);
}

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 4rem 0;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title h2 {
  margin-bottom: 0.75rem;
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
}

.section-title p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Grid System */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Cards */
.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  padding: 1.5rem;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}

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

.card-img {
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 1rem;
}

.card-img img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform 0.4s var(--ease-out);
}

.card:hover .card-img img {
  transform: scale(1.03);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.16s var(--ease-out), box-shadow 0.2s var(--ease-out), background 0.2s;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
  color: #fff;
  box-shadow: 0 4px 16px rgba(29,78,216,0.3);
}

.btn-secondary {
  background: var(--secondary);
  color: #fff;
}

.btn-secondary:hover {
  background: var(--secondary-dark);
  color: #fff;
}

.btn-accent {
  background: var(--accent);
  color: #fff;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: #fff;
}

/* Header / Navigation */
.site-header {
  background: var(--card);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--border);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.nav-brand svg {
  width: 32px;
  height: 32px;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 0.25rem;
}

.nav-menu a {
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  color: var(--text-light);
  font-weight: 500;
  font-size: 0.9rem;
  transition: background 0.2s, color 0.2s;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: var(--bg);
  color: var(--primary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s;
}

/* Hero Section */
.hero {
  padding: 4rem 0 3rem;
  position: relative;
  overflow: hidden;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.hero-text h1 {
  font-size: 2.75rem;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-text .subtitle {
  font-size: 1.15rem;
  color: var(--text-light);
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

/* Deadline Banner */
.deadline-banner {
  background: linear-gradient(135deg, var(--accent), #F97316);
  color: #fff;
  padding: 1rem 0;
  text-align: center;
  font-weight: 600;
}

.deadline-banner .countdown {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  margin-left: 1rem;
}

.bell-icon {
  display: inline-block;
  animation: bellShake 2s ease-in-out infinite;
}

@keyframes bellShake {
  0%, 100% { transform: rotate(0); }
  10% { transform: rotate(12deg); }
  20% { transform: rotate(-10deg); }
  30% { transform: rotate(8deg); }
  40% { transform: rotate(-6deg); }
  50% { transform: rotate(0); }
}

/* Campus Zone Tabs */
.zone-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.zone-tab {
  padding: 0.6rem 1.25rem;
  border-radius: 50px;
  background: var(--card);
  border: 2px solid var(--border);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s var(--ease-out);
}

.zone-tab:hover,
.zone-tab.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* Ranking Table */
.ranking-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0 0.5rem;
}

.ranking-table th {
  text-align: left;
  padding: 0.75rem 1rem;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.ranking-table td {
  padding: 1rem;
  background: var(--card);
  font-size: 0.95rem;
}

.ranking-table tr td:first-child {
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}

.ranking-table tr td:last-child {
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.85rem;
}

.rank-1 { background: #FEF3C7; color: #D97706; }
.rank-2 { background: #F1F5F9; color: #64748B; }
.rank-3 { background: #FED7AA; color: #C2410C; }

/* Poster Wall */
.poster-wall {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}

.poster-card {
  background: var(--card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s;
}

.poster-card:hover {
  transform: translateY(-6px) rotate(1deg);
  box-shadow: var(--shadow-lg);
}

.poster-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.poster-card .poster-info {
  padding: 1rem;
}

.poster-card .poster-tag {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  background: var(--bg);
  color: var(--primary);
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

/* Process Steps */
.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  position: relative;
}

.process-step {
  text-align: center;
  position: relative;
}

.step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

.step-number.green { background: var(--secondary); }

.process-step h4 {
  margin-bottom: 0.5rem;
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--card);
  border-radius: var(--radius);
  margin-bottom: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.faq-question {
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
  transition: background 0.2s;
}

.faq-question:hover {
  background: var(--bg);
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--primary);
  transition: transform 0.3s;
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 1.5rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s var(--ease-out), padding 0.3s;
}

.faq-item.active .faq-answer {
  padding: 0 1.5rem 1.25rem;
  max-height: 500px;
}

/* Footer */
.site-footer {
  background: var(--text);
  color: #CBD5E1;
  padding: 3rem 0 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}

.footer-desc {
  font-size: 0.9rem;
  line-height: 1.7;
  color: #94A3B8;
}

.footer-title {
  font-weight: 600;
  color: #fff;
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: #94A3B8;
  font-size: 0.9rem;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: #64748B;
}

/* Breadcrumb */
.breadcrumb {
  padding: 1rem 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--primary);
}

.breadcrumb span {
  margin: 0 0.5rem;
}

/* Tags */
.tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 500;
}

.tag-blue { background: #DBEAFE; color: var(--primary); }
.tag-green { background: #DCFCE7; color: var(--secondary-dark); }
.tag-amber { background: #FEF3C7; color: #D97706; }

/* Wave Divider */
.wave-divider {
  width: 100%;
  overflow: hidden;
  line-height: 0;
}

.wave-divider svg {
  width: 100%;
  height: 60px;
}

/* Page Header */
.page-header {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  padding: 3rem 0;
  text-align: center;
}

.page-header h1 {
  color: #fff;
  margin-bottom: 0.5rem;
}

.page-header p {
  color: rgba(255,255,255,0.85);
  max-width: 600px;
  margin: 0 auto;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-in {
  animation: fadeInUp 0.5s var(--ease-out) forwards;
  opacity: 0;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }

/* Sticker wobble */
@keyframes stickerWobble {
  0%, 100% { transform: rotate(-1deg); }
  50% { transform: rotate(1deg); }
}

.wobble {
  animation: stickerWobble 3s ease-in-out infinite;
}

/* Content Styles */
.content-area {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 0;
}

.content-area h2 {
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--border);
}

.content-area h3 {
  margin: 1.5rem 0 0.75rem;
}

.content-area ul, .content-area ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.content-area li {
  margin-bottom: 0.5rem;
  color: var(--text-light);
}

/* Responsive */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .process-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--card);
    flex-direction: column;
    padding: 1rem;
    box-shadow: var(--shadow);
    border-top: 1px solid var(--border);
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-text h1 {
    font-size: 2rem;
  }

  .hero-actions {
    justify-content: center;
  }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }

  .process-steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .poster-wall {
    grid-template-columns: 1fr;
  }

  .zone-tabs {
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 0.5rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  .section {
    padding: 2.5rem 0;
  }

  .hero {
    padding: 2rem 0;
  }

  .process-steps {
    grid-template-columns: 1fr;
  }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-primary { color: var(--primary); }
.text-secondary { color: var(--secondary); }
.text-accent { color: var(--accent); }
.bg-white { background: var(--card); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }