/* =============================================
   科技感渐变主题 - AI创造社团 (轻量版)
   ============================================= */

:root {
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-bg: rgba(17, 24, 39, 0.6);
  --gradient-main: linear-gradient(135deg, #0a0e17 0%, #0f172a 25%, #1e1b4b 50%, #0f172a 75%, #0a0e17 100%);
  --gradient-accent: linear-gradient(135deg, #00e5ff, #7c4dff);
  --glow-cyan: 0 0 30px rgba(0, 229, 255, 0.15);
}

* { scrollbar-width: thin; scrollbar-color: #00e5ff #0a0e17; }
*::-webkit-scrollbar { width: 6px; }
*::-webkit-scrollbar-track { background: #0a0e17; }
*::-webkit-scrollbar-thumb { background: linear-gradient(180deg, #00e5ff, #7c4dff); border-radius: 3px; }

body {
  background: var(--gradient-main);
  background-attachment: fixed;
  color: #e2e8f0;
  overflow-x: hidden;
  min-height: 100vh;
  font-family: system-ui, -apple-system, sans-serif;
}

/* 科技感网格背景 */
body::before {
  content: '';
  position: fixed; inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 10% 20%, rgba(0,229,255,0.07) 0%, transparent 50%),
    radial-gradient(ellipse 60% 80% at 90% 80%, rgba(124,77,255,0.08) 0%, transparent 50%),
    radial-gradient(ellipse 50% 50% at 50% 0%, rgba(255,64,129,0.04) 0%, transparent 40%);
  z-index: -2; pointer-events: none;
}
body::after {
  content: '';
  position: fixed; inset: 0;
  background-image:
    linear-gradient(rgba(0,229,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,229,255,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: -1; pointer-events: none;
}

/* ===== Container ===== */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 1rem; }

/* ===== Navbar ===== */
.navbar {
  background: rgba(10,14,23,0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--glass-border);
  padding: 0.8rem 0;
  transition: all 0.3s ease;
}
.navbar-scrolled {
  background: rgba(10,14,23,0.95) !important;
  box-shadow: 0 4px 30px rgba(0,0,0,0.3), var(--glow-cyan);
}
.navbar-brand {
  font-weight: 700; font-size: 1.4rem;
  background: var(--gradient-accent);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  text-decoration: none;
}
.navbar-brand:hover { opacity: 0.8; }
.text-gradient {
  background: var(--gradient-accent);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.nav-link {
  color: #94a3b8 !important;
  margin: 0 0.3rem; padding: 0.5rem 1rem;
  position: relative; transition: all 0.3s ease;
  font-weight: 500; font-size: 0.95rem;
  border-radius: 8px; text-decoration: none;
}
.nav-link:hover { color: #00e5ff !important; background: rgba(0,229,255,0.08); }
.nav-link.active { color: #00e5ff !important; background: rgba(0,229,255,0.1); }
.nav-link::after {
  content: ''; position: absolute; bottom: 2px; left: 50%;
  width: 0; height: 2px;
  background: var(--gradient-accent);
  transition: all 0.3s ease; transform: translateX(-50%); border-radius: 1px;
}
.nav-link:hover::after, .nav-link.active::after { width: 60%; }

.navbar-collapse { display: none; flex-direction: column; width: 100%; }
.navbar-collapse.show { display: flex; }
.nav-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 0.25rem; width: 100%; }
.navbar-toggler {
  background: none; border: 1px solid var(--glass-border);
  border-radius: 8px; padding: 6px 10px; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
}
.navbar-toggler-icon {
  display: block; width: 24px; height: 2px;
  background: #e2e8f0; position: relative;
}
.navbar-toggler-icon::before,
.navbar-toggler-icon::after {
  content: ''; position: absolute; left: 0;
  width: 100%; height: 2px; background: #e2e8f0;
}
.navbar-toggler-icon::before { top: -7px; }
.navbar-toggler-icon::after { top: 7px; }
@media (min-width: 992px) {
  .navbar-collapse { display: flex !important; flex-direction: row; width: auto; }
  .navbar-toggler { display: none; }
  .nav-list { flex-direction: row !important; width: auto !important; gap: 0 !important; }
}

/* ===== Hero ===== */
.hero {
  height: 85vh; min-height: 600px;
  display: flex; align-items: center;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute;
  top: -50%; left: -50%; width: 200%; height: 200%;
  background: conic-gradient(from 0deg at 50% 50%,
    transparent 0deg, rgba(0,229,255,0.03) 60deg, transparent 120deg,
    rgba(124,77,255,0.03) 180deg, transparent 240deg,
    rgba(255,64,129,0.03) 300deg, transparent 360deg);
  animation: heroRotate 30s linear infinite; z-index: -1;
}
@keyframes heroRotate { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
.hero-content { max-width: 800px; margin: 0 auto; text-align: center; padding: 2rem; }
.hero-title { font-size: 3.5rem; font-weight: 800; margin-bottom: 1.5rem; line-height: 1.2; letter-spacing: -0.02em; }
.hero-subtitle { font-size: 1.4rem; margin-bottom: 2.5rem; color: #94a3b8; font-weight: 300; }

/* ===== Buttons ===== */
.btn {
  display: inline-block; text-align: center;
  text-decoration: none; cursor: pointer;
  border: none; border-radius: 50px;
  font-weight: 600; transition: all 0.3s ease; line-height: 1.5;
}
.btn-primary {
  background: var(--gradient-accent);
  padding: 0.75rem 2rem; color: #fff;
  box-shadow: 0 4px 20px rgba(0,229,255,0.25);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 8px 30px rgba(0,229,255,0.4); }
.btn-outline-light {
  padding: 0.75rem 2rem; color: #fff;
  border: 2px solid rgba(255,255,255,0.5);
  background: transparent;
}
.btn-outline-light:hover { transform: translateY(-3px); box-shadow: 0 8px 30px rgba(255,255,255,0.1); border-color: #fff; }
.btn-sm { padding: 0.4rem 1rem; font-size: 0.875rem; }
.btn-lg { padding: 1rem 2.5rem; font-size: 1.125rem; }

/* ===== Section ===== */
.section { padding: 5rem 0; }
.bg-dark-section { background: linear-gradient(180deg, transparent 0%, rgba(124,77,255,0.03) 50%, transparent 100%); }
.section-title {
  font-size: 2.5rem; font-weight: 700;
  margin-bottom: 3rem; text-align: center;
  position: relative;
}
.section-title::after {
  content: ''; position: absolute; bottom: -15px; left: 50%;
  transform: translateX(-50%);
  width: 80px; height: 3px;
  background: var(--gradient-accent);
  border-radius: 2px; box-shadow: 0 0 15px rgba(0,229,255,0.4);
}

/* ===== Card ===== */
.card {
  background: var(--glass-bg); border: 1px solid var(--glass-border);
  border-radius: 16px; overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4,0,0.2,1);
  backdrop-filter: blur(10px);
}
.card:hover { transform: translateY(-8px); border-color: rgba(0,229,255,0.2); box-shadow: var(--glow-cyan); }
.card-img-top { height: 200px; object-fit: cover; width: 100%; }
.card-body { padding: 1.5rem; }
.card-title {
  font-size: 1.2rem; font-weight: 600; margin-bottom: 1rem;
  background: var(--gradient-accent);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.card-text { color: #94a3b8; line-height: 1.7; }

/* ===== Glow ===== */
.glow { position: relative; }
.glow::before {
  content: ''; position: absolute;
  top: -2px; left: -2px; right: -2px; bottom: -2px;
  background: var(--gradient-accent);
  z-index: -1; border-radius: 18px;
  opacity: 0; filter: blur(15px); transition: all 0.4s ease;
}
.glow:hover::before { opacity: 0.4; filter: blur(20px); }

/* ===== Feature Icon ===== */
.feature-icon {
  font-size: 2.5rem; margin-bottom: 1.5rem;
  background: var(--gradient-accent);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 10px rgba(0,229,255,0.3));
}

/* ===== About ===== */
.about-content { max-width: 800px; margin: 0 auto; }
.about-content .lead { color: #e2e8f0; font-size: 1.2rem; line-height: 1.8; }
.about-content p { color: #94a3b8; line-height: 1.8; }
.about-content h3 { color: #e2e8f0; font-weight: 600; position: relative; padding-left: 16px; }
.about-content h3::before {
  content: ''; position: absolute; left: 0; top: 50%; transform: translateY(-50%);
  width: 4px; height: 60%; background: var(--gradient-accent); border-radius: 2px;
}
.about-content ul { list-style: none; padding: 0; }
.about-content ul li { color: #94a3b8; margin-bottom: 0.5rem; }
.about-content ul li i { color: #00e5ff !important; }
.about-image {
  border-radius: 16px; overflow: hidden; margin: 2rem 0;
  border: 1px solid var(--glass-border);
}
.about-image img { width: 100%; height: auto; display: block; transition: transform 0.5s ease; }
.about-image:hover img { transform: scale(1.03); }

/* ===== Timeline ===== */
.timeline { position: relative; max-width: 1200px; margin: 0 auto; padding: 2rem 0; }
.timeline::after {
  content: ''; position: absolute; width: 3px;
  background: linear-gradient(180deg, #00e5ff, #7c4dff, #ff4081);
  top: 0; bottom: 0; left: 50%; margin-left: -1.5px;
  border-radius: 2px;
}
.timeline-item { padding: 10px 40px; position: relative; width: 50%; box-sizing: border-box; }
.timeline-item:nth-child(odd) { left: 0; }
.timeline-item:nth-child(even) { left: 50%; }
.timeline-content {
  padding: 24px; background: var(--glass-bg);
  border-radius: 16px; position: relative;
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(10px); transition: all 0.3s ease;
}
.timeline-content:hover { border-color: rgba(0,229,255,0.2); box-shadow: var(--glow-cyan); }
.timeline-content h4 { color: #00e5ff; font-weight: 600; font-size: 1.1rem; margin-bottom: 0.75rem; }
.timeline-content p { color: #e2e8f0; line-height: 1.7; margin-bottom: 0; }
.timeline-item::after {
  content: ''; position: absolute; width: 16px; height: 16px;
  background: #0a0e17; border: 3px solid #00e5ff;
  top: 20px; border-radius: 50%; z-index: 1;
  box-shadow: 0 0 10px rgba(0,229,255,0.4);
}
.timeline-item:nth-child(odd)::after { right: -8px; }
.timeline-item:nth-child(even)::after { left: -8px; }
@media screen and (max-width: 768px) {
  .timeline::after { left: 31px; }
  .timeline-item { width: 100%; padding-left: 70px; padding-right: 25px; }
  .timeline-item:nth-child(even) { left: 0; }
  .timeline-item::after { left: 23px; }
}

/* ===== Footer ===== */
.footer {
  background: rgba(10,14,23,0.9);
  backdrop-filter: blur(20px);
  border-top: 1px solid var(--glass-border);
  padding: 3rem 0; margin-top: 3rem;
}
.footer-grid { display: flex; flex-wrap: wrap; gap: 2rem; }
.footer-grid > div { flex: 1; min-width: 220px; }
.footer h5 {
  background: var(--gradient-accent);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  margin-bottom: 1rem; font-weight: 600;
}
.footer p, .footer a { color: #94a3b8; transition: color 0.3s ease; text-decoration: none; }
.footer a:hover { color: #00e5ff; }
.footer ul { list-style: none; padding: 0; }
.footer-copy { text-align: center; margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--glass-border); }

/* ===== Social Links ===== */
.social-links a {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 12px;
  background: var(--glass-bg); border: 1px solid var(--glass-border);
  color: #94a3b8 !important; margin-right: 10px; font-size: 1.2rem;
  transition: all 0.3s ease;
}
.social-links a:hover {
  color: #00e5ff !important; border-color: rgba(0,229,255,0.3);
  background: rgba(0,229,255,0.08); transform: translateY(-3px); box-shadow: var(--glow-cyan);
}

/* ===== Media Gallery ===== */
.media-gallery {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px; padding: 20px 0;
}
.media-item {
  position: relative; border-radius: 16px; overflow: hidden;
  border: 1px solid var(--glass-border);
  transition: all 0.4s ease; cursor: pointer; background: var(--glass-bg);
}
.media-item:hover { transform: translateY(-5px); border-color: rgba(0,229,255,0.2); box-shadow: var(--glow-cyan); }
.media-item img, .media-item video { width: 100%; height: 250px; object-fit: cover; display: block; transition: transform 0.5s ease; }
.media-item:hover img, .media-item:hover video { transform: scale(1.05); }

/* ===== Carousel ===== */
.carousel-track { display: flex; transition: transform 0.5s ease; height: 100%; }
.carousel-slide { min-width: 100%; flex-shrink: 0; height: 100%; }
.media-carousel {
  position: relative; overflow: hidden; border-radius: 16px; height: 500px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.4); border: 1px solid var(--glass-border);
}
.carousel-prev, .carousel-next {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 48px; height: 48px;
  background: rgba(0,0,0,0.4); border: 1px solid rgba(255,255,255,0.2);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  color: white; font-size: 1.2rem; z-index: 10;
  transition: all 0.3s ease; cursor: pointer; backdrop-filter: blur(10px);
}
.carousel-prev { left: 16px; }
.carousel-next { right: 16px; }
.carousel-prev:hover, .carousel-next:hover { background: rgba(0,0,0,0.6); border-color: rgba(0,229,255,0.3); }
.carousel-prev-icon, .carousel-next-icon { display: block; width: 20px; height: 20px; background: no-repeat center/contain; }
.carousel-prev-icon {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='white'%3E%3Cpath d='M11.354 1.646a.5.5 0 0 1 0 .708L5.707 8l5.647 5.646a.5.5 0 0 1-.708.708l-6-6a.5.5 0 0 1 0-.708l6-6a.5.5 0 0 1 .708 0z'/%3E%3C/svg%3E");
}
.carousel-next-icon {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='white'%3E%3Cpath d='M4.646 1.646a.5.5 0 0 1 .708 0l6 6a.5.5 0 0 1 0 .708l-6 6a.5.5 0 0 1-.708-.708L10.293 8 4.646 2.354a.5.5 0 0 1 0-.708z'/%3E%3C/svg%3E");
}
.carousel-indicators {
  position: absolute; bottom: 16px; left: 50%; transform: translateX(-50%);
  display: flex; gap: 8px; z-index: 10;
}
.carousel-indicators button {
  width: 10px; height: 10px; border-radius: 50%;
  background: rgba(255,255,255,0.3); border: none; cursor: pointer;
  transition: all 0.3s ease;
}
.carousel-indicators button.active { background: #00e5ff; box-shadow: 0 0 10px rgba(0,229,255,0.5); }

/* ===== Alerts ===== */
.alert { border-radius: 12px; padding: 1rem 1.5rem; border: 1px solid var(--glass-border); backdrop-filter: blur(10px); }
.alert-info { background: rgba(0,229,255,0.08); border-color: rgba(0,229,255,0.2); color: #00e5ff; }

/* ===== Tables ===== */
.table { color: #94a3b8; width: 100%; border-collapse: collapse; }
.table th, .table td { padding: 0.75rem; text-align: left; }
.table-dark { background: var(--glass-bg); border-radius: 12px; overflow: hidden; }
.table-dark thead th { background: rgba(0,229,255,0.08); color: #00e5ff; border-bottom: 1px solid var(--glass-border); font-weight: 600; }
.table-dark td { border-bottom: 1px solid var(--glass-border); color: #94a3b8; }
.table-dark tbody tr:hover { background: rgba(0,229,255,0.05); }
.table-responsive { overflow-x: auto; border-radius: 12px; }

code { background: rgba(0,229,255,0.1); color: #00e5ff; padding: 0.2em 0.6em; border-radius: 6px; font-size: 0.9em; }

/* ===== Animations ===== */
@keyframes floating { 0% { transform: translateY(0px); } 50% { transform: translateY(-15px); } 100% { transform: translateY(0px); } }
.rotating { animation: rotating 20s linear infinite; }
@keyframes rotating { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
.particle {
  position: absolute; width: 5px; height: 5px;
  background-color: #00e5ff; border-radius: 50%; opacity: 0.5;
  box-shadow: 0 0 6px #00e5ff;
}

/* ===== Inline layout helpers ===== */
.text-primary { color: #00e5ff !important; }
.list-unstyled { list-style: none; padding: 0; margin: 0; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mb-5 { margin-bottom: 3rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }
.me-2 { margin-right: 0.5rem; }
.text-center { text-align: center; }
.lead { font-size: 1.25rem; font-weight: 300; }
.img-fluid { max-width: 100%; height: auto; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero-title { font-size: 2.2rem; }
  .hero-subtitle { font-size: 1.1rem; }
  .section-title { font-size: 2rem; }
  .media-carousel { height: 300px; }
}
@media (max-width: 576px) {
  .hero { height: 75vh; min-height: 500px; }
  .hero-title { font-size: 1.8rem; }
  .media-gallery { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
}