/* =============================================
   Next课程平台 — Apple Liquid Glass Dark Theme
   ============================================= */

/* === Reset & Base === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "Noto Sans SC", sans-serif;
  color: #f0f0f5;
  background: #000000;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
button { cursor: pointer; border: none; font: inherit; }
img { display: block; max-width: 100%; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* === Liquid Glass Effect === */
.glass-panel {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(40px) saturate(180%);
  -webkit-backdrop-filter: blur(40px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 20px;
  box-shadow:
    0 8px 32px rgba(0, 0, 0, 0.4),
    inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

/* === Page Visibility === */
.page { display: none; }
.page.active { display: block; }

/* === Navbar === */
.navbar {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(40px) saturate(200%);
  -webkit-backdrop-filter: blur(40px) saturate(200%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.navbar-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; height: 56px; gap: 24px;
}
.logo {
  font-size: 1.25rem; font-weight: 700; color: #fff;
  display: flex; align-items: center; gap: 6px; flex-shrink: 0;
  letter-spacing: -0.02em;
}
.logo-icon {
  width: 28px; height: 28px; border-radius: 8px;
  background: linear-gradient(135deg, #2563eb, #7c3aed, #ec4899);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.85rem; font-weight: 800; color: #fff;
}
.nav-links { display: flex; gap: 2px; }
.nav-link {
  padding: 6px 16px; border-radius: 10px;
  font-size: 0.88rem; font-weight: 500;
  color: rgba(255,255,255,0.5); transition: all 0.25s ease;
}
.nav-link:hover { color: rgba(255,255,255,0.85); background: rgba(255,255,255,0.06); }
.nav-link.active { color: #fff; background: rgba(255,255,255,0.1); }
.search-box {
  position: relative; flex: 1; max-width: 280px; margin-left: auto;
}
.search-box input {
  width: 100%; padding: 7px 12px 7px 34px;
  border: 1px solid rgba(255,255,255,0.08); border-radius: 12px;
  font-size: 0.85rem; color: #f0f0f5;
  background: rgba(255,255,255,0.05);
  backdrop-filter: blur(20px);
  transition: all 0.25s; outline: none;
}
.search-box input::placeholder { color: rgba(255,255,255,0.3); }
.search-box input:focus {
  border-color: rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.08);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}
.search-icon {
  position: absolute; left: 10px; top: 50%; transform: translateY(-50%);
  color: rgba(255,255,255,0.3); pointer-events: none;
}
.btn-avatar {
  width: 32px; height: 32px; border-radius: 50%; overflow: hidden;
  flex-shrink: 0; background: none; padding: 0;
  border: 2px solid rgba(255,255,255,0.15); transition: border-color 0.2s;
}
.btn-avatar:hover { border-color: rgba(255,255,255,0.4); }
.btn-avatar img { width: 100%; height: 100%; object-fit: cover; }
.mobile-menu-btn {
  display: none; flex-direction: column; gap: 4px;
  background: none; padding: 6px;
}
.mobile-menu-btn span {
  display: block; width: 18px; height: 1.5px;
  background: rgba(255,255,255,0.7); border-radius: 1px; transition: 0.2s;
}
.mobile-menu {
  display: none; padding: 12px 24px 16px;
  border-top: 1px solid rgba(255,255,255,0.06);
}
.mobile-menu.open { display: block; }
.mobile-search { margin-bottom: 12px; }
.mobile-search input {
  width: 100%; padding: 10px 14px; color: #f0f0f5;
  border: 1px solid rgba(255,255,255,0.08); border-radius: 12px;
  font-size: 0.9rem; background: rgba(255,255,255,0.05); outline: none;
}
.mobile-search input::placeholder { color: rgba(255,255,255,0.3); }
.mobile-nav-links {
  display: flex; flex-wrap: wrap; gap: 6px;
}

/* === Banner === */
.banner {
  position: relative; overflow: hidden;
  max-width: 1200px; margin: 20px auto; border-radius: 24px;
  padding: 0 24px;
}
.banner-track {
  display: flex; transition: transform 0.6s cubic-bezier(0.25, 0.1, 0.25, 1);
}
.banner-slide {
  min-width: 100%; position: relative; border-radius: 24px; overflow: hidden;
}
.banner-slide img {
  width: 100%; height: 400px; object-fit: cover; display: block;
}
.banner-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0.3) 100%);
  backdrop-filter: blur(2px);
  display: flex; align-items: flex-end; padding: 48px 56px;
}
.banner-text { max-width: 560px; }
.banner-text h2 {
  font-size: 2.2rem; font-weight: 800; color: #fff; margin-bottom: 8px;
  letter-spacing: -0.03em; line-height: 1.2;
}
.banner-text p {
  font-size: 1rem; color: rgba(255,255,255,0.65); margin-bottom: 20px; line-height: 1.5;
}
.banner-text .btn-banner {
  padding: 10px 28px; border-radius: 14px; font-weight: 600; font-size: 0.9rem;
  color: #000; background: rgba(255,255,255,0.9);
  backdrop-filter: blur(10px);
  transition: all 0.25s;
}
.banner-text .btn-banner:hover {
  background: #fff;
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(255,255,255,0.15);
}
.banner-btn {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 36px; height: 36px; border-radius: 50%;
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.8);
  font-size: 0.95rem; display: flex; align-items: center; justify-content: center;
  transition: all 0.25s; z-index: 2;
}
.banner-btn:hover {
  background: rgba(255,255,255,0.18);
  border-color: rgba(255,255,255,0.25);
}
.banner-prev { left: 40px; }
.banner-next { right: 40px; }
.banner-dots {
  position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%);
  display: flex; gap: 6px; z-index: 2;
}
.banner-dot {
  width: 6px; height: 6px; border-radius: 3px; border: none;
  background: rgba(255,255,255,0.25); transition: all 0.35s; cursor: pointer;
}
.banner-dot.active { background: rgba(255,255,255,0.9); width: 20px; }

/* === Filter Bar === */
.filter-bar {
  display: flex; gap: 4px; padding: 6px;
  margin: 24px 0 8px; width: fit-content;
}
.filter-tag {
  padding: 6px 16px; border-radius: 12px;
  font-size: 0.84rem; font-weight: 500;
  color: rgba(255,255,255,0.45); transition: all 0.25s;
}
.filter-tag:hover { color: rgba(255,255,255,0.75); background: rgba(255,255,255,0.05); }
.filter-tag.active {
  color: #fff;
  background: rgba(255,255,255,0.12);
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

/* === Section Title === */
.section-title {
  font-size: 1.3rem; font-weight: 700; margin: 24px 0 16px;
  color: rgba(255,255,255,0.9); letter-spacing: -0.02em;
}

/* === Course Grid === */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 20px; padding-bottom: 48px;
}
.course-card {
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(40px) saturate(150%);
  -webkit-backdrop-filter: blur(40px) saturate(150%);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 20px; overflow: hidden;
  transition: all 0.35s cubic-bezier(0.25, 0.1, 0.25, 1);
  cursor: pointer;
}
.course-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255,255,255,0.12);
  box-shadow: 0 20px 40px rgba(0,0,0,0.5), 0 0 0 1px rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.07);
}
.card-cover { position: relative; overflow: hidden; }
.card-cover img {
  width: 100%; height: 170px; object-fit: cover;
  transition: transform 0.5s cubic-bezier(0.25, 0.1, 0.25, 1);
}
.course-card:hover .card-cover img { transform: scale(1.06); }
.card-tag {
  position: absolute; top: 12px; left: 12px;
  padding: 4px 10px; border-radius: 8px;
  font-size: 0.72rem; font-weight: 600; color: #fff;
  background: rgba(255,255,255,0.12);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,0.1);
}
.card-body { padding: 16px; }
.card-title {
  font-size: 1rem; font-weight: 650; margin-bottom: 6px;
  color: rgba(255,255,255,0.92); line-height: 1.4;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden; letter-spacing: -0.01em;
}
.card-instructor {
  font-size: 0.82rem; color: rgba(255,255,255,0.35); margin-bottom: 12px;
}
.card-footer {
  display: flex; align-items: center; justify-content: space-between;
}
.card-price {
  font-size: 1.05rem; font-weight: 700;
  background: linear-gradient(135deg, #818cf8, #c084fc);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.card-price.free {
  background: linear-gradient(135deg, #34d399, #2dd4bf);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.card-stats {
  display: flex; align-items: center; gap: 8px;
  font-size: 0.78rem; color: rgba(255,255,255,0.3);
}
.card-stats .star { color: #fbbf24; }

/* === No Results === */
.no-results {
  text-align: center; padding: 80px 20px;
  color: rgba(255,255,255,0.25); font-size: 1rem;
}

/* === Detail Page === */
.btn-back {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 16px; border-radius: 12px;
  font-size: 0.85rem; font-weight: 500;
  color: rgba(255,255,255,0.5);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.06);
  margin: 24px 0 20px; transition: all 0.2s;
}
.btn-back svg { opacity: 0.6; }
.btn-back:hover { color: #fff; border-color: rgba(255,255,255,0.15); background: rgba(255,255,255,0.08); }

.detail-hero {
  display: flex; gap: 40px; padding: 0; overflow: hidden; margin-bottom: 28px;
}
.detail-cover {
  width: 45%; min-height: 320px; object-fit: cover; flex-shrink: 0;
  border-radius: 20px 0 0 20px;
}
.detail-hero-info {
  padding: 36px 36px 36px 0;
  display: flex; flex-direction: column; justify-content: center;
}
.detail-tag {
  display: inline-block; padding: 4px 12px; border-radius: 8px;
  font-size: 0.75rem; font-weight: 600; color: rgba(255,255,255,0.8);
  background: rgba(255,255,255,0.08); margin-bottom: 12px; width: fit-content;
}
.detail-title {
  font-size: 1.7rem; font-weight: 800; margin-bottom: 12px;
  color: #fff; letter-spacing: -0.03em; line-height: 1.25;
}
.detail-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 16px;
  margin-bottom: 16px; font-size: 0.88rem; color: rgba(255,255,255,0.4);
}
.detail-meta .price {
  font-size: 1.4rem; font-weight: 800;
  background: linear-gradient(135deg, #818cf8, #c084fc);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.detail-meta .price.free {
  background: linear-gradient(135deg, #34d399, #2dd4bf);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.detail-meta .star { color: #fbbf24; }
.detail-desc {
  font-size: 0.92rem; color: rgba(255,255,255,0.45); line-height: 1.7; margin-bottom: 24px;
}
.detail-actions { display: flex; gap: 12px; }
.btn-enroll {
  padding: 12px 36px; border-radius: 14px; font-size: 0.95rem; font-weight: 700;
  color: #000; background: rgba(255,255,255,0.9);
  transition: all 0.25s;
}
.btn-enroll:hover {
  background: #fff; transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(255,255,255,0.15);
}
.btn-enroll-outline {
  padding: 12px 28px; border-radius: 14px; font-size: 0.95rem; font-weight: 600;
  color: rgba(255,255,255,0.7);
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  transition: all 0.25s;
}
.btn-enroll-outline:hover {
  color: #fff; border-color: rgba(255,255,255,0.25); background: rgba(255,255,255,0.1);
}

.detail-layout {
  display: grid; grid-template-columns: 1fr 360px; gap: 24px;
  padding-bottom: 60px;
}
.detail-card {
  padding: 28px; margin-bottom: 20px;
}
.detail-card h3 {
  font-size: 1.05rem; font-weight: 700; margin-bottom: 20px;
  color: rgba(255,255,255,0.85); padding-bottom: 14px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.outline-list { list-style: none; counter-reset: outline; }
.outline-list li {
  counter-increment: outline;
  padding: 12px 0; border-bottom: 1px solid rgba(255,255,255,0.04);
  font-size: 0.88rem; color: rgba(255,255,255,0.5);
  display: flex; align-items: center; gap: 12px;
}
.outline-list li::before {
  content: counter(outline);
  width: 28px; height: 28px; border-radius: 8px; flex-shrink: 0;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.06);
  color: rgba(255,255,255,0.5);
  font-size: 0.75rem; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.outline-list li:last-child { border-bottom: none; }
.instructor-info { display: flex; align-items: center; gap: 14px; }
.instructor-avatar {
  width: 52px; height: 52px; border-radius: 50%; object-fit: cover;
  flex-shrink: 0; border: 2px solid rgba(255,255,255,0.08);
}
.instructor-name {
  font-weight: 700; font-size: 0.92rem; margin-bottom: 4px;
  color: rgba(255,255,255,0.85);
}
.instructor-bio { font-size: 0.82rem; color: rgba(255,255,255,0.35); line-height: 1.5; }
.info-list {
  list-style: none;
}
.info-list li {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 0; border-bottom: 1px solid rgba(255,255,255,0.04);
  font-size: 0.85rem;
}
.info-list li:last-child { border-bottom: none; }
.info-list .label { color: rgba(255,255,255,0.35); }
.info-list .value { color: rgba(255,255,255,0.7); font-weight: 500; }

/* === Page Header === */
.page-header {
  padding: 48px 0 32px; text-align: center;
}
.page-header h1 {
  font-size: 2rem; font-weight: 800; color: #fff;
  letter-spacing: -0.03em; margin-bottom: 8px;
}
.page-header p {
  font-size: 1rem; color: rgba(255,255,255,0.35);
}

/* === Learning Paths === */
.paths-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 20px; padding-bottom: 60px;
}
.path-card {
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(40px);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 20px; padding: 28px;
  transition: all 0.3s; cursor: pointer;
  position: relative; overflow: hidden;
}
.path-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 3px;
  border-radius: 20px 20px 0 0;
  opacity: 0; transition: opacity 0.3s;
}
.path-card:hover {
  border-color: rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  transform: translateY(-2px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.4);
}
.path-card:hover::before { opacity: 1; }
.path-card.gradient-blue::before { background: linear-gradient(90deg, #3b82f6, #06b6d4); }
.path-card.gradient-purple::before { background: linear-gradient(90deg, #8b5cf6, #ec4899); }
.path-card.gradient-green::before { background: linear-gradient(90deg, #10b981, #34d399); }
.path-card.gradient-orange::before { background: linear-gradient(90deg, #f59e0b, #ef4444); }
.path-icon {
  width: 48px; height: 48px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; margin-bottom: 16px;
}
.path-icon.blue { background: rgba(59,130,246,0.15); }
.path-icon.purple { background: rgba(139,92,246,0.15); }
.path-icon.green { background: rgba(16,185,129,0.15); }
.path-icon.orange { background: rgba(245,158,11,0.15); }
.path-card h3 {
  font-size: 1.1rem; font-weight: 700; color: rgba(255,255,255,0.9);
  margin-bottom: 8px; letter-spacing: -0.01em;
}
.path-card p {
  font-size: 0.85rem; color: rgba(255,255,255,0.35); margin-bottom: 16px; line-height: 1.5;
}
.path-meta {
  display: flex; gap: 16px; font-size: 0.8rem; color: rgba(255,255,255,0.3);
}
.path-courses {
  display: flex; gap: 6px; margin-top: 16px; flex-wrap: wrap;
}
.path-course-tag {
  padding: 3px 10px; border-radius: 6px;
  font-size: 0.72rem; color: rgba(255,255,255,0.45);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.04);
}

/* === Community === */
.community-layout {
  display: grid; grid-template-columns: 1fr 320px;
  gap: 24px; padding-bottom: 60px;
}
.post-card {
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(40px);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 20px; padding: 24px;
  margin-bottom: 16px; transition: all 0.25s;
}
.post-card:hover {
  border-color: rgba(255,255,255,0.1);
  background: rgba(255,255,255,0.06);
}
.post-header { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.post-avatar {
  width: 36px; height: 36px; border-radius: 50%; object-fit: cover;
  border: 1px solid rgba(255,255,255,0.08);
}
.post-author { font-size: 0.88rem; font-weight: 600; color: rgba(255,255,255,0.8); }
.post-time { font-size: 0.78rem; color: rgba(255,255,255,0.25); }
.post-body {
  font-size: 0.9rem; color: rgba(255,255,255,0.55); line-height: 1.7;
  margin-bottom: 16px;
}
.post-tags { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 14px; }
.post-tag {
  padding: 3px 10px; border-radius: 6px; font-size: 0.72rem;
  color: rgba(255,255,255,0.4);
  background: rgba(255,255,255,0.05);
}
.post-actions {
  display: flex; gap: 20px; padding-top: 14px;
  border-top: 1px solid rgba(255,255,255,0.04);
}
.post-action {
  font-size: 0.8rem; color: rgba(255,255,255,0.3);
  background: none; display: flex; align-items: center; gap: 5px;
  transition: color 0.2s;
}
.post-action:hover { color: rgba(255,255,255,0.7); }

.sidebar-widget { padding: 24px; margin-bottom: 16px; }
.sidebar-widget h3 {
  font-size: 0.95rem; font-weight: 700; color: rgba(255,255,255,0.8);
  margin-bottom: 16px; padding-bottom: 12px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.topic-item {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 0; font-size: 0.85rem;
}
.topic-rank {
  width: 20px; text-align: center;
  font-weight: 700; font-size: 0.78rem; color: rgba(255,255,255,0.25);
}
.topic-rank.top { color: #fbbf24; }
.topic-name { color: rgba(255,255,255,0.6); flex: 1; }
.topic-count { font-size: 0.75rem; color: rgba(255,255,255,0.2); }
.contributor-item {
  display: flex; align-items: center; gap: 10px; padding: 8px 0;
}
.contributor-item img {
  width: 32px; height: 32px; border-radius: 50%; object-fit: cover;
  border: 1px solid rgba(255,255,255,0.06);
}
.contributor-name { font-size: 0.85rem; color: rgba(255,255,255,0.6); }
.contributor-score { margin-left: auto; font-size: 0.78rem; color: rgba(255,255,255,0.25); }

/* === Profile === */
.profile-header {
  display: flex; align-items: center; gap: 32px; padding: 36px;
  margin: 24px 0;
}
.profile-avatar {
  width: 100px; height: 100px; border-radius: 50%; object-fit: cover;
  flex-shrink: 0;
  border: 3px solid rgba(255,255,255,0.1);
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}
.profile-info h1 {
  font-size: 1.5rem; font-weight: 800; color: #fff;
  margin-bottom: 4px; letter-spacing: -0.02em;
}
.profile-bio { font-size: 0.9rem; color: rgba(255,255,255,0.35); margin-bottom: 16px; }
.profile-stats { display: flex; gap: 28px; }
.stat { display: flex; flex-direction: column; align-items: center; }
.stat-num {
  font-size: 1.3rem; font-weight: 800; color: #fff;
}
.stat-label { font-size: 0.75rem; color: rgba(255,255,255,0.3); margin-top: 2px; }

.profile-body {
  display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
  padding-bottom: 60px;
}
.learning-item {
  display: flex; align-items: center; gap: 14px;
  padding: 14px 0; border-bottom: 1px solid rgba(255,255,255,0.04);
}
.learning-item:last-child { border-bottom: none; }
.learning-thumb {
  width: 64px; height: 44px; border-radius: 8px;
  object-fit: cover; flex-shrink: 0;
}
.learning-info { flex: 1; }
.learning-name {
  font-size: 0.88rem; font-weight: 600; color: rgba(255,255,255,0.8);
  margin-bottom: 6px;
}
.learning-progress {
  height: 4px; border-radius: 2px; background: rgba(255,255,255,0.06);
  overflow: hidden;
}
.learning-progress-bar {
  height: 100%; border-radius: 2px;
  background: linear-gradient(90deg, #818cf8, #c084fc);
}
.learning-pct {
  font-size: 0.75rem; color: rgba(255,255,255,0.3); margin-top: 4px;
}
.achievement-item {
  text-align: center; padding: 20px 12px;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.04);
  border-radius: 16px; transition: all 0.25s;
}
.achievement-item:hover {
  background: rgba(255,255,255,0.06);
  border-color: rgba(255,255,255,0.1);
}
.achievement-icon { font-size: 2rem; margin-bottom: 8px; }
.achievement-name {
  font-size: 0.8rem; font-weight: 600; color: rgba(255,255,255,0.6);
  margin-bottom: 4px;
}
.achievement-desc { font-size: 0.72rem; color: rgba(255,255,255,0.25); }
.achievements-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px;
}

/* === Footer === */
.footer {
  margin-top: auto;
  background: rgba(255,255,255,0.02);
  border-top: 1px solid rgba(255,255,255,0.04);
  padding: 48px 0 24px; font-size: 0.84rem;
}
.footer-inner { display: flex; flex-direction: column; gap: 32px; }
.footer-brand { display: flex; flex-direction: column; gap: 8px; }
.footer-brand p { color: rgba(255,255,255,0.25); font-size: 0.85rem; }
.footer-cols {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.footer-cols h4 {
  font-size: 0.85rem; font-weight: 700; color: rgba(255,255,255,0.5);
  margin-bottom: 12px;
}
.footer-cols a {
  display: block; color: rgba(255,255,255,0.25);
  padding: 3px 0; transition: color 0.2s; font-size: 0.84rem;
}
.footer-cols a:hover { color: rgba(255,255,255,0.6); }
.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.04);
}
.footer-bottom p { color: rgba(255,255,255,0.15); font-size: 0.8rem; }

/* === Responsive === */
@media (max-width: 900px) {
  .detail-hero { flex-direction: column; }
  .detail-cover { width: 100%; min-height: 220px; border-radius: 20px 20px 0 0; }
  .detail-hero-info { padding: 24px; }
  .detail-layout { grid-template-columns: 1fr; }
  .community-layout { grid-template-columns: 1fr; }
  .profile-body { grid-template-columns: 1fr; }
  .banner-slide img { height: 280px; }
  .paths-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-links, .navbar-inner .search-box, .btn-avatar { display: none; }
  .mobile-menu-btn { display: flex; }
  .navbar-inner { gap: 12px; }
  .banner { padding: 0 16px; margin: 12px auto; }
  .banner-slide img { height: 220px; }
  .banner-overlay { padding: 24px 28px; }
  .banner-text h2 { font-size: 1.3rem; }
  .banner-text p { font-size: 0.85rem; }
  .banner-prev { left: 24px; }
  .banner-next { right: 24px; }
  .course-grid { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
  .footer-cols { grid-template-columns: repeat(2, 1fr); }
  .profile-header { flex-direction: column; text-align: center; padding: 28px; }
  .profile-stats { justify-content: center; }
  .achievements-grid { grid-template-columns: repeat(2, 1fr); }
  .filter-bar { flex-wrap: wrap; }
}
@media (max-width: 480px) {
  .course-grid { grid-template-columns: 1fr; }
  .banner-text h2 { font-size: 1.05rem; }
  .banner-btn { width: 30px; height: 30px; font-size: 0.8rem; }
  .detail-title { font-size: 1.3rem; }
  .detail-actions { flex-direction: column; }
  .footer-cols { grid-template-columns: 1fr; }
}