/* ========================================
   课程页样式
   ======================================== */

/* ========== 页面 Hero ========== */
.page-hero {
  background: linear-gradient(180deg, #F0F7FF 0%, #FFFFFF 100%);
  padding: 56px 0 48px;
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: "";
  position: absolute;
  top: -100px;
  right: -100px;
  width: 360px;
  height: 360px;
  background: radial-gradient(circle, rgba(79, 195, 247, 0.20) 0%, transparent 70%);
  border-radius: 50%;
}

.page-hero-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.page-hero-breadcrumb a {
  color: var(--text-soft);
  transition: color 0.2s;
}

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

.page-hero h1 {
  font-size: 44px;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 12px;
  position: relative;
}

.page-hero p {
  font-size: 16px;
  color: var(--text-soft);
  max-width: 640px;
  position: relative;
}

.hero-promise {
  margin-top: 18px;
  font-size: 18px;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 0.3px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: rgba(21, 101, 192, 0.10);
  border: 1px solid rgba(21, 101, 192, 0.22);
  border-radius: 999px;
  max-width: none;
  position: relative;
}

.hero-promise::before {
  content: "✔";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  font-size: 12px;
  color: #fff;
  background: var(--primary);
  border-radius: 50%;
}

/* ========== 工具栏 ========== */
.courses-page {
  padding: 40px 0 80px;
}

.courses-toolbar {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px 20px;
  margin-bottom: 28px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.categories {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.cat-tab {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  background: transparent;
  color: var(--text-soft);
  font-size: 14px;
  font-weight: 600;
  border-radius: 10px;
  transition: all 0.2s ease;
}

.cat-tab:hover {
  background: var(--bg-soft);
  color: var(--primary);
}

.cat-tab.active {
  background: var(--primary);
  color: #fff;
  box-shadow: var(--shadow-blue);
}

.cat-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 20px;
  padding: 0 6px;
  background: rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  font-size: 11px;
  font-weight: 700;
}

.cat-tab:not(.active) .cat-num {
  background: var(--bg-soft);
  color: var(--text-muted);
}

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: var(--bg-soft);
  border: 1.5px solid transparent;
  border-radius: 10px;
  width: 280px;
  transition: all 0.2s ease;
  color: var(--text-muted);
}

.search-box:focus-within {
  background: #fff;
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: 0 0 0 4px rgba(21, 101, 192, 0.10);
}

.search-box input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  font-size: 14px;
  color: var(--text);
}

.search-box input::placeholder {
  color: var(--text-muted);
}

.search-clear {
  display: none;
  width: 20px;
  height: 20px;
  background: var(--text-muted);
  color: #fff;
  border-radius: 50%;
  font-size: 14px;
  line-height: 1;
  align-items: center;
  justify-content: center;
}

.search-clear.visible {
  display: flex;
}

.sort-box {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px;
  background: var(--bg-soft);
  border-radius: 10px;
}

.sort-label {
  font-size: 13px;
  color: var(--text-muted);
  padding: 0 8px;
  font-weight: 500;
}

.sort-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 12px;
  border-radius: 8px;
  color: var(--text-soft);
  font-size: 13px;
  font-weight: 600;
  transition: all 0.2s ease;
}

.sort-btn:hover {
  color: var(--primary);
}

.sort-btn.active {
  background: #fff;
  color: var(--primary);
  box-shadow: var(--shadow-sm);
}

/* ========== 课程网格 ========== */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.course-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(21, 101, 192, 0.20);
}

.course-cover {
  height: 160px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent-glow) 100%);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.course-cover-emoji {
  font-size: 72px;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.15));
  position: relative;
  z-index: 1;
}

.course-cover::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 200px;
  height: 200px;
  background: rgba(255, 255, 255, 0.10);
  border-radius: 50%;
}

.course-cover::after {
  content: "";
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 160px;
  height: 160px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 50%;
}

.course-cover[data-theme="cog-1"] { background: linear-gradient(135deg, #1565C0 0%, #42A5F5 100%); }
.course-cover[data-theme="cog-2"] { background: linear-gradient(135deg, #5E35B1 0%, #7E57C2 100%); }
.course-cover[data-theme="cog-3"] { background: linear-gradient(135deg, #00838F 0%, #26C6DA 100%); }
.course-cover[data-theme="cog-4"] { background: linear-gradient(135deg, #2E7D32 0%, #66BB6A 100%); }
.course-cover[data-theme="cog-5"] { background: linear-gradient(135deg, #EF6C00 0%, #FFA726 100%); }
.course-cover[data-theme="tool-1"] { background: linear-gradient(135deg, #C2185B 0%, #EC407A 100%); }
.course-cover[data-theme="tool-2"] { background: linear-gradient(135deg, #AD1457 0%, #F06292 100%); }
.course-cover[data-theme="tool-3"] { background: linear-gradient(135deg, #6A1B9A 0%, #AB47BC 100%); }
.course-cover[data-theme="tool-4"] { background: linear-gradient(135deg, #283593 0%, #5C6BC0 100%); }
.course-cover[data-theme="tool-5"] { background: linear-gradient(135deg, #00695C 0%, #26A69A 100%); }
.course-cover[data-theme="tool-6"] { background: linear-gradient(135deg, #006064 0%, #00B8D4 100%); }
.course-cover[data-theme="tool-7"] { background: linear-gradient(135deg, #2E7D32 0%, #66BB6A 100%); }

.course-cover-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  background: rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(10px);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  border-radius: 999px;
  z-index: 2;
}

.course-cover-extra {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 2;
}

.course-cover-extra .tag {
  background: rgba(255, 255, 255, 0.95);
  color: var(--text);
}

.course-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.course-cat {
  display: inline-block;
  font-size: 12px;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 6px;
}

.course-title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 8px;
  color: var(--text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.course-desc {
  font-size: 13px;
  color: var(--text-soft);
  line-height: 1.6;
  margin-bottom: 16px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 1;
}

.course-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.course-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 3px;
}

.course-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.course-price {
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.price-num {
  font-size: 22px;
  font-weight: 800;
  color: var(--primary);
}

.price-currency {
  font-size: 13px;
  color: var(--primary);
  font-weight: 600;
}

.price-orig {
  font-size: 13px;
  color: var(--text-muted);
  text-decoration: line-through;
}

.price-free {
  font-size: 18px;
  font-weight: 800;
  color: var(--success);
}

.course-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 8px 14px;
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.course-btn:hover {
  background: var(--primary-dark);
  gap: 8px;
}

.course-btn-secondary {
  background: var(--bg-soft);
  color: var(--primary);
}

.course-btn-secondary:hover {
  background: rgba(21, 101, 192, 0.15);
}

/* ========== 空状态 ========== */
.empty-state {
  text-align: center;
  padding: 80px 24px;
  background: #fff;
  border-radius: var(--radius-lg);
  border: 1px dashed var(--border);
}

.empty-icon {
  font-size: 64px;
  margin-bottom: 16px;
  opacity: 0.6;
}

.empty-state h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
}

.empty-state p {
  font-size: 14px;
  color: var(--text-soft);
  margin-bottom: 20px;
}

/* ========== 价值强化区 ========== */
.value-banner {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: center;
  color: #fff;
  position: relative;
  overflow: hidden;
}

.value-banner::before {
  content: "";
  position: absolute;
  top: -100px;
  right: -100px;
  width: 320px;
  height: 320px;
  background: radial-gradient(circle, rgba(79, 195, 247, 0.20) 0%, transparent 70%);
  border-radius: 50%;
}

.value-banner-content {
  position: relative;
}

.value-banner h2 {
  font-size: 32px;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 12px;
}

.value-banner p {
  font-size: 15px;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.7;
  margin-bottom: 24px;
}

.value-banner strong {
  color: #FFD54F;
  font-weight: 700;
}

.value-banner-art {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  position: relative;
}

.art-item {
  padding: 20px;
  background: rgba(255, 255, 255, 0.10);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  text-align: center;
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.art-item:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateY(-3px);
}

.art-item-1 { grid-row: 1; grid-column: 1; }
.art-item-2 { grid-row: 1; grid-column: 2; }
.art-item-3 { grid-row: 2; grid-column: 1; }
.art-item-4 { grid-row: 2; grid-column: 2; }

/* ========== 响应式 ========== */
@media (max-width: 960px) {
  .page-hero h1 { font-size: 32px; }
  .courses-toolbar { flex-direction: column; align-items: stretch; }
  .toolbar-right { justify-content: space-between; }
  .search-box { width: 100%; }
  .courses-grid { grid-template-columns: repeat(2, 1fr); }
  .value-banner { grid-template-columns: 1fr; padding: 40px 28px; }
  .value-banner h2 { font-size: 26px; }
}

@media (max-width: 640px) {
  .page-hero { padding: 40px 0 32px; }
  .page-hero h1 { font-size: 28px; }
  .courses-grid { grid-template-columns: 1fr; }
  .categories { overflow-x: auto; flex-wrap: nowrap; padding-bottom: 4px; }
  .cat-tab { white-space: nowrap; }
  .value-banner { padding: 32px 20px; }
  .value-banner h2 { font-size: 22px; }
}