/* ===== 页面头部 ===== */
.page-hero { padding: 56px 0 40px; background: var(--bg); border-bottom: 1px solid var(--border); }
.page-title { font-size: 36px; font-weight: 900; letter-spacing: -1px; margin-bottom: 8px; }
.page-subtitle { color: var(--text-secondary); font-size: 15px; margin-bottom: 28px; }

.search-bar { display: flex; align-items: center; background: var(--bg); border: 1.5px solid var(--border); border-radius: var(--radius); padding: 12px 16px; gap: 10px; max-width: 560px; margin-bottom: 20px; transition: border-color .2s; }
.search-bar:focus-within { border-color: var(--text); }
.search-icon { font-size: 16px; }
.search-input { flex: 1; border: none; outline: none; font-size: 15px; font-family: inherit; color: var(--text); background: transparent; }
.search-input::placeholder { color: #9CA3AF; }
.search-kbd { background: #F3F4F6; border: 1px solid var(--border); border-radius: 6px; padding: 2px 8px; font-size: 12px; color: var(--text-secondary); }

/* 难度筛选 */
.level-tabs { display: flex; gap: 8px; flex-wrap: wrap; }
.level-tab { background: var(--bg-secondary); border: 1px solid var(--border); border-radius: 100px; padding: 7px 18px; font-size: 13px; font-weight: 500; color: var(--text-secondary); cursor: pointer; transition: all .2s; font-family: inherit; display: flex; align-items: center; gap: 6px; }
.level-tab:hover { background: var(--bg); color: var(--text); border-color: var(--text); }
.level-tab.active { background: var(--text); color: var(--bg); border-color: var(--text); }

.level-dot { width: 8px; height: 8px; border-radius: 50%; }
.level-dot--beginner { background: #10B981; }
.level-dot--intermediate { background: #F59E0B; }
.level-dot--advanced { background: #EF4444; }

/* ===== 主布局 ===== */
.tutorials-main { padding: 40px 0 80px; }
.tutorials-layout { display: block; }

/* ===== 左侧分类 ===== */
.tutorials-nav-inner { position: sticky; top: 84px; }
.nav-section-title { font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: .8px; color: var(--text-secondary); margin-bottom: 8px; padding: 0 8px; }
.category-nav { display: flex; flex-direction: column; gap: 2px; }
.category-item { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 10px; font-size: 14px; color: var(--text-secondary); transition: all .2s; cursor: pointer; }
.category-item:hover { background: var(--bg-secondary); color: var(--text); }
.category-item.active { background: var(--bg-secondary); color: var(--text); font-weight: 600; border-left: 2px solid var(--text); }
.category-icon { font-size: 16px; flex-shrink: 0; }
.category-name { flex: 1; }
.category-count { font-size: 12px; background: var(--bg-secondary); color: var(--text-secondary); padding: 1px 7px; border-radius: 100px; }
.category-item.active .category-count { background: var(--border); color: var(--text); }

/* ===== 教程内容 ===== */
.tutorials-section { margin-bottom: 48px; }
.tutorials-section-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; }
.tutorials-section-title { font-size: 18px; font-weight: 800; }

.sort-select select { border: 1px solid var(--border); border-radius: var(--radius); padding: 6px 12px; font-size: 13px; font-family: inherit; color: var(--text); background: var(--bg); cursor: pointer; outline: none; }

/* ===== 学习路径 ===== */
.paths-grid { display: flex; flex-direction: column; gap: 12px; }

.path-card {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 20px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  transition: transform .2s, border-color .2s;
  cursor: pointer;
}
.path-card:hover { transform: translateX(4px); border-color: var(--text); }
.path-card--1 { border-left: 3px solid var(--text); }
.path-card--2 { border-left: 3px solid var(--text-secondary); }
.path-card--3 { border-left: 3px solid var(--text-muted); }
.path-card.locked { opacity: .75; }
.path-info { flex: 1; }
.path-name { font-size: 17px; font-weight: 700; margin-bottom: 4px; }
.path-desc { font-size: 13px; color: var(--text-secondary); margin-bottom: 10px; line-height: 1.5; }
.path-meta { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-secondary); }

.level-badge { font-size: 11px; font-weight: 700; padding: 2px 10px; border-radius: 100px; border: 1px solid var(--border); color: var(--text-secondary); background: var(--bg-secondary); }
.level-badge--beginner { }
.level-badge--intermediate { }
.level-badge--advanced { }

.path-arrow { font-size: 18px; color: var(--text-secondary); flex-shrink: 0; }
.locked-icon { font-size: 18px; flex-shrink: 0; }

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

.tutorial-card {
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s, transform .2s;
  color: inherit;
  cursor: pointer;
}
.tutorial-card:hover { border-color: var(--text); transform: translateY(-2px); }
.tutorial-card.locked { opacity: .8; }

.tutorial-body { padding: 16px; flex: 1; display: flex; flex-direction: column; gap: 8px; }

.tutorial-meta-top { display: flex; align-items: center; gap: 8px; }

/* 在卡片内 level-badge 保持统一黑白风格 */
.tutorial-body .level-badge--beginner    { }
.tutorial-body .level-badge--intermediate{ }
.tutorial-body .level-badge--advanced    { }

.tutorial-category { font-size: 12px; color: var(--text-secondary); }

.tutorial-card h3 { font-size: 14px; font-weight: 700; line-height: 1.5; flex: 1; }
.tutorial-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

.tutorial-footer { display: flex; align-items: center; justify-content: space-between; margin-top: auto; padding-top: 12px; border-top: 1px solid var(--border); }
.tutorial-stats { display: flex; gap: 6px; font-size: 12px; color: var(--text-secondary); }
.tutorial-rating { display: flex; align-items: center; gap: 4px; font-size: 12px; font-weight: 600; }
.stars { font-size: 11px; color: var(--text); }

.locked-badge { background: var(--bg-secondary); color: var(--text-secondary); font-size: 11px; font-weight: 600; padding: 3px 10px; border-radius: var(--radius); }

.load-more { text-align: center; margin-top: 32px; }

/* ===== 分类导览卡片 ===== */
.cat-cards-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.cat-card { display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 20px 12px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg); color: var(--text); text-align: center; transition: border-color .2s, background .2s; cursor: pointer; }
.cat-card:hover { border-color: var(--text); background: var(--bg-secondary); }
.cat-card-name { font-size: 14px; font-weight: 700; margin-bottom: 6px; line-height: 1.4; }
.cat-card-count { font-size: 12px; color: var(--text-secondary); }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .level-tabs { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
  .level-tabs::-webkit-scrollbar { display: none; }
  .level-tab { flex-shrink: 0; }
}