/* ============================================================
   毕设题目参考专栏样式（配合 css/styles.css 使用）
   ============================================================ */

.nav-links a.active { color: #fff; }
.nav-links a.active::after { width: 100%; }

.thesis-hero { min-height: 52vh; }

.thesis-hero .hero-badge { margin-bottom: var(--sp-md); }

.thesis-hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-xl);
  margin-top: var(--sp-lg);
}
.thesis-hero-stats .hero-stat-number { font-size: 34px; font-weight: 900; }
.thesis-hero-stats .hero-stat-label { font-size: 13px; color: var(--c-text-muted); }

/* ──────────── 工具栏 ──────────── */
.thesis-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-md);
  margin: var(--sp-lg) 0 var(--sp-md);
}

.thesis-search {
  position: relative;
  flex: 1 1 380px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: 999px;
  transition: border-color 0.25s, background 0.25s;
}
.thesis-search:focus-within {
  border-color: rgba(56, 189, 248, 0.55);
  background: var(--c-bg-card-hover);
}
.thesis-search svg { width: 18px; height: 18px; color: var(--c-text-muted); flex: none; }
.thesis-search input {
  flex: 1;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: 15px;
}
.thesis-search input::placeholder { color: rgba(148, 163, 184, 0.75); }

.thesis-toolbar-meta {
  display: flex;
  align-items: center;
  gap: var(--sp-md);
  font-size: 14px;
  color: var(--c-text-muted);
}
.thesis-reset {
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px solid var(--c-border);
  background: transparent;
  color: var(--c-text-muted);
  font-family: var(--font-sans);
  font-size: 13px;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s;
}
.thesis-reset:hover { color: #fff; border-color: rgba(56, 189, 248, 0.5); }

/* ──────────── 方向筛选 ──────────── */
.thesis-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: var(--sp-lg);
}
.thesis-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--c-border);
  background: var(--c-bg-card);
  color: var(--c-text-muted);
  font-family: var(--font-sans);
  font-size: 13px;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s, transform 0.2s var(--ease-out-expo);
}
.thesis-chip:hover { color: var(--c-text); transform: translateY(-1px); }
.thesis-chip.active {
  color: #041018;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  border-color: transparent;
  font-weight: 600;
}
.thesis-chip-num {
  padding: 1px 7px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.18);
  font-size: 11px;
  font-family: var(--font-mono);
}
.thesis-chip.active .thesis-chip-num { background: rgba(4, 16, 24, 0.18); }

/* ──────────── 题目卡片 ──────────── */
.thesis-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--sp-md);
}

.thesis-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 20px 16px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  background: var(--c-bg-card);
  cursor: pointer;
  transition: transform 0.35s var(--ease-out-expo), border-color 0.25s, background 0.25s;
}
.thesis-card:hover {
  transform: translateY(-4px);
  border-color: rgba(56, 189, 248, 0.4);
  background: var(--c-bg-card-hover);
}
.thesis-card.copied { border-color: rgba(56, 189, 248, 0.75); }

.thesis-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-sm);
}
.thesis-card-cat {
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--c-primary);
  text-transform: none;
}
.thesis-card-no {
  font-family: var(--font-mono);
  font-size: 11px;
  color: rgba(148, 163, 184, 0.7);
}

.thesis-card-title {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-text);
}

.thesis-card-stack {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-muted);
}

.thesis-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
  padding-top: 4px;
}
.thesis-tag {
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--c-border);
  background: rgba(56, 189, 248, 0.07);
  color: #cbd5e1;
  font-size: 11px;
}

.thesis-card-copy {
  font-size: 11px;
  color: rgba(148, 163, 184, 0.55);
  opacity: 0;
  transition: opacity 0.25s;
}
.thesis-card:hover .thesis-card-copy,
.thesis-card.copied .thesis-card-copy { opacity: 1; }
.thesis-card.copied .thesis-card-copy { color: var(--c-primary); }

.thesis-empty {
  padding: var(--sp-xl) var(--sp-md);
  text-align: center;
  color: var(--c-text-muted);
  border: 1px dashed var(--c-border);
  border-radius: var(--r-md);
}

.thesis-more-wrap {
  display: flex;
  justify-content: center;
  margin-top: var(--sp-lg);
}

/* ──────────── 选题建议 ──────────── */
.thesis-tips { background: var(--c-surface); }
.thesis-tip-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--sp-md);
  margin-top: var(--sp-lg);
}
.thesis-tip-card {
  padding: 24px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  background: var(--c-bg-card);
}
.thesis-tip-card h3 {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--c-text);
}
.thesis-tip-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text-muted);
}

.thesis-disclaimer {
  margin-top: var(--sp-lg);
  font-size: 12px;
  color: rgba(148, 163, 184, 0.65);
}

/* ──────────── 响应式 ──────────── */
@media (max-width: 768px) {
  .thesis-hero-stats { gap: var(--sp-lg); }
  .thesis-toolbar { flex-direction: column; align-items: stretch; }
  .thesis-toolbar-meta { justify-content: space-between; }
  .thesis-grid { grid-template-columns: 1fr; }
}

/* ─────────── 方向分区块（默认视图） ─────────── */
.thesis-grid--grouped {
  display: block;
}

.thesis-cat-block + .thesis-cat-block {
  margin-top: 48px;
  padding-top: 40px;
  border-top: 1px solid var(--c-border);
}

.thesis-cat-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 20px;
}
.thesis-cat-heading {
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.thesis-cat-name {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.thesis-cat-count {
  font-size: 13px;
  color: var(--c-text-muted);
}
.thesis-cat-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.thesis-cat-expand,
.thesis-cat-all {
  padding: 7px 14px;
  font-size: 13px;
  color: var(--c-text-muted);
  background: transparent;
  border: 1px solid var(--c-border);
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.25s, border-color 0.25s, background 0.25s;
}
.thesis-cat-expand:hover,
.thesis-cat-all:hover {
  color: #fff;
  border-color: rgba(56, 189, 248, 0.45);
  background: rgba(56, 189, 248, 0.08);
}

.thesis-cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 18px;
}

@media (max-width: 768px) {
  .thesis-cat-block + .thesis-cat-block { margin-top: 32px; padding-top: 28px; }
  .thesis-cat-name { font-size: 18px; }
  .thesis-cat-grid { grid-template-columns: 1fr; }
}

.thesis-wechat-tip {
  margin-top: 16px;
  font-size: 14px;
  color: var(--c-primary);
}