/* ===== 学虎教育 · 学习门户 ===== */
.portal-page { padding-top: 24px; }

/* ===== 大类 Tab ===== */
.portal-tabs {
  display: flex;
  gap: 10px;
  margin: 24px 0 18px;
}
.portal-tab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 28px;
  border: 1.5px solid var(--line);
  border-radius: 14px;
  background: var(--card-bg);
  color: var(--text-2);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.portal-tab svg { width: 19px; height: 19px; }
.portal-tab:hover { border-color: var(--brand-blue); color: var(--brand-blue); }
.portal-tab.active {
  background: linear-gradient(135deg, #2d6bff, #4d8dff);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 10px 24px rgba(45, 107, 255, 0.3);
}

/* ===== 学科 / 年级 ===== */
.portal-filter {
  margin-bottom: 18px;
}
.portal-filter-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-3);
  letter-spacing: 1px;
  margin-bottom: 8px;
  text-transform: uppercase;
}

/* 学科：分段控件（主层级） */
.portal-subjects {
  display: inline-flex;
  flex-wrap: nowrap;
  gap: 4px;
  padding: 5px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.45);
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  border: 1px solid rgba(255, 255, 255, 0.6);
  box-shadow: 0 4px 16px rgba(24, 80, 150, 0.08), inset 0 1px 0 rgba(255,255,255,0.6);
}
.portal-subjects .pill {
  padding: 9px 22px;
  border: none;
  border-radius: 12px;
  background: transparent;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  white-space: nowrap;
}
.portal-subjects .pill:hover { color: var(--brand-blue); }
.portal-subjects .pill.active {
  background: #fff;
  color: var(--brand-blue);
  box-shadow: 0 3px 12px rgba(24, 80, 150, 0.15);
}

/* 年级：次级 pill（子层级） */
.portal-grades {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 10px;
  margin-bottom: 12px;
}
.portal-grades .pill {
  padding: 6px 14px;
  border: 1px solid rgba(45, 107, 255, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.5);
  color: var(--text-3);
  font-size: 12.5px;
}
.portal-grades .pill:hover { border-color: var(--brand-blue); color: var(--brand-blue); }
.portal-grades .pill.active {
  background: var(--brand-blue);
  border-color: var(--brand-blue);
  color: #fff;
  box-shadow: 0 4px 12px rgba(24, 134, 253, 0.25);
}
.grade-detail-row {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  width: 100%;
  padding: 8px 0 0 18px;
  border-left: 2px solid rgba(45, 107, 255, 0.18);
}

/* 基础 pill（其他页面沿用） */
.pill {
  padding: 7px 18px;
  border: 1px solid rgba(255, 255, 255, 0.75);
  border-radius: 999px;
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.68), rgba(255, 255, 255, 0.32));
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  color: var(--text-2);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.18s;
}
.pill:hover { border-color: var(--brand-blue); color: var(--brand-blue); }
.pill.active {
  background: var(--brand-blue);
  border-color: var(--brand-blue);
  color: #fff;
  box-shadow: 0 5px 14px rgba(24, 134, 253, 0.28);
}
.pill.disabled { opacity: 0.4; pointer-events: none; }

/* ===== 内容网格 ===== */
.portal-grid { margin-top: 20px; }
.portal-card {
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.72), rgba(255, 255, 255, 0.38));
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: var(--glass-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow), var(--glass-highlight);
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
}
.portal-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.portal-card .thumb-wrap {
  position: relative;
  aspect-ratio: 16 / 10;
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.5), rgba(220, 235, 255, 0.35));
  overflow: hidden;
  border-bottom: 1px solid rgba(255, 255, 255, 0.5);
}
.portal-card .thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s;
}
.portal-card:hover .thumb { transform: scale(1.05); }
.portal-card .thumb-fallback {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 34px;
  color: #9db8d8;
}
.portal-card .card-body { padding: 12px 14px 14px; display: flex; flex-direction: column; gap: 6px; flex: 1; }
.portal-card .card-title {
  font-size: 14.5px;
  font-weight: 600;
  line-height: 1.45;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.portal-card .card-meta {
  margin-top: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 11.5px;
  color: var(--text-3);
}
.portal-card .card-tag {
  padding: 2px 9px;
  border-radius: 6px;
  background: var(--brand-blue-soft);
  color: var(--brand-blue-deep);
  font-size: 11px;
}
.portal-card .card-tag.orange { background: var(--brand-orange-soft); color: #d97100; }

@media (max-width: 480px) {
  .portal-tab { padding: 9px 18px; font-size: 14px; }
}

/* ===== 探索平台 ===== */
.card-desc {
  font-size: 12.5px;
  color: var(--text-2);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ===== 加载更多 ===== */
.load-more-btn {
  display: block;
  margin: 26px auto 6px;
  padding: 11px 34px;
  border: 1.5px solid rgba(45, 107, 255, 0.28);
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.92), rgba(240, 247, 255, 0.92));
  color: var(--brand-blue-deep);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(45, 107, 255, 0.12);
  transition: transform 0.2s, box-shadow 0.2s;
}
.load-more-btn:hover { transform: translateY(-1px); box-shadow: 0 8px 20px rgba(45, 107, 255, 0.2); }
.load-more-btn[hidden] { display: none; }