.study-page-main { max-width: 60rem; margin: 0 auto; padding: clamp(2rem, 5vw, 3rem) clamp(1.25rem, 4vw, 2rem) 4rem; }
.study-page-main h1 { font-family: var(--font-serif); font-size: clamp(1.4rem, 3.5vw, 1.85rem); margin: 0 0 0.5rem; letter-spacing: 0.06em; }
.study-page-lead { color: var(--ink-muted); margin: 0 0 2rem; line-height: 1.7; font-size: 0.95rem; }

/* 三才分类 */
.study-section {
  margin-bottom: 3rem;
  padding: 2rem;
  background: var(--bg-card);
  border-radius: 16px;
  border: 1px solid rgba(26,26,26,0.06);
}
.study-section h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.2rem, 3vw, 1.5rem);
  margin: 0 0 1.5rem;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.study-section h2::before {
  content: '';
  width: 4px;
  height: 24px;
  border-radius: 2px;
}
.study-section:nth-child(4) h2::before { background: #b79f18; } /* 天·时 */
.study-section:nth-child(5) h2::before { background: #2a3a85; } /* 地·势 */
.study-section:nth-child(6) h2::before { background: #1a6c1a; } /* 人·和 */

/* 视频列表 */
.study-video-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 1rem; }
.video-item {
  position: relative;
}
.video-link {
  display: block; padding: 1.1rem 1.25rem; background: var(--bg-paper); border: 1px solid rgba(26,26,26,0.08);
  border-radius: 12px; text-decoration: none; color: var(--ink); transition: box-shadow 0.2s, border-color 0.2s;
  border-left: 4px solid #00A1D6;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.video-link:hover { box-shadow: 0 8px 24px rgba(26,26,26,0.08); border-color: rgba(0,161,214,0.35); }
.video-info strong { display: block; font-size: 1rem; margin-bottom: 0.35rem; font-family: var(--font-serif); }
.video-info span { font-size: 0.82rem; color: var(--ink-muted); }

/* 营造秘籍 */
.secret-icon {
  width: 32px;
  height: 32px;
  background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="10"/><path d="M12 6v6l4 2"/></svg>') no-repeat center;
  cursor: pointer;
  opacity: 0.6;
  transition: opacity 0.2s;
}
.secret-icon:hover {
  opacity: 1;
}
.secret-popup {
  position: absolute;
  right: 0;
  top: 100%;
  margin-top: 0.5rem;
  width: 300px;
  background: var(--bg-paper);
  border: 1px solid rgba(26,26,26,0.1);
  border-radius: 12px;
  padding: 1.25rem;
  box-shadow: 0 8px 24px rgba(26,26,26,0.12);
  z-index: 100;
  display: none;
}
.secret-popup.show {
  display: block;
  animation: fadeIn 0.3s ease-out;
}
.secret-popup h4 {
  margin: 0 0 0.75rem;
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--c-government);
}
.secret-popup p {
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--ink);
}
.secret-popup::before {
  content: '';
  position: absolute;
  top: -8px;
  right: 12px;
  width: 16px;
  height: 16px;
  background: var(--bg-paper);
  border-top: 1px solid rgba(26,26,26,0.1);
  border-left: 1px solid rgba(26,26,26,0.1);
  transform: rotate(45deg);
}

.study-back { display: inline-block; margin-bottom: 1.25rem; font-size: 0.88rem; color: var(--c-government); }
.study-back:hover { color: var(--c-palace); }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}