:root {
  --bg: #faf9f7;
  --text: #1a1a1a;
  --muted: #6b6b6b;
  --accent: #e2482e;
  --link: #1d5fa8;
  --card: #ffffff;
  --border: #e5e2dc;
}
html[data-theme="dark"] {
  --bg: #161513;
  --text: #ece9e2;
  --muted: #a3a099;
  --accent: #ff6a4d;
  --link: #7db4f0;
  --card: #201e1b;
  --border: #35322c;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: transparent;
  color: var(--text);
  font-family: "Songti SC", "Noto Serif SC", "STSong", serif;
  line-height: 1.8;
  transition: background .25s, color .25s;
}

/* 全屏固定雪山背景图 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background: url('bg.jpg') center 30% / cover no-repeat;
}
/* 半透明罩：顶部渐变变透，让雪山透出来；下方加深，保证文字清晰可读 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background: linear-gradient(rgba(250, 249, 247, 0.28) 0%, rgba(250, 249, 247, 0.85) 34%);
  pointer-events: none;
}
html[data-theme="dark"] body::after {
  background: linear-gradient(rgba(22, 21, 19, 0.28) 0%, rgba(22, 21, 19, 0.85) 34%);
}

.wrap { max-width: 760px; margin: 0 auto; padding: 0 20px; }

.hidden { display: none !important; }

.site-header {
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0;
  background: transparent;
  z-index: 10;
}
html[data-theme="dark"] .site-header {
  background: transparent;
}

.header-inner {
  display: flex; flex-direction: column; align-items: center;
  padding: 14px 20px 10px; gap: 6px;
  position: relative;
}
.header-tools {
  position: absolute; top: 6px; right: 8px;
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  z-index: 50;
}
.gear-btn svg { display: block; }
html[data-theme="dark"] .gear-btn svg .gear-fill { fill: #e8e8e8; }

.brand {
  font-weight: 800; font-size: 1.7rem; text-decoration: none;
  background: linear-gradient(90deg, #ff5f6d, #ff9f43, #feca57, #1dd1a1, #54a0ff, #a55eea, #ff5f6d);
  background-size: 200% auto;
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
  animation: rainbow-flow 5s linear infinite;
}

@keyframes rainbow-flow {
  to { background-position: 200% center; }
}

.rainbow-text {
  font-weight: 800;
  background: linear-gradient(90deg, #ff5f6d, #ff9f43, #feca57, #1dd1a1, #54a0ff, #a55eea, #ff5f6d);
  background-size: 200% auto;
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
  animation: rainbow-flow 5s linear infinite;
}

.main-nav { display: flex; align-items: center; gap: 18px; }

.main-nav a { color: var(--text); text-decoration: none; font-size: .95rem; }

.main-nav a:hover { color: var(--accent); }

.main-nav a { display: inline-flex; align-items: center; }
.main-nav a svg { width: 26px; height: 26px; display: block; }

.icon-btn {
  background: none; border: none; cursor: pointer;
  font-size: 1.1rem; padding: 4px;
}

.search-bar { padding: 10px 20px 14px; }

.search-bar input {
  width: 100%; padding: 10px 14px; font-size: 1rem;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--card); color: var(--text);
}

.section-head {
  display: flex; align-items: baseline; justify-content: space-between;
  border-top: 2px solid var(--text);
  padding-top: 18px; margin-top: 10px; flex-wrap: wrap; gap: 10px;
}

.section-head h2 { margin: 0; font-size: 1.6rem; }

.cats { display: flex; gap: 8px; flex-wrap: wrap; }

.cat-btn {
  border: 1px solid var(--border); background: var(--card); color: var(--text);
  border-radius: 999px; padding: 4px 14px; cursor: pointer; font-size: .85rem;
}

.cat-btn.active { background: var(--text); color: var(--bg); border-color: var(--text); }

.post-list { margin: 8px 0 40px; }

.post-card {
  display: block; padding: 22px 0; border-bottom: 1px solid var(--border);
  text-decoration: none; color: inherit; cursor: pointer;
}

.post-card:hover .post-card-title { color: var(--accent); }

.post-card-cat { color: var(--link); font-size: .85rem; margin: 0 0 8px; }

.post-card-title { font-size: 1.45rem; margin: 0 0 8px; line-height: 1.5; }

.post-card-excerpt { color: var(--muted); margin: 0 0 6px; font-size: .95rem; }

.post-card-date { color: var(--muted); font-size: .82rem; margin: 0; }

.empty { color: var(--muted); padding: 30px 0; }

.back { color: var(--link); text-decoration: none; font-size: .9rem; }

.post-full { padding: 24px 0 50px; }

.post-meta { color: var(--link); font-size: .9rem; margin: 0 0 10px; }

.post-full h1 { font-size: clamp(1.8rem, 6vw, 2.6rem); line-height: 1.4; margin: 0 0 26px; }

.post-body { font-size: 1.06rem; }

.post-body p { margin: 0 0 1.2em; }

.post-body .demo-note {
  border-left: 3px solid var(--accent);
  background: var(--card);
  padding: 10px 16px; color: var(--muted); font-size: .9rem;
}

#view-about h1 { font-size: 2.2rem; margin: 40px 0 20px; }

#view-about { padding-bottom: 60px; }


.site-footer {
  border-top: 1px solid var(--border);
  padding: 26px 0; color: var(--muted); font-size: .85rem;
  text-align: center;
}

.site-footer p { margin: 0; }

.footer-line { font-size: 1.05rem; } .brand-row { display: flex; align-items: center; gap: 10px; } .brand-logo { width: 46px; height: 46px; border-radius: 50%; object-fit: cover; }

.pen-link { position: absolute; top: 12px; left: 16px; font-size: 1.35rem; text-decoration: none; z-index: 20; }