/* ===== 极简风 / 设计变量 ===== */
:root {
  --bg: #ffffff;
  --bg-soft: #fafafa;
  --text: #111111;
  --text-soft: #6b6b6b;
  --text-faint: #9a9a9a;
  --border: #ececec;
  --accent: #2f6feb;
  --maxw: 720px;
  --sans: "Segoe UI", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --ease: ease;
}

[data-theme="dark"] {
  --bg: #0b0b0c;
  --bg-soft: #121214;
  --text: #ededed;
  --text-soft: #9a9a9a;
  --text-faint: #5f5f5f;
  --border: #232326;
  --accent: #6f9bff;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 64px; }
body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s, color 0.3s;
}
a { color: inherit; text-decoration: none; }

/* ===== 导航 ===== */
.nav { position: fixed; inset: 0 0 auto 0; z-index: 50; background: color-mix(in srgb, var(--bg) 85%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.nav__inner { max-width: var(--maxw); margin: 0 auto; padding: 14px 24px; display: flex; align-items: center; justify-content: space-between; }
.nav__brand { font-weight: 600; font-size: 16px; letter-spacing: 0.5px; }
.nav__links { display: flex; gap: 24px; }
.nav__links a { color: var(--text-soft); font-size: 14px; transition: color 0.2s; }
.nav__links a:hover { color: var(--text); }
.theme-toggle { width: 34px; height: 34px; border: 0; background: none; color: var(--text-soft); cursor: pointer; display: grid; place-items: center; transition: color 0.2s; }
.theme-toggle:hover { color: var(--text); }
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }
.nav__burger { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav__burger span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; }

/* ===== Hero ===== */
.hero { max-width: var(--maxw); margin: 0 auto; padding: 150px 24px 70px; }
.hero__label { font-size: 13px; letter-spacing: 1px; color: var(--text-faint); margin-bottom: 16px; }
.hero__title { font-size: clamp(40px, 8vw, 64px); font-weight: 600; letter-spacing: -0.5px; line-height: 1.05; }
.hero__lead { color: var(--text-soft); max-width: 540px; margin-top: 22px; }
.hero__links { margin-top: 28px; display: flex; gap: 22px; }
.hero__links a { color: var(--accent); font-size: 15px; font-weight: 500; }
.hero__links a:hover { text-decoration: underline; }

/* ===== 通用 section ===== */
.section { max-width: var(--maxw); margin: 0 auto; padding: 54px 24px; }
.section__title { font-size: 15px; font-weight: 600; letter-spacing: 1px; text-transform: uppercase; color: var(--text-faint); margin-bottom: 26px; padding-bottom: 14px; border-bottom: 1px solid var(--border); }
.section__count { font-weight: 400; letter-spacing: 0; text-transform: none; margin-left: 8px; }

/* ===== 关于 ===== */
.about p { color: var(--text-soft); margin-bottom: 16px; }
.about__meta { font-size: 14px; color: var(--text-faint) !important; }

/* ===== 文章列表 ===== */
.posts { display: flex; flex-direction: column; }
.post { display: block; padding: 20px 0; border-bottom: 1px solid var(--border); transition: opacity 0.2s; }
.post:hover { opacity: 0.65; }
.post__meta { font-size: 12px; letter-spacing: 0.5px; color: var(--text-faint); text-transform: uppercase; }
.post__title { font-size: 19px; font-weight: 500; margin-top: 6px; line-height: 1.4; }
.post__excerpt { color: var(--text-soft); font-size: 14px; margin-top: 6px; }

/* ===== 文章分类筛选 ===== */
.posts-filter { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.filter-pill {
  font: inherit;
  font-size: 13px;
  color: var(--text-soft);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 14px;
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.filter-pill:hover { color: var(--text); }
.filter-pill.active { color: #fff; background: var(--accent); border-color: var(--accent); }

/* ===== 项目 ===== */
.projects { display: flex; flex-direction: column; gap: 28px; }
.project h3 { font-size: 18px; font-weight: 500; display: flex; align-items: baseline; gap: 10px; }
.project__stars { font-size: 12px; color: var(--text-faint); font-weight: 400; }
.project p { color: var(--text-soft); font-size: 14px; margin: 8px 0 12px; }
.project__tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 10px; }
.project__tags span { font-size: 12px; color: var(--text-faint); }
.project__link { color: var(--accent); font-size: 14px; font-weight: 500; }
.project__link:hover { text-decoration: underline; }

/* ===== 联系 ===== */
.section--contact { text-align: left; }
.contact__lead { color: var(--text-soft); margin-bottom: 16px; }
.contact__mail { font-size: clamp(20px, 4vw, 28px); font-weight: 600; color: var(--accent); border-bottom: 1px solid transparent; transition: border-color 0.2s; }
.contact__mail:hover { border-color: var(--accent); }
.contact__socials { margin-top: 22px; display: flex; gap: 22px; }
.contact__socials a { color: var(--text-soft); font-size: 14px; font-weight: 500; }
.contact__socials a:hover { color: var(--text); }

/* ===== 页脚 ===== */
.footer { max-width: var(--maxw); margin: 0 auto; padding: 40px 24px; border-top: 1px solid var(--border); color: var(--text-faint); font-size: 13px; }

/* ===== 滚动出现动画（极轻） ===== */
.reveal { opacity: 0; transform: translateY(10px); transition: opacity 0.6s var(--ease), transform 0.6s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 640px) {
  .hero { padding-top: 120px; }
  .nav__links { position: fixed; inset: 57px 0 auto 0; flex-direction: column; gap: 0; background: var(--bg-soft); border-bottom: 1px solid var(--border); padding: 8px 24px 16px; transform: translateY(-120%); transition: transform 0.3s var(--ease); }
  .nav__links.open { transform: translateY(0); }
  .nav__links a { padding: 13px 0; border-bottom: 1px solid var(--border); }
  .nav__burger { display: flex; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}