/* =========================================================
   cuijiawei.cn — personal site + blog
   Design system: editorial, calm, light/dark aware
   ========================================================= */

:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --bg-card: #ffffff;
  --text: #1a1d21;
  --text-soft: #5b626b;
  --text-faint: #8b929c;
  --border: #e7e9ee;
  --accent: #2a7ae2;
  --accent-2: #6d5efc;
  --accent-soft: #eaf1fc;
  --code-bg: #f4f5f7;
  --code-text: #c7254e;
  --shadow: 0 1px 2px rgba(16,24,40,.04), 0 8px 24px rgba(16,24,40,.06);
  --shadow-lg: 0 12px 40px rgba(16,24,40,.10);
  --radius: 14px;
  --radius-sm: 9px;
  --maxw: 1080px;
  --readw: 720px;
  --navh: 64px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --font-serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --font-head: var(--font-sans);
}

[data-theme="dark"] {
  --bg: #0f1115;
  --bg-soft: #161a20;
  --bg-card: #171b22;
  --text: #e7eaee;
  --text-soft: #aab2bd;
  --text-faint: #6c7682;
  --border: #262c35;
  --accent: #5b9bff;
  --accent-2: #9b8cff;
  --accent-soft: #16243a;
  --code-bg: #1b2027;
  --code-text: #ff8aa6;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.35);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.5);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background .25s ease, color .25s ease;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 { font-family: var(--font-head); }

img { max-width: 100%; height: auto; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.read { max-width: var(--readw); margin: 0 auto; padding: 0 24px; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  height: var(--navh);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { height: 100%; display: flex; align-items: center; gap: 18px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--text); font-size: 1.05rem; }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.nav-links { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav-links a {
  color: var(--text-soft); padding: 8px 12px; border-radius: 8px; font-weight: 500; font-size: .95rem;
}
.nav-links a:hover { background: var(--bg-soft); color: var(--text); text-decoration: none; }
.nav-links a.active { color: var(--accent); }
.theme-btn {
  margin-left: 6px; width: 38px; height: 38px; border-radius: 9px; border: 1px solid var(--border);
  background: var(--bg-soft); color: var(--text); cursor: pointer; font-size: 1.05rem; display: grid; place-items: center;
}
.theme-btn:hover { border-color: var(--accent); }
.nav-toggle { display: none; }

/* ---------- Hero ---------- */
.hero { padding: 84px 0 56px; }
.hero-eyebrow { color: var(--accent); font-weight: 700; font-size: .85rem; text-transform: uppercase; letter-spacing: .12em; margin-bottom: 10px; }
.hero-grid { display: grid; grid-template-columns: 132px 1fr; gap: 34px; align-items: center; }
.avatar { width: 132px; height: 132px; border-radius: 26px; box-shadow: var(--shadow-lg); }
.hero h1 { font-size: clamp(2.1rem, 5vw, 3.1rem); line-height: 1.08; margin: 0 0 14px; letter-spacing: -.02em; }
.hero .tag { font-size: 1.18rem; color: var(--text-soft); margin: 0 0 18px; max-width: 36ch; }
.hero .lede { color: var(--text-soft); margin: 0 0 26px; max-width: 52ch; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 11px 18px; border-radius: 10px;
  font-weight: 600; font-size: .96rem; border: 1px solid transparent; cursor: pointer;
}
.btn-primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff; box-shadow: var(--shadow); }
.btn-primary:hover { text-decoration: none; filter: brightness(1.05); }
.btn-ghost { background: var(--bg-soft); color: var(--text); border-color: var(--border); }
.btn-ghost:hover { text-decoration: none; border-color: var(--accent); }

/* ---------- Sections ---------- */
.section { padding: 46px 0; }
.section h2 { font-size: 1.6rem; letter-spacing: -.01em; margin: 0 0 6px; }
.section .eyebrow { color: var(--accent); font-weight: 700; font-size: .82rem; text-transform: uppercase; letter-spacing: .08em; margin-bottom: 6px; }
.section .sub { color: var(--text-soft); margin: 0 0 28px; }

/* cards */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 18px; }
.card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px; box-shadow: var(--shadow); transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.card h3 { margin: 0 0 8px; font-size: 1.12rem; }
.card p { margin: 0 0 14px; color: var(--text-soft); font-size: .95rem; }
.card .meta { font-size: .82rem; color: var(--text-faint); }
.card a.more { font-weight: 600; font-size: .9rem; }

/* projects */
.project { display: flex; gap: 16px; align-items: flex-start; padding: 18px 0; border-bottom: 1px solid var(--border); }
.project:last-child { border-bottom: 0; }
.project .pico { width: 44px; height: 44px; border-radius: 11px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-weight: 800; flex: 0 0 44px; }
.project h3 { margin: 0 0 4px; font-size: 1.08rem; }
.project h3 a { color: var(--text); }
.project p { margin: 0; color: var(--text-soft); font-size: .94rem; }

/* recent writing list */
.writing { display: flex; flex-direction: column; }
.wrow { display: flex; gap: 18px; align-items: baseline; padding: 14px 0; border-bottom: 1px solid var(--border); }
.wrow:last-child { border-bottom: 0; }
.wrow .date { color: var(--text-faint); font-size: .85rem; flex: 0 0 92px; font-variant-numeric: tabular-nums; }
.wrow a { color: var(--text); font-weight: 600; }
.wrow a:hover { color: var(--accent); text-decoration: none; }

/* ---------- Blog index ---------- */
.blog-head { padding: 56px 0 8px; }
.blog-head h1 { font-size: 2.2rem; margin: 0 0 8px; letter-spacing: -.02em; }
.blog-head p { color: var(--text-soft); margin: 0; }
.tagbar { display: flex; flex-wrap: wrap; gap: 8px; padding: 26px 0 8px; }
.chip {
  border: 1px solid var(--border); background: var(--bg-soft); color: var(--text-soft);
  padding: 5px 12px; border-radius: 999px; font-size: .85rem; cursor: pointer; font-weight: 500;
}
.chip:hover { border-color: var(--accent); color: var(--text); }
.chip.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.post-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 18px; padding: 22px 0 40px; }
.post-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden;
  display: flex; flex-direction: column; box-shadow: var(--shadow); transition: transform .15s ease, box-shadow .15s ease;
}
.post-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.post-card .pc-body { padding: 20px; display: flex; flex-direction: column; flex: 1; }
.post-card h3 { margin: 0 0 8px; font-size: 1.14rem; line-height: 1.3; }
.post-card h3 a { color: var(--text); }
.post-card h3 a:hover { color: var(--accent); text-decoration: none; }
.post-card .ex { color: var(--text-soft); font-size: .92rem; margin: 0 0 16px; flex: 1; }
.post-card .pc-foot { display: flex; justify-content: space-between; align-items: center; font-size: .82rem; color: var(--text-faint); }
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.tag { font-size: .76rem; color: var(--accent); background: var(--accent-soft); padding: 2px 9px; border-radius: 999px; }

/* ---------- Article ---------- */
.article { padding: 52px 0 40px; }
.article .a-head { margin-bottom: 26px; }
.article .a-meta { color: var(--text-faint); font-size: .9rem; margin-bottom: 14px; display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.article h1 { font-size: clamp(1.9rem, 4vw, 2.7rem); line-height: 1.12; letter-spacing: -.02em; margin: 0 0 14px; }
.article .a-lede { font-size: 1.18rem; color: var(--text-soft); margin: 0 0 8px; font-family: var(--font-serif); }
.content { font-size: 1.06rem; }
.content h2 { font-size: 1.5rem; margin: 2.1em 0 .6em; letter-spacing: -.01em; }
.content h3 { font-size: 1.22rem; margin: 1.7em 0 .5em; }
.content p { margin: 1.05em 0; }
.content ul, .content ol { padding-left: 1.4em; margin: 1.05em 0; }
.content li { margin: .4em 0; }
.content blockquote {
  margin: 1.4em 0; padding: 4px 20px; border-left: 3px solid var(--accent); color: var(--text-soft); font-style: italic;
}
.content code {
  font-family: var(--font-mono); font-size: .88em; background: var(--code-bg); color: var(--code-text);
  padding: .15em .4em; border-radius: 5px;
}
.content pre {
  background: var(--code-bg); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 16px 18px; overflow-x: auto; margin: 1.4em 0; line-height: 1.55;
}
.content pre code { background: none; color: var(--text); padding: 0; font-size: .86rem; }
.content table { border-collapse: collapse; width: 100%; margin: 1.4em 0; font-size: .95rem; }
.content th, .content td { border: 1px solid var(--border); padding: 9px 12px; text-align: left; }
.content th { background: var(--bg-soft); }
.content img { border-radius: var(--radius-sm); margin: 1.2em 0; }
.content hr { border: 0; border-top: 1px solid var(--border); margin: 2.2em 0; }
.content a { text-decoration: underline; text-underline-offset: 2px; }

.a-foot { margin-top: 40px; padding-top: 22px; border-top: 1px solid var(--border); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.a-foot a { font-weight: 600; }

/* ---------- About (homepage) ---------- */
.about-home { padding-top: 26px; }
.about-wrap { max-width: 760px; margin: 0 auto; }
.about-section { margin: 2.2em 0; }
.about-section h2 { font-size: 1.4rem; margin: 0 0 .6em; border-bottom: 1px solid var(--border); padding-bottom: .3em; }

/* "What I'm doing now" highlight callout */
.now-box {
  margin: 1.8em 0 .4em; padding: 20px 22px; border-radius: var(--radius);
  background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 32%, var(--border));
}
.now-box h2 { border-bottom: 0 !important; padding-bottom: 0 !important; margin-top: 0 !important; color: var(--accent); }
.now-box p:last-child { margin-bottom: 0; }

/* CV card layout (preserved from the original About page) */
.cv { margin: 6px 0 20px; }
.cv-item { display: flex; align-items: center; gap: 16px; margin: 16px 0; }
.cv-logo {
  width: 64px; flex: 0 0 64px; height: 64px; display: flex; align-items: center; justify-content: center;
  background: #fff; border-radius: 12px; padding: 7px; box-shadow: 0 1px 3px rgba(16,24,40,.12);
}
.cv-logo img { max-height: 100%; max-width: 100%; width: auto; height: auto; object-fit: contain; }
/* Wide wordmark logos (e.g. Tencent) keep the same chip width as square logos */
.cv-logo--wide { width: 64px; flex-basis: 64px; }
.cv-body { flex: 1; min-width: 0; }
.cv-row { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
.cv-title { font-weight: 700; font-size: 1.04rem; line-height: 1.25; color: var(--text); text-decoration: none; }
a.cv-title:hover { text-decoration: underline; color: var(--accent); }
.cv-date { color: var(--text-faint); font-size: .84rem; white-space: nowrap; font-variant-numeric: tabular-nums; }
.cv-sub { color: var(--text-soft); font-size: .94rem; line-height: 1.4; margin-top: 3px; }
.cv-sub a { color: var(--accent); text-decoration: none; }
.cv-sub a:hover { text-decoration: underline; }

.patents, .patents ul { list-style: none; padding: 0; margin: 6px 0 18px; }
.patents li { padding: 6px 0 6px 1.2em; position: relative; color: var(--text-soft); font-size: .95rem; }
.patents li::before { content: "▪"; position: absolute; left: 0; top: 6px; color: var(--accent); }
.patents li a { color: var(--text); text-decoration: none; }
.patents li a:hover { color: var(--accent); text-decoration: underline; }

@media (max-width: 600px) {
  .cv-item { gap: 12px; }
  .cv-logo { width: 52px; flex-basis: 52px; height: 52px; }
  .cv-logo--wide { width: 52px; flex-basis: 52px; }
  .cv-row { flex-direction: column; align-items: flex-start; gap: 2px; }
  .cv-date { font-size: .8rem; }
}

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); padding: 40px 0 56px; margin-top: 40px; color: var(--text-soft); }
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 18px; align-items: center; }
.footer .social { display: flex; gap: 14px; }
.footer .social a { color: var(--text-soft); font-weight: 600; }
.footer .social a:hover { color: var(--accent); }
.footer .copy { font-size: .86rem; color: var(--text-faint); }

/* ---------- Responsive ---------- */
@media (max-width: 760px) {
  body { font-size: 16px; }
  .hero-grid { grid-template-columns: 1fr; text-align: center; justify-items: center; }
  .hero .lede, .hero .tag { margin-left: auto; margin-right: auto; }
  .cta-row { justify-content: center; }
  .nav-links { display: none; position: absolute; top: var(--navh); left: 0; right: 0; flex-direction: column; align-items: stretch;
    background: var(--bg); border-bottom: 1px solid var(--border); padding: 8px 16px 16px; gap: 2px; }
  .nav-links.open { display: flex; }
  .nav-toggle { display: grid; place-items: center; margin-left: auto; width: 40px; height: 40px; border: 1px solid var(--border);
    background: var(--bg-soft); border-radius: 9px; cursor: pointer; color: var(--text); font-size: 1.2rem; }
  .theme-btn { margin-left: 0; }
  .wrow { flex-direction: column; gap: 2px; }
  .wrow .date { flex-basis: auto; }
}