/* ============================================================
   ailexc · personal site
   简洁明亮 / 深浅色自适应 / 无外部依赖
   ============================================================ */

:root {
  --bg: #fbfbfd;
  --bg-soft: #f3f4f8;
  --surface: #ffffff;
  --text: #12141a;
  --text-2: #4b5563;
  --muted: #6b7280;
  --border: #e6e8ef;
  --accent: #3155f5;
  --accent-2: #6d8bff;
  --accent-soft: #eef2ff;
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 12px 32px rgba(16, 24, 40, .06);
  --radius: 18px;
  --max: 1120px;
  color-scheme: light;
}

html[data-theme="dark"] {
  --bg: #0e1015;
  --bg-soft: #14171e;
  --surface: #171a22;
  --text: #e9ebf2;
  --text-2: #b9bfcc;
  --muted: #8b93a3;
  --border: #262b37;
  --accent: #7f9bff;
  --accent-2: #9db2ff;
  --accent-soft: #1a2030;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 16px 40px rgba(0, 0, 0, .35);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }

code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: .9em;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: .1em .38em;
}

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: 0 0 8px 0;
  z-index: 100;
}
.skip:focus { left: 0; }

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}
.site-header.scrolled { border-bottom-color: var(--border); }

.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: .2px;
}
.brand-mark {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  font-size: 17px;
  font-weight: 700;
  line-height: 1;
}
.brand-name { font-size: 15.5px; }

.nav {
  display: flex;
  gap: 4px;
  margin-left: 8px;
}
.nav a {
  padding: 7px 12px;
  border-radius: 999px;
  font-size: 14px;
  color: var(--text-2);
  transition: background .18s ease, color .18s ease;
}
.nav a:hover { background: var(--bg-soft); color: var(--text); }

.header-actions {
  margin-left: auto;
  display: flex;
  gap: 8px;
}
.icon-btn {
  height: 34px;
  min-width: 38px;
  padding: 0 10px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-2);
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: color .18s ease, border-color .18s ease, transform .18s ease;
}
.icon-btn:hover { color: var(--text); border-color: var(--accent-2); }
.icon-btn:active { transform: scale(.96); }
.icon-btn svg { fill: currentColor; }

/* ---------- hero ---------- */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: 48px;
  align-items: center;
  padding: 76px 24px 56px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  font-size: 13px;
  font-weight: 600;
  color: #0f7b4f;
  background: #e9f9f0;
  border: 1px solid #bfeeda;
  padding: 5px 12px;
  border-radius: 999px;
}
html[data-theme="dark"] .eyebrow {
  color: #7ee2b8;
  background: #10261d;
  border-color: #1c4a38;
}
.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #12b76a;
  box-shadow: 0 0 0 3px rgba(18, 183, 106, .16);
}

.hero h1 {
  margin: 0;
  font-size: clamp(46px, 7vw, 76px);
  line-height: 1.02;
  letter-spacing: -2.2px;
  font-weight: 800;
}

.hero-title {
  margin: 14px 0 0;
  font-size: clamp(20px, 2.4vw, 27px);
  font-weight: 650;
  letter-spacing: -.4px;
  color: var(--text);
}

.hero-sub {
  margin: 16px 0 0;
  max-width: 560px;
  color: var(--text-2);
  font-size: 16.5px;
}

.hero-tags { margin-top: 22px; }

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 30px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 42px;
  padding: 0 18px;
  border-radius: 11px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 14.5px;
  font-weight: 600;
  cursor: pointer;
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease, background .16s ease;
}
.btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); border-color: var(--accent-2); }
.btn:active { transform: translateY(0); }
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-color: transparent;
  color: #fff;
}
.btn-ghost { background: transparent; }
.btn-sm { height: 36px; padding: 0 14px; font-size: 13.5px; border-radius: 10px; }

.hero-figure {
  display: grid;
  place-items: center;
  position: relative;
}
.hero-figure::before {
  content: "";
  position: absolute;
  inset: 12% 6%;
  background: radial-gradient(circle at 50% 45%, var(--accent-soft), transparent 68%);
  filter: blur(6px);
  z-index: 0;
}
.hero-figure img { position: relative; z-index: 1; width: min(320px, 78vw); }

/* ---------- stats ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding-bottom: 20px;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.stat strong {
  font-size: 30px;
  line-height: 1.1;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat span { font-size: 13px; color: var(--muted); }

/* ---------- sections ---------- */
.section { padding: 88px 24px; }
.section-compact { padding-top: 40px; }

.section-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 34px;
}
.section-no {
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: .08em;
  font-variant-numeric: tabular-nums;
}
.section-head h2 {
  margin: 0;
  font-size: clamp(24px, 3vw, 32px);
  letter-spacing: -.7px;
}

.prose p { margin: 0 0 16px; color: var(--text-2); font-size: 16.5px; }
.prose p:last-child { margin-bottom: 0; }

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, .9fr);
  gap: 40px;
  align-items: start;
}

.facts {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
}
.facts dl { margin: 0; display: grid; gap: 14px; }
.facts dl > div { display: flex; justify-content: space-between; gap: 16px; }
.facts dt { color: var(--muted); font-size: 13.5px; }
.facts dd { margin: 0; font-size: 14px; font-weight: 600; text-align: right; }
.dot {
  display: inline-block;
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #12b76a;
  margin-right: 6px;
  vertical-align: 1px;
}

/* ---------- capabilities ---------- */
.cap-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.cap {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.cap:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--accent) 35%, var(--border)); }
.cap h3 { margin: 0 0 8px; font-size: 17px; }
.cap p { margin: 0 0 14px; color: var(--text-2); font-size: 14.5px; }
.cap .tags { margin: 0; }

.tags { display: flex; flex-wrap: wrap; gap: 7px; }
.tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text-2);
  font-size: 12.5px;
  line-height: 1.7;
  white-space: nowrap;
}
.tag-accent {
  background: var(--accent-soft);
  border-color: color-mix(in srgb, var(--accent) 30%, var(--border));
  color: var(--accent);
  font-weight: 600;
}

/* ---------- projects ---------- */
.project {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.project:hover { transform: translateY(-3px); box-shadow: var(--shadow); }

.project-main {
  padding: 32px;
  margin-bottom: 18px;
  background:
    radial-gradient(1200px 240px at 0% 0%, color-mix(in srgb, var(--accent) 8%, transparent), transparent 70%),
    var(--surface);
}
.project-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 20px;
  flex-wrap: wrap;
}
.project-kicker {
  margin: 0 0 4px;
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--accent);
  text-transform: none;
}
.project h3 { margin: 0; font-size: 23px; letter-spacing: -.4px; }
.project-main h3 { font-size: 28px; }
.project-desc { margin: 6px 0 2px; color: var(--text-2); font-size: 15.5px; }
.project-links { display: flex; gap: 8px; flex-wrap: wrap; }
.highlights {
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}
.highlights li {
  position: relative;
  padding-left: 18px;
  color: var(--text-2);
  font-size: 15px;
}
.highlights li::before {
  content: "";
  position: absolute;
  left: 0; top: .62em;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  opacity: .7;
}
.highlights b { color: var(--text); }

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.project-grid .project h3 { font-size: 19px; }

.text-link {
  margin-top: auto;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
}
.text-link:hover { text-decoration: underline; text-underline-offset: 3px; }

/* 项目卡片底部双链接：介绍页 + 仓库 */
.project-links-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  margin-top: auto;
  padding-top: 4px;
}
.project-links-row .text-link { margin-top: 0; }
.link-secondary { color: var(--muted); }
.link-secondary:hover { color: var(--accent); }

/* ---------- timeline ---------- */
.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.timeline > li {
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  gap: 28px;
  padding: 24px 0;
  border-top: 1px solid var(--border);
}
.timeline > li:first-child { border-top: 0; padding-top: 6px; }
.time {
  color: var(--muted);
  font-size: 13.5px;
  font-variant-numeric: tabular-nums;
  padding-top: 3px;
}
.time-body h3 { margin: 0; font-size: 18px; }
.muted { color: var(--muted); font-weight: 400; font-size: 14px; }
.role { margin: 3px 0 10px; color: var(--accent); font-size: 14px; font-weight: 600; }
.time-body ul { margin: 0; padding-left: 18px; color: var(--text-2); font-size: 15px; display: grid; gap: 6px; }

/* ---------- stack / education ---------- */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.stack-col {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 24px;
}
.stack-col h3 { margin: 0 0 12px; font-size: 14px; color: var(--muted); font-weight: 600; }

.edu p { margin: 0 0 6px; color: var(--text-2); }
.edu b { color: var(--text); }

/* ---------- contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
}
.contact-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 18px 20px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  text-align: left;
  font: inherit;
  color: inherit;
  cursor: pointer;
  transition: border-color .18s ease, transform .18s ease, box-shadow .18s ease;
}
.contact-card:hover { border-color: var(--accent-2); transform: translateY(-2px); box-shadow: var(--shadow); }
.contact-label { font-size: 12px; color: var(--muted); }
.contact-value { font-size: 14px; font-weight: 600; word-break: break-all; }

.qr-panel {
  margin-top: 16px;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}
.qr-panel[hidden] { display: none; }
.qr-panel img { width: 200px; height: 200px; object-fit: contain; }
.qr-panel p { margin: 0; font-size: 12.5px; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 40px;
  padding: 28px 0 40px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--muted);
}
.footer-inner p { margin: 0; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .hero { grid-template-columns: 1fr; gap: 24px; padding-top: 48px; }
  .hero-figure { order: -1; }
  .hero-figure img { width: min(240px, 62vw); }
  .about-grid, .cap-grid, .project-grid, .stack-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 680px) {
  .nav { display: none; }
  .section { padding: 64px 20px; }
  .stats { grid-template-columns: 1fr 1fr; }
  .about-grid, .cap-grid, .project-grid, .stack-grid, .contact-grid { grid-template-columns: 1fr; }
  .timeline > li { grid-template-columns: 1fr; gap: 8px; padding: 20px 0; }
  .project-main { padding: 24px; }
  .project-head { flex-direction: column; }
  .hero h1 { letter-spacing: -1.6px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}