/* ============================================================
   极简黑白 · 个人主页
   ============================================================ */

:root {
  --ink: #111111;
  --ink-soft: #3d3d3d;
  --muted: #787878;
  --line: #e3e3e3;
  --line-strong: #c9c9c9;
  --bg: #ffffff;
  --bg-alt: #fafafa;

  --serif: "Georgia", "Times New Roman", "Songti SC", "Noto Serif SC", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;

  --maxw: 960px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

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

::selection { background: var(--ink); color: #fff; }

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 28px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: #fff;
  padding: 10px 16px;
  z-index: 100;
}
.skip-link:focus { left: 12px; top: 12px; }

/* ---------- Header ---------- */

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0);
  border-bottom: 1px solid transparent;
  transition: background 0.35s var(--ease), border-color 0.35s var(--ease);
}
.site-header.is-stuck {
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom-color: var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}

.brand { display: flex; align-items: center; gap: 10px; }

.brand-mark {
  width: 26px; height: 26px;
  display: grid; place-items: center;
  background: var(--ink);
  color: #fff;
  font-family: var(--serif);
  font-size: 15px;
  line-height: 1;
  padding-bottom: 2px;
}

.brand-text {
  font-size: 14px;
  letter-spacing: 0.08em;
}

.nav { display: flex; gap: 30px; }

.nav a {
  position: relative;
  font-size: 13.5px;
  color: var(--muted);
  letter-spacing: 0.06em;
  padding: 4px 0;
  transition: color 0.25s var(--ease);
}
.nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 100%; height: 1px;
  background: var(--ink);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
}
.nav a:hover { color: var(--ink); }
.nav a:hover::after,
.nav a.is-active::after { transform: scaleX(1); }
.nav a.is-active { color: var(--ink); }

.nav-toggle {
  display: none;
  width: 34px; height: 34px;
  border: 1px solid var(--line);
  background: #fff;
  cursor: pointer;
  padding: 0;
  position: relative;
}
.nav-toggle span {
  position: absolute;
  left: 9px; right: 9px;
  height: 1px;
  background: var(--ink);
  transition: transform 0.3s var(--ease), opacity 0.2s;
}
.nav-toggle span:nth-child(1) { top: 14px; }
.nav-toggle span:nth-child(2) { bottom: 14px; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { top: 16px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { bottom: 17px; transform: rotate(-45deg); }

/* ---------- Hero ---------- */

.hero {
  padding: 190px 0 120px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 22px;
}

.hero-name {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(3.2rem, 9vw, 6rem);
  line-height: 1.02;
  letter-spacing: -0.02em;
  margin: 0 0 26px;
}

.hero-role {
  font-size: clamp(1rem, 2.2vw, 1.22rem);
  color: var(--ink-soft);
  margin: 0 0 26px;
  letter-spacing: 0.04em;
}
.hero-role .dot { color: var(--line-strong); margin: 0 12px; }

.hero-lede {
  max-width: 30em;
  font-size: 1.02rem;
  color: var(--muted);
  margin: 0 0 42px;
}

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 46px;
  padding: 0 26px;
  font-size: 14px;
  letter-spacing: 0.06em;
  border: 1px solid var(--ink);
  transition: background 0.28s var(--ease), color 0.28s var(--ease);
}
.btn-solid { background: var(--ink); color: #fff; }
.btn-solid:hover { background: #fff; color: var(--ink); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--ink); }

.hero-status {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 46px 0 0;
  font-size: 13px;
  color: var(--muted);
  font-family: var(--mono);
  letter-spacing: 0.04em;
}
.pulse {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--ink);
  animation: pulse 2.4s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.25; transform: scale(0.82); }
}

/* ---------- Section shell ---------- */

.section {
  padding: 104px 0;
  border-bottom: 1px solid var(--line);
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 18px;
  margin-bottom: 54px;
}

.section-num {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.section-title {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(1.5rem, 3.4vw, 2rem);
  letter-spacing: 0.02em;
  margin: 0;
}

/* ---------- About ---------- */

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  gap: 64px;
}

.about-text p { margin: 0 0 22px; color: var(--ink-soft); }
.about-text p:last-child { margin-bottom: 0; }
.about-text .lede {
  font-family: var(--serif);
  font-size: 1.18rem;
  line-height: 1.72;
  color: var(--ink);
}

.about-meta dl { margin: 0; }
.about-meta dl > div {
  padding: 15px 0;
  border-top: 1px solid var(--line);
}
.about-meta dl > div:last-child { border-bottom: 1px solid var(--line); }
.about-meta dt {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 5px;
}
.about-meta dd { margin: 0; font-size: 14.5px; }

/* ---------- Work ---------- */

.work-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.work-item { border-bottom: 1px solid var(--line); }

.work-link {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) 40px;
  align-items: start;
  gap: 8px;
  padding: 32px 0;
  transition: padding 0.35s var(--ease);
}
.work-link:hover { padding-left: 10px; }

.work-index {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  padding-top: 9px;
  letter-spacing: 0.1em;
}

.work-title {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.35rem;
  margin: 0 0 10px;
  letter-spacing: 0.01em;
  transition: opacity 0.25s var(--ease);
}
.work-link:hover .work-title { opacity: 0.55; }

.work-desc {
  margin: 0 0 15px;
  font-size: 14.5px;
  color: var(--muted);
  max-width: 44em;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.tags li {
  font-size: 11.5px;
  font-family: var(--mono);
  letter-spacing: 0.04em;
  color: var(--muted);
  border: 1px solid var(--line);
  padding: 3px 10px;
}

.work-arrow {
  justify-self: end;
  font-size: 17px;
  color: var(--line-strong);
  padding-top: 4px;
  transition: transform 0.3s var(--ease), color 0.3s var(--ease);
}
.work-link:hover .work-arrow { color: var(--ink); transform: translate(3px, -3px); }

.work-more { margin: 34px 0 0; font-size: 14px; color: var(--muted); }

.inline-link {
  border-bottom: 1px solid var(--line-strong);
  transition: border-color 0.25s var(--ease);
}
.inline-link:hover { border-color: var(--ink); }

/* ---------- Skills ---------- */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 48px;
}

.skill-group-title {
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.skill-tags li {
  font-size: 13px;
  border: 1px solid var(--line-strong);
  padding: 5px 13px;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.skill-tags li:hover {
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
}

/* ---------- Timeline ---------- */

.timeline { list-style: none; margin: 0; padding: 0; }

.timeline-item {
  display: grid;
  grid-template-columns: 168px minmax(0, 1fr);
  gap: 24px;
  padding: 30px 0;
  border-top: 1px solid var(--line);
  position: relative;
}
.timeline-item:last-child { border-bottom: 1px solid var(--line); }

.timeline-date {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  padding-top: 6px;
}

.timeline-body h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.18rem;
  margin: 0 0 8px;
}
.timeline-body p {
  margin: 0;
  font-size: 14.5px;
  color: var(--muted);
  max-width: 42em;
}

/* ---------- Contact ---------- */

.section-contact { border-bottom: none; }

.contact-lede {
  font-family: var(--serif);
  font-size: clamp(1.2rem, 3vw, 1.6rem);
  line-height: 1.55;
  margin: 0 0 40px;
  max-width: 22em;
}

.email-row {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--line);
}

.email {
  font-family: var(--serif);
  font-size: clamp(1.3rem, 4vw, 2.1rem);
  letter-spacing: -0.01em;
  border-bottom: 1px solid var(--line-strong);
  transition: border-color 0.3s var(--ease), opacity 0.3s var(--ease);
}
.email:hover { border-color: var(--ink); opacity: 0.6; }

.copy-btn {
  font-family: var(--sans);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
  background: #fff;
  border: 1px solid var(--line-strong);
  height: 32px;
  padding: 0 14px;
  cursor: pointer;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.copy-btn:hover { border-color: var(--ink); color: var(--ink); }
.copy-btn.is-done { background: var(--ink); color: #fff; border-color: var(--ink); }

.social-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 40px;
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
}
.social-list a {
  font-size: 14px;
  color: var(--ink-soft);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease);
}
.social-list a:hover { color: var(--ink); border-bottom-color: var(--ink); }
.social-list .ext { font-size: 11px; color: var(--muted); }

/* ---------- Footer ---------- */

.site-footer { border-top: 1px solid var(--line); padding: 30px 0 42px; }

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 12.5px;
  color: var(--muted);
  font-family: var(--mono);
  letter-spacing: 0.04em;
}

.to-top { transition: color 0.25s var(--ease); }
.to-top:hover { color: var(--ink); }

/* ---------- Reveal ---------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}
.reveal.is-in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: 0.08s; }
.reveal[data-delay="2"] { transition-delay: 0.16s; }
.reveal[data-delay="3"] { transition-delay: 0.24s; }
.reveal[data-delay="4"] { transition-delay: 0.32s; }
.reveal[data-delay="5"] { transition-delay: 0.4s; }

/* ---------- Responsive ---------- */

@media (max-width: 860px) {
  .about-grid { grid-template-columns: 1fr; gap: 44px; }
  .skills-grid { grid-template-columns: 1fr; gap: 36px; }
  .timeline-item { grid-template-columns: 1fr; gap: 8px; }
  .timeline-date { padding-top: 0; }
}

@media (max-width: 720px) {
  .wrap { padding: 0 20px; }
  .hero { padding: 140px 0 84px; }
  .section { padding: 76px 0; }
  .section-head { margin-bottom: 38px; }

  .nav-toggle { display: block; }
  .nav {
    position: fixed;
    top: 66px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 6px 20px 18px;
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease);
  }
  .nav.is-open {
    opacity: 1;
    transform: none;
    pointer-events: auto;
  }
  .nav a {
    padding: 13px 0;
    border-bottom: 1px solid var(--line);
    font-size: 15px;
  }
  .nav a:last-child { border-bottom: none; }
  .nav a::after { display: none; }

  .work-link { grid-template-columns: 36px minmax(0, 1fr) 24px; padding: 26px 0; }
  .work-link:hover { padding-left: 0; }
  .hero-actions { gap: 10px; }
  .btn { flex: 1 1 auto; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .pulse { animation: none; }
}

@media print {
  .site-header, .nav-toggle, .hero-actions, .copy-btn, .to-top { display: none; }
  .reveal { opacity: 1; transform: none; }
  .section { padding: 28px 0; }
}