/* =====================================================================
   刘静 · 个人主页  |  style.css
   目录
   01 设计令牌 / 主题变量
   02 基础重置
   03 背景装饰层（网格 / 光斑 / 噪点 / 聚光）
   04 通用组件（按钮 / 卡片 / 标签 / 区块标题）
   05 顶部导航
   06 Hero
   07 关键词跑马灯
   08 关于我
   09 技能（标签云 / 能力条）
   10 时间轴
   11 项目网格
   12 联系方式
   13 页脚 / 返回顶部 / 模态框 / Toast
   14 进场动画
   15 响应式 & 可访问性降级
   ===================================================================== */

/* ---------------------------------------------------------------------
   01 设计令牌 / 主题变量
   --------------------------------------------------------------------- */
:root {
  /* 品牌渐变 */
  --c1: #6366f1;   /* indigo */
  --c2: #22d3ee;   /* cyan   */
  --c3: #a855f7;   /* purple */
  --c4: #f472b6;   /* pink   */
  --grad: linear-gradient(100deg, var(--c1), var(--c2) 45%, var(--c3) 85%);
  --grad-soft: linear-gradient(100deg, rgba(99,102,241,.16), rgba(34,211,238,.14), rgba(168,85,247,.16));

  /* 版式 */
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  /* 尺寸 */
  --wrap: 1180px;
  --pad: 24px;
  --r-sm: 10px;
  --r-md: 16px;
  --r-lg: 22px;
  --r-xl: 30px;
  --nav-h: 68px;

  /* 动效 */
  --ease: cubic-bezier(.22, 1, .36, 1);
  --ease-io: cubic-bezier(.65, .05, .36, 1);
  --t-fast: .18s;
  --t: .34s;
  --t-slow: .7s;
}

/* 深色主题（默认） */
[data-theme="dark"] {
  --bg: #070a14;
  --bg-2: #0a0f1e;
  --surface: rgba(255, 255, 255, .045);
  --surface-2: rgba(255, 255, 255, .075);
  --line: rgba(255, 255, 255, .1);
  --line-strong: rgba(255, 255, 255, .2);
  --text: #e9edfa;
  --text-2: #aab4d0;
  --text-3: #7b87a8;
  --shadow: 0 24px 60px -24px rgba(2, 4, 12, .9);
  --glow: 0 0 0 1px rgba(255, 255, 255, .06), 0 20px 60px -30px rgba(99, 102, 241, .8);
  --grid-line: rgba(255, 255, 255, .045);
  --particle: 232, 238, 255;
  --noise-op: .035;
  --blob-op: .55;
  /* 玻璃层实色回退（不依赖 color-mix） */
  --glass: rgba(10, 15, 30, .86);
  --nav-glass: rgba(7, 10, 20, .72);
}

/* 浅色主题 */
[data-theme="light"] {
  --bg: #f6f7fc;
  --bg-2: #eef1fa;
  --surface: rgba(255, 255, 255, .78);
  --surface-2: #ffffff;
  --line: rgba(15, 23, 42, .1);
  --line-strong: rgba(15, 23, 42, .2);
  --text: #101528;
  --text-2: #4a5471;
  --text-3: #6d7794;
  --shadow: 0 22px 50px -26px rgba(30, 41, 92, .3);
  --glow: 0 0 0 1px rgba(15, 23, 42, .05), 0 18px 44px -28px rgba(99, 102, 241, .55);
  --grid-line: rgba(15, 23, 42, .05);
  --particle: 60, 76, 140;
  --noise-op: .02;
  --blob-op: .32;
  --glass: rgba(255, 255, 255, .9);
  --nav-glass: rgba(246, 247, 252, .78);
}

/* ---------------------------------------------------------------------
   02 基础重置
   --------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  transition: background var(--t) var(--ease), color var(--t) var(--ease);
}

body.is-locked { overflow: hidden; }

h1, h2, h3, h4 { margin: 0; line-height: 1.22; font-weight: 700; letter-spacing: -.02em; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img, svg, canvas { display: block; max-width: 100%; }
button { font: inherit; color: inherit; border: 0; background: none; cursor: pointer; }
strong { font-weight: 650; color: var(--text); }
em { font-style: normal; font-family: var(--mono); font-size: .92em; color: var(--c2); }

svg { fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }

::selection { background: rgba(99, 102, 241, .35); color: #fff; }

:focus-visible {
  outline: 2px solid var(--c2);
  outline-offset: 3px;
  border-radius: 6px;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.skip-link {
  position: fixed;
  top: 8px; left: 50%;
  transform: translate(-50%, -160%);
  z-index: 200;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  font-size: 14px;
  transition: transform var(--t) var(--ease);
}
.skip-link:focus { transform: translate(-50%, 0); }

/* 自定义滚动条 */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: linear-gradient(var(--c1), var(--c3));
  border-radius: 99px;
  border: 3px solid var(--bg);
}

/* ---------------------------------------------------------------------
   03 背景装饰层
   --------------------------------------------------------------------- */
.backdrop {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  background:
    radial-gradient(120% 80% at 50% -10%, var(--bg-2), transparent 60%),
    var(--bg);
}

.backdrop__grid {
  position: absolute;
  inset: -1px;
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 62px 62px;
  mask-image: radial-gradient(circle at 50% 22%, #000 0%, transparent 78%);
  -webkit-mask-image: radial-gradient(circle at 50% 22%, #000 0%, transparent 78%);
}

.backdrop__canvas { position: absolute; inset: 0; width: 100%; height: 100%; }

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: var(--blob-op);
  will-change: transform;
}
.blob--1 {
  width: 46vw; height: 46vw; min-width: 340px; min-height: 340px;
  top: -12vw; left: -8vw;
  background: radial-gradient(circle, var(--c1), transparent 68%);
  animation: drift1 22s var(--ease-io) infinite alternate;
}
.blob--2 {
  width: 40vw; height: 40vw; min-width: 300px; min-height: 300px;
  top: 18vh; right: -10vw;
  background: radial-gradient(circle, var(--c2), transparent 68%);
  animation: drift2 26s var(--ease-io) infinite alternate;
}
.blob--3 {
  width: 44vw; height: 44vw; min-width: 320px; min-height: 320px;
  bottom: -16vw; left: 26vw;
  background: radial-gradient(circle, var(--c3), transparent 68%);
  animation: drift3 30s var(--ease-io) infinite alternate;
}
@keyframes drift1 { to { transform: translate3d(9vw, 7vh, 0) scale(1.15); } }
@keyframes drift2 { to { transform: translate3d(-11vw, 10vh, 0) scale(1.1); } }
@keyframes drift3 { to { transform: translate3d(7vw, -9vh, 0) scale(1.18); } }

.backdrop__noise {
  position: absolute;
  inset: 0;
  opacity: var(--noise-op);
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* 跟随鼠标的聚光 */
.spotlight {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0;
  transition: opacity .5s var(--ease);
  background: radial-gradient(
    320px circle at var(--mx, 50%) var(--my, 50%),
    rgba(99, 102, 241, .1), transparent 70%
  );
}
body.has-pointer .spotlight { opacity: 1; }

/* 滚动进度条 */
.progress {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 2px;
  z-index: 120;
  background: transparent;
}
.progress__bar {
  display: block;
  height: 100%;
  width: 0;
  background: var(--grad);
  box-shadow: 0 0 12px rgba(99, 102, 241, .8);
}

/* ---------------------------------------------------------------------
   04 通用组件
   --------------------------------------------------------------------- */
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  background-size: 220% 100%;
  animation: hue 9s linear infinite;
}
@keyframes hue { to { background-position: 220% 0; } }

.btn {
  --btn-bg: var(--surface-2);
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .01em;
  white-space: nowrap;
  isolation: isolate;
  transition: transform var(--t) var(--ease), box-shadow var(--t) var(--ease),
              background var(--t) var(--ease), border-color var(--t) var(--ease);
}
.btn svg { width: 18px; height: 18px; }
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0) scale(.985); }

.btn--primary {
  color: #fff;
  background: var(--grad);
  background-size: 180% 100%;
  box-shadow: 0 12px 30px -12px rgba(99, 102, 241, .85);
}
.btn--primary:hover { background-position: 100% 0; box-shadow: 0 18px 40px -14px rgba(99, 102, 241, .95); }

.btn--ghost {
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  backdrop-filter: blur(10px);
}
.btn--ghost:hover { border-color: var(--line-strong); background: var(--surface-2); }

.btn--link { padding: 13px 8px; color: var(--text-2); }
.btn--link:hover { color: var(--text); }

.btn--block { width: 100%; justify-content: center; }

/* 玻璃卡片 + 光泽跟随 */
.card {
  position: relative;
  padding: 30px;
  border-radius: var(--r-lg);
  background: var(--surface);
  border: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: transform var(--t) var(--ease), border-color var(--t) var(--ease),
              box-shadow var(--t) var(--ease);
}
.card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(140deg, rgba(255,255,255,.22), transparent 45%);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: .7;
}
.card__shine {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  transition: opacity var(--t) var(--ease);
  background: radial-gradient(
    240px circle at var(--cx, 50%) var(--cy, 50%),
    rgba(99, 102, 241, .22), transparent 65%
  );
}
.card:hover .card__shine { opacity: 1; }
.card:hover { border-color: var(--line-strong); box-shadow: var(--shadow), var(--glow); }

.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; }
.chip {
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--text-2);
  background: var(--surface-2);
  border: 1px solid var(--line);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease),
              transform var(--t-fast) var(--ease);
}
.chip:hover { color: var(--text); border-color: var(--c2); transform: translateY(-2px); }

.section { position: relative; padding: clamp(70px, 10vw, 130px) 0; }
.section--alt::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--grad-soft);
  opacity: .5;
  mask-image: linear-gradient(to bottom, transparent, #000 18%, #000 82%, transparent);
  -webkit-mask-image: linear-gradient(to bottom, transparent, #000 18%, #000 82%, transparent);
  pointer-events: none;
}
.section > .wrap { position: relative; z-index: 1; }

.sec-head { max-width: 640px; margin-bottom: clamp(34px, 5vw, 56px); }
.sec-kicker {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c2);
}
.sec-title { font-size: clamp(28px, 4.6vw, 44px); }
.sec-title::after {
  content: "";
  display: block;
  width: 56px; height: 3px;
  margin-top: 16px;
  border-radius: 99px;
  background: var(--grad);
}
.sec-sub { margin-top: 16px; color: var(--text-2); font-size: 16.5px; }

/* ---------------------------------------------------------------------
   05 顶部导航
   --------------------------------------------------------------------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 110;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background var(--t) var(--ease), backdrop-filter var(--t) var(--ease),
              border-color var(--t) var(--ease);
  border-bottom: 1px solid transparent;
}
.nav.is-stuck {
  background: var(--nav-glass);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  border-bottom-color: var(--line);
}
.nav__inner {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
  display: flex;
  align-items: center;
  gap: 18px;
}

.brand { display: flex; align-items: center; gap: 11px; margin-right: auto; }
.brand__mark {
  display: grid;
  place-items: center;
  width: 38px; height: 38px;
  border-radius: 12px;
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  background: var(--grad);
  box-shadow: 0 8px 22px -10px rgba(99, 102, 241, .9);
}
.brand__text { font-weight: 700; font-size: 16px; letter-spacing: .01em; }
.brand__text i {
  display: block;
  font-family: var(--mono);
  font-style: normal;
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: .14em;
  color: var(--text-3);
}

.nav__links { position: relative; display: flex; align-items: center; gap: 2px; }
.nav__link {
  position: relative;
  z-index: 1;
  padding: 9px 15px;
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text-2);
  transition: color var(--t-fast) var(--ease);
}
.nav__link:hover { color: var(--text); }
.nav__link.is-active { color: var(--text); font-weight: 600; }
.nav__indicator {
  position: absolute;
  top: 50%;
  left: 0;
  height: 36px;
  width: 0;
  transform: translateY(-50%);
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  opacity: 0;
  transition: transform var(--t) var(--ease), width var(--t) var(--ease), opacity var(--t) var(--ease);
}
.nav__indicator.is-on { opacity: 1; }

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

.icon-btn {
  display: grid;
  place-items: center;
  width: 38px; height: 38px;
  border-radius: 12px;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--line);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease),
              transform var(--t-fast) var(--ease);
}
.icon-btn:hover { color: var(--text); border-color: var(--line-strong); transform: translateY(-1px); }
.icon-btn svg { width: 19px; height: 19px; }
[data-theme="dark"] .i-sun { display: block; }
[data-theme="dark"] .i-moon { display: none; }
[data-theme="light"] .i-sun { display: none; }
[data-theme="light"] .i-moon { display: block; }

.burger { display: none; width: 38px; height: 38px; border-radius: 12px; border: 1px solid var(--line); background: var(--surface); }
.burger span {
  display: block;
  width: 17px; height: 1.8px;
  margin: 3.5px auto;
  border-radius: 2px;
  background: var(--text);
  transition: transform var(--t) var(--ease), opacity var(--t-fast) var(--ease);
}
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(5.3px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-5.3px) rotate(-45deg); }

/* ---------------------------------------------------------------------
   06 Hero
   --------------------------------------------------------------------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding: calc(var(--nav-h) + 40px) 0 110px;
}
.hero__inner { text-align: left; }

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 26px;
  padding: 7px 16px 7px 12px;
  border-radius: 999px;
  font-size: 13.5px;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--line);
  backdrop-filter: blur(10px);
}
.hero__badge .dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 0 0 rgba(52, 211, 153, .7);
  animation: pulse 2.2s var(--ease-io) infinite;
}
@keyframes pulse {
  70% { box-shadow: 0 0 0 9px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

.hero__title {
  font-size: clamp(44px, 9.4vw, 108px);
  font-weight: 800;
  letter-spacing: -.045em;
  margin-bottom: 18px;
}
.hero__title .grad-text { position: relative; display: inline-block; }
.hero__title .grad-text::after {
  content: attr(data-text);
  position: absolute;
  inset: 0;
  z-index: -1;
  color: transparent;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  filter: blur(26px);
  opacity: .6;
}

.hero__typing {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 34px;
  margin-bottom: 20px;
  font-size: clamp(17px, 2.4vw, 24px);
  font-weight: 600;
  color: var(--text);
}
.hero__typing-prefix { color: var(--text-3); font-weight: 500; }
.type { background: linear-gradient(90deg, var(--c2), var(--c4)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.caret {
  width: 2px;
  height: 1.15em;
  background: var(--c2);
  animation: blink 1s steps(2) infinite;
}
@keyframes blink { 50% { opacity: 0; } }

.hero__desc { max-width: 620px; margin-bottom: 34px; color: var(--text-2); font-size: 17px; }

.hero__cta { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; margin-bottom: 56px; }

.hero__stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  max-width: 760px;
  padding-top: 30px;
  border-top: 1px solid var(--line);
}
.hero__stats li { display: flex; flex-direction: column; gap: 2px; }
.hero__stats b {
  font-size: clamp(22px, 3.4vw, 34px);
  font-weight: 800;
  letter-spacing: -.03em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__stats span { font-size: 13px; color: var(--text-3); }

.hero__scroll {
  position: absolute;
  left: 50%;
  bottom: 26px;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-3);
  transition: color var(--t-fast) var(--ease);
}
.hero__scroll:hover { color: var(--text); }
.hero__mouse {
  display: grid;
  place-items: start center;
  width: 22px; height: 34px;
  padding-top: 6px;
  border-radius: 12px;
  border: 1.5px solid currentColor;
}
.hero__mouse i {
  width: 3px; height: 7px;
  border-radius: 2px;
  background: currentColor;
  animation: wheel 1.7s var(--ease-io) infinite;
}
@keyframes wheel { 0%, 100% { transform: translateY(0); opacity: 1; } 60% { transform: translateY(9px); opacity: .2; } }
.hero__scroll-text { font-family: var(--mono); font-size: 9.5px; letter-spacing: .28em; }

/* ---------------------------------------------------------------------
   07 关键词跑马灯
   --------------------------------------------------------------------- */
.marquee {
  position: relative;
  padding: 18px 0;
  border-block: 1px solid var(--line);
  background: var(--surface);
  overflow: hidden;
  mask-image: linear-gradient(to right, transparent, #000 12%, #000 88%, transparent);
  -webkit-mask-image: linear-gradient(to right, transparent, #000 12%, #000 88%, transparent);
}
.marquee__track {
  display: flex;
  align-items: center;
  gap: 26px;
  width: max-content;
  animation: slide 32s linear infinite;
}
.marquee:hover .marquee__track { animation-play-state: paused; }
.marquee__track span {
  font-size: clamp(15px, 2.2vw, 22px);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--text-2);
  white-space: nowrap;
}
.marquee__track i { font-size: 9px; color: var(--c2); font-style: normal; }
@keyframes slide { to { transform: translateX(-50%); } }

/* ---------------------------------------------------------------------
   08 关于我
   --------------------------------------------------------------------- */
.about { display: grid; grid-template-columns: 1.5fr 1fr; gap: 22px; align-items: start; }
.about__main p { color: var(--text-2); }
.about__name { font-size: clamp(22px, 3vw, 28px); margin-bottom: 18px; }
.about__meta {
  display: inline-block;
  margin-left: 10px;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text-3);
  letter-spacing: 0;
}
.about__side { display: grid; gap: 16px; }

.mini { padding: 22px 24px; }
.mini__icon {
  display: grid;
  place-items: center;
  width: 40px; height: 40px;
  margin-bottom: 14px;
  border-radius: 12px;
  color: #fff;
  background: var(--grad);
  box-shadow: 0 10px 26px -12px rgba(99, 102, 241, .9);
}
.mini__icon svg { width: 21px; height: 21px; }
.mini h4 { font-size: 16px; margin-bottom: 6px; }
.mini p { font-size: 14.5px; color: var(--text-2); line-height: 1.66; }

/* ---------------------------------------------------------------------
   09 技能
   --------------------------------------------------------------------- */
.skills { display: grid; grid-template-columns: 1.25fr 1fr; gap: 22px; align-items: stretch; }

.cloud { display: flex; align-items: center; }
.cloud__inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 10px 12px;
  padding: 6px;
  transform: translate3d(0, 0, 0);
  transition: transform .5s var(--ease);
}
.tag {
  --tag-c: var(--c2);
  position: relative;
  padding: 8px 16px;
  border-radius: 999px;
  font-weight: 600;
  color: var(--text-2);
  background: var(--surface-2);
  border: 1px solid var(--line);
  cursor: default;
  transition: transform .25s var(--ease), color .25s var(--ease),
              border-color .25s var(--ease), box-shadow .25s var(--ease);
  animation: float 7s var(--ease-io) infinite alternate;
}
.tag:nth-child(3n)   { animation-duration: 8.5s; animation-delay: -1.4s; }
.tag:nth-child(4n)   { animation-duration: 9.5s; animation-delay: -2.8s; }
.tag:nth-child(5n)   { animation-duration: 7.8s; animation-delay: -3.6s; }
@keyframes float { to { transform: translateY(-6px); } }

.tag[data-w="5"] { font-size: 21px; padding: 11px 22px; color: var(--text); --tag-c: var(--c1); }
.tag[data-w="4"] { font-size: 17.5px; padding: 10px 19px; --tag-c: var(--c2); }
.tag[data-w="3"] { font-size: 15px; --tag-c: var(--c3); }
.tag[data-w="2"] { font-size: 13.5px; padding: 7px 14px; color: var(--text-3); --tag-c: var(--c4); }

.tag:hover {
  color: #fff;
  border-color: transparent;
  background: linear-gradient(120deg, var(--tag-c), var(--c3));
  transform: translateY(-4px) scale(1.06);
  box-shadow: 0 14px 30px -14px var(--tag-c);
  z-index: 2;
}

.bars__title { font-size: 18px; margin-bottom: 22px; }
.bars__list { display: grid; gap: 18px; }
.bar {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas: "k v" "t t";
  gap: 8px 12px;
  align-items: center;
}
.bar__k { grid-area: k; font-size: 14.5px; color: var(--text-2); }
.bar b {
  grid-area: v;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--c2);
}
.bar__track {
  grid-area: t;
  position: relative;
  height: 7px;
  border-radius: 99px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  overflow: hidden;
}
.bar__track i {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
  border-radius: 99px;
  background: var(--grad);
  transition: width 1.3s var(--ease);
}
.bar__track i::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, .5), transparent);
  transform: translateX(-100%);
  animation: sheen 2.6s var(--ease-io) infinite;
}
@keyframes sheen { 60%, 100% { transform: translateX(100%); } }

/* ---------------------------------------------------------------------
   10 时间轴
   --------------------------------------------------------------------- */
.tl { position: relative; padding-left: 34px; }
.tl::before {
  content: "";
  position: absolute;
  top: 6px; bottom: 6px; left: 7px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(var(--c1), var(--c2) 50%, transparent);
}
.tl__item { position: relative; margin-bottom: 20px; }
.tl__item:last-child { margin-bottom: 0; }
.tl__dot {
  position: absolute;
  top: 30px; left: -34px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--c2);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, .18);
}
.tl__dot::after {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--grad);
}
.tl__dot--edu { border-color: var(--c4); box-shadow: 0 0 0 4px rgba(244, 114, 182, .18); }

.tl__time { margin: 0 0 8px; font-family: var(--mono); font-size: 12.5px; letter-spacing: .06em; color: var(--c2); }
.tl__role { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; font-size: 20px; }
.tl__tag {
  padding: 3px 10px;
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .04em;
  color: #34d399;
  background: rgba(52, 211, 153, .14);
  border: 1px solid rgba(52, 211, 153, .34);
}
.tl__org { margin: 6px 0 16px; font-size: 14.5px; color: var(--text-3); }
.tl__list { display: grid; gap: 9px; }
.tl__list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  color: var(--text-2);
}
.tl__list li::before {
  content: "";
  position: absolute;
  top: 11px; left: 2px;
  width: 7px; height: 7px;
  border-radius: 2px;
  background: var(--grad);
  transform: rotate(45deg);
}

/* ---------------------------------------------------------------------
   11 项目网格
   --------------------------------------------------------------------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}
.proj { display: flex; flex-direction: column; cursor: pointer; }
.proj__time { margin: 0 0 10px; font-family: var(--mono); font-size: 12px; letter-spacing: .06em; color: var(--text-3); }
.proj__title { font-size: 20px; margin-bottom: 12px; }
.proj__brief { font-size: 14.8px; color: var(--text-2); line-height: 1.7; }
.proj__tags { display: flex; flex-wrap: wrap; gap: 7px; margin: 18px 0 0; }
.proj__tags li {
  padding: 5px 11px;
  border-radius: 7px;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--c2);
  background: rgba(34, 211, 238, .1);
  border: 1px solid rgba(34, 211, 238, .26);
}
.proj__more {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin-top: auto;
  padding-top: 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}
.proj__more svg { width: 17px; height: 17px; transition: transform var(--t) var(--ease); }
.proj:hover .proj__more svg { transform: translateX(5px); }
.proj:hover { transform: translateY(-5px); }

.proj--cta {
  cursor: default;
  justify-content: center;
  gap: 16px;
  background: var(--grad-soft);
  border-style: dashed;
  border-color: var(--line-strong);
}
.proj--cta:hover { transform: none; }
.proj--cta .btn { align-self: flex-start; }

/* ---------------------------------------------------------------------
   12 联系方式
   --------------------------------------------------------------------- */
.contact {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: clamp(28px, 5vw, 56px);
  padding: clamp(28px, 4vw, 46px);
}
.contact__left h3 { font-size: clamp(21px, 2.8vw, 26px); margin-bottom: 12px; }
.contact__left > p { color: var(--text-2); font-size: 15.5px; margin-bottom: 26px; }

.contact__list { display: grid; gap: 12px; }
.contact__list li {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border-radius: var(--r-md);
  background: var(--surface-2);
  border: 1px solid var(--line);
  transition: border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}
.contact__list li:hover { border-color: var(--c2); transform: translateX(3px); }
.contact__ico {
  display: grid;
  place-items: center;
  flex: none;
  width: 38px; height: 38px;
  border-radius: 11px;
  color: var(--c2);
  background: rgba(34, 211, 238, .12);
}
.contact__ico svg { width: 19px; height: 19px; }
.contact__k { margin: 0; font-size: 12px; color: var(--text-3); line-height: 1.4; }
.contact__v { font-size: 15.5px; font-weight: 600; letter-spacing: .01em; }
a.contact__v:hover { color: var(--c2); }
.copy {
  margin-left: auto;
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 12.5px;
  color: var(--text-3);
  border: 1px solid var(--line);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}
.copy:hover { color: var(--text); border-color: var(--line-strong); }

.contact__form { display: grid; gap: 14px; align-content: start; }
.field { position: relative; }
.field input, .field textarea {
  width: 100%;
  padding: 20px 16px 10px;
  font: inherit;
  font-size: 15px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  resize: vertical;
  transition: border-color var(--t-fast) var(--ease), box-shadow var(--t-fast) var(--ease);
}
.field textarea { min-height: 116px; line-height: 1.6; }
.field label {
  position: absolute;
  top: 15px; left: 17px;
  font-size: 15px;
  color: var(--text-3);
  pointer-events: none;
  transition: transform var(--t-fast) var(--ease), font-size var(--t-fast) var(--ease),
              color var(--t-fast) var(--ease);
  transform-origin: left top;
}
.field input:focus, .field textarea:focus {
  outline: none;
  border-color: var(--c2);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, .18);
}
.field input:focus + label,
.field input:not(:placeholder-shown) + label,
.field textarea:focus + label,
.field textarea:not(:placeholder-shown) + label {
  transform: translateY(-9px) scale(.78);
  color: var(--c2);
}
.field.is-error input, .field.is-error textarea { border-color: #f87171; }
.contact__hint { margin: 2px 0 0; font-size: 12.5px; color: var(--text-3); text-align: center; }

/* ---------------------------------------------------------------------
   13 页脚 / 返回顶部 / 模态框 / Toast
   --------------------------------------------------------------------- */
.footer { padding: 34px 0 40px; border-top: 1px solid var(--line); }
.footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  justify-content: space-between;
  align-items: center;
  font-size: 13.5px;
  color: var(--text-3);
}
.footer p { margin: 0; }
.footer__meta { font-family: var(--mono); font-size: 12px; }

.to-top {
  position: fixed;
  right: 22px; bottom: 22px;
  z-index: 100;
  display: grid;
  place-items: center;
  width: 44px; height: 44px;
  border-radius: 14px;
  color: #fff;
  background: var(--grad);
  box-shadow: 0 14px 30px -12px rgba(99, 102, 241, .9);
  opacity: 0;
  transform: translateY(14px) scale(.9);
  pointer-events: none;
  transition: opacity var(--t) var(--ease), transform var(--t) var(--ease);
}
.to-top.is-on { opacity: 1; transform: none; pointer-events: auto; }
.to-top:hover { transform: translateY(-3px); }
.to-top svg { width: 20px; height: 20px; }

.modal { position: fixed; inset: 0; z-index: 200; display: grid; place-items: center; padding: 20px; }
.modal[hidden] { display: none; }
.modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(4, 6, 16, .68);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  opacity: 0;
  transition: opacity var(--t) var(--ease);
}
.modal__panel {
  position: relative;
  width: min(720px, 100%);
  max-height: min(84vh, 780px);
  overflow-y: auto;
  padding: clamp(26px, 4vw, 40px);
  border-radius: var(--r-xl);
  background: var(--glass);
  border: 1px solid var(--line-strong);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 40px 90px -30px rgba(0, 0, 0, .8);
  opacity: 0;
  transform: translateY(18px) scale(.97);
  transition: opacity var(--t) var(--ease), transform var(--t) var(--ease);
}
.modal.is-open .modal__backdrop { opacity: 1; }
.modal.is-open .modal__panel { opacity: 1; transform: none; }
.modal__close {
  position: absolute;
  top: 16px; right: 16px;
  display: grid;
  place-items: center;
  width: 36px; height: 36px;
  border-radius: 11px;
  color: var(--text-2);
  border: 1px solid var(--line);
  background: var(--surface);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}
.modal__close:hover { color: var(--text); border-color: var(--line-strong); transform: rotate(90deg); }
.modal__close svg { width: 18px; height: 18px; }
.modal__time { margin: 0 0 8px; font-family: var(--mono); font-size: 12px; color: var(--c2); letter-spacing: .06em; }
.modal__title { font-size: clamp(21px, 3.4vw, 28px); padding-right: 44px; margin-bottom: 14px; }
.modal__body { margin-top: 22px; }
.modal__body h4 {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 26px 0 12px;
  font-size: 15px;
  color: var(--text);
}
.modal__body h4::before {
  content: "";
  width: 4px; height: 15px;
  border-radius: 2px;
  background: var(--grad);
}
.modal__body h4:first-child { margin-top: 0; }
.modal__body p, .modal__body li { font-size: 14.8px; color: var(--text-2); line-height: 1.78; }
.modal__body ul, .modal__body ol { display: grid; gap: 9px; }
.modal__body li { position: relative; padding-left: 22px; }
.modal__body ul li::before {
  content: "";
  position: absolute;
  top: 11px; left: 4px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--c2);
}
.modal__body ol { counter-reset: n; }
.modal__body ol li::before {
  counter-increment: n;
  content: counter(n);
  position: absolute;
  left: 0; top: 3px;
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 700;
  color: var(--c3);
}
.modal__body b { color: var(--text); font-weight: 650; }

.toast {
  position: fixed;
  left: 50%; bottom: 28px;
  z-index: 210;
  transform: translate(-50%, 20px);
  padding: 11px 20px;
  border-radius: 999px;
  font-size: 14px;
  color: var(--text);
  background: var(--glass);
  border: 1px solid var(--line-strong);
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t) var(--ease), transform var(--t) var(--ease);
}
.toast.is-on { opacity: 1; transform: translate(-50%, 0); }

/* ---------------------------------------------------------------------
   14 进场动画
   --------------------------------------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .75s var(--ease), transform .75s var(--ease);
  transition-delay: calc(var(--d, 0) * 90ms);
}
.reveal.is-in { opacity: 1; transform: none; }

/* ---------------------------------------------------------------------
   15 响应式 & 可访问性降级
   --------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .about, .skills { grid-template-columns: 1fr; }
  .contact { grid-template-columns: 1fr; }
  .about__side { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
}

@media (max-width: 860px) {
  :root { --pad: 18px; --nav-h: 62px; }

  .nav__links {
    position: fixed;
    top: var(--nav-h); left: 12px; right: 12px;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 12px;
    border-radius: var(--r-lg);
    background: var(--glass);
    border: 1px solid var(--line);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    box-shadow: var(--shadow);
    opacity: 0;
    transform: translateY(-12px) scale(.98);
    pointer-events: none;
    transition: opacity var(--t) var(--ease), transform var(--t) var(--ease);
  }
  .nav__links.is-open { opacity: 1; transform: none; pointer-events: auto; }
  .nav__link { padding: 12px 16px; border-radius: var(--r-md); font-size: 15.5px; }
  .nav__link.is-active { background: var(--surface-2); }
  .nav__indicator { display: none; }
  .burger { display: block; }

  .hero { min-height: auto; padding-bottom: 92px; }
  .hero__stats { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px 12px; }
  .hero__cta { gap: 10px; }
  .btn { padding: 12px 20px; font-size: 14.5px; }

  .card { padding: 24px 22px; }
  .grid { grid-template-columns: 1fr; }
  .tl { padding-left: 26px; }
  .tl__dot { left: -26px; top: 26px; width: 14px; height: 14px; }
  .contact__list li { flex-wrap: wrap; }
  .footer__inner { flex-direction: column; text-align: center; }
  .to-top { right: 14px; bottom: 14px; }
}

@media (max-width: 480px) {
  .hero__title { letter-spacing: -.03em; }
  .tag[data-w="5"] { font-size: 18px; }
  .tag[data-w="4"] { font-size: 15.5px; }
  .about__meta { display: block; margin: 8px 0 0; }
  .modal__panel { padding: 24px 18px; }
}

/* 大屏轻微放大留白 */
@media (min-width: 1440px) { :root { --wrap: 1240px; } }

/* 触屏设备不做 hover 位移 */
@media (hover: none) {
  .card:hover, .proj:hover, .tag:hover { transform: none; }
  .card:hover .card__shine { opacity: 0; }
}

/* 尊重系统「减少动态效果」设置 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .backdrop__canvas { display: none; }
}

/* 打印：只留内容 */
@media print {
  .backdrop, .spotlight, .nav, .progress, .to-top, .marquee, .hero__scroll, .modal, .toast { display: none !important; }
  body { background: #fff; color: #000; }
  .card { border-color: #ddd; box-shadow: none; backdrop-filter: none; }
}