/* ============================================================
   Chookyin · 个人主页 — 玻璃拟态 + 暗黑/亮色双主题
   ============================================================ */

/* ---------- 主题变量 ---------- */
:root {
  --font-sans: 'Outfit', 'Noto Sans SC', -apple-system, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;

  --nav-h: 68px;
  --max-w: 1120px;

  --dur: .35s;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

[data-theme="dark"] {
  --bg: #0a0e1a;
  --bg-soft: #10152b;
  --text: #eef1ff;
  --text-dim: #9aa3c7;
  --text-faint: #6b7398;
  --glass-bg: rgba(255, 255, 255, .055);
  --glass-bg-strong: rgba(255, 255, 255, .085);
  --glass-border: rgba(255, 255, 255, .12);
  --glass-shadow: 0 20px 60px rgba(0, 0, 0, .45);
  --nav-bg: rgba(10, 14, 26, .62);
  --orb-1: #6366f1;
  --orb-2: #a855f7;
  --orb-3: #06b6d4;
  --grad: linear-gradient(135deg, #818cf8 0%, #c084fc 50%, #22d3ee 100%);
  --card-hover: rgba(255, 255, 255, .10);
  --grid-line: rgba(255, 255, 255, .045);
  --input-bg: rgba(255, 255, 255, .06);
  --footer: rgba(255, 255, 255, .4);
}

[data-theme="light"] {
  --bg: #eef1fb;
  --bg-soft: #f6f8ff;
  --text: #1b2140;
  --text-dim: #5b6488;
  --text-faint: #8a92b4;
  --glass-bg: rgba(255, 255, 255, .55);
  --glass-bg-strong: rgba(255, 255, 255, .72);
  --glass-border: rgba(255, 255, 255, .75);
  --glass-shadow: 0 20px 50px rgba(99, 102, 241, .16);
  --nav-bg: rgba(238, 241, 251, .62);
  --orb-1: #6366f1;
  --orb-2: #a855f7;
  --orb-3: #06b6d4;
  --grad: linear-gradient(135deg, #4f46e5 0%, #a855f7 50%, #0891b2 100%);
  --card-hover: rgba(255, 255, 255, .9);
  --grid-line: rgba(27, 33, 64, .05);
  --input-bg: rgba(255, 255, 255, .8);
  --footer: rgba(27, 33, 64, .5);
}

/* ---------- 基础 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
  -webkit-font-smoothing: antialiased;
}

::selection { background: rgba(139, 92, 246, .4); color: #fff; }

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #6366f1, #a855f7);
  border-radius: 8px;
  border: 2px solid var(--bg);
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img, svg { display: block; }

/* ---------- 背景装饰 ---------- */
.bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  background: var(--bg);
  transition: background var(--dur) var(--ease);
}

#stars { position: absolute; inset: 0; width: 100%; height: 100%; }

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 30%, transparent 75%);
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: .45;
  will-change: transform;
}

[data-theme="dark"] .orb { opacity: .4; }
[data-theme="light"] .orb { opacity: .32; }

.orb-1 { width: 520px; height: 520px; top: -160px; left: -120px; background: var(--orb-1); animation: drift 26s ease-in-out infinite alternate; }
.orb-2 { width: 460px; height: 460px; top: 12%; right: -160px; background: var(--orb-2); animation: drift 32s ease-in-out infinite alternate-reverse; }
.orb-3 { width: 420px; height: 420px; bottom: -140px; left: 30%; background: var(--orb-3); animation: drift 38s ease-in-out infinite alternate; }

@keyframes drift {
  0%   { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(60px, -40px) scale(1.12); }
  100% { transform: translate(-50px, 50px) scale(.94); }
}

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease), backdrop-filter var(--dur) var(--ease);
}

.nav.scrolled {
  background: var(--nav-bg);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  box-shadow: 0 8px 32px rgba(0, 0, 0, .12);
  border-bottom: 1px solid var(--glass-border);
}

.nav-inner {
  width: min(var(--max-w), 92%);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; }

.logo-mark {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  border-radius: 11px;
  background: var(--grad);
  color: #fff;
  font-size: 19px;
  font-weight: 800;
  box-shadow: 0 6px 18px rgba(139, 92, 246, .4);
  transition: transform .3s var(--ease);
}

.logo:hover .logo-mark { transform: rotate(-8deg) scale(1.06); }

.logo-text { font-size: 18px; letter-spacing: .4px; background: var(--grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }

.nav-links { display: flex; gap: 6px; }

.nav-link {
  position: relative;
  padding: 8px 14px;
  font-size: 14.5px;
  color: var(--text-dim);
  border-radius: 10px;
  transition: color .25s, background .25s;
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 14px; right: 14px; bottom: 4px;
  height: 2px;
  border-radius: 2px;
  background: var(--grad);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .3s var(--ease);
}

.nav-link:hover, .nav-link.active { color: var(--text); }
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }

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

.theme-toggle {
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  background: var(--glass-bg);
  color: var(--text-dim);
  cursor: pointer;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: all .3s var(--ease);
}

.theme-toggle:hover { color: var(--text); border-color: rgba(139, 92, 246, .6); transform: translateY(-1px); }
.theme-toggle svg { width: 19px; height: 19px; }

.icon-sun { display: none; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }
[data-theme="light"] .icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: none; }

.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px; height: 40px;
  padding: 0 10px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  cursor: pointer;
}

.hamburger span { display: block; height: 2px; border-radius: 2px; background: var(--text-dim); transition: all .3s var(--ease); }
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-h) + 40px) 24px 80px;
  position: relative;
}

.hero-content { display: flex; flex-direction: column; align-items: center; gap: 22px; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  font-size: 13.5px;
  color: var(--text-dim);
  border: 1px solid var(--glass-border);
  border-radius: 999px;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--glass-shadow);
}

.pulse-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 0 0 rgba(52, 211, 153, .6);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(52, 211, 153, .55); }
  70% { box-shadow: 0 0 0 10px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

.hero-title { display: flex; flex-direction: column; gap: 6px; }

.hello {
  font-size: clamp(20px, 3.4vw, 30px);
  font-weight: 400;
  color: var(--text-dim);
  letter-spacing: 2px;
}

.name {
  font-size: clamp(56px, 11vw, 128px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: 2px;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 8px 40px rgba(139, 92, 246, .35));
  animation: floaty 6s ease-in-out infinite;
}

@keyframes floaty {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.hero-typing {
  font-family: 'Outfit', monospace;
  font-size: clamp(17px, 2.6vw, 24px);
  color: var(--text-dim);
  min-height: 1.6em;
}

.type-label { color: #34d399; font-weight: 700; }

.caret {
  display: inline-block;
  width: 2px;
  height: 1.1em;
  margin-left: 3px;
  vertical-align: text-bottom;
  background: var(--grad);
  animation: blink 1s step-end infinite;
}

@keyframes blink { 50% { opacity: 0; } }

.hero-desc { font-size: clamp(14.5px, 2vw, 17.5px); color: var(--text-dim); max-width: 560px; }

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; margin-top: 8px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all .3s var(--ease);
}

.btn svg { width: 17px; height: 17px; transition: transform .3s var(--ease); }

.btn-primary {
  color: #fff;
  background: var(--grad);
  border: none;
  box-shadow: 0 10px 30px rgba(139, 92, 246, .38);
}

.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 16px 40px rgba(139, 92, 246, .5); }
.btn-primary:hover svg { transform: translateX(4px); }

.btn-ghost {
  color: var(--text);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.btn-ghost:hover { transform: translateY(-3px); border-color: rgba(139, 92, 246, .55); background: var(--glass-bg-strong); }

.hero-meta { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-top: 10px; }

.meta-chip {
  padding: 7px 16px;
  font-size: 13px;
  color: var(--text-dim);
  border-radius: 999px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: all .3s var(--ease);
}

.meta-chip:hover { transform: translateY(-2px); color: var(--text); border-color: rgba(139, 92, 246, .5); }

.scroll-hint {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-faint);
  font-size: 12px;
  letter-spacing: 1.5px;
}

.mouse {
  width: 24px; height: 38px;
  border: 2px solid var(--text-faint);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 6px;
}

.wheel {
  width: 3px; height: 7px;
  border-radius: 3px;
  background: var(--text-faint);
  animation: wheel 1.8s ease-in-out infinite;
}

@keyframes wheel {
  0% { transform: translateY(0); opacity: 1; }
  60% { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ---------- 通用区块 ---------- */
.section {
  width: min(var(--max-w), 92%);
  margin: 0 auto;
  padding: 110px 0;
  scroll-margin-top: calc(var(--nav-h) + 16px);
}

.section-head { text-align: center; margin-bottom: 56px; }

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 2.5px;
  text-transform: uppercase;
  color: #818cf8;
  background: rgba(129, 140, 248, .12);
  border: 1px solid rgba(129, 140, 248, .3);
  border-radius: 999px;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(30px, 5vw, 44px);
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 10px;
}

.section-sub { color: var(--text-dim); font-size: 15.5px; }

/* ---------- 玻璃卡片 ---------- */
.glass-card {
  position: relative;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(18px) saturate(150%);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  box-shadow: var(--glass-shadow);
  transition: transform .45s var(--ease), box-shadow .45s var(--ease), border-color .45s var(--ease), background .45s var(--ease);
}

.glass-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, rgba(255,255,255,.35), transparent 40%, transparent 60%, rgba(255,255,255,.12));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: .6;
}

.glass-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 60px rgba(99, 102, 241, .22);
  border-color: rgba(139, 92, 246, .45);
  background: var(--card-hover);
}

/* ---------- 关于 ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 24px;
  align-items: stretch;
}

.about-card { padding: 44px 40px; text-align: center; }

.avatar {
  position: relative;
  width: 110px; height: 110px;
  margin: 0 auto 22px;
}

.avatar-inner {
  position: absolute;
  inset: 6px;
  display: grid;
  place-items: center;
  font-size: 52px;
  font-weight: 800;
  color: #fff;
  background: var(--grad);
  border-radius: 50%;
  box-shadow: 0 14px 34px rgba(139, 92, 246, .4);
}

.avatar-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px dashed rgba(139, 92, 246, .6);
  animation: spin 14s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.about-card h3 { font-size: 26px; font-weight: 800; margin-bottom: 4px; }
.about-role { color: #818cf8; font-size: 14.5px; margin-bottom: 18px; }
.about-text { color: var(--text-dim); font-size: 14.5px; margin-bottom: 20px; }

.about-tags { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }

.about-tags span {
  padding: 5px 14px;
  font-size: 13px;
  border-radius: 999px;
  background: rgba(129, 140, 248, .12);
  border: 1px solid rgba(129, 140, 248, .28);
  color: var(--text-dim);
}

.stats-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }

.stat-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 34px 20px;
  text-align: center;
  gap: 4px;
}

.stat-num {
  font-size: 44px;
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.2;
}

.stat-unit { font-size: 22px; font-weight: 700; color: #818cf8; }

.stat-label { color: var(--text-dim); font-size: 13.5px; margin-top: 4px; }

/* ---------- 技能 ---------- */
.skills-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }

.skill-card { padding: 30px 32px; }

.skill-head { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; }

.skill-icon {
  width: 46px; height: 46px;
  display: grid; place-items: center;
  font-size: 22px;
  border-radius: 13px;
  background: color-mix(in srgb, var(--i) 16%, transparent);
  border: 1px solid color-mix(in srgb, var(--i) 40%, transparent);
}

.skill-name { font-size: 17px; font-weight: 700; }

.progress {
  height: 8px;
  border-radius: 8px;
  background: var(--input-bg);
  overflow: hidden;
  margin-bottom: 12px;
}

.progress-fill {
  display: block;
  height: 100%;
  width: 0;
  border-radius: 8px;
  background: var(--grad);
  box-shadow: 0 0 12px rgba(139, 92, 246, .5);
  transition: width 1.4s var(--ease);
}

.skill-level { font-size: 13px; color: var(--text-faint); }

/* ---------- 项目 ---------- */
.projects-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

.project-card { overflow: hidden; display: flex; flex-direction: column; }

.project-thumb {
  height: 170px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--t1), var(--t2));
  position: relative;
}

.project-thumb::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(255,255,255,.35), transparent 45%),
    repeating-linear-gradient(45deg, rgba(255,255,255,.06) 0 10px, transparent 10px 20px);
}

.thumb-emoji { font-size: 54px; filter: drop-shadow(0 8px 18px rgba(0,0,0,.35)); z-index: 1; animation: floaty 5s ease-in-out infinite; }

.project-body { padding: 26px 26px 28px; display: flex; flex-direction: column; gap: 12px; flex: 1; }

.project-body h3 { font-size: 19px; font-weight: 700; }
.project-body p { font-size: 14px; color: var(--text-dim); flex: 1; }

.project-tags { display: flex; gap: 8px; flex-wrap: wrap; }

.project-tags span {
  padding: 4px 12px;
  font-size: 12px;
  border-radius: 999px;
  background: rgba(129, 140, 248, .12);
  border: 1px solid rgba(129, 140, 248, .28);
  color: var(--text-dim);
}

.project-links { display: flex; align-items: center; justify-content: space-between; padding-top: 6px; }

.project-links a:first-child { font-size: 14px; font-weight: 600; color: #818cf8; transition: color .25s; }
.project-links a:first-child:hover { color: var(--text); }

.link-icon {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  border-radius: 10px;
  border: 1px solid var(--glass-border);
  background: var(--glass-bg);
  color: var(--text-dim);
  font-size: 16px;
  transition: all .3s var(--ease);
}

.link-icon:hover { color: #fff; background: var(--grad); border-color: transparent; transform: translateY(-2px); }

/* ---------- 历程 ---------- */
.timeline { position: relative; max-width: 720px; margin: 0 auto; padding-left: 34px; }

.timeline::before {
  content: '';
  position: absolute;
  left: 10px; top: 8px; bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, #6366f1, #a855f7, #06b6d4, transparent);
  border-radius: 2px;
}

.timeline-item { position: relative; padding-bottom: 30px; }

.timeline-item:last-child { padding-bottom: 0; }

.timeline-dot {
  position: absolute;
  left: -30px; top: 26px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--grad);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 4px rgba(139, 92, 246, .25), 0 0 16px rgba(139, 92, 246, .6);
}

.timeline-card { padding: 26px 30px; }

.timeline-date {
  display: inline-block;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 1.5px;
  color: #818cf8;
  background: rgba(129, 140, 248, .12);
  border: 1px solid rgba(129, 140, 248, .28);
  border-radius: 999px;
  padding: 4px 14px;
  margin-bottom: 12px;
}

.timeline-card h3 { font-size: 18px; margin-bottom: 6px; }
.timeline-card p { font-size: 14px; color: var(--text-dim); }

/* ---------- 联系 ---------- */
.contact-card {
  max-width: 720px;
  margin: 0 auto;
  padding: 46px 46px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 26px;
}

.contact-intro h3 { font-size: 24px; font-weight: 800; margin-bottom: 10px; }
.contact-intro p { color: var(--text-dim); font-size: 15px; max-width: 480px; }

.contact-actions { display: flex; flex-direction: column; align-items: center; gap: 22px; }

.socials { display: flex; gap: 12px; }

.social-btn {
  width: 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: 13px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-dim);
  transition: all .3s var(--ease);
}

.social-btn svg { width: 20px; height: 20px; }

.social-btn:hover { color: #fff; background: var(--grad); border-color: transparent; transform: translateY(-4px); box-shadow: 0 10px 24px rgba(139, 92, 246, .4); }

/* ---------- 页脚 ---------- */
.footer {
  text-align: center;
  padding: 36px 20px 40px;
  font-size: 13.5px;
  color: var(--footer);
  border-top: 1px solid var(--glass-border);
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.heart { color: #f472b6; animation: beat 1.4s ease-in-out infinite; display: inline-block; }

@keyframes beat {
  0%, 100% { transform: scale(1); }
  25% { transform: scale(1.25); }
  40% { transform: scale(1); }
  60% { transform: scale(1.18); }
}

/* ---------- 回到顶部 ---------- */
.back-top {
  position: fixed;
  right: 26px; bottom: 26px;
  z-index: 90;
  width: 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: 14px;
  background: var(--grad);
  color: #fff;
  box-shadow: 0 12px 30px rgba(139, 92, 246, .45);
  opacity: 0;
  pointer-events: none;
  transform: translateY(16px);
  transition: all .4s var(--ease);
}

.back-top svg { width: 20px; height: 20px; }

.back-top.show { opacity: 1; pointer-events: auto; transform: translateY(0); }
.back-top:hover { transform: translateY(-4px); }

/* ---------- 滚动显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(34px);
  transition: opacity .9s var(--ease), transform .9s var(--ease);
  transition-delay: var(--d, 0s);
}

.reveal.visible { opacity: 1; transform: translateY(0); }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .about-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; max-width: 460px; margin: 0 auto; }
}

@media (max-width: 720px) {
  :root { --nav-h: 60px; }

  .nav-links {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    gap: 4px;
    padding: 16px 6vw 22px;
    background: var(--nav-bg);
    backdrop-filter: blur(22px) saturate(160%);
    -webkit-backdrop-filter: blur(22px) saturate(160%);
    border-bottom: 1px solid var(--glass-border);
    box-shadow: 0 18px 40px rgba(0, 0, 0, .2);
    transform: translateY(-16px);
    opacity: 0;
    pointer-events: none;
    transition: all .35s var(--ease);
  }

  .nav-links.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .nav-link { padding: 12px 16px; font-size: 16px; }
  .nav-link::after { display: none; }

  .hamburger { display: flex; }

  .section { padding: 84px 0; }
  .skills-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 16px; }
  .stat-num { font-size: 34px; }
  .contact-card { padding: 36px 24px; }
  .hide-mobile { display: none; }
  .hero { padding-top: calc(var(--nav-h) + 30px); }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}