/* ============ 主题变量 ============ */
/* 色系参考国际米兰队徽:深蓝 + 黑 */
:root {
  --bg: #f3f5f9;
  --bg-elev: #ffffff;
  --text: #0a0f1c;
  --text-muted: #4a5568;
  --border: #dbe1eb;
  --accent: #0a4ea2;
  --accent-contrast: #ffffff;
  --accent-soft: #e5edf8;
  --glass-edge: rgb(255 255 255 / 0.75);
  --glass-sheen: rgb(255 255 255 / 0.55);
  --glow-strength: 22%;
  --success: #16a34a;
  --danger: #dc2626;
  --radius: 14px;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.04), 0 8px 24px rgb(0 0 0 / 0.06);
  --max-w: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #05070d;
    --bg-elev: #0c1322;
    --text: #e8edf5;
    --text-muted: #94a3b8;
    --border: #1b2740;
    --accent: #4d8fe0;
    --accent-contrast: #05070d;
    --accent-soft: #0f2346;
    --glass-edge: rgb(255 255 255 / 0.08);
    --glass-sheen: rgb(140 185 255 / 0.12);
    --glow-strength: 30%;
    --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 8px 24px rgb(0 0 0 / 0.3);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #05070d;
  --bg-elev: #0c1322;
  --text: #e8edf5;
  --text-muted: #94a3b8;
  --border: #1b2740;
  --accent: #4d8fe0;
  --accent-contrast: #05070d;
  --accent-soft: #0f2346;
  --glass-edge: rgb(255 255 255 / 0.08);
  --glass-sheen: rgb(140 185 255 / 0.12);
  --glow-strength: 30%;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 8px 24px rgb(0 0 0 / 0.3);
  color-scheme: dark;
}

/* ============ 基础 ============ */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 0.5em; }

.container { width: 100%; max-width: var(--max-w); margin: 0 auto; padding: 0 20px; }

.skip-link {
  position: absolute; left: -9999px; top: 8px;
  background: var(--accent); color: var(--accent-contrast); padding: 8px 12px; border-radius: 8px; z-index: 100;
}
.skip-link:focus { left: 8px; }

/* ============ 导航 ============ */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 700; font-size: 1.15rem; color: var(--text); }
.logo span { color: var(--accent); }
.logo:hover { text-decoration: none; }

.nav-links { display: flex; align-items: center; gap: 28px; list-style: none; margin: 0; padding: 0; }
.nav-links a { color: var(--text-muted); font-size: 0.95rem; }
.nav-links a:hover, .nav-links a.active { color: var(--text); text-decoration: none; }

.theme-toggle {
  display: grid; place-items: center; width: 36px; height: 36px;
  border: 1px solid var(--border); border-radius: 50%; background: var(--bg-elev); color: var(--text); cursor: pointer;
}
.theme-toggle svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; }
.icon-moon { display: none; }
:root[data-theme="dark"] .icon-sun { display: none; }
:root[data-theme="dark"] .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-sun { display: none; }
  :root:not([data-theme="light"]) .icon-moon { display: block; }
}

.nav-actions { display: flex; align-items: center; gap: 10px; }
.lang-toggle {
  height: 36px; min-width: 44px; padding: 0 12px;
  border: 1px solid var(--border); border-radius: 999px; background: var(--bg-elev);
  color: var(--text); font: inherit; font-size: 0.85rem; font-weight: 600; cursor: pointer;
}
.lang-toggle:hover, .theme-toggle:hover { border-color: var(--accent); color: var(--accent); }

.nav-toggle { display: none; }

@media (max-width: 720px) {
  .nav-toggle {
    display: flex; flex-direction: column; gap: 5px; padding: 8px;
    background: none; border: 0; cursor: pointer;
  }
  .nav-toggle span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: transform .2s, opacity .2s; }
  .nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .nav-links {
    position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 0;
    background: var(--bg); border-bottom: 1px solid var(--border);
    padding: 8px 20px 16px; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 12px 0; font-size: 1rem; }
  .nav-actions { margin-top: 8px; }
  .hide-sm { display: none; }
}

/* ============ Hero ============ */
.hero { padding: 120px 20px 96px; }
.eyebrow { color: var(--accent); font-weight: 600; margin: 0 0 8px; }
.hero h1 { font-size: clamp(2.5rem, 7vw, 4.5rem); letter-spacing: -0.02em; }
.hero-sub { font-size: clamp(1.05rem, 2.2vw, 1.3rem); color: var(--text-muted); max-width: 640px; margin: 0 0 32px; }
.hero-sub strong { color: var(--text); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.availability { display: flex; align-items: center; gap: 8px; color: var(--text-muted); font-size: 0.9rem; margin-top: 28px; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--success); box-shadow: 0 0 0 4px color-mix(in srgb, var(--success) 25%, transparent); }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 22px; border-radius: 999px; font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer; font-family: inherit;
  transition: transform .15s, background .15s, border-color .15s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: var(--accent-contrast); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--text-muted); }
.btn[disabled] { opacity: .6; cursor: not-allowed; transform: none; }

/* ============ 通用区块 ============ */
.section { padding: 72px 20px; }
.section-title { font-size: clamp(1.6rem, 3.5vw, 2.2rem); margin-bottom: 32px; }
.section-title::after {
  content: ""; display: block; width: 40px; height: 3px; margin-top: 12px; background: var(--accent); border-radius: 2px;
}

.card {
  position: relative; overflow: hidden;
  background: color-mix(in srgb, var(--bg-elev) 62%, transparent);
  backdrop-filter: blur(16px) saturate(170%);
  -webkit-backdrop-filter: blur(16px) saturate(170%);
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow), inset 0 1px 0 var(--glass-edge);
}
/* 液态玻璃高光:跟随鼠标在卡片表面移动 */
.card::before {
  content: ""; position: absolute; inset: 0; pointer-events: none; border-radius: inherit;
  background: radial-gradient(320px circle at var(--mx, 50%) var(--my, -40%), var(--glass-sheen), transparent 65%);
  opacity: 0; transition: opacity .4s ease;
}
.card:hover::before { opacity: 1; }
.card h3 { font-size: 1.1rem; }

.tags { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; padding: 0; margin: 0; }
.tags li {
  background: var(--accent-soft); color: var(--accent);
  padding: 4px 12px; border-radius: 999px; font-size: 0.85rem; font-weight: 500;
}
.tags.small li { font-size: 0.78rem; padding: 2px 10px; }

/* 关于 */
.about-grid { display: grid; grid-template-columns: 1.6fr 1fr; gap: 48px; align-items: start; }
.about-text p { color: var(--text-muted); margin: 0 0 1em; }
.about-text strong { color: var(--text); }
.stats { list-style: none; padding: 0; margin: 0; display: grid; gap: 16px; }
.stats li { display: flex; align-items: baseline; gap: 12px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
.stats strong { font-size: 2rem; color: var(--accent); min-width: 96px; }
.stats span { color: var(--text-muted); }

/* 技能 */
.skills-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 20px; }

/* 项目 */
.projects-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; }
.project { display: flex; flex-direction: column; gap: 12px; transition: transform .2s, border-color .2s; }
.project:hover { transform: translateY(-4px); border-color: var(--accent); }
.project h3 { margin: 0; }
.project p { color: var(--text-muted); margin: 0; flex: 1; }
.project-thumb {
  aspect-ratio: 16 / 9; border-radius: 10px; display: grid; place-items: center;
  font-size: 2.5rem; font-weight: 800; color: var(--accent);
  background: linear-gradient(135deg, var(--accent-soft), color-mix(in srgb, var(--accent) 20%, var(--bg-elev)));
}
.project-links { display: flex; gap: 16px; font-size: 0.9rem; font-weight: 500; }

/* 联系 */
.contact-intro { color: var(--text-muted); max-width: 620px; margin: -8px 0 32px; }
.contact-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: 40px; align-items: start; }
.contact-methods { display: flex; flex-direction: column; gap: 24px; align-items: flex-start; }
.contact-item { width: 100%; }
.contact-item .label { display: block; font-size: 0.8rem; text-transform: uppercase; letter-spacing: .08em; color: var(--text-muted); margin-bottom: 4px; }
.contact-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; font-size: 1.1rem; font-weight: 500; }
.copy-btn {
  font: inherit; font-size: 0.8rem; padding: 4px 12px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--border); background: var(--bg-elev); color: var(--text-muted);
}
.copy-btn:hover { color: var(--text); border-color: var(--text-muted); }
.socials { display: flex; gap: 16px; flex-wrap: wrap; list-style: none; padding: 0; margin: 0; font-weight: 500; }

.contact-form { display: flex; flex-direction: column; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 0.9rem; font-weight: 600; }
.field input, .field textarea {
  font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--border); border-radius: 10px; padding: 10px 14px; resize: vertical;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.field.invalid input, .field.invalid textarea { border-color: var(--danger); }
.error { color: var(--danger); font-size: 0.82rem; margin: 0; min-height: 1em; }
.form-status { margin: 0; font-size: 0.9rem; min-height: 1.4em; }
.form-status.ok { color: var(--success); }
.form-status.fail { color: var(--danger); }

@media (max-width: 820px) {
  .about-grid, .contact-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero { padding: 80px 20px 64px; }
  .section { padding: 56px 20px; }
}

/* ============ 页脚 & 提示 ============ */
.site-footer { border-top: 1px solid var(--border); padding: 28px 0; color: var(--text-muted); font-size: 0.9rem; }
.site-footer .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.site-footer p { margin: 0; }

.toast {
  position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 20px);
  background: var(--text); color: var(--bg); padding: 10px 18px; border-radius: 999px;
  font-size: 0.9rem; opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s; z-index: 200;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ============ 鼠标光晕 ============ */
.cursor-glow {
  position: fixed; top: 0; left: 0; z-index: 0; pointer-events: none;
  width: 560px; height: 560px; margin: -280px 0 0 -280px; border-radius: 50%;
  background: radial-gradient(circle, color-mix(in srgb, var(--accent) var(--glow-strength), transparent) 0%, transparent 68%);
  filter: blur(40px);
  opacity: 0; transition: opacity .6s ease;
  will-change: transform;
}
.cursor-glow.active { opacity: 1; }
main, .site-footer { position: relative; z-index: 1; }
@media (hover: none), (pointer: coarse) { .cursor-glow { display: none; } }

/* 滚动进入动画 */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.visible { opacity: 1; transform: none; }