/* ============================================================
   Personal Portfolio - Theme-aware Stylesheet
   Cross-Document View Transitions enabled
   Projects: 图片按自然比例显示，卡片整体缩小一圈
   ============================================================ */

@view-transition {
  navigation: auto;
}

/* ============ 0. Fonts ============ */
@font-face {
  font-family: "Geist Sans";
  src: url("../fonts/Geist-Regular.woff2") format("woff2");
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Geist Sans";
  src: url("../fonts/Geist-Medium.woff2") format("woff2");
  font-weight: 500; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Geist Sans";
  src: url("../fonts/Geist-SemiBold.woff2") format("woff2");
  font-weight: 600; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Geist Mono";
  src: url("../fonts/GeistMono-Regular.woff2") format("woff2");
  font-weight: 400; font-style: normal; font-display: swap;
}

/* ============ 1. Structural tokens ============ */
:root {
  --radius: 14px;
  --radius-lg: 20px;
  --radius-card: 12px;
  --nav-h: 64px;

  --font-sans: "Geist Sans", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "Geist Mono", "SFMono-Regular", Consolas, monospace;

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);

  --code-bg: #0f0f12;
  --code-bar-border: #26262b;
  --code-text: #d4d4d8;
  --code-muted: #71717a;
}

/* ============ 2. Dark theme ============ */
html[data-theme="dark"] {
  --bg: #09090b;
  --bg-elevated: #111113;
  --surface: #18181b;
  --surface-hover: #1f1f23;
  --border: #27272a;
  --border-strong: #3f3f46;

  --text: #fafafa;
  --text-secondary: #a1a1aa;
  --text-tertiary: #71717a;

  --accent: #10b981;
  --accent-hover: #34d399;
  --accent-ink: #05100c;
  --accent-dim: rgba(16, 185, 129, 0.12);
  --accent-border: rgba(16, 185, 129, 0.32);

  --nav-bg: rgba(9, 9, 11, 0.82);
  --nav-shadow: none;
  --shadow-soft: 0 10px 30px -12px rgba(0, 0, 0, 0.7);
  --shadow-fab: 0 8px 24px -6px rgba(0, 0, 0, 0.65);
  --shadow-panel: 0 40px 80px -20px rgba(0, 0, 0, 0.9);

  --grain-opacity: 0.028;
  --glow-opacity: 0;
}

/* ============ 3. Light theme ============ */
html[data-theme="light"] {
  --bg: #f7f7f5;
  --bg-elevated: #ffffff;
  --surface: #ffffff;
  --surface-hover: #f2f2ef;
  --border: #e8e6e1;
  --border-strong: #d6d3cd;

  --text: #1a1a18;
  --text-secondary: #57534e;
  --text-tertiary: #8a847e;

  --accent: #059669;
  --accent-hover: #047857;
  --accent-ink: #ffffff;
  --accent-dim: rgba(5, 150, 105, 0.09);
  --accent-border: rgba(5, 150, 105, 0.28);

  --nav-bg: rgba(247, 247, 245, 0.85);
  --nav-shadow: 0 1px 0 rgba(0, 0, 0, 0.04);
  --shadow-soft: 0 8px 24px -12px rgba(28, 25, 23, 0.12);
  --shadow-fab: 0 8px 20px -6px rgba(28, 25, 23, 0.18);
  --shadow-panel: 0 40px 80px -24px rgba(28, 25, 23, 0.28);

  --grain-opacity: 0.02;
  --glow-opacity: 1;
}

/* ============ 4. Theme transition ============ */
html.theme-transitioning,
html.theme-transitioning *,
html.theme-transitioning *::before,
html.theme-transitioning *::after {
  transition: background-color 0.5s ease, color 0.5s ease,
    border-color 0.5s ease, box-shadow 0.5s ease,
    fill 0.5s ease, stroke 0.5s ease !important;
}

/* ============ 5. Reset ============ */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 20px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, p, dl, dd, dt { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

::selection { background: var(--accent-dim); color: var(--text); }

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 99px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-tertiary); }

/* ============ 6. Background ============ */
.bg-deco {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.glow {
  position: absolute;
  top: -260px;
  right: -260px;
  width: 820px;
  height: 820px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(5, 150, 105, 0.1), transparent 62%);
  opacity: var(--glow-opacity);
  transition: opacity 0.5s ease;
}

.grain {
  position: absolute;
  inset: 0;
  opacity: var(--grain-opacity);
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  transition: opacity 0.5s ease;
}

main, .nav, .footer { position: relative; z-index: 2; }

/* ============ 7. Container ============ */
.container {
  width: min(1120px, 100% - 40px);
  margin-inline: auto;
}

/* ============ 8. Navigation ============ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 50;
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease,
    box-shadow 0.3s ease;
}

.nav.scrolled {
  background: var(--nav-bg);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom-color: var(--border);
  box-shadow: var(--nav-shadow);
}

.nav__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 20px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-weight: 600;
  letter-spacing: -0.2px;
}

.logo__mark {
  display: grid;
  place-items: center;
  width: 30px; height: 30px;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-ink);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  transition: background 0.3s ease, color 0.3s ease;
}

.logo__text { font-size: 15px; }

.nav__menu {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
}

.nav__link {
  position: relative;
  padding: 7px 13px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--text-tertiary);
  transition: color 0.2s ease, background 0.2s ease;
}

.nav__link:hover { color: var(--text); background: var(--surface); }
.nav__link.active { color: var(--text); }

.nav__link.active::after {
  content: "";
  position: absolute;
  left: 50%; bottom: 1px;
  transform: translateX(-50%);
  width: 14px; height: 1.5px;
  border-radius: 2px;
  background: var(--accent);
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ============ 9. Theme toggle ============ */
.theme-toggle {
  position: relative;
  display: grid;
  place-items: center;
  width: 36px; height: 36px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  transition: color 0.2s ease, border-color 0.2s ease,
    background 0.2s ease, transform 0.15s ease,
    box-shadow 0.3s ease;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent-border);
  background: var(--accent-dim);
}

.theme-toggle:active { transform: translateY(1px) scale(0.96); }

.theme-toggle .icon {
  position: absolute;
  top: 50%; left: 50%;
  transition: opacity 0.3s var(--ease-out), transform 0.4s var(--ease-out);
}

html[data-theme="dark"] .theme-toggle .icon-sun {
  opacity: 1;
  transform: translate(-50%, -50%) rotate(0deg);
}
html[data-theme="dark"] .theme-toggle .icon-moon {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(-90deg);
}
html[data-theme="light"] .theme-toggle .icon-sun {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(90deg);
}
html[data-theme="light"] .theme-toggle .icon-moon {
  opacity: 1;
  transform: translate(-50%, -50%) rotate(0deg);
}

/* ============ 10. Mobile nav toggle ============ */
.nav__toggle {
  display: none;
  place-items: center;
  width: 40px; height: 40px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  flex-shrink: 0;
}

.nav__toggle span {
  display: block;
  width: 16px; height: 1.5px;
  margin: 2.5px auto;
  border-radius: 2px;
  background: var(--text);
  transition: transform 0.28s var(--ease-out), opacity 0.28s ease;
}

.nav__toggle.active span:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.nav__toggle.active span:nth-child(2) { opacity: 0; }
.nav__toggle.active span:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }

/* ============ 11. Hero ============ */
.hero {
  padding: calc(var(--nav-h) + 80px) 0 80px;
  display: block;
}

.hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: 56px;
  align-items: center;
  width: 100%;
}

.hero__text { max-width: 620px; }

.hero__eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 18px;
}

.hero__title {
  font-size: clamp(2.8rem, 6vw, 4rem);
  font-weight: 600;
  letter-spacing: -2px;
  line-height: 1.05;
  text-wrap: balance;
}

.hero__role {
  margin-top: 14px;
  font-size: clamp(1rem, 2vw, 1.2rem);
  font-weight: 400;
  color: var(--text-secondary);
  min-height: 1.6em;
  white-space: normal;
  word-break: break-word;
  overflow-wrap: anywhere;
}

.typed { color: var(--text); font-weight: 500; }

.caret {
  display: inline-block;
  width: 1.5px; height: 1em;
  margin-left: 3px;
  vertical-align: -0.13em;
  background: var(--accent);
  animation: blink 1s steps(1) infinite;
}

@keyframes blink {
  0%, 49% { opacity: 1; }
  50%, 100% { opacity: 0; }
}

.hero__desc {
  margin-top: 20px;
  max-width: 46ch;
  color: var(--text-secondary);
  font-size: 15px;
  text-wrap: pretty;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  transition: background 0.2s ease, border-color 0.2s ease,
    color 0.2s ease, transform 0.15s ease;
}

.btn:active { transform: translateY(1px) scale(0.98); }

.btn--primary {
  background: var(--accent);
  color: var(--accent-ink);
}
.btn--primary:hover { background: var(--accent-hover); }

.btn--ghost {
  border: 1px solid var(--border-strong);
  color: var(--text);
}
.btn--ghost:hover {
  border-color: var(--accent-border);
  background: var(--accent-dim);
  color: var(--accent);
}

/* ---- Socials ---- */
.socials {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 32px;
}

.socials li a {
  display: grid;
  place-items: center;
  width: 38px; height: 38px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-tertiary);
  transition: color 0.2s ease, border-color 0.2s ease,
    background 0.2s ease, transform 0.15s ease;
}

.socials li a:hover {
  color: var(--accent);
  border-color: var(--accent-border);
  background: var(--accent-dim);
}
.socials li a:active { transform: translateY(1px) scale(0.98); }
.socials--center { justify-content: center; }

/* ---- Code card ---- */
.hero__card { perspective: 1000px; }

.code-card {
  border-radius: var(--radius-lg);
  border: 1px solid var(--code-bar-border);
  background: var(--code-bg);
  box-shadow: 0 20px 50px -20px rgba(0, 0, 0, 0.55);
  overflow: hidden;
  transform: rotate(-1.2deg);
  transition: transform 0.5s var(--ease-out);
}

.code-card:hover { transform: rotate(0deg) translateY(-4px); }

.code-card__bar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--code-bar-border);
}

.cdot { width: 9px; height: 9px; border-radius: 50%; flex: none; }
.cdot--red   { background: #ef4444; }
.cdot--amber { background: #f59e0b; }
.cdot--green { background: #22c55e; }

.code-card__file {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--code-muted);
}

.code-card__body {
  margin: 0;
  padding: 20px 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.9;
  color: var(--code-text);
  overflow-x: auto;
}

.code-card__body::-webkit-scrollbar { height: 5px; }
.code-card__body::-webkit-scrollbar-thumb {
  background: #3f3f46;
  border-radius: 99px;
  border: 0;
}

.c-key  { color: #a78bfa; }
.c-var  { color: #93c5fd; }
.c-type { color: #6ee7b7; }
.c-prop { color: #7dd3fc; }
.c-str  { color: #fcd34d; }
.c-bool { color: #fca5a5; }

/* ============ 12. Section ============ */
.section { padding: 88px 0; }
.section__head { margin-bottom: 44px; }

.section__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 1.8px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section__title {
  font-size: clamp(1.7rem, 3.5vw, 2.3rem);
  font-weight: 600;
  letter-spacing: -1px;
  line-height: 1.2;
}

/* ============ 13. About ============ */
.about__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
  gap: 56px;
  align-items: start;
}

.about__text p {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 16px;
  text-wrap: pretty;
}

.about__text p:last-child { margin-bottom: 0; }
.about__text strong { color: var(--text); font-weight: 500; }

.stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid var(--border);
}

.stat {
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

.stat:nth-child(odd) { padding-right: 20px; border-right: 1px solid var(--border); }
.stat:nth-child(even) { padding-left: 20px; }

.stat__label {
  font-size: 12.5px;
  color: var(--text-tertiary);
  margin-bottom: 6px;
}

.stat__num {
  font-size: 1.8rem;
  font-weight: 600;
  letter-spacing: -1px;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.stat__num sup {
  font-size: 0.55em;
  color: var(--accent);
  vertical-align: super;
}

/* ============ 14. Skills ============ */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px 48px;
}

.skill__top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 9px;
  font-size: 14px;
}

.skill__pct {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.bar {
  height: 5px;
  border-radius: 99px;
  background: var(--surface);
  overflow: hidden;
  transition: background 0.3s ease;
}

.bar__fill {
  display: block;
  width: 0;
  height: 100%;
  border-radius: 99px;
  background: var(--accent);
  transition: width 1s var(--ease-out);
}

/* ============================================================
   15. Projects - 图片按自然比例，卡片整体缩小
   ============================================================ */
.projects__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.project {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  border-radius: var(--radius-card);
  border: 1px solid var(--border);
  background: var(--surface);
  overflow: hidden;
  transition: border-color 0.3s ease, background 0.3s ease,
    transform 0.3s var(--ease-out), box-shadow 0.3s ease;
  cursor: pointer;
}

.project:hover {
  border-color: var(--border-strong);
  transform: translateY(-3px);
  box-shadow: var(--shadow-soft);
}

/* 图片按自然比例显示，不限制宽高比 */
.project__media {
  position: relative;
  width: 100%;
  overflow: hidden;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
}

.project__img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.6s var(--ease-out);
  will-change: transform;
}

.project:hover .project__img { transform: scale(1.03); }

.project__body {
  position: relative;
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: 14px 16px 16px;
}

.project__arrow {
  position: absolute;
  top: 14px; right: 14px;
  display: grid;
  place-items: center;
  width: 24px; height: 24px;
  border-radius: 50%;
  border: 1px solid var(--border);
  color: var(--text-tertiary);
  opacity: 0;
  transform: translate(-3px, 3px);
  transition: opacity 0.25s ease, transform 0.25s var(--ease-out),
    color 0.25s ease, border-color 0.25s ease;
  background: var(--bg);
}

.project:hover .project__arrow {
  opacity: 1;
  transform: translate(0, 0);
  color: var(--accent);
  border-color: var(--accent-border);
}

.project__title {
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: -0.2px;
  margin-bottom: 6px;
}

.project__desc {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text-secondary);
  text-wrap: pretty;
  flex: 1;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-top: 12px;
}

.chip {
  padding: 2px 8px;
  border-radius: 5px;
  border: 1px solid var(--border);
  background: var(--bg);
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-tertiary);
  transition: background 0.3s ease, border-color 0.3s ease;
}

/* ============ 16. Contact ============ */
.contact__card {
  text-align: center;
  padding: 60px 36px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow-soft);
}

.contact__title {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  font-weight: 600;
  letter-spacing: -1px;
}

.contact__desc {
  max-width: 48ch;
  margin: 14px auto 0;
  color: var(--text-secondary);
  font-size: 15px;
  text-wrap: pretty;
}

.contact__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 28px;
}

/* ============ 17. Footer & To-top ============ */
.footer {
  border-top: 1px solid var(--border);
  padding: 26px 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.to-top {
  position: fixed;
  right: 22px; bottom: 22px;
  z-index: 40;
  display: grid;
  place-items: center;
  width: 44px; height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--bg-elevated);
  color: var(--text);
  box-shadow: var(--shadow-fab);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s ease, transform 0.3s ease,
    visibility 0.3s ease, border-color 0.3s ease,
    color 0.3s ease, background 0.3s ease, box-shadow 0.3s ease;
}

.to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { border-color: var(--accent-border); color: var(--accent); }
.to-top:active { transform: translateY(1px) scale(0.96); }

/* ============ 18. Reveal ============ */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
  will-change: opacity, transform;
}

.reveal.visible { opacity: 1; transform: none; }

/* ============================================================
   19. Project Detail Page
   ============================================================ */
.project-page { padding-bottom: 0; }

.project-detail {
  padding: calc(var(--nav-h) + 48px) 0 88px;
}

.project-detail__hero {
  margin-bottom: 40px;
}

/* 详情页图片同样按自然比例显示 */
.project-detail__media {
  position: relative;
  width: 100%;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.project-detail__img {
  width: 100%;
  height: auto;
  display: block;
}

.project-detail__content {
  max-width: 720px;
  margin: 0 auto;
}

.project-detail__title {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 600;
  letter-spacing: -1px;
  line-height: 1.15;
  margin: 12px 0 16px;
  text-wrap: balance;
}

.project-detail__chips {
  margin-top: 0;
  margin-bottom: 28px;
}

.project-detail__desc {
  color: var(--text-secondary);
  font-size: 15.5px;
  margin-bottom: 18px;
  text-wrap: pretty;
}

.project-detail__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

/* 详情页返回按钮 */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  font-size: 13.5px;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.back-link:hover {
  color: var(--accent);
  border-color: var(--accent-border);
  background: var(--accent-dim);
}

.back-link svg { width: 14px; height: 14px; }

/* ============================================================
   20. Cross-Document View Transitions
   ============================================================ */

::view-transition-old(root),
::view-transition-new(root) {
  animation-duration: 0.4s;
  animation-timing-function: var(--ease-out);
}

::view-transition-old(root) { animation-name: vt-fade-out; }
::view-transition-new(root) { animation-name: vt-fade-in; }

@keyframes vt-fade-out {
  to { opacity: 0.6; }
}
@keyframes vt-fade-in {
  from { opacity: 0.6; }
  to { opacity: 1; }
}

::view-transition-old(project-1-image),
::view-transition-new(project-1-image),
::view-transition-old(project-2-image),
::view-transition-new(project-2-image),
::view-transition-old(project-3-image),
::view-transition-new(project-3-image),
::view-transition-old(project-4-image),
::view-transition-new(project-4-image),
::view-transition-old(project-5-image),
::view-transition-new(project-5-image),
::view-transition-old(project-6-image),
::view-transition-new(project-6-image) {
  animation-duration: 0.5s;
  animation-timing-function: var(--ease-out);
}

/* ============ 21. Responsive: Tablet ============ */
@media (max-width: 1024px) {
  .hero { padding-top: calc(var(--nav-h) + 56px); }
  .hero__inner { grid-template-columns: 1fr; gap: 40px; }
  .hero__card { max-width: 520px; }
  .about__grid { grid-template-columns: 1fr; gap: 36px; }
  .projects__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .project-detail { padding: calc(var(--nav-h) + 32px) 0 64px; }
  .project-detail__hero { margin-bottom: 28px; }
}

/* ============ 22. Responsive: Mobile ============ */
@media (max-width: 768px) {
  .container { width: min(1120px, 100% - 32px); }

  .nav__inner { justify-content: space-between; gap: 12px; }

  .nav__toggle { display: grid; }

  .nav__menu {
    position: absolute;
    top: calc(var(--nav-h) - 4px);
    left: 16px; right: 16px;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 10px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--bg-elevated);
    box-shadow: var(--shadow-soft);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
    margin-left: 0;
  }

  .nav__menu.open { opacity: 1; visibility: visible; transform: translateY(0); }

  .nav__link { padding: 11px 13px; font-size: 14.5px; }
  .nav__link.active::after { display: none; }
  .nav__link.active { background: var(--surface); }

  .theme-toggle {
    position: fixed !important;
    top: auto !important;
    right: 16px;
    bottom: 80px;
    z-index: 45;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    border-color: var(--border-strong);
    background: var(--bg-elevated);
    color: var(--text);
    box-shadow: var(--shadow-fab);
  }

  .to-top {
    right: 16px;
    bottom: 18px;
    width: 46px;
    height: 46px;
  }

  .hero { padding-top: calc(var(--nav-h) + 32px); padding-bottom: 40px; }

  .hero__role {
    font-size: clamp(0.9rem, 3.5vw, 1.1rem);
    word-break: break-word;
    overflow-wrap: anywhere;
  }

  .section { padding: 64px 0; }
  .skills__grid { grid-template-columns: 1fr; gap: 20px; }

  /* 移动端卡片：单列 + 限制最大宽度，避免过大 */
  .projects__grid {
    grid-template-columns: 1fr;
    gap: 16px;
    max-width: 520px;
    margin-inline: auto;
  }

  .contact__card { padding: 44px 20px; border-radius: var(--radius); }
  .footer__inner { flex-direction: column; text-align: center; gap: 4px; }

  .project-detail { padding: calc(var(--nav-h) + 20px) 0 48px; }
  .project-detail__hero { margin-bottom: 24px; }
  .project-detail__media { border-radius: var(--radius); }
  .project-detail__desc { font-size: 15px; }
}

@media (max-width: 420px) {
  .hero__title { letter-spacing: -1.2px; }
  .btn { padding: 10px 18px; font-size: 13.5px; }
  .theme-toggle, .to-top { width: 44px; height: 44px; }
  .projects__grid { max-width: 100%; }
}

/* ============ 23. Reduced motion ============ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .reveal { opacity: 1; transform: none; }
  .bar__fill { transition: none; }
  .caret { animation: none; opacity: 1; }
  .code-card { transform: none; }
  .theme-toggle .icon { transition: none !important; }
  .project__img { transition: none !important; }

  ::view-transition-group(*),
  ::view-transition-old(*),
  ::view-transition-new(*) {
    animation: none !important;
  }
}