/* ============================================================
   个人网站 · 样式
   主题：深色 · 简洁 · 渐变点缀
   ============================================================ */

:root {
  --bg: #0a0b10;
  --bg-soft: #10121a;
  --card: rgba(255, 255, 255, 0.03);
  --card-hover: rgba(255, 255, 255, 0.055);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text: #e9ebf2;
  --text-dim: #9aa2b4;
  --text-faint: #6b7385;
  --accent-a: #7b8bff;
  --accent-b: #2fd4ee;
  --gradient: linear-gradient(135deg, var(--accent-a), var(--accent-b));
  --radius: 18px;
  --radius-sm: 10px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  --font-head: "Space Grotesk", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --header-h: 72px;
}

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

html {
  scroll-behavior: smooth;
}

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

::selection {
  background: rgba(123, 139, 255, 0.35);
  color: #fff;
}

img,
svg {
  display: block;
  max-width: 100%;
}

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

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 104px 0;
  scroll-margin-top: var(--header-h);
}

.section-alt {
  background: linear-gradient(180deg, transparent, rgba(123, 139, 255, 0.035) 18%, rgba(47, 212, 238, 0.025) 82%, transparent);
}

.icon {
  width: 20px;
  height: 20px;
  flex: none;
}

/* ---------- 背景装饰 ---------- */

.bg-decor {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(110px);
  opacity: 0.16;
}

.blob-a {
  width: 560px;
  height: 560px;
  top: -180px;
  right: -140px;
  background: radial-gradient(circle, var(--accent-a), transparent 65%);
}

.blob-b {
  width: 460px;
  height: 460px;
  bottom: -160px;
  left: -140px;
  background: radial-gradient(circle, var(--accent-b), transparent 65%);
}

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 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%);
}

/* ---------- 导航栏 ---------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  transition: background 0.35s ease, border-color 0.35s ease, backdrop-filter 0.35s ease;
  border-bottom: 1px solid transparent;
}

.site-header.scrolled {
  background: rgba(10, 11, 16, 0.72);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--border);
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.brand {
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-right: auto;
}

.brand-dot {
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 30px;
}

.nav-link {
  position: relative;
  font-size: 15px;
  color: var(--text-dim);
  padding: 6px 2px;
  transition: color 0.25s ease;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--text);
}

.nav-link.is-active::after {
  transform: scaleX(1);
}

.nav-cta {
  padding: 9px 20px;
  font-size: 14px;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}

.menu-toggle span {
  width: 22px;
  height: 2px;
  border-radius: 2px;
  background: var(--text);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.menu-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.open span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 26px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease, background 0.25s ease;
  will-change: transform;
}

.btn-primary {
  color: #0a0b10;
  background: var(--gradient);
  box-shadow: 0 8px 26px rgba(99, 120, 255, 0.28);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(99, 140, 255, 0.38);
}

.btn-ghost {
  color: var(--text);
  border: 1px solid var(--border-strong);
  background: rgba(255, 255, 255, 0.02);
}

.btn-ghost:hover {
  border-color: rgba(123, 139, 255, 0.65);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 15px 34px;
  font-size: 16px;
}

/* ---------- 通用区块头 ---------- */

.section-head {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 64px;
}

.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 14px;
}

.section-head h2 {
  font-family: var(--font-head);
  font-size: clamp(30px, 4.4vw, 42px);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.section-sub {
  margin-top: 12px;
  color: var(--text-dim);
  font-size: 16px;
}

/* ---------- 卡片 ---------- */

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.3s ease, border-color 0.3s ease, background 0.3s ease, box-shadow 0.3s ease;
}

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

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  padding: calc(var(--header-h) + 48px) 0 88px;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.12fr 0.88fr;
  align-items: center;
  gap: 64px;
}

.hero-content .eyebrow {
  margin-bottom: 20px;
}

.hero-name {
  font-family: var(--font-head);
  font-size: clamp(52px, 9vw, 88px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.025em;
  background: linear-gradient(120deg, #ffffff 20%, var(--accent-a) 55%, var(--accent-b) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-role {
  margin-top: 18px;
  font-family: var(--font-head);
  font-size: clamp(18px, 2.6vw, 24px);
  font-weight: 600;
  color: var(--text-dim);
  min-height: 1.6em;
}

.caret {
  display: inline-block;
  width: 2px;
  height: 1.05em;
  margin-left: 3px;
  vertical-align: -0.14em;
  background: var(--gradient);
  animation: blink 1s steps(1) infinite;
}

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

.hero-desc {
  max-width: 520px;
  margin-top: 22px;
  color: var(--text-dim);
  font-size: 17px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 36px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, auto);
  justify-content: start;
  gap: 44px;
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}

.hero-stats strong {
  display: block;
  font-family: var(--font-head);
  font-size: 30px;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-stats span {
  font-size: 14px;
  color: var(--text-faint);
}

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.avatar {
  width: min(360px, 72vw);
  border-radius: 28px;
  box-shadow: var(--shadow), 0 0 0 1px var(--border);
  animation: avatar-in 1s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}

@keyframes avatar-in {
  from {
    opacity: 0;
    transform: translateY(24px) scale(0.97);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.float-card {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border-radius: 14px;
  background: rgba(18, 20, 28, 0.82);
  border: 1px solid var(--border-strong);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45);
  font-size: 13px;
  color: var(--text-dim);
  animation: float 5.5s ease-in-out infinite;
}

.float-card .icon {
  color: var(--accent-b);
}

.float-card strong {
  display: block;
  color: var(--text);
  font-size: 15px;
  line-height: 1.2;
}

.float-card-a {
  top: 8%;
  left: -6%;
}

.float-card-b {
  bottom: 10%;
  right: -4%;
  animation-delay: 1.4s;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-12px);
  }
}

.scroll-hint {
  position: absolute;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-faint);
  font-size: 12px;
  letter-spacing: 0.18em;
  transition: color 0.25s ease;
}

.scroll-hint:hover {
  color: var(--text-dim);
}

.scroll-hint-line {
  width: 1px;
  height: 44px;
  background: linear-gradient(180deg, var(--accent-a), transparent);
  animation: scroll-line 2s ease-in-out infinite;
  transform-origin: top;
}

@keyframes scroll-line {
  0% {
    transform: scaleY(0);
  }
  45% {
    transform: scaleY(1);
  }
  100% {
    transform: scaleY(1);
    opacity: 0;
  }
}

/* ---------- 关于 ---------- */

.about-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 36px;
  align-items: start;
}

.about-text p {
  color: var(--text-dim);
  font-size: 16.5px;
  margin-bottom: 20px;
}

.about-text strong {
  color: var(--text);
  font-weight: 600;
  background: linear-gradient(120deg, var(--accent-a), var(--accent-b));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.about-facts {
  padding: 28px 30px;
}

.about-quote {
  margin-top: 28px;
  padding: 18px 22px;
  border-left: 3px solid var(--accent-a);
  background: linear-gradient(90deg, rgba(123, 139, 255, 0.08), transparent 72%);
  border-radius: 0 12px 12px 0;
  color: var(--text);
  font-size: 17px;
  line-height: 1.8;
}

.about-facts h3 {
  font-family: var(--font-head);
  font-size: 19px;
  margin-bottom: 6px;
}

.about-facts .eyebrow {
  font-size: 11px;
  margin-bottom: 16px;
}

.fact-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}

.fact-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.fact-row dt {
  color: var(--text-faint);
  font-size: 14px;
}

.fact-row dd {
  font-weight: 500;
  text-align: right;
}

/* ---------- 技能 ---------- */

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

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

.skill-card:hover,
.project-card:hover {
  transform: translateY(-6px);
  border-color: rgba(123, 139, 255, 0.45);
  background: var(--card-hover);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.38);
}

.skill-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(123, 139, 255, 0.16), rgba(47, 212, 238, 0.12));
  border: 1px solid rgba(123, 139, 255, 0.25);
  color: var(--accent-a);
  margin-bottom: 22px;
}

.skill-icon .icon {
  width: 24px;
  height: 24px;
}

.skill-card h3 {
  font-family: var(--font-head);
  font-size: 20px;
  margin-bottom: 10px;
}

.skill-card > p {
  color: var(--text-dim);
  font-size: 14.5px;
  margin-bottom: 20px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag-list li {
  padding: 5px 13px;
  border-radius: 999px;
  font-size: 12.5px;
  color: var(--text-dim);
  background: rgba(255, 255, 255, 0.045);
  border: 1px solid var(--border);
  transition: color 0.25s ease, border-color 0.25s ease;
}

.tag-list li:hover {
  color: var(--text);
  border-color: rgba(123, 139, 255, 0.5);
}

/* ---------- 经历 ---------- */

.timeline {
  max-width: 780px;
  margin: 0 auto;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 168px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--accent-a), var(--accent-b), transparent);
  opacity: 0.35;
}

.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 168px 1fr;
  gap: 40px;
  padding-bottom: 48px;
}

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

.timeline-item::before {
  content: "";
  position: absolute;
  left: 163px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent-a);
  box-shadow: 0 0 0 4px rgba(123, 139, 255, 0.14);
}

.timeline-meta {
  text-align: right;
  padding-top: 2px;
}

.timeline-company {
  display: block;
  font-weight: 600;
  font-size: 15px;
}

.timeline-period {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--text-faint);
  font-variant-numeric: tabular-nums;
}

.timeline-body {
  padding: 24px 26px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.timeline-body:hover {
  border-color: rgba(47, 212, 238, 0.45);
  transform: translateY(-3px);
}

.timeline-body h3 {
  font-family: var(--font-head);
  font-size: 18px;
  margin-bottom: 8px;
}

.timeline-body p {
  color: var(--text-dim);
  font-size: 14.5px;
  margin-bottom: 16px;
}

/* ---------- 我的学习成就 ---------- */

.achievements-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 760px;
  margin: 0 auto;
}

.achievement-card {
  padding: 36px 32px;
  text-align: center;
}

.achievement-card:hover {
  transform: translateY(-6px);
  border-color: rgba(47, 212, 238, 0.45);
  background: var(--card-hover);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.38);
}

.achievement-card .skill-icon {
  margin: 0 auto 20px;
}

.achievement-card h3 {
  font-family: var(--font-head);
  font-size: 22px;
  margin-bottom: 8px;
}

.achievement-desc {
  color: var(--text-dim);
  font-size: 15px;
  margin-bottom: 18px;
}

.achievement-badge {
  display: inline-block;
  padding: 6px 18px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(123, 139, 255, 0.16), rgba(47, 212, 238, 0.12));
  border: 1px solid rgba(123, 139, 255, 0.3);
  color: var(--accent-b);
  font-weight: 600;
  font-size: 14px;
}

/* ---------- 旅游足迹 ---------- */

.travel-groups {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  max-width: 860px;
  margin: 0 auto;
}

.travel-group {
  padding: 30px 32px;
}

.travel-group h3 {
  font-family: var(--font-head);
  font-size: 18px;
  margin-bottom: 18px;
}

.travel-group .tag-list li {
  font-size: 14px;
  padding: 8px 16px;
}

/* ---------- 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 {
  position: relative;
  height: 158px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid var(--border);
}

.project-thumb span {
  font-family: var(--font-head);
  font-size: 54px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.85);
  letter-spacing: -0.03em;
  transition: transform 0.35s ease;
}

.project-card:hover .project-thumb span {
  transform: scale(1.08) rotate(-2deg);
}

.project-thumb::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 25%, rgba(255, 255, 255, 0.14), transparent 45%);
}

.thumb-a {
  background: linear-gradient(135deg, #5159e8, #22d3ee);
}

.thumb-b {
  background: linear-gradient(135deg, #0ea5a5, #34d399);
}

.thumb-c {
  background: linear-gradient(135deg, #7c3aed, #d946ef);
}

.thumb-d {
  background: linear-gradient(135deg, #e11d48, #fb923c);
}

.thumb-e {
  background: linear-gradient(135deg, #2563eb, #38bdf8);
}

.thumb-f {
  background: linear-gradient(135deg, #64748b, #a5b4fc);
}

.project-body {
  padding: 24px 26px 26px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.project-body h3 {
  font-family: var(--font-head);
  font-size: 19px;
  margin-bottom: 10px;
}

.project-body p {
  color: var(--text-dim);
  font-size: 14.5px;
  margin-bottom: 18px;
}

.project-links {
  display: flex;
  gap: 18px;
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.project-links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-dim);
  transition: color 0.25s ease;
}

.project-links a:hover {
  color: var(--accent-b);
}

/* ---------- 联系 ---------- */

.contact-card {
  max-width: 640px;
  margin: 0 auto;
  padding: 64px 48px;
  text-align: center;
  background:
    radial-gradient(ellipse 80% 70% at 50% 0%, rgba(123, 139, 255, 0.09), transparent 65%),
    var(--card);
}

.contact-card h2 {
  font-family: var(--font-head);
  font-size: clamp(30px, 4.4vw, 42px);
  margin-bottom: 14px;
}

.contact-desc {
  max-width: 420px;
  margin: 0 auto 36px;
  color: var(--text-dim);
  font-size: 16px;
}

.contact-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
}

.contact-genshin {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 28px;
  color: var(--text-dim);
  font-size: 15px;
}

.contact-genshin .icon {
  color: var(--accent-b);
}

.contact-genshin strong {
  color: var(--text);
  font-family: var(--font-head);
  font-size: 17px;
  letter-spacing: 0.04em;
}

.socials {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 36px;
}

.tag-list li a {
  color: inherit;
  display: inline-block;
}

.inline-link {
  color: var(--accent-b);
  text-decoration: underline;
  text-decoration-color: rgba(47, 212, 238, 0.4);
  text-underline-offset: 4px;
  transition: text-decoration-color 0.25s ease;
}

.inline-link:hover {
  text-decoration-color: var(--accent-b);
}

.social-link {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: rgba(255, 255, 255, 0.02);
  color: var(--text-dim);
  transition: all 0.3s ease;
}

.social-link:hover {
  color: var(--accent-b);
  border-color: rgba(47, 212, 238, 0.6);
  transform: translateY(-3px);
  box-shadow: 0 10px 26px rgba(47, 212, 238, 0.18);
}

/* ---------- 页脚 ---------- */

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

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  color: var(--text-faint);
  font-size: 13.5px;
}

.footer-note {
  letter-spacing: 0.08em;
}

/* ---------- 回到顶部 ---------- */

.back-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  z-index: 90;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(18, 20, 28, 0.85);
  border: 1px solid var(--border-strong);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--text-dim);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all 0.3s ease;
}

.back-top.show {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.back-top:hover {
  color: var(--accent-b);
  border-color: rgba(47, 212, 238, 0.6);
}

/* ---------- 滚动显现动画 ---------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.2, 0.7, 0.2, 1);
}

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

.skills-grid .reveal:nth-child(2),
.projects-grid .reveal:nth-child(2),
.timeline .reveal:nth-child(2) {
  transition-delay: 0.08s;
}

.skills-grid .reveal:nth-child(3),
.projects-grid .reveal:nth-child(3),
.timeline .reveal:nth-child(3) {
  transition-delay: 0.16s;
}

.projects-grid .reveal:nth-child(4) {
  transition-delay: 0.08s;
}

.projects-grid .reveal:nth-child(5) {
  transition-delay: 0.16s;
}

.projects-grid .reveal:nth-child(6) {
  transition-delay: 0.24s;
}

/* ---------- 响应式 ---------- */

@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 72px;
    text-align: center;
  }

  .hero-desc,
  .hero-content {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-stats {
    justify-content: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .float-card-a {
    left: 2%;
  }

  .float-card-b {
    right: 2%;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .timeline::before {
    left: 6px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 14px;
    padding-left: 28px;
  }

  .timeline-item::before {
    left: 1px;
  }

  .timeline-meta {
    text-align: left;
  }
}

@media (max-width: 720px) {
  .section {
    padding: 76px 0;
  }

  .section-head {
    margin-bottom: 44px;
  }

  .nav-links {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 14px 24px 20px;
    background: rgba(10, 11, 16, 0.96);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--border);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
  }

  .nav-links.open {
    transform: none;
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    display: block;
    padding: 13px 4px;
    font-size: 16px;
    border-bottom: 1px solid var(--border);
  }

  .nav-link::after {
    display: none;
  }

  .nav-link.is-active {
    color: var(--accent-b);
  }

  .nav-cta {
    display: none;
  }

  .menu-toggle {
    display: flex;
  }

  .hero-stats {
    gap: 28px;
  }

  .skills-grid,
  .projects-grid,
  .achievements-grid,
  .travel-groups {
    grid-template-columns: 1fr;
  }

  .float-card {
    display: none;
  }

  .contact-card {
    padding: 48px 26px;
  }

  .footer-inner {
    justify-content: center;
    text-align: center;
  }

  .back-top {
    right: 18px;
    bottom: 18px;
  }
}

/* ---------- 无障碍：减少动效 ---------- */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

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