:root {
  --bg: #ffffff;
  --bg-subtle: #f5f7f8;
  --surface: #ffffff;
  --text: #1d2933;
  --muted: #687680;
  --accent: #4f7e68;
  --accent-dark: #3d6654;
  --accent-soft: #e8f0ec;
  --border: #dfe6e2;
  --shadow: 0 14px 36px rgba(24, 42, 33, 0.09);
  --radius: 8px;
  --container: 1160px;
  --header-height: 68px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
img, video { display: block; max-width: 100%; }

.container { width: min(calc(100% - 40px), var(--container)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid rgba(223, 230, 226, 0.9);
  backdrop-filter: blur(14px);
}

.nav { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-size: 17px; font-weight: 750; white-space: nowrap; }
.brand-mark { width: 30px; height: 30px; display: grid; place-items: center; color: #fff; background: var(--accent); border-radius: 6px; font-size: 14px; font-weight: 800; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { position: relative; padding: 7px 0; color: #4f5d66; font-size: 14px; font-weight: 650; }
.nav-links a::after { content: ""; position: absolute; right: 0; bottom: 0; left: 0; height: 2px; background: var(--accent); transform: scaleX(0); transition: transform 180ms ease; }
.nav-links a:hover, .nav-links a:focus-visible, .nav-links a.is-active { color: var(--accent-dark); }
.nav-links a:hover::after, .nav-links a:focus-visible::after, .nav-links a.is-active::after { transform: scaleX(1); }
.nav-toggle { display: none; width: 40px; height: 40px; padding: 0; border: 1px solid var(--border); border-radius: 6px; color: var(--text); background: var(--surface); cursor: pointer; }
.nav-toggle svg { width: 21px; height: 21px; margin: auto; }

.hero { min-height: 550px; display: flex; align-items: center; padding: 78px 0 84px; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1fr; gap: 44px; align-items: center; }
.hero-grid > .reveal { max-width: 820px; }
.eyebrow { margin: 0 0 12px; color: var(--accent-dark); font-size: 13px; font-weight: 800; letter-spacing: 0.08em; }
.hero h1 { margin: 0; font-size: clamp(46px, 7vw, 76px); font-weight: 800; line-height: 1.02; }
.hero-role { margin: 16px 0 0; color: var(--accent-dark); font-size: clamp(24px, 3.2vw, 38px); font-weight: 680; line-height: 1.25; }
.hero-summary { max-width: 650px; margin: 26px 0 0; color: var(--muted); font-size: 17px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }

.button { min-height: 46px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 0 22px; border: 1px solid transparent; border-radius: 7px; font-size: 14px; font-weight: 700; line-height: 1; transition: transform 180ms ease, background 180ms ease, border-color 180ms ease, color 180ms ease, box-shadow 180ms ease; }
.button svg { width: 18px; height: 18px; flex: 0 0 auto; }
.button-primary { color: #fff; background: var(--accent); box-shadow: 0 7px 18px rgba(79, 126, 104, 0.22); }
.button-secondary { color: var(--text); background: #fff; border-color: var(--border); }
.button:hover { transform: translateY(-2px); }
.button-primary:hover { background: var(--accent-dark); box-shadow: 0 10px 24px rgba(79, 126, 104, 0.28); }
.button-secondary:hover { color: var(--accent-dark); border-color: #a9beb4; }
.button:focus-visible, .nav-toggle:focus-visible { outline: 3px solid rgba(79, 126, 104, 0.25); outline-offset: 3px; }

.profile-card { position: relative; padding: 34px; background: var(--bg-subtle); border: 1px solid var(--border); border-radius: var(--radius); }
.profile-card::before { content: ""; position: absolute; top: 0; right: 34px; left: 34px; height: 3px; background: var(--accent); }
.profile-card h2 { margin: 0 0 22px; font-size: 17px; text-align: center; }
.wide-profile-card { width: 100%; }
.wide-profile-card .profile-list { display: grid; grid-template-columns: 1fr 1.25fr 0.9fr 1fr 1.35fr; }
.wide-profile-card .profile-row { display: block; padding: 15px 20px; border-top: 0; border-left: 1px solid var(--border); }
.wide-profile-card .profile-row:first-child { border-left: 0; }
.wide-profile-card .profile-row dt { margin-bottom: 6px; }
.wide-profile-card .profile-row dt { font-size: 20px; }
.wide-profile-card .profile-row dd { font-size: 20px; }
.wide-profile-card .profile-row:last-child dd { white-space: nowrap; overflow-wrap: normal; }
.profile-list { margin: 0; }
.profile-row { display: grid; grid-template-columns: 90px minmax(0, 1fr); gap: 18px; padding: 14px 0; border-top: 1px solid var(--border); }
.profile-row dt { color: var(--muted); font-size: 13px; font-weight: 650; }
.profile-row dd { min-width: 0; margin: 0; font-size: 14px; font-weight: 650; overflow-wrap: anywhere; }
.profile-row a:hover { color: var(--accent-dark); }

.page-hero { padding: 84px 0 72px; background: var(--bg-subtle); border-bottom: 1px solid var(--border); }
.page-hero h1 { max-width: 760px; margin: 0; font-size: clamp(38px, 6vw, 62px); line-height: 1.08; }
.page-hero p { max-width: 700px; margin: 22px 0 0; color: var(--muted); font-size: 17px; }
.section { padding: 84px 0; }
.section-subtle { background: var(--bg-subtle); }
.section-heading { display: grid; grid-template-columns: minmax(180px, 0.4fr) minmax(0, 0.6fr); gap: 48px; align-items: end; margin-bottom: 48px; }
.section-heading-single { display: block; }
.section-heading h2 { margin: 0; font-size: clamp(30px, 4vw, 44px); line-height: 1.15; }
.section-heading p { max-width: 610px; margin: 0; color: var(--muted); }

.quick-links { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.link-card, .skill-card, .project-card, .contact-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.link-card { min-height: 170px; display: flex; flex-direction: column; justify-content: space-between; padding: 24px; transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease; }
.link-card:hover, .project-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #b9cdc1; }
.link-card strong { font-size: 21px; }
.link-card p { margin: 10px 0 0; color: var(--muted); font-size: 14px; }
.link-card span { color: var(--accent-dark); font-size: 13px; font-weight: 800; }

.home-overview { display: grid; grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr); gap: 16px; }
.home-overview .profile-card { height: 100%; }
.home-education { padding: 28px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.home-education h2 { margin: 0 0 20px; font-size: 22px; }
.home-education .timeline-item { align-items: center; }
.home-education .timeline-date { font-size: 20px; line-height: 1.35; }
.home-education .timeline-item h2 { font-size: 20px; }
.home-education .timeline-item { grid-template-columns: 190px minmax(0, 1fr); padding: 20px 0; }
.home-education .timeline-date { white-space: nowrap; }

.skills-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.skill-card { min-height: 215px; padding: 30px; }
.skill-index { display: block; margin-bottom: 16px; color: var(--accent); font-size: 13px; font-weight: 800; }
.skill-card h2 { margin: 0 0 12px; font-size: 21px; }
.skill-card p { margin: 0; color: var(--muted); font-size: 15px; }
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.tag { padding: 4px 9px; color: var(--accent-dark); background: var(--accent-soft); border-radius: 5px; font-size: 12px; font-weight: 700; }

.project-layout { display: block; }
.project-heading { margin-bottom: 24px; }
.project-heading h2 { margin: 0; font-size: 36px; line-height: 1.2; }
.project-heading .project-meta { margin: 8px 0 0; }
.video-shell { overflow: hidden; background: #111820; border: 1px solid #26333d; border-radius: var(--radius); box-shadow: var(--shadow); }
.video-shell video { width: 100%; aspect-ratio: 16 / 9; background: #111820; object-fit: contain; }
.video-caption { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 16px 18px; color: #dfe8e3; background: #18222b; font-size: 13px; }
.video-caption a { color: #9bd0b7; font-weight: 700; white-space: nowrap; }
.project-copy h2 { margin: 0; font-size: 30px; line-height: 1.25; }
.project-details { max-width: 980px; margin: 30px auto 0; }
.project-meta { margin: 9px 0 24px; color: var(--accent-dark); font-size: 16px; font-weight: 750; }
.project-description { margin: 0 0 22px; color: var(--muted); font-size: 18px; line-height: 1.8; }
.project-points { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--border); }
.project-points li { position: relative; padding: 17px 0 17px 23px; border-bottom: 1px solid var(--border); color: #44525b; font-size: 16px; line-height: 1.8; }
.project-points strong { color: var(--accent-dark); font-weight: 800; }
.project-points li::before { content: ""; position: absolute; top: 25px; left: 1px; width: 7px; height: 7px; background: var(--accent); border-radius: 2px; }

.timeline { border-top: 1px solid var(--border); }
.timeline-item { display: grid; grid-template-columns: 160px minmax(0, 1fr); gap: 26px; padding: 29px 0; border-bottom: 1px solid var(--border); }
.timeline-date { color: var(--accent-dark); font-size: 13px; font-weight: 750; }
.timeline-item h2 { margin: 0 0 5px; font-size: 20px; }
.timeline-item p { margin: 0; color: var(--muted); font-size: 14px; }

.experience-card { padding: 32px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.experience-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; margin-bottom: 24px; }
.experience-head h2 { margin: 0; font-size: 25px; line-height: 1.25; }
.experience-role { margin: 7px 0 0; color: var(--accent-dark); font-size: 14px; font-weight: 750; }
.experience-date { flex: 0 0 auto; color: var(--muted); font-size: 16px; font-weight: 700; text-align: right; }
.experience-list { margin: 0; padding: 0 0 0 22px; color: #44525b; font-size: 14px; }
.experience-list li { padding: 7px 0; }
.experience-gallery { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 28px; }
.experience-gallery figure { min-width: 0; overflow: hidden; margin: 0; background: #101828; border-radius: 7px; }
.experience-gallery img { display: block; width: 100%; height: auto; object-fit: contain; }
.experience-gallery figcaption { padding: 10px 13px; color: #dfe8e3; background: #18222b; font-size: 12px; }
.experience-note { margin: 14px 0 0; color: var(--muted); font-size: 12px; }

.contact-grid { display: grid; grid-template-columns: minmax(0, 1fr) 350px; gap: 60px; align-items: start; }
.contact-grid h2 { margin: 0 0 18px; font-size: clamp(30px, 4vw, 44px); line-height: 1.15; }
.contact-grid > div > p { max-width: 680px; margin: 0; color: var(--muted); font-size: 17px; }
.contact-card { padding: 28px; background: var(--accent-soft); border-color: #cadbd2; }
.contact-card h2 { margin: 0 0 18px; font-size: 19px; }
.contact-card a { display: block; padding: 11px 0; border-top: 1px solid #cadbd2; color: var(--accent-dark); font-size: 14px; font-weight: 700; overflow-wrap: anywhere; }
.contact-card a:first-of-type { border-top: 0; }
.contact-grid > .self-eval-copy > p { margin: 0; color: #3f4b52; font-size: 19px; line-height: 1.85; text-indent: 2em; }

.site-footer { padding: 28px 0; color: #75818a; background: #fff; border-top: 1px solid var(--border); font-size: 13px; }
.footer-row { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.filing-info { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 8px 14px; margin-top: 16px; text-align: center; }
.filing-info .flex { display: inline-flex; align-items: center; }
.filing-info a { display: inline-flex; align-items: center; gap: 5px; color: #749AE3; font-size: 12px; }
.filing-info a:hover { color: var(--accent-dark); }
.filing-info img { width: 16px; height: 16px; object-fit: contain; }
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 480ms ease, transform 480ms ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
  .hero { min-height: auto; padding: 64px 0 68px; }
  .hero-grid, .project-layout, .contact-grid { grid-template-columns: 1fr; }
  .hero-grid, .project-layout { gap: 42px; }
  .contact-grid { gap: 38px; }
  .section-heading { grid-template-columns: 1fr; gap: 15px; }
  .contact-card { max-width: 520px; }
  .quick-links { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .wide-profile-card .profile-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .wide-profile-card .profile-row, .wide-profile-card .profile-row:first-child { padding: 14px 0; border-top: 1px solid var(--border); border-left: 0; }
  .wide-profile-card .profile-row:first-child { border-top: 0; }
  .wide-profile-card .profile-row:nth-child(odd) { border-left: 0; }
  .wide-profile-card .profile-row:nth-child(even) { border-left: 1px solid var(--border); padding-left: 20px; }
}

@media (max-width: 720px) {
  :root { --header-height: 62px; }
  .container { width: min(calc(100% - 32px), var(--container)); }
  .nav-toggle { display: grid; }
  .nav-links { position: absolute; top: var(--header-height); right: 0; left: 0; display: grid; gap: 0; padding: 8px 16px 14px; background: #fff; border-bottom: 1px solid var(--border); box-shadow: 0 12px 24px rgba(29, 41, 51, 0.08); opacity: 0; visibility: hidden; transform: translateY(-8px); transition: opacity 180ms ease, visibility 180ms ease, transform 180ms ease; }
  .nav-links.is-open { opacity: 1; visibility: visible; transform: translateY(0); }
  .nav-links a { padding: 13px 8px; border-bottom: 1px solid var(--border); }
  .nav-links a:last-child { border-bottom: 0; }
  .nav-links a::after { display: none; }
  .hero { padding-top: 48px; }
  .hero h1 { font-size: clamp(44px, 15vw, 62px); }
  .hero-role { font-size: clamp(25px, 8.3vw, 34px); }
  .hero-summary { font-size: 16px; }
  .profile-card { padding: 28px 22px; }
  .profile-row { grid-template-columns: 74px minmax(0, 1fr); gap: 12px; }
  .wide-profile-card .profile-list { grid-template-columns: 1fr; }
  .wide-profile-card .profile-row, .wide-profile-card .profile-row:first-child { padding: 14px 0; border-top: 1px solid var(--border); border-left: 0; }
  .wide-profile-card .profile-row:first-child { border-top: 0; }
  .page-hero { padding: 62px 0 54px; }
  .section { padding: 68px 0; }
  .section-heading { margin-bottom: 34px; }
  .quick-links, .skills-grid { grid-template-columns: 1fr; }
  .home-overview { grid-template-columns: 1fr; }
  .home-education .timeline-item { grid-template-columns: 1fr; gap: 8px; }
  .video-caption { align-items: flex-start; flex-direction: column; gap: 6px; }
  .experience-card { padding: 24px 20px; }
  .experience-head { flex-direction: column; gap: 8px; }
  .experience-date { text-align: left; }
  .experience-gallery { grid-template-columns: 1fr; }
  .timeline-item { grid-template-columns: 1fr; gap: 8px; }
  .footer-row { align-items: flex-start; flex-direction: column; gap: 6px; }
  .filing-info { justify-content: flex-start; text-align: left; }
}

@media (max-width: 420px) {
  .hero-actions { display: grid; }
  .button { width: 100%; }
  .profile-row { grid-template-columns: 1fr; gap: 4px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .reveal { opacity: 1; transform: none; }
}