:root {
  --bg: #ffffff;
  --bg-alt: #f3f6f8;
  --ink: #1b2430;
  --muted: #5a6573;
  --line: #dde3e9;
  --accent: #0d6e6e;
  --accent-ink: #ffffff;
  --tag-bg: #e6f1f1;
  --dark: #0f2227;
  --dark-ink: #eef5f5;
  --dark-muted: #9db5b8;
  --dark-accent: #5fcfca;
  --font: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12171d; --bg-alt: #1a212a; --ink: #e8edf2; --muted: #a0abb8;
    --line: #2b3541; --accent: #4fc0bd; --accent-ink: #0b1418; --tag-bg: #1f2e33;
    --dark: #0a1417;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 4rem; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body { margin: 0; font-family: var(--font); line-height: 1.8; color: var(--ink); background: var(--bg); }
a { color: var(--accent); }
a:focus-visible, .btn:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
.wrap { width: min(100% - 2.5rem, 62rem); margin-inline: auto; }

/* Header: floats over the hero */
.site-header { position: fixed; inset: 0 0 auto 0; z-index: 10; background: rgba(15, 34, 39, .92); backdrop-filter: blur(6px); }
.bar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 3.5rem; }
.brand { color: var(--dark-ink); font-weight: 700; text-decoration: none; white-space: nowrap; }
.site-header nav { display: flex; gap: 1.25rem; overflow-x: auto; scrollbar-width: none; }
.site-header nav::-webkit-scrollbar { display: none; }
.site-header nav a { color: var(--dark-muted); text-decoration: none; font-size: .9rem; white-space: nowrap; }
.site-header nav a:hover { color: var(--dark-accent); }

/* Hero */
.hero { min-height: 100svh; display: flex; align-items: center; padding: 6rem 0 4rem; background: var(--dark); color: var(--dark-ink); }
.hello { margin: 0 0 .5rem; color: var(--dark-accent); font-size: 1.25rem; }
h1 { margin: 0 0 1.5rem; font-size: clamp(2.4rem, 8vw, 4.5rem); line-height: 1.2; }
h1 span { display: block; margin-top: .4rem; font-size: .5em; font-weight: 400; color: var(--dark-muted); }
.lead { max-width: 36rem; margin: 0 0 2rem; font-size: 1.125rem; color: var(--dark-muted); }
.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin: 0; }
.btn { display: inline-block; padding: .65rem 1.3rem; border: 1.5px solid var(--dark-accent); border-radius: 999px; color: var(--dark-accent); text-decoration: none; font-weight: 600; }
.btn.primary { background: var(--dark-accent); color: var(--dark); }
.btn:hover { opacity: .85; }

/* Sections */
.section { padding: clamp(3rem, 8vw, 5.5rem) 0; }
.section.alt { background: var(--bg-alt); }
.kicker { margin: 0 0 .25rem; color: var(--accent); font-weight: 600; font-size: .95rem; }
h2 { margin: 0 0 2rem; font-size: clamp(1.7rem, 4vw, 2.2rem); line-height: 1.3; }
h3 { margin: 0; font-size: 1.1rem; line-height: 1.4; }
ul { padding-left: 1.2rem; }

.split { display: grid; gap: 1rem 4rem; }
@media (min-width: 52rem) { .split { grid-template-columns: 1fr 2fr; } }
.prose p { margin: 0 0 1rem; max-width: 40rem; }
.facts { color: var(--muted); font-size: .92rem; border-top: 1px solid var(--line); padding-top: 1rem; margin-top: 1.5rem !important; }

/* What I do */
.cols { display: grid; gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); }
.cols h3 { padding-bottom: .5rem; margin-bottom: .6rem; border-bottom: 3px solid var(--accent); }
.cols ul { margin: 0; padding: 0; list-style: none; color: var(--muted); }
.cols li { padding: .15rem 0; }

/* Timeline */
.timeline { list-style: none; margin: 0; padding: 0; }
.timeline > li { display: grid; gap: .25rem 2.5rem; padding: 0 0 2.5rem 1.25rem; border-left: 2px solid var(--line); position: relative; }
.timeline > li::before { content: ""; position: absolute; left: -7px; top: .5rem; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); }
.timeline > li:last-child { padding-bottom: 0; }
.date { margin: 0; color: var(--accent); font-weight: 600; font-size: .95rem; }
.org { margin: .1rem 0 .75rem; }
.org span { display: block; color: var(--muted); font-size: .85rem; }
.timeline ul { margin: 0; }
.timeline li li { margin-bottom: .4rem; }
@media (min-width: 52rem) {
  .timeline > li { grid-template-columns: 11rem 1fr; padding-left: 0; border-left: 0; }
  .timeline > li::before { display: none; }
  .date { padding-top: .2rem; }
  .timeline > li > div { padding-left: 2rem; border-left: 2px solid var(--line); position: relative; }
  .timeline > li > div::before { content: ""; position: absolute; left: -7px; top: .5rem; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); }
}

/* Works */
.works { display: grid; gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr)); }
.work h3 { margin-top: .9rem; }
.work .role { margin: 0 0 .5rem; color: var(--accent); font-size: .88rem; }
.work p:last-child { margin: 0; color: var(--muted); font-size: .95rem; line-height: 1.7; }
.work-img, .cert-img { aspect-ratio: 16 / 10; border: 1.5px dashed var(--line); border-radius: 8px; background: var(--bg); overflow: hidden; }
.work-img img, .cert-img img { width: 100%; height: 100%; display: block; object-fit: cover; }

/* Stats */
.stats { background: var(--dark); color: var(--dark-ink); padding: 3.5rem 0; }
.stats ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(10rem, 1fr)); text-align: center; }
.stats strong { display: block; font-size: clamp(2rem, 6vw, 3rem); line-height: 1.2; color: var(--dark-accent); }
.stats span { color: var(--dark-muted); font-size: .95rem; }

/* Certificates */
.certs { list-style: none; margin: 0; padding: 0; display: grid; gap: 1.5rem; grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr)); }
.cert-img { aspect-ratio: 4 / 3; }
.cert-img img { object-fit: contain; background: #fff; }
.cert h3 { font-size: 1rem; margin-top: .6rem; }
.cert p { margin: .15rem 0 0; color: var(--muted); font-size: .88rem; }

/* Contact */
.contact { padding: clamp(4rem, 10vw, 7rem) 0; background: var(--bg-alt); }
.contact h2 { max-width: 34rem; margin-bottom: 1rem; }
.contact p { max-width: 34rem; }
.mail { margin: 1.5rem 0 0; font-size: clamp(1.3rem, 4vw, 1.9rem); font-weight: 700; word-break: break-all; }

.site-footer { padding: 1.5rem 0; color: var(--muted); font-size: .85rem; border-top: 1px solid var(--line); }
.site-footer p { margin: 0; }

@media (max-width: 40rem) { .brand { display: none; } }
@media print { .site-header, .actions { display: none; } .hero { min-height: auto; } }