/* Enoch Cheung — portfolio stylesheet */
:root {
  --bg: #fafaf8;
  --bg-alt: #f1f1ec;
  --card: #ffffff;
  --text: #1c2321;
  --muted: #5b6663;
  --accent: #0e7a6d;
  --accent-soft: #e2f0ee;
  --border: #e3e3dd;
  --shadow: 0 1px 3px rgba(28, 35, 33, 0.07), 0 8px 24px rgba(28, 35, 33, 0.05);
  --radius: 14px;
  --max: 1060px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14181a;
    --bg-alt: #1a2023;
    --card: #1e2528;
    --text: #e8ebe9;
    --muted: #9aa6a2;
    --accent: #4fc3b2;
    --accent-soft: #1d3330;
    --border: #2b3438;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; border-radius: 10px; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 14px; padding-bottom: 14px;
}
.brand { font-weight: 700; font-size: 1.05rem; color: var(--text); letter-spacing: -0.01em; }
.brand:hover { text-decoration: none; color: var(--accent); }
nav.main-nav { display: flex; gap: 22px; font-size: 0.95rem; }
nav.main-nav a { color: var(--muted); font-weight: 500; }
nav.main-nav a:hover, nav.main-nav a.active { color: var(--accent); text-decoration: none; }

/* Hero */
.hero { padding: 84px 0 56px; }
.hero .kicker {
  color: var(--accent); font-weight: 600; font-size: 0.9rem;
  text-transform: uppercase; letter-spacing: 0.12em; margin-bottom: 14px;
}
.hero h1 {
  font-size: clamp(2.1rem, 5vw, 3.3rem);
  line-height: 1.12; letter-spacing: -0.025em; margin: 0 0 20px;
}
.hero h1 em { font-style: normal; color: var(--accent); }
.hero .lede { font-size: 1.18rem; color: var(--muted); max-width: 46em; margin: 0 0 30px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-block; padding: 11px 22px; border-radius: 999px;
  font-weight: 600; font-size: 0.97rem; border: 1px solid transparent;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { filter: brightness(1.08); }
.btn-ghost { border-color: var(--border); color: var(--text); background: var(--card); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* Proof bar */
.proof {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 14px; padding: 34px 0 10px;
}
.proof .stat {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 18px 18px 15px; box-shadow: var(--shadow);
}
.proof .num { font-size: 1.55rem; font-weight: 750; letter-spacing: -0.02em; color: var(--accent); }
.proof .lbl { font-size: 0.85rem; color: var(--muted); line-height: 1.4; margin-top: 3px; }

/* Sections */
section { padding: 58px 0 8px; }
.section-kicker {
  color: var(--accent); font-weight: 600; font-size: 0.82rem;
  text-transform: uppercase; letter-spacing: 0.12em; margin-bottom: 6px;
}
h2.section-title { font-size: 1.75rem; letter-spacing: -0.02em; margin: 0 0 10px; }
.section-intro { color: var(--muted); max-width: 46em; margin-top: 0; }

/* Cards */
.grid { display: grid; gap: 20px; margin-top: 28px; }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 860px) { .grid.cols-3, .grid.cols-2 { grid-template-columns: 1fr; } }
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow);
  display: flex; flex-direction: column;
}
.card h3 { margin: 0 0 8px; font-size: 1.18rem; letter-spacing: -0.01em; }
.card p { color: var(--muted); font-size: 0.97rem; margin: 0 0 14px; }
.card .more { margin-top: auto; font-weight: 600; font-size: 0.95rem; }
.pill-row { display: flex; flex-wrap: wrap; gap: 7px; margin: 0 0 14px; }
.pill {
  font-size: 0.78rem; padding: 3px 11px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); font-weight: 600;
}

/* Timeline */
.timeline { margin-top: 30px; border-left: 2px solid var(--border); padding-left: 28px; }
.tl-item { position: relative; padding-bottom: 30px; }
.tl-item:last-child { padding-bottom: 8px; }
.tl-item::before {
  content: ""; position: absolute; left: -35px; top: 7px;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--accent); border: 3px solid var(--bg);
}
.tl-date { font-size: 0.82rem; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 0.08em; }
.tl-item h3 { margin: 4px 0 4px; font-size: 1.08rem; }
.tl-item p { margin: 0; color: var(--muted); font-size: 0.95rem; max-width: 44em; }
.tl-layer { font-size: 0.85rem; font-weight: 600; color: var(--text); background: var(--accent-soft); display: inline-block; border-radius: 6px; padding: 2px 9px; margin-top: 8px; }

/* Case-study pages */
.page-hero { padding: 64px 0 20px; }
.page-hero .kicker { color: var(--accent); font-weight: 600; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.12em; }
.page-hero h1 { font-size: clamp(1.7rem, 4vw, 2.5rem); letter-spacing: -0.02em; line-height: 1.18; margin: 10px 0 14px; }
.page-hero .meta { color: var(--muted); font-size: 1.02rem; max-width: 48em; }
.summary-box {
  background: var(--card); border: 1px solid var(--border); border-left: 4px solid var(--accent);
  border-radius: var(--radius); padding: 20px 24px; margin: 26px 0;
}
.summary-box strong { color: var(--accent); }
article h2 { font-size: 1.4rem; letter-spacing: -0.015em; margin: 44px 0 12px; }
article h3 { font-size: 1.12rem; margin: 30px 0 8px; }
article p, article li { color: var(--text); }
article .note { color: var(--muted); font-size: 0.93rem; }
figure { margin: 26px 0; }
figure img { border: 1px solid var(--border); box-shadow: var(--shadow); }
figcaption { font-size: 0.9rem; color: var(--muted); margin-top: 10px; }
.result-list { list-style: none; padding: 0; margin: 18px 0; }
.result-list li {
  padding: 12px 16px; margin-bottom: 10px; background: var(--card);
  border: 1px solid var(--border); border-radius: 10px;
}
.result-list li strong { color: var(--accent); }

/* Footer */
.site-footer { margin-top: 80px; border-top: 1px solid var(--border); padding: 34px 0 44px; }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 14px; color: var(--muted); font-size: 0.92rem; }
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--accent); }

/* Back link */
.backlink { display: inline-block; margin-top: 34px; font-weight: 600; }

@media (max-width: 640px) {
  .hero { padding: 56px 0 40px; }
  nav.main-nav { gap: 14px; font-size: 0.88rem; }
  body { font-size: 16px; }
}