/* 4x Tools — 香港實用工具 */
:root {
  --ink: #0c1f2e;
  --ink-soft: #1a3347;
  --sea: #0d7377;
  --sea-deep: #095456;
  --sea-light: #e6f4f4;
  --amber: #e8a317;
  --amber-soft: #fff4d6;
  --paper: #f7f5f0;
  --card: #ffffff;
  --line: #d9d4c8;
  --muted: #5c6b76;
  --ok: #1b7a4e;
  --warn: #9a5b00;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(12, 31, 46, 0.08);
  --shadow-sm: 0 2px 10px rgba(12, 31, 46, 0.06);
  --font: "IBM Plex Sans", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --max: 1080px;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #d7f0ef 0%, transparent 55%),
    radial-gradient(900px 400px at 100% 0%, #ffe9b8 0%, transparent 50%),
    var(--paper);
  line-height: 1.6;
  min-height: 100vh;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--sea-deep); text-underline-offset: 3px; }
a:hover { color: var(--sea); }
:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 2px;
}

.wrap { width: min(100% - 2rem, var(--max)); margin-inline: auto; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 40;
  backdrop-filter: blur(10px);
  background: rgba(247, 245, 240, 0.86);
  border-bottom: 1px solid rgba(217, 212, 200, 0.7);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; padding: 0.85rem 0;
}
.brand {
  display: flex; align-items: center; gap: 0.7rem;
  text-decoration: none; color: inherit; font-weight: 700;
}
.brand-mark {
  width: 36px; height: 36px; border-radius: 10px;
  background: linear-gradient(145deg, var(--sea), var(--ink));
  color: #fff; display: grid; place-items: center;
  font-family: var(--mono); font-size: 0.85rem; letter-spacing: -0.04em;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.15);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-size: 1.05rem; }
.brand-text span { font-size: 0.75rem; color: var(--muted); font-weight: 500; }
.nav-links { display: flex; flex-wrap: wrap; gap: 0.35rem 0.9rem; font-size: 0.92rem; }
.nav-links a { text-decoration: none; color: var(--ink-soft); font-weight: 550; }
.nav-links a:hover { color: var(--sea); }

/* Hero / page heads */
.hero {
  padding: 2.6rem 0 1.4rem;
}
.hero h1 {
  margin: 0 0 0.55rem;
  font-size: clamp(1.85rem, 4vw, 2.6rem);
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.hero p.lead {
  margin: 0;
  max-width: 46rem;
  color: var(--muted);
  font-size: 1.05rem;
}
.badge-row { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1rem; }
.badge {
  display: inline-flex; align-items: center; gap: 0.35rem;
  padding: 0.28rem 0.7rem; border-radius: 999px;
  background: var(--card); border: 1px solid var(--line);
  font-size: 0.8rem; color: var(--ink-soft); font-weight: 550;
}
.badge.amber { background: var(--amber-soft); border-color: #f0d48a; }
.badge.sea { background: var(--sea-light); border-color: #b7dede; }

/* Tool cards */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  padding: 0.5rem 0 2.5rem;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem 1.35rem;
  box-shadow: var(--shadow-sm);
  text-decoration: none;
  color: inherit;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
  display: flex; flex-direction: column; gap: 0.55rem;
  min-height: 180px;
}
a.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: #b9d8d8;
}
.card-icon {
  width: 42px; height: 42px; border-radius: 12px;
  display: grid; place-items: center;
  font-size: 1.25rem;
  background: var(--sea-light);
}
.card h2 { margin: 0; font-size: 1.15rem; letter-spacing: -0.01em; }
.card p { margin: 0; color: var(--muted); font-size: 0.94rem; flex: 1; }
.card .cta {
  font-size: 0.88rem; font-weight: 650; color: var(--sea-deep);
  display: inline-flex; align-items: center; gap: 0.3rem;
}

/* Calculator layout */
.tool-layout {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 1.1rem;
  padding: 0 0 2.5rem;
}
@media (max-width: 820px) {
  .tool-layout { grid-template-columns: 1fr; }
  .nav-links { display: none; }
}
.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem 1.4rem;
  box-shadow: var(--shadow-sm);
}
.panel h2 {
  margin: 0 0 1rem;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}
.field { margin-bottom: 1rem; }
.field label {
  display: block; font-weight: 600; font-size: 0.9rem; margin-bottom: 0.35rem;
}
.field .hint { display: block; color: var(--muted); font-size: 0.8rem; margin-top: 0.3rem; }
.field input[type="number"],
.field input[type="text"],
.field select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.7rem 0.85rem;
  font: inherit;
  background: #fff;
  color: var(--ink);
}
.field input:focus, .field select:focus {
  border-color: var(--sea);
  box-shadow: 0 0 0 3px rgba(13,115,119,0.15);
  outline: none;
}
.seg {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.4rem;
}
.seg label {
  display: flex; align-items: center; justify-content: center;
  gap: 0.35rem; padding: 0.65rem 0.4rem;
  border: 1px solid var(--line); border-radius: 10px;
  cursor: pointer; font-weight: 600; font-size: 0.88rem;
  background: #fff; margin: 0;
}
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg label:has(input:checked) {
  background: var(--sea-light);
  border-color: var(--sea);
  color: var(--sea-deep);
}
.row-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0.8rem; }
@media (max-width: 520px) { .row-2, .seg { grid-template-columns: 1fr; } }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 0.4rem; border: 0; cursor: pointer;
  background: var(--ink); color: #fff;
  font: inherit; font-weight: 650;
  padding: 0.75rem 1.1rem; border-radius: 11px;
  width: 100%;
}
.btn:hover { background: var(--ink-soft); }
.btn.secondary {
  background: transparent; color: var(--ink);
  border: 1px solid var(--line);
}
.btn.secondary:hover { background: #f0ebe2; }

.result-box {
  background: linear-gradient(160deg, var(--ink) 0%, #14384f 100%);
  color: #fff;
  border-radius: calc(var(--radius) - 2px);
  padding: 1.2rem 1.25rem;
  margin-bottom: 1rem;
}
.result-box .label { font-size: 0.85rem; opacity: 0.8; margin: 0 0 0.25rem; }
.result-box .amount {
  font-family: var(--mono);
  font-size: clamp(1.7rem, 4vw, 2.2rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  margin: 0;
}
.result-box .sub {
  margin: 0.45rem 0 0;
  font-size: 0.88rem;
  opacity: 0.85;
}
.breakdown {
  list-style: none; padding: 0; margin: 0;
}
.breakdown li {
  display: flex; justify-content: space-between; gap: 1rem;
  padding: 0.55rem 0;
  border-bottom: 1px dashed var(--line);
  font-size: 0.92rem;
}
.breakdown li:last-child { border-bottom: 0; }
.breakdown .k { color: var(--muted); }
.breakdown .v { font-family: var(--mono); font-weight: 550; }
.note {
  margin-top: 1rem;
  padding: 0.85rem 0.95rem;
  background: var(--amber-soft);
  border: 1px solid #f0d48a;
  border-radius: 10px;
  color: var(--warn);
  font-size: 0.86rem;
}
.note strong { color: var(--ink); }
.info-block {
  margin-top: 1.5rem;
  padding: 1.2rem 0 2rem;
  color: var(--muted);
  font-size: 0.95rem;
}
.info-block h2 { color: var(--ink); font-size: 1.15rem; margin: 0 0 0.6rem; }
.info-block ul { padding-left: 1.2rem; }
.ads-slot {
  margin: 1rem 0;
  min-height: 90px;
  border: 1px dashed #cfc8b8;
  border-radius: 10px;
  display: grid; place-items: center;
  color: #9aa3ab;
  font-size: 0.8rem;
  background: rgba(255,255,255,0.45);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.6rem 0 2.2rem;
  color: var(--muted);
  font-size: 0.88rem;
}
.footer-grid {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem;
}
.footer-links { display: flex; flex-wrap: wrap; gap: 0.8rem 1.1rem; }
.footer-links a { color: var(--ink-soft); text-decoration: none; }
.footer-links a:hover { color: var(--sea); text-decoration: underline; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}