/* Shared shell. Themes set the colors; Traditional Chinese uses the device's own font. */
:root { color-scheme: light; }
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: "PingFang TC", "Hiragino Sans CNS", "Noto Sans CJK TC", "Noto Sans TC", "Microsoft JhengHei", "Microsoft JhengHei UI", "WenQuanYi Micro Hei", "Droid Sans Fallback", sans-serif;
  font-size: 17px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
}
body[data-theme="fly"] {
  --bg: #f3efe7;
  --surface: #fffdf8;
  --ink: #1c2430;
  --muted: #3f4a56;
  --brand: #16324f;
  --brand-2: #0f5c58;
  --line: #e4dacb;
  --hero-bg: #16324f;
  --hero-ink: #f7f3eb;
  --kicker: #f0c7a4;
  --pill-bg: #e5eef4;
  --link: #0e4d68;
  --btn: #f3d7b5;
  --btn-ink: #16324f;
  --warn: #7a3e0b;
  --warn-bg: #fff6e4;
  --warn-line: #e0b56a;
  --ok: #0d5a42;
  --ok-bg: #e7f6ef;
  --flag-bg: #f8e7c8;
  --flag-ink: #6a3208;
  --chip: #9a3e12;
  --shadow: 0 12px 32px rgba(22, 50, 79, 0.08);
}
body[data-theme="ia"] {
  --bg: #eef2ef;
  --surface: #fffcf8;
  --ink: #16211c;
  --muted: #3d4c45;
  --brand: #0f3d34;
  --brand-2: #176b4a;
  --line: #d5e0d9;
  --hero-bg: #0f3d34;
  --hero-ink: #f4f7f4;
  --kicker: #e7c27a;
  --pill-bg: #e3f0ea;
  --link: #0f4f3c;
  --btn: #e7c27a;
  --btn-ink: #1c2a22;
  --warn: #7a3e0b;
  --warn-bg: #fff6e4;
  --warn-line: #e0b56a;
  --ok: #0d5a42;
  --ok-bg: #e7f6ef;
  --flag-bg: #f8e7c8;
  --flag-ink: #6a3208;
  --chip: #9a3e12;
  --shadow: 0 12px 32px rgba(15, 61, 52, 0.08);
}
img { max-width: 100%; }
a { color: var(--link); }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--brand-2); outline-offset: 2px; }
.skip {
  position: absolute;
  left: 12px;
  top: -48px;
  background: #fff;
  color: var(--ink);
  padding: 8px 12px;
  z-index: 50;
  border-radius: 8px;
}
.skip:focus { top: 8px; }
.wrap { width: min(1080px, calc(100% - 32px)); margin-inline: auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  padding-top: 12px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  min-width: 0;
}
.brand-name {
  display: block;
  font-weight: 800;
  font-size: 1.28rem;
  letter-spacing: 0.04em;
  line-height: 1.15;
}
.brand-domain {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 650;
  letter-spacing: 0.01em;
}
.mark { width: 36px; height: 36px; flex: 0 0 auto; display: block; }
.ai-pill {
  margin: 0;
  font-size: 0.78rem;
  font-weight: 800;
  line-height: 1.35;
  color: var(--brand);
  background: var(--pill-bg);
  border-radius: 999px;
  padding: 6px 10px;
  white-space: nowrap;
}
.nav-scroll {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding: 8px 0 12px;
  scrollbar-width: none;
}
.nav-scroll::-webkit-scrollbar { display: none; }
.nav-scroll a {
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--ink);
  border-radius: 999px;
  padding: 8px 12px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  font-weight: 700;
  font-size: 0.95rem;
}
.nav-scroll a[aria-current="page"] { background: var(--brand); color: #fff; }
.hero {
  background:
    radial-gradient(900px 280px at 100% -20%, rgba(240, 199, 164, 0.18), transparent 55%),
    var(--hero-bg);
  color: var(--hero-ink);
  padding: 22px 0 26px;
}
.hero h1 {
  color: var(--hero-ink);
  font-size: clamp(1.85rem, 5vw, 2.65rem);
  line-height: 1.22;
  letter-spacing: -0.02em;
  margin: 8px 0 12px;
}
.hero .lede { max-width: 40rem; color: rgba(247, 243, 235, 0.92); margin-top: 0; }
.kicker {
  margin: 0;
  font-weight: 800;
  letter-spacing: 0.06em;
  font-size: 0.78rem;
  color: var(--kicker);
}
.hero-warn {
  max-width: 40rem;
  background: rgba(255, 255, 255, 0.08);
  border-left: 4px solid var(--kicker);
  padding: 10px 12px;
  border-radius: 8px;
  font-weight: 700;
}
.path-card {
  margin-top: 16px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 16px;
  padding: 12px 12px 8px;
}
.path {
  list-style: none;
  position: relative;
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  gap: 0;
  margin: 4px 0 8px;
  padding: 6px 0 0;
}
.path::before {
  content: "";
  position: absolute;
  left: 8px;
  right: 12px;
  top: 10px;
  height: 2px;
  background: rgba(247, 243, 235, 0.35);
}
.path li {
  position: relative;
  flex: 1;
  margin: 0;
  padding: 16px 4px 0 0;
  min-width: 0;
}
.path li::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--kicker);
}
.path b { display: block; line-height: 1.25; font-size: 0.95rem; }
.path small { display: block; color: rgba(247, 243, 235, 0.78); font-size: 0.72rem; line-height: 1.3; }
.path-note { margin: 0 0 6px; font-size: 0.85rem; color: rgba(247, 243, 235, 0.8); }
.trust {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0;
  margin: 12px 0 0;
  list-style: none;
}
.trust li {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 0.85rem;
  font-weight: 700;
}
.actions { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 0; }
.btn, button {
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 16px;
  border-radius: 999px;
  border: 0;
  background: var(--btn);
  color: var(--btn-ink);
  font-weight: 800;
  font-size: 1rem;
  text-decoration: none;
  cursor: pointer;
}
.btn-ghost {
  background: transparent;
  color: var(--hero-ink);
  border: 1px solid rgba(247, 243, 235, 0.45);
}
.page-body { padding-top: 22px; padding-bottom: 8px; }
.section { margin-top: 28px; }
h1 { font-size: clamp(1.7rem, 4vw, 2.15rem); line-height: 1.3; margin: 0 0 12px; }
h2 { font-size: 1.35rem; line-height: 1.35; margin: 1.6em 0 0.55em; }
h3 { font-size: 1.08rem; line-height: 1.4; margin: 1.2em 0 0.4em; }
p { margin: 0.65em 0; }
.lede { font-size: 1.05rem; }
.fine, small { color: var(--muted); font-size: 0.86rem; }
.fares-block h2 { margin-top: 0; }
.fares { display: grid; gap: 14px; }
.fare {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.flag {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  margin: 0;
  padding: 10px 14px;
  background: var(--flag-bg);
  color: var(--flag-ink);
  font-weight: 700;
  line-height: 1.45;
}
.flag strong {
  flex: 0 0 auto;
  background: var(--chip);
  color: #fff;
  border-radius: 999px;
  padding: 2px 8px;
  font-size: 0.82rem;
  line-height: 1.5;
}
.fare-body { padding: 14px 14px 16px; }
.airline {
  margin: 0;
  color: var(--brand-2);
  font-weight: 800;
  font-size: 0.92rem;
}
.fare h3 { margin: 2px 0 4px; font-size: 1.2rem; }
.meta { margin: 2px 0; color: var(--muted); font-size: 0.88rem; }
.cmp {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 12px 0;
}
.cmp > div {
  background: var(--bg);
  border-radius: 12px;
  padding: 10px 12px 12px;
  min-width: 0;
}
.k {
  margin: 0;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.price {
  margin: 2px 0 0;
  font-size: clamp(1.45rem, 4.4vw, 2rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  line-height: 1.15;
  overflow-wrap: anywhere;
}
.sub { margin: 0 0 10px; color: var(--muted); font-size: 0.9rem; }
.save {
  margin: 0 0 8px;
  background: var(--ok-bg);
  color: var(--ok);
  border-radius: 12px;
  padding: 10px 12px;
  font-weight: 800;
}
.save-neg { background: var(--warn-bg); color: var(--warn); }
.save-zero { background: var(--bg); color: var(--ink); }
.note { font-size: 0.95rem; }
.lcc {
  margin: 10px 0;
  border: 1px dashed var(--chip);
  background: #fffaf3;
  border-radius: 12px;
  padding: 10px 12px;
}
.lcc h4 { margin: 0 0 6px; font-size: 1rem; color: var(--chip); }
.lcc p { margin: 0.35em 0; }
.sources { margin: 4px 0 0; padding-left: 1.15rem; }
.sources a { font-weight: 800; }
.empty {
  background: var(--surface);
  border: 1px dashed var(--line);
  border-radius: 16px;
  padding: 18px 16px;
}
.empty-title { font-weight: 800; font-size: 1.15rem; margin: 0 0 6px; }
.cards { display: grid; gap: 12px; }
.cards a {
  display: block;
  background: var(--surface);
  color: inherit;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px;
  box-shadow: var(--shadow);
}
.cards a:hover { border-color: var(--brand-2); }
.cards h3 { margin: 4px 0 6px; color: var(--brand); }
.cards p { margin: 0.35em 0; }
.risk-bank { border-top: 4px solid #1f7a4d; }
.risk-tw { border-top: 4px solid #a67c12; }
.risk-os { border-top: 4px solid #c0562a; }
.sheet {
  width: min(1080px, calc(100% - 32px));
  margin: 22px auto 8px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 22px 18px 8px;
  box-shadow: var(--shadow);
}
.pattern {
  margin: 12px 0 16px;
  padding: 14px 16px;
  background: var(--bg);
  border-radius: 14px;
  border: 1px solid var(--line);
}
.pattern figcaption {
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.pattern-line { font-weight: 800; font-size: 1.08rem; margin: 0; line-height: 1.5; }
.route-list { display: grid; gap: 12px; }
.route-card {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 14px;
  background: var(--bg);
}
.route-card h3 { margin: 0 0 8px; font-size: 1.02rem; }
.linkrow { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.linkrow a {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  text-decoration: none;
  font-weight: 800;
  font-size: 0.88rem;
}
.warn, .ok {
  border-radius: 12px;
  padding: 12px 14px;
}
.warn {
  background: var(--warn-bg);
  border: 1px solid var(--warn-line);
  border-left: 4px solid #c47d12;
  color: var(--ink);
}
.ok {
  background: var(--ok-bg);
  border: 1px solid #b7dfc8;
  border-left: 4px solid var(--ok);
}
.tbd {
  display: inline-block;
  color: #7a3412;
  background: #fff1e6;
  border: 1px solid #f0c9a0;
  border-radius: 999px;
  padding: 0 8px;
  font-weight: 800;
  font-size: 0.85em;
  line-height: 1.6;
}
.ref { font-size: 0.85em; color: #8a4b08; font-weight: 700; }
.tbl { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 8px 0 18px; }
.scroll-hint { margin: 0 0 6px; }
table {
  border-collapse: collapse;
  width: 100%;
  min-width: 920px;
  background: #fff;
  font-size: 0.92rem;
  line-height: 1.55;
}
th, td {
  border: 1px solid var(--line);
  padding: 8px 10px;
  vertical-align: top;
  text-align: left;
}
th { background: #f3f6f7; font-weight: 800; }
body[data-theme="ia"] th { background: #f2f7f4; }
tr.total th { background: var(--brand); color: #fff; }
main ul, main ol { padding-left: 1.25rem; }
main li + li { margin-top: 0.28em; }
main a { overflow-wrap: anywhere; }
form {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px;
  margin: 8px 0 18px;
}
.field { display: block; font-weight: 800; margin-top: 8px; }
input[type="email"] {
  width: 100%;
  margin: 6px 0 10px;
  padding: 12px;
  font-size: 16px;
  font-family: inherit;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
}
.check { display: flex; gap: 8px; align-items: flex-start; font-weight: 700; margin: 8px 0 12px; }
input[type="checkbox"] { width: 1.15rem; height: 1.15rem; margin-top: 0.25rem; accent-color: var(--brand); flex: 0 0 auto; }
form button { width: 100%; border-radius: 12px; background: var(--brand); color: #fff; }
.site-footer {
  margin-top: 28px;
  background: var(--brand);
  color: #f6f2ea;
  padding: 28px 0 36px;
  font-size: 0.95rem;
}
.site-footer a { color: #fff; }
.site-footer .fine { color: rgba(246, 242, 234, 0.78); }
.foot-lead { font-weight: 800; }
.foot-nav { display: flex; flex-wrap: wrap; gap: 8px 14px; margin: 12px 0; }
.foot-nav a { text-decoration: none; font-weight: 800; }
@media (max-width: 799px) {
  .nav-scroll {
    mask-image: linear-gradient(to right, #000 calc(100% - 28px), transparent);
  }
}
.tool {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 18px 16px 8px;
  margin: 0 0 8px;
}
.tool-plain {
  background: transparent;
  border: 0;
  box-shadow: none;
  padding: 0;
}
.tool h2 { margin-top: 0; }
.choice { display: flex; flex-direction: column; gap: 8px; margin: 12px 0; }
.choice label {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 12px;
  background: #fff;
  font-weight: 800;
}
.tool select,
.tool input[type="number"] {
  width: 100%;
  margin: 6px 0 0;
  padding: 12px;
  font-size: 16px;
  font-family: inherit;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
}
.pair { display: grid; gap: 12px; }
.panel[hidden] { display: none; }
.tool .btn { margin: 14px 0; }
.plan, .match {
  border-top: 1px solid var(--line);
  padding: 14px 0 6px;
}
.plan h3, .fare-match h3, .plan h4, .match h4 { margin: 0.4em 0; }
.plan-legs { margin: 8px 0 12px; padding-left: 1.2em; font-weight: 700; }
.round-title { margin: 10px 0 0; font-weight: 800; }
.fare-match { margin-top: 8px; }
@media (min-width: 800px) {
  .pair { grid-template-columns: 1fr 1fr; }
  .tool { padding: 22px 22px 10px; }
  .tool .btn { width: auto; }
}
@media (min-width: 800px) {
  .hero { padding: 48px 0 52px; }
  .hero-grid.has-aside {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 32px;
    align-items: center;
  }
  .path-card { margin-top: 0; }
  .path li { padding: 20px 8px 0 0; }
  .path::before { top: 14px; }
  .path li::after { top: 4px; }
  .fares { grid-template-columns: 1fr 1fr; align-items: start; }
  .cards { grid-template-columns: repeat(3, 1fr); }
  .route-list { grid-template-columns: 1fr 1fr; }
  .sheet { padding: 34px 40px 16px; }
  form button { width: auto; }
}
@media (min-width: 960px) {
  .scroll-hint { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto; }
}