/* 中性占位樣式：品牌色與字體確認前，僅用系統字體與灰藍色系。 */
:root {
  color-scheme: light dark;
  --bg: #f7f8fa;
  --bg-alt: #ecf0f5;
  --fg: #14171c;
  --muted: #4a5360;
  --line: #cfd6df;
  --accent: #1d4e89; /* 品牌深藍（取自 Logo） */
  --accent-fg: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171c;
    --bg-alt: #1b2028;
    --fg: #eef1f5;
    --muted: #aab3bf;
    --line: #333b47;
    --accent: #7fb0ff;
    --accent-fg: #0b1220;
  }
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 1rem/1.75 -apple-system, BlinkMacSystemFont, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
}
.wrap { width: min(100% - 2rem, 68rem); margin-inline: auto; }
.narrow { max-width: 42rem; }
section { padding-block: 3.5rem; }
.alt { background: var(--bg-alt); }
h1, h2, h3 { line-height: 1.25; margin: 0 0 .75rem; }
h1 { font-size: clamp(2rem, 7vw, 3.5rem); letter-spacing: -.02em; }
h2 { font-size: clamp(1.4rem, 4vw, 2rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1rem; }
a { color: var(--accent); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: var(--accent-fg); padding: .5rem 1rem; z-index: 10; }
.skip:focus { left: 0; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }

.site-header { border-bottom: 1px solid var(--line); }
.bar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 3.5rem; flex-wrap: wrap; }
.brand { display: inline-flex; align-items: center; gap: .5rem; font-weight: 700; color: var(--fg); text-decoration: none; }
nav ul { display: flex; align-items: center; gap: 1rem; list-style: none; margin: 0; padding: 0; }
nav a:not(.btn) { color: var(--fg); }

.hero { padding-block: 4rem 3.5rem; }
.eyebrow { color: var(--muted); font-weight: 600; margin-bottom: .5rem; }
.lead { font-size: 1.15rem; max-width: 36rem; color: var(--muted); }
.cta { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.5rem; }

.btn {
  display: inline-block; min-height: 44px; padding: .6rem 1.25rem;
  background: var(--accent); color: var(--accent-fg);
  border: 2px solid var(--accent); border-radius: .6rem;
  font: inherit; font-weight: 600; text-decoration: none; cursor: pointer;
}
.btn.small { min-height: 36px; padding: .25rem .9rem; }
.btn.ghost { background: transparent; color: var(--accent); }
.btn.disabled, button:disabled { opacity: .7; cursor: not-allowed; }

.note { color: var(--muted); font-size: .95rem; }
.cards { list-style: none; margin: 1.5rem 0 0; padding: 0; display: grid; gap: 1rem; }
.cards li { background: var(--bg); border: 1px solid var(--line); border-radius: .8rem; padding: 1.25rem; }
.cards p { margin: 0; color: var(--muted); }
.tag { margin-left: .5rem; padding: .1rem .5rem; border: 1px solid var(--line); border-radius: 99px; font-size: .75rem; font-weight: 500; color: var(--muted); vertical-align: middle; }

.placeholder {
  margin: 1.5rem 0 1rem; aspect-ratio: 16 / 9; display: grid; place-items: center;
  border: 2px dashed var(--line); border-radius: 1rem; color: var(--muted);
}

fieldset { border: 0; padding: 0; margin: 0; min-width: 0; }
.signup label { display: block; font-weight: 600; margin-bottom: .25rem; }
.signup input {
  width: 100%; min-height: 44px; padding: .5rem .75rem; margin-bottom: .75rem;
  font: inherit; color: var(--fg); background: var(--bg); border: 1px solid var(--muted); border-radius: .5rem;
}
.privacy-note { margin-top: 1rem; font-size: .9rem; color: var(--muted); }

details { border-bottom: 1px solid var(--line); padding-block: .75rem; }
summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; }
details p { margin: .25rem 0 .5rem; color: var(--muted); }

.site-footer { border-top: 1px solid var(--line); padding-block: 2rem; color: var(--muted); font-size: .9rem; }
.site-footer p { margin: 0 0 .25rem; }

@media (min-width: 48rem) {
  section { padding-block: 5rem; }
  .cards { grid-template-columns: repeat(3, 1fr); }
  .signup fieldset { display: grid; grid-template-columns: 1fr auto; gap: 0 .75rem; align-items: end; }
  .signup label { grid-column: 1 / -1; }
}

/* 只給螢幕閱讀器讀的文字（例如「另開新視窗」提示） */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* 頁首品牌小圖 */
.brand .mark {
  border-radius: 22%;
  display: block;
}

/* 政策／條款／支援頁的長文排版 */
.doc { padding-block: 3rem; }
.doc h2 { margin-top: 2rem; }
.doc h3 { margin-top: 1.5rem; }
.doc ul { padding-left: 1.25rem; margin: 0 0 1rem; }
.doc li { margin-bottom: .5rem; }
.doc .meta { color: var(--muted); font-size: .95rem; }
.doc .callout { background: var(--bg-alt); border: 1px solid var(--line); border-radius: .8rem; padding: 1rem 1.25rem; }
.doc ul.contact { list-style: none; padding-left: 0; }
nav a[aria-current="page"] { font-weight: 700; text-decoration: none; }