:root {
  --bg: #f7f8f7;
  --surface: #ffffff;
  --surface-2: #f0f3f2;
  --text: #17201e;
  --muted: #5b6764;
  --border: #dde3e1;
  --accent: #0f766e;
  --accent-ink: #ffffff;
  --accent-soft: #e2f3f0;
  --danger: #b42318;
  --ok: #15803d;
  --shadow: 0 1px 2px rgba(16, 24, 22, .06), 0 4px 16px rgba(16, 24, 22, .05);
  --radius: 14px;
  --font: system-ui, -apple-system, "Segoe UI", "PingFang TC", "Microsoft JhengHei", "Noto Sans TC", sans-serif;
  --mono: ui-monospace, "Cascadia Mono", Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1413;
    --surface: #161d1b;
    --surface-2: #1d2624;
    --text: #e6ecea;
    --muted: #9aa8a4;
    --border: #2a3533;
    --accent: #2dd4bf;
    --accent-ink: #062320;
    --accent-soft: #123430;
    --danger: #f97066;
    --ok: #4ade80;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f1413; --surface: #161d1b; --surface-2: #1d2624; --text: #e6ecea; --muted: #9aa8a4;
  --border: #2a3533; --accent: #2dd4bf; --accent-ink: #062320; --accent-soft: #123430;
  --danger: #f97066; --ok: #4ade80; --shadow: 0 1px 2px rgba(0, 0, 0, .3); color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.75 var(--font); }
a { color: var(--accent); text-underline-offset: 3px; }
img, svg { max-width: 100%; }
h1, h2, h3 { line-height: 1.35; letter-spacing: .01em; }
h1 { font-size: clamp(1.7rem, 4vw, 2.4rem); margin: 0 0 .5rem; }
h2 { font-size: 1.4rem; margin: 2.2rem 0 .8rem; }
h3 { font-size: 1.1rem; margin: 1.6rem 0 .5rem; }
p { margin: 0 0 1rem; }
code { font-family: var(--mono); font-size: .9em; background: var(--surface-2); padding: .1em .35em; border-radius: 5px; }
.muted { color: var(--muted); }
.wrap { width: min(1120px, 100% - 32px); margin-inline: auto; }
.narrow { width: min(780px, 100% - 32px); margin-inline: auto; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 8px; z-index: 10; background: var(--surface); padding: 8px 12px; border-radius: 8px; }

/* header */
.site-header { position: sticky; top: 0; z-index: 5; background: color-mix(in srgb, var(--surface) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; gap: 16px; min-height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--accent); text-decoration: none; font-weight: 700; font-size: 1.1rem; }
.brand span { color: var(--text); }
.site-nav { display: flex; gap: 4px; margin-left: auto; flex-wrap: wrap; }
.site-nav a { color: var(--text); text-decoration: none; padding: 6px 12px; border-radius: 999px; font-size: .95rem; }
.site-nav a:hover { background: var(--surface-2); }
.site-nav a[aria-current="page"] { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav-toggle { display: none; margin-left: auto; background: none; border: 0; color: var(--text); padding: 8px; cursor: pointer; }
@media (max-width: 860px) {
  .nav-toggle { display: block; }
  .site-nav { display: none; position: absolute; left: 0; right: 0; top: 60px; background: var(--surface); border-bottom: 1px solid var(--border); padding: 8px 16px 16px; flex-direction: column; }
  .site-nav.open { display: flex; }
}

/* hero */
.hero { padding: 48px 0 24px; }
.hero p.lead { font-size: 1.1rem; color: var(--muted); max-width: 720px; }
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 0; padding: 0; list-style: none; }
.badges li { background: var(--accent-soft); color: var(--accent); border-radius: 999px; padding: 4px 12px; font-size: .88rem; font-weight: 600; }

/* cards */
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
a.card { color: inherit; text-decoration: none; transition: border-color .15s, transform .15s; display: block; }
a.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card h3 { margin: 0 0 .4rem; }
.card p { margin: 0; color: var(--muted); font-size: .95rem; }
.card .fmt { margin-top: 10px; font-family: var(--mono); font-size: .8rem; color: var(--accent); }
.icon { width: 40px; height: 40px; border-radius: 10px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; margin-bottom: 12px; }

/* converter */
.converter { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px; margin: 8px 0 24px; }
.drop { border: 2px dashed var(--border); border-radius: 12px; padding: 36px 16px; text-align: center; cursor: pointer; transition: border-color .15s, background .15s; background: var(--surface-2); }
.drop:hover, .drop:focus-visible, .drop.over { border-color: var(--accent); background: var(--accent-soft); outline: none; }
.drop strong { display: block; font-size: 1.1rem; margin: 8px 0 4px; }
.drop .muted { font-size: .9rem; }
.drop svg { color: var(--accent); }
.bar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; margin-top: 16px; }
.bar[hidden], .opts[hidden], .combos[hidden] { display: none; }
.bar .spacer { flex: 1; }
.opts { display: flex; flex-wrap: wrap; gap: 10px 20px; margin-top: 14px; padding: 12px 14px; background: var(--surface-2); border-radius: 10px; font-size: .92rem; }
.opts label { display: flex; align-items: center; gap: 8px; }
.opts input[type="number"], .opts input[type="text"] { width: 110px; }
select, input[type="text"], input[type="number"], textarea { font: inherit; color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 6px 10px; }
textarea { width: 100%; font-family: var(--mono); font-size: .88rem; line-height: 1.5; }
select:focus, input:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.btn { font: inherit; font-weight: 600; border: 1px solid var(--border); background: var(--surface); color: var(--text); padding: 8px 16px; border-radius: 10px; cursor: pointer; text-decoration: none; display: inline-flex; align-items: center; gap: 6px; }
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.small { padding: 4px 10px; font-size: .88rem; }
.combos { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; align-items: center; }
.combos .muted { font-size: .9rem; }
.files { list-style: none; margin: 16px 0 0; padding: 0; display: grid; gap: 10px; }
.file { display: grid; grid-template-columns: 1fr auto; gap: 8px 12px; align-items: center; border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; }
.file .name { font-weight: 600; overflow-wrap: anywhere; }
.file .meta { color: var(--muted); font-size: .85rem; }
.file .ctrl { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
.file .out { grid-column: 1 / -1; display: flex; flex-wrap: wrap; gap: 8px; font-size: .9rem; }
.file .out:empty { display: none; }
.file .status { font-size: .85rem; color: var(--muted); }
.file .status.err { color: var(--danger); }
.file .status.ok { color: var(--ok); }
.x { background: none; border: 0; color: var(--muted); cursor: pointer; font-size: 1.2rem; line-height: 1; padding: 4px 6px; }
.x:hover { color: var(--danger); }
.dl { display: inline-flex; align-items: center; gap: 4px; padding: 3px 10px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); text-decoration: none; font-weight: 600; }
.combo-out { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 8px; }
.privacy-note { display: flex; gap: 8px; align-items: center; margin: 14px 0 0; font-size: .88rem; color: var(--muted); }
@media (max-width: 560px) {
  .converter { padding: 14px; }
  .drop { padding: 28px 12px; }
  .file { grid-template-columns: 1fr; }
  .file .ctrl { justify-content: flex-start; }
}

/* text tool */
.texttool { display: grid; gap: 12px; grid-template-columns: 1fr 1fr; }
.texttool .head { display: flex; gap: 8px; align-items: center; margin-bottom: 6px; flex-wrap: wrap; }
.texttool .head .spacer { flex: 1; }
.prose pre { background: var(--surface-2); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; overflow-x: auto; margin: 0 0 1rem; }
.prose pre code { background: none; padding: 0; }
@media (max-width: 760px) { .texttool { grid-template-columns: 1fr; } }

/* article */
.prose { font-size: 1.02rem; }
.prose ul, .prose ol { padding-left: 1.4em; margin: 0 0 1rem; }
.prose li { margin: .3rem 0; }
.prose table { width: 100%; border-collapse: collapse; margin: 0 0 1.2rem; font-size: .95rem; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
.prose th { background: var(--surface-2); }
.prose blockquote { margin: 0 0 1rem; padding: 10px 16px; border-left: 4px solid var(--accent); background: var(--surface-2); border-radius: 0 8px 8px 0; }
.article-meta { color: var(--muted); font-size: .9rem; margin-bottom: 1.5rem; }
.crumbs { font-size: .88rem; color: var(--muted); margin: 24px 0 8px; }
.crumbs a { color: var(--muted); }
.steps { counter-reset: s; list-style: none; padding: 0; }
.steps li { counter-increment: s; position: relative; padding-left: 40px; margin: 0 0 12px; }
.steps li::before { content: counter(s); position: absolute; left: 0; top: 2px; width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); display: grid; place-items: center; font-weight: 700; font-size: .9rem; }
details { border: 1px solid var(--border); border-radius: 10px; padding: 10px 14px; margin: 0 0 10px; background: var(--surface); }
details summary { cursor: pointer; font-weight: 600; }
details[open] summary { margin-bottom: 8px; }
.section { padding: 8px 0 32px; }
.related { margin-top: 32px; }
.ad-slot { margin: 24px 0; min-height: 100px; }

/* footer */
.site-footer { margin-top: 48px; border-top: 1px solid var(--border); background: var(--surface); padding: 32px 0 20px; font-size: .93rem; }
.footer-grid { display: grid; gap: 24px; grid-template-columns: 2fr 1fr 1fr; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin: 4px 0; }
.footer-grid a { color: var(--text); text-decoration: none; }
.footer-grid a:hover { color: var(--accent); }
.footer-brand { font-weight: 700; font-size: 1.05rem; margin-bottom: 6px; }
.footer-brand span { color: var(--muted); font-weight: 500; }
.footer-h { font-weight: 700; margin-bottom: 6px; }
.copyright { margin-top: 24px; font-size: .85rem; }
@media (max-width: 700px) { .footer-grid { grid-template-columns: 1fr 1fr; } .footer-grid > div:first-child { grid-column: 1 / -1; } }

/* ===== 工具網站群共用元件 ===== */
.panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px; margin: 8px 0 24px; }
.form-grid { display: grid; gap: 14px 18px; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.field { display: flex; flex-direction: column; gap: 6px; font-size: .95rem; }
.field > span { font-weight: 600; }
.field small { color: var(--muted); font-size: .82rem; }
.field input, .field select { width: 100%; }
.inline { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.result { margin-top: 18px; padding: 16px; border-radius: 12px; background: var(--accent-soft); }
.result:empty { display: none; }
.stats { display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
.stat { background: var(--surface); border-radius: 10px; padding: 10px 14px; border: 1px solid var(--border); }
.stat b { display: block; font-size: 1.35rem; color: var(--accent); font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.stat span { color: var(--muted); font-size: .85rem; }
.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; flex-wrap: wrap; }
.seg button { font: inherit; border: 0; background: var(--surface); color: var(--text); padding: 7px 14px; cursor: pointer; }
.seg button + button { border-left: 1px solid var(--border); }
.seg button[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); font-weight: 600; }
.table-wrap { overflow-x: auto; margin-top: 12px; max-height: 420px; overflow-y: auto; border: 1px solid var(--border); border-radius: 10px; }
.table-wrap table { width: 100%; border-collapse: collapse; font-size: .9rem; font-variant-numeric: tabular-nums; }
.table-wrap th, .table-wrap td { padding: 6px 10px; border-bottom: 1px solid var(--border); text-align: right; white-space: nowrap; }
.table-wrap th { position: sticky; top: 0; background: var(--surface-2); }
.table-wrap td:first-child, .table-wrap th:first-child { text-align: center; }
.two-col { display: grid; gap: 14px; grid-template-columns: 1fr 1fr; }
@media (max-width: 760px) { .two-col { grid-template-columns: 1fr; } }
.toolbar { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 10px 0; }
.toolbar .spacer { flex: 1; }
.sisters li { margin: 4px 0; }
.sisters .muted { font-size: .85rem; }
.preview-box { display: grid; place-items: center; min-height: 260px; background: #fff; border-radius: 12px; border: 1px solid var(--border); padding: 16px; }
.preview-box canvas, .preview-box svg, .preview-box img { max-width: 100%; height: auto; }
.diff ins { background: #c8f2d4; color: #0b3d1a; text-decoration: none; }
.diff del { background: #f9d0d0; color: #5c0b0b; }
.diff { white-space: pre-wrap; font-family: var(--mono); font-size: .9rem; line-height: 1.6; padding: 12px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); min-height: 80px; overflow-wrap: anywhere; }
.big-out { font-family: var(--mono); font-size: 1.2rem; letter-spacing: .03em; overflow-wrap: anywhere; }
.thumbs { display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); margin-top: 14px; }
.thumb { position: relative; padding: 0; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; background: #000; cursor: pointer; }
.thumb img { display: block; width: 100%; height: auto; }
.thumb span { position: absolute; right: 6px; bottom: 6px; background: rgba(0,0,0,.65); color: #fff; font-size: .8rem; padding: 1px 6px; border-radius: 6px; }
.thumb:hover { outline: 2px solid var(--accent); }