/* ===========================================================================
   cf-todo-demo — 樣式
   ---------------------------------------------------------------------------
   設計原則：顏色帶資訊。每個 Cloudflare 綁定各有一個固定色相，
   在路由表、Edge Trace、綁定卡片三處保持一致，看久了就會記住。
   =========================================================================== */

:root {
  /* 讓瀏覽器的原生元件（捲軸、表單控制項）也用深色，不然會出現白色捲軸 */
  color-scheme: dark;

  /* 底色：帶藍調的深靛墨，不是純黑 —— 純黑會讓上面的語意色顯得刺眼 */
  --bg:        #080D14;
  --bg-2:      #0B121B;
  --panel:     #0F1926;
  --panel-2:   #13202F;
  --line:      #1E2E42;
  --line-soft: #16222F;

  /* 互動控制項的邊框。WCAG SC 1.4.11 要求「靠邊框才認得出來的元件」
     邊框對背景至少 3:1，--line 只有 1.37:1 遠遠不夠。
     只用在核取方塊與輸入框這類沒有文字就認不出來的東西上，
     純裝飾的分隔線仍然用 --line，才不會整個版面變吵。 */
  --line-control: #546A83;

  --ink:   #E6EEF8;
  --ink-2: #94AABF;
  /* 這個值原本是 #5F7488，對比只有 3.40–4.03，小字達不到 AA 的 4.5:1。
     現在是 5.48–6.48，四種底色上都合格。 */
  --ink-3: #8497AA;

  /* 語意色 —— 一個綁定一個色 */
  --c-client: #8397AC;
  --c-assets: #57A8F0;
  --c-worker: #F6821F;
  --c-d1:     #B98CFF;
  --c-r2:     #2BD4C0;
  --c-error:  #FF7A85;

  --font-display: 'Space Grotesk', 'PingFang TC', 'Noto Sans TC', 'Microsoft JhengHei', sans-serif;
  --font-body: system-ui, -apple-system, 'PingFang TC', 'Noto Sans TC', 'Microsoft JhengHei', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;

  --shell: 1100px;
  --pad: clamp(1.25rem, 4vw, 2.5rem);
  --radius: 10px;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 5.5rem; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3 { font-family: var(--font-display); font-weight: 700; margin: 0; line-height: 1.15; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

code, pre { font-family: var(--font-mono); }

/* 程式碼區塊會橫向捲動，把捲軸調細調暗，不要打斷版面 */
pre {
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}
pre::-webkit-scrollbar { height: 6px; }
pre::-webkit-scrollbar-track { background: transparent; }
pre::-webkit-scrollbar-thumb { background: var(--line); border-radius: 3px; }
pre::-webkit-scrollbar-thumb:hover { background: #2b4058; }

code {
  font-size: 0.86em;
  color: var(--ink);
  background: #0000004d;
  border: 1px solid var(--line-soft);
  border-radius: 4px;
  padding: 0.08em 0.34em;
}

a { color: var(--ink); text-decoration-color: #ffffff3d; text-underline-offset: 3px; }
a:hover { text-decoration-color: var(--c-worker); }

:focus-visible {
  outline: 2px solid var(--c-worker);
  outline-offset: 2px;
  border-radius: 3px;
}

.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;
}

.skip-link {
  position: absolute;
  left: 0.5rem; top: -4rem;
  z-index: 100;
  background: var(--c-worker);
  color: #0B0B0B;
  font-weight: 700;
  padding: 0.6rem 1rem;
  border-radius: 6px;
  text-decoration: none;
  transition: top 0.15s;
}
.skip-link:focus { top: 0.5rem; }

/* ── 頂欄 ─────────────────────────────────────────────────────────────── */

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 0.85rem var(--pad);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line-soft);
}

.topbar-brand { display: flex; align-items: center; gap: 0.6rem; }

.topbar-name {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ink-2);
}

/* 狀態燈：有請求在飛的時候會亮起來 */
.signal {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--ink-3);
  box-shadow: 0 0 0 0 transparent;
  transition: background 0.2s, box-shadow 0.2s;
}
.signal[data-state="busy"] {
  background: var(--c-worker);
  animation: signal-pulse 0.9s ease-out infinite;
}
.signal[data-state="ok"]    { background: var(--c-r2); box-shadow: 0 0 10px #2bd4c066; }
.signal[data-state="error"] { background: var(--c-error); box-shadow: 0 0 10px #ff7a8566; }

@keyframes signal-pulse {
  0%   { box-shadow: 0 0 0 0 #f6821f80; }
  100% { box-shadow: 0 0 0 9px #f6821f00; }
}

.topbar-nav {
  display: flex;
  gap: 1.1rem;
  margin-inline-start: auto;
  font-size: 0.85rem;
}
.topbar-nav a { color: var(--ink-2); text-decoration: none; }
.topbar-nav a:hover { color: var(--ink); }

.topbar-auth { display: flex; align-items: center; gap: 0.7rem; min-height: 34px; }

/* ── Hero ─────────────────────────────────────────────────────────────── */

.hero {
  position: relative;
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(3.5rem, 9vw, 6.5rem) var(--pad) clamp(2.5rem, 6vw, 4rem);
}

/* 極淡的方格底紋，像監控面板的背板。純裝飾，所以 aria 無關。 */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, #ffffff08 1px, transparent 1px),
    linear-gradient(to bottom, #ffffff08 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 90% 70% at 30% 20%, #000 20%, transparent 75%);
  pointer-events: none;
}

.hero > * { position: relative; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-worker);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(2.5rem, 7.5vw, 4.75rem);
  letter-spacing: -0.015em;
  line-height: 1.05;
  margin-bottom: 1.75rem;
}

.hero-title em {
  font-style: normal;
  color: var(--c-worker);
  position: relative;
  white-space: nowrap;
}
.hero-title em::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -0.12em;
  height: 3px;
  background: var(--c-worker);
  transform-origin: left;
  animation: rule-in 0.7s 0.35s cubic-bezier(0.2, 0.8, 0.2, 1) backwards;
}
@keyframes rule-in { from { transform: scaleX(0); } to { transform: scaleX(1); } }

.hero-lede {
  max-width: 56ch;
  font-size: clamp(1rem, 1.6vw, 1.1rem);
  color: var(--ink-2);
  margin-bottom: clamp(2.5rem, 5vw, 3.5rem);
}

/* ── Edge Trace（本頁的主角）──────────────────────────────────────────── */

.trace {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, var(--panel-2), var(--panel));
  overflow: hidden;
  box-shadow: 0 24px 60px -30px #000c;
}

.trace-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.8rem 1.1rem;
  border-bottom: 1px solid var(--line-soft);
  background: #ffffff05;
}

.trace-title {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.19em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.trace-meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  display: flex;
  gap: 0.5rem;
}
.trace-meta-value { color: var(--c-r2); }

.trace-list { display: flex; flex-direction: column; }

.trace-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto 90px 58px;
  align-items: center;
  gap: 0.9rem;
  padding: 0.62rem 1.1rem;
  border-bottom: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}
.trace-row:last-child { border-bottom: 0; }

.trace-row[data-fresh="true"] { animation: row-in 0.45s cubic-bezier(0.2, 0.8, 0.2, 1); }
@keyframes row-in {
  from { opacity: 0; transform: translateX(-10px); background: #f6821f14; }
  to   { opacity: 1; transform: none; background: transparent; }
}

.trace-row[data-status="error"] { background: #ff7a850f; }

.trace-route {
  color: var(--ink-2);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.trace-route .verb { color: var(--ink); font-weight: 700; margin-inline-end: 0.5em; }

.trace-chain { display: flex; align-items: center; gap: 0.3rem; flex-wrap: nowrap; }

.trace-bar {
  height: 4px;
  border-radius: 2px;
  background: #ffffff0d;
  overflow: hidden;
}
/* 顏色由 <i> 上的 data-node 決定，跟 chip 共用同一組語意色 */
.trace-bar i {
  display: block;
  height: 100%;
  width: var(--w, 0%);
  background: var(--chip, var(--ink-3));
  border-radius: 2px;
  animation: bar-in 0.5s cubic-bezier(0.2, 0.8, 0.2, 1);
}
@keyframes bar-in { from { width: 0; } }

.trace-ms { text-align: right; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.trace-ms[data-skipped="true"] { color: var(--c-assets); }

.trace-hint {
  padding: 0.75rem 1.1rem;
  font-size: 0.78rem;
  color: var(--ink-3);
  border-top: 1px dashed var(--line-soft);
}
.trace-hint[hidden] { display: none; }

/* ── 綁定色票（chip）：路由表與 Trace 共用同一套 ─────────────────────── */

.chip {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1;
  padding: 0.32em 0.6em;
  border-radius: 999px;
  border: 1px solid var(--chip, var(--ink-3));
  color: var(--chip, var(--ink-3));
  background: color-mix(in srgb, var(--chip, var(--ink-3)) 12%, transparent);
  white-space: nowrap;
}

[data-node="CLIENT"] { --chip: var(--c-client); }
[data-node="ASSETS"] { --chip: var(--c-assets); }
[data-node="WORKER"] { --chip: var(--c-worker); }
[data-node="D1"]     { --chip: var(--c-d1); }
[data-node="R2"]     { --chip: var(--c-r2); }

/* ── 區塊通用 ─────────────────────────────────────────────────────────── */

.section {
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(3rem, 7vw, 5.5rem) var(--pad);
  border-top: 1px solid var(--line-soft);
}

.section-head { max-width: 62ch; margin-bottom: clamp(2rem, 4vw, 3rem); }

.section-index {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.19em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 0.85rem;
  padding-inline-start: 0.9rem;
  border-inline-start: 2px solid var(--c-worker);
}

.section-title {
  font-size: clamp(1.65rem, 3.6vw, 2.4rem);
  letter-spacing: -0.012em;
  margin-bottom: 1rem;
}

.section-lede { color: var(--ink-2); }

/* ── 路由表 ───────────────────────────────────────────────────────────── */

.routes { display: flex; flex-direction: column; gap: 1px; background: var(--line-soft); border: 1px solid var(--line-soft); border-radius: var(--radius); overflow: hidden; }

.route {
  display: grid;
  grid-template-columns: minmax(0, 20rem) minmax(0, 1fr);
  grid-template-areas: "path chain" "note note";
  gap: 0.45rem 1.5rem;
  padding: 1.15rem clamp(1rem, 2.5vw, 1.4rem);
  background: var(--bg-2);
  transition: background 0.25s;
}

/* 有真實請求打中這條路徑時亮一下 */
.route[data-live="true"] { animation: route-flash 1.1s ease-out; }
@keyframes route-flash {
  0%   { background: #f6821f1f; }
  100% { background: var(--bg-2); }
}

.route-path {
  grid-area: path;
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--ink);
  word-break: break-all;
}
.route-path .verb {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink-2);
  background: #ffffff0d;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.1em 0.45em;
  margin-inline-end: 0.55em;
}

.route-chain { grid-area: chain; display: flex; align-items: center; gap: 0.35rem; flex-wrap: wrap; }

/* 用「›」把 chip 串成一條鏈，視覺上就是請求的流向 */
.route-chain .chip:not(:last-child),
.trace-chain .chip:not(:last-child) { margin-inline-end: 0.55rem; position: relative; }
.route-chain .chip:not(:last-child)::after,
.trace-chain .chip:not(:last-child)::after {
  content: "›";
  position: absolute;
  right: -0.62rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--ink-3);
  font-family: var(--font-mono);
}

.route-note {
  grid-area: note;
  font-size: 0.9rem;
  color: var(--ink-2);
  max-width: 70ch;
  margin-top: 0.35rem;
}

/* ── Demo ─────────────────────────────────────────────────────────────── */

.gate {
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  padding: clamp(1.75rem, 4vw, 2.75rem);
  background: var(--bg-2);
  text-align: center;
}
.gate[hidden], .workbench[hidden] { display: none; }

.gate-title { font-size: 1.2rem; margin-bottom: 0.6rem; }
.gate-note { color: var(--ink-2); font-size: 0.92rem; margin-bottom: 1.5rem; }
.gate-actions { display: flex; flex-direction: column; align-items: center; gap: 0.85rem; }

.composer { display: flex; gap: 0.7rem; margin-bottom: 1.1rem; }

.composer-input {
  flex: 1;
  min-width: 0;
  font: inherit;
  font-size: 0.98rem;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line-control);
  border-radius: 8px;
  padding: 0.75rem 0.95rem;
  transition: border-color 0.15s;
}
.composer-input::placeholder { color: var(--ink-3); }
.composer-input:focus { border-color: var(--c-worker); outline: none; }
.composer-input:focus-visible { outline: none; }

.btn {
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--ink);
  padding: 0.7rem 1.15rem;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s, border-color 0.15s, color 0.15s, opacity 0.15s;
}
.btn:hover:not(:disabled) { background: #1a2a3d; border-color: #2b4058; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }

.btn-primary { background: var(--c-worker); border-color: var(--c-worker); color: #140A02; }
.btn-primary:hover:not(:disabled) { background: #ff9433; border-color: #ff9433; }

.btn-ghost {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  padding: 0.4rem 0.7rem;
  background: transparent;
  color: var(--ink-3);
}
.btn-ghost:hover:not(:disabled) { background: #ffffff0a; color: var(--ink); border-color: var(--line); }
.btn-danger:hover:not(:disabled) { color: var(--c-error); border-color: #ff7a8555; background: #ff7a850f; }

.feedback {
  font-size: 0.86rem;
  color: var(--c-error);
  background: #ff7a850f;
  border: 1px solid #ff7a8533;
  border-radius: 8px;
  padding: 0.65rem 0.9rem;
  margin-bottom: 1.1rem;
}
.feedback[hidden] { display: none; }
.feedback[data-tone="ok"] { color: var(--c-r2); background: #2bd4c00f; border-color: #2bd4c033; }

/* 待辦清單 */

.todos { display: flex; flex-direction: column; gap: 0.6rem; }

.todo {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  grid-template-areas: "check body actions" ". image image";
  align-items: start;
  gap: 0.5rem 0.9rem;
  padding: 0.9rem 1rem;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.2s, opacity 0.2s;
}
.todo:hover { border-color: #2b4058; }
.todo[data-busy="true"] { opacity: 0.5; pointer-events: none; }

.todo-check {
  grid-area: check;
  /* 24×24 是 WCAG SC 2.5.8 的最小點擊目標 */
  width: 24px; height: 24px;
  margin-top: 0.1rem;
  padding: 0;
  border-radius: 6px;
  border: 1.5px solid var(--line-control);
  background: transparent;
  color: transparent;
  font-size: 0.72rem;
  line-height: 1;
  cursor: pointer;
  transition: all 0.15s;
}
.todo-check:hover { border-color: var(--c-d1); }
.todo-check[aria-pressed="true"] {
  background: var(--c-d1);
  border-color: var(--c-d1);
  color: #140A24;
}

.todo-body { grid-area: body; min-width: 0; }

.todo-title { font-size: 0.98rem; word-break: break-word; }
.todo[data-done="true"] .todo-title { color: var(--ink-3); text-decoration: line-through; }

.todo-meta {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--ink-3);
  margin-top: 0.3rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.todo-meta b { font-weight: 500; color: var(--chip, var(--ink-3)); }

.todo-actions { grid-area: actions; display: flex; align-items: center; gap: 0.35rem; }

.todo-image { grid-area: image; margin: 0.2rem 0 0; }
.todo-image img {
  display: block;
  max-width: min(100%, 280px);
  height: auto;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--panel);
}
.todo-image figcaption {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  color: var(--ink-3);
  margin-top: 0.4rem;
  word-break: break-all;
}

.empty {
  border: 1px dashed var(--line-soft);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
}
.empty[hidden] { display: none; }
.empty-title { font-size: 1rem; margin-bottom: 0.35rem; }
.empty-note { font-size: 0.88rem; color: var(--ink-3); }

/* 使用者列（頂欄） */

.user { display: flex; align-items: center; gap: 0.55rem; }
.user-avatar {
  width: 26px; height: 26px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--panel-2);
  object-fit: cover;
}
.user-name {
  font-size: 0.82rem;
  color: var(--ink-2);
  max-width: 12ch;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ── 綁定卡片 ─────────────────────────────────────────────────────────── */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
  gap: 1rem;
}

.card {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: 1.4rem;
  background: var(--bg-2);
  border: 1px solid var(--line-soft);
  border-top: 2px solid var(--chip, var(--ink-3));
  border-radius: var(--radius);
}

.card-title { font-size: 1.15rem; color: var(--chip, var(--ink)); }
.card-binding { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-3); margin-top: -0.45rem; }
.card-binding code { background: transparent; border: 0; padding: 0; color: var(--ink-2); }
.card-desc { font-size: 0.9rem; color: var(--ink-2); }

.card-code {
  margin: 0.2rem 0 0;
  padding: 0.85rem;
  background: #00000059;
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.74rem;
  line-height: 1.65;
  color: var(--ink-2);
}
.card-code code { background: transparent; border: 0; padding: 0; font-size: inherit; }

.card-limit {
  margin-top: auto;
  padding-top: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--ink-3);
}

/* ── 部署步驟 ─────────────────────────────────────────────────────────── */

.steps { display: flex; flex-direction: column; }

.step {
  display: grid;
  grid-template-columns: 4rem minmax(0, 1fr);
  gap: 0 1.25rem;
  padding: 1.6rem 0;
  border-top: 1px solid var(--line-soft);
}
.step:first-child { border-top: 0; padding-top: 0; }

.step-no {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--c-worker);
  letter-spacing: 0.06em;
}

.step-body { min-width: 0; display: flex; flex-direction: column; gap: 0.7rem; }
.step-title { font-size: 1.05rem; }

.step-code {
  margin: 0;
  padding: 0.9rem 1rem;
  background: #00000059;
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.78rem;
  line-height: 1.75;
  color: var(--ink-2);
}
.step-code code { background: transparent; border: 0; padding: 0; font-size: inherit; }

.step-note { font-size: 0.88rem; color: var(--ink-2); }

.callout {
  margin-top: 2.5rem;
  padding: 1.4rem 1.5rem;
  background: #f6821f0a;
  border: 1px solid #f6821f33;
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}
.callout-title { font-size: 1rem; color: var(--c-worker); }
.callout p { font-size: 0.9rem; color: var(--ink-2); }

/* ── 頁尾 ─────────────────────────────────────────────────────────────── */

.footer {
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(2.5rem, 5vw, 4rem) var(--pad) clamp(3rem, 6vw, 5rem);
  border-top: 1px solid var(--line-soft);
}
.footer-line { max-width: 60ch; color: var(--ink-2); font-size: 0.92rem; margin-bottom: 1rem; }
.footer-meta { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-3); letter-spacing: 0.04em; }

/* ── 響應式 ───────────────────────────────────────────────────────────── */

@media (max-width: 860px) {
  .route {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas: "path" "chain" "note";
    gap: 0.6rem;
  }
  .trace-row {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas: "route ms" "chain chain";
    gap: 0.45rem 0.8rem;
  }
  .trace-route { grid-area: route; }
  .trace-chain { grid-area: chain; flex-wrap: wrap; row-gap: 0.4rem; }
  .trace-ms { grid-area: ms; }
  .trace-bar { display: none; }
}

@media (max-width: 640px) {
  .topbar { flex-wrap: wrap; gap: 0.75rem 1rem; }
  .topbar-nav { order: 3; width: 100%; margin-inline-start: 0; justify-content: space-between; }
  .topbar-auth { margin-inline-start: auto; }

  .composer { flex-direction: column; }
  .composer .btn { width: 100%; }

  .todo {
    grid-template-columns: auto minmax(0, 1fr);
    grid-template-areas: "check body" ". image" ". actions";
  }
  .todo-actions { justify-content: flex-start; margin-top: 0.3rem; }

  .step { grid-template-columns: minmax(0, 1fr); gap: 0.5rem; }
  .step-no { margin-bottom: 0.2rem; }
}

/* ── 尊重系統的動態偏好 ───────────────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    /* 延遲也要歸零，否則 hero 底線那類「延遲後才出現」的動畫，
       在 reduce 模式下會變成「先看不見、幾百毫秒後才突然冒出來」。 */
    animation-delay: 0s !important;
    transition-delay: 0s !important;
  }
}