:root {
  --bg: #f6f7f9; --surface: #fff; --line: #e6e8ec; --ink: #1a1d23;
  --muted: #6b7280; --accent: #4f7cff; --accent-ink: #3f63d6;
  --warn: #d1493a; --high: #d1493a; --low: #6b7280;
  --shadow: 0 1px 2px rgba(20,25,40,.05), 0 6px 20px -12px rgba(20,25,40,.2);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115; --surface: #191c22; --line: #2a2e37; --ink: #eceef2;
    --muted: #9aa2b1; --accent: #6b93ff; --accent-ink: #8fb0ff;
    --warn: #ff6b5c; --high: #ff6b5c; --low: #9aa2b1;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px -14px rgba(0,0,0,.7);
  }
}
:root[data-theme="light"] { --bg:#f6f7f9;--surface:#fff;--line:#e6e8ec;--ink:#1a1d23;--muted:#6b7280;--accent:#4f7cff;--accent-ink:#3f63d6;--warn:#d1493a;--high:#d1493a;--low:#6b7280;--shadow:0 1px 2px rgba(20,25,40,.05),0 6px 20px -12px rgba(20,25,40,.2); }
:root[data-theme="dark"] { --bg:#0f1115;--surface:#191c22;--line:#2a2e37;--ink:#eceef2;--muted:#9aa2b1;--accent:#6b93ff;--accent-ink:#8fb0ff;--warn:#ff6b5c;--high:#ff6b5c;--low:#9aa2b1;--shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px -14px rgba(0,0,0,.7); }

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg); color: var(--ink);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  max-width: 640px; margin: 0 auto;
  padding: max(12px, env(safe-area-inset-top)) 16px calc(24px + env(safe-area-inset-bottom));
  -webkit-font-smoothing: antialiased;
}
header { display: flex; align-items: center; justify-content: space-between; padding: 8px 0 4px; }
h1 { font-size: 26px; margin: 0; letter-spacing: -.02em; }
.header-actions { display: flex; gap: 8px; }
.ghost { background: none; border: 1px solid var(--line); color: var(--ink); border-radius: 10px; padding: 6px 12px; font-size: 14px; cursor: pointer; }
.ghost:hover { border-color: var(--accent); }

.stats { display: flex; gap: 14px; color: var(--muted); font-size: 13.5px; margin: 6px 2px 14px; }
.stats .warn { color: var(--warn); font-weight: 600; }

form { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 10px; box-shadow: var(--shadow); }
#title { width: 100%; border: none; background: none; color: var(--ink); font-size: 16px; padding: 8px 6px; outline: none; }
.add-row { display: flex; gap: 8px; margin-top: 6px; }
.add-row input, .add-row select { flex: 1; min-width: 0; border: 1px solid var(--line); background: var(--bg); color: var(--ink); border-radius: 10px; padding: 8px; font-size: 14px; }
.primary { flex: 0 0 auto; background: var(--accent); color: #fff; border: none; border-radius: 10px; padding: 8px 18px; font-weight: 600; cursor: pointer; }
.primary:hover { background: var(--accent-ink); }

.tabs { display: flex; gap: 6px; margin: 18px 0 10px; overflow-x: auto; }
.tabs button { flex: 0 0 auto; background: none; border: none; color: var(--muted); font-size: 15px; padding: 6px 12px; border-radius: 999px; cursor: pointer; }
.tabs button.active { background: var(--surface); color: var(--ink); border: 1px solid var(--line); font-weight: 600; }

.list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.task { display: flex; align-items: center; gap: 12px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 12px; box-shadow: var(--shadow); }
.task.overdue { border-color: color-mix(in srgb, var(--warn) 45%, var(--line)); }
.check { flex: none; width: 26px; height: 26px; border-radius: 50%; border: 2px solid var(--line); background: none; color: #fff; font-size: 14px; line-height: 1; cursor: pointer; display: grid; place-items: center; }
.task.done .check { background: var(--accent); border-color: var(--accent); }
.task-main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.task-title { font-size: 15.5px; word-break: break-word; }
.task.done .task-title { text-decoration: line-through; color: var(--muted); }
.task-meta { font-size: 12.5px; color: var(--muted); }
.task-meta.pr-high { color: var(--high); }
.task.overdue .task-meta { color: var(--warn); font-weight: 600; }
.del { flex: none; background: none; border: none; color: var(--muted); font-size: 15px; cursor: pointer; padding: 4px 6px; }
.del:hover { color: var(--warn); }

.empty { text-align: center; color: var(--muted); padding: 40px 0; }

@media (prefers-reduced-motion: no-preference) {
  .task { transition: border-color .15s; }
}