:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --text: #1d2430;
  --muted: #5b6575;
  --accent: #0b6e8a;
  --accent-text: #ffffff;
  --ok: #2e7d4f;
  --danger: #b3261e;
  --line: #d9dee6;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14181f;
    --card: #1d232d;
    --text: #e6eaf0;
    --muted: #a3adbb;
    --accent: #3fb3d1;
    --accent-text: #0c1116;
    --ok: #5cc68a;
    --danger: #ff8a80;
    --line: #2f3845;
  }
}
:root[data-theme="dark"] {
  --bg: #14181f;
  --card: #1d232d;
  --text: #e6eaf0;
  --muted: #a3adbb;
  --accent: #3fb3d1;
  --accent-text: #0c1116;
  --ok: #5cc68a;
  --danger: #ff8a80;
  --line: #2f3845;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 760px; margin: 0 auto; padding: 16px; }
h1 { font-size: 1.4rem; margin: 0; }
h2 { font-size: 1.1rem; margin: 0 0 8px; }

.top {
  display: flex; justify-content: space-between; align-items: center;
  max-width: 760px; margin: 0 auto; padding: 16px;
}
.card {
  max-width: 360px; margin: 12vh auto; padding: 24px;
  background: var(--card); border-radius: 12px; border: 1px solid var(--line);
}
.login form { display: grid; gap: 12px; }
.login label { font-weight: 600; }

input[type="password"] {
  width: 100%; padding: 12px; font-size: 16px;
  border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--text);
}

.btn {
  display: inline-block; padding: 10px 16px; border-radius: 8px; border: 0;
  background: var(--accent); color: var(--accent-text);
  font: inherit; font-weight: 600; text-decoration: none; cursor: pointer;
}
.btn.wide { display: block; text-align: center; }
.btn.small { padding: 6px 10px; font-size: 0.9rem; }
button.link, .link {
  background: none; border: 0; padding: 4px; color: var(--accent);
  font: inherit; cursor: pointer; text-decoration: underline;
}
.danger { color: var(--danger); }

.deadlines, .progress, .card-section {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 16px; margin-bottom: 16px;
}
.deadlines ul { margin: 0; padding-left: 18px; }
.bar { height: 12px; background: var(--line); border-radius: 6px; overflow: hidden; }
#bar-fill { height: 100%; width: 0; background: var(--ok); transition: none; }
.counts { display: flex; gap: 16px; flex-wrap: wrap; margin: 10px 0 0; }

.error { color: var(--danger); font-weight: 600; min-height: 1em; }

details.category {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  margin-bottom: 12px; overflow: hidden;
}
details.category > summary {
  padding: 14px 16px; font-weight: 700; cursor: pointer; list-style: none;
}
details.category > summary::-webkit-details-marker { display: none; }
details.category > summary::after { content: "▾"; float: right; color: var(--muted); }
details.category[open] > summary::after { content: "▴"; }

ul.tasks { list-style: none; margin: 0; padding: 0; }
li.task { padding: 14px 16px; border-top: 1px solid var(--line); }
li.task.done .title { text-decoration: line-through; color: var(--muted); }
li.task.na { opacity: 0.6; }
.task-head { display: flex; gap: 10px; align-items: flex-start; cursor: pointer; }
.task-head input[type="checkbox"] { width: 22px; height: 22px; margin-top: 2px; flex: none; }
.title { font-weight: 600; }
.badge {
  font-size: 0.75rem; padding: 2px 8px; border-radius: 999px;
  border: 1px solid var(--line); color: var(--muted); white-space: nowrap;
}
.badge.req { border-color: var(--accent); color: var(--accent); }
.desc { margin: 6px 0 4px 32px; color: var(--muted); font-size: 0.95rem; }
.hint { margin: 0 0 8px 32px; font-size: 0.85rem; color: var(--muted); word-break: break-all; }
.na-toggle { margin: 0 0 8px 32px; font-size: 0.9rem; }
.actions { margin-left: 32px; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.files { list-style: none; margin: 8px 0 0 32px; padding: 0; font-size: 0.95rem; }
.files li { padding: 4px 0; word-break: break-all; }
input.hidden-file { display: none; }

@media (min-width: 720px) {
  .desc, .hint, .actions, .files, .na-toggle { margin-left: 32px; }
}