:root {
  --bg: #f7f7f5;
  --card-bg: #ffffff;
  --text: #1c1c1c;
  --muted: #6b6b6b;
  --border: #e0e0dc;
  --accent: #2c5eea;
  --accent-text: #ffffff;
  --success: #1f8a4c;
  --danger: #c0392b;
  --warn: #b7791f;
  --tag-bg: #eef1fb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16171a;
    --card-bg: #1f2024;
    --text: #eaeaea;
    --muted: #9a9a9a;
    --border: #34353a;
    --accent: #6d8dfa;
    --accent-text: #10131a;
    --success: #3fbf75;
    --danger: #e0685c;
    --warn: #e0a84a;
    --tag-bg: #24273a;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  font-size: 15px;
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--card-bg);
}

.topbar h1 {
  font-size: 18px;
  margin: 0;
  white-space: nowrap;
}

#nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

#nav button {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
}

#nav button.active {
  background: var(--accent);
  color: var(--accent-text);
  border-color: var(--accent);
}

main {
  max-width: 880px;
  margin: 0 auto;
  padding: 20px 16px 60px;
}

.hidden { display: none !important; }

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
  margin-bottom: 16px;
}

.card.empty { text-align: center; color: var(--muted); }

.filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-bottom: 14px;
}

label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 13px;
  color: var(--muted);
}

input, select, textarea, button {
  font-family: inherit;
  font-size: 14px;
  padding: 7px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
}

textarea { width: 100%; resize: vertical; }

button {
  cursor: pointer;
  background: var(--accent);
  color: var(--accent-text);
  border: none;
  font-weight: 600;
}

button.danger { background: var(--danger); }
button.success { background: var(--success); }
button.edit-q, button.toggle-answer { background: var(--border); color: var(--text); }

.meta { color: var(--muted); font-size: 12px; margin-bottom: 8px; }

.qtext, .atext { line-height: 1.5; }

.answer, .browse-answer { margin-top: 10px; }

.grade-row { display: flex; gap: 10px; margin-top: 10px; }

.tags { margin-top: 10px; display: flex; gap: 6px; flex-wrap: wrap; }

.tag {
  background: var(--tag-bg);
  color: var(--accent);
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 12px;
}

.row-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }

.timer { font-size: 13px; color: var(--muted); margin-bottom: 8px; }
.timer.overdue { color: var(--danger); font-weight: 600; }

.result-table { width: 100%; border-collapse: collapse; margin-top: 10px; }
.result-table th, .result-table td {
  text-align: left;
  padding: 6px 8px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}
.row-correct td:nth-child(3) { color: var(--success); }
.row-wrong td:nth-child(3) { color: var(--danger); }

#add-form { display: flex; flex-direction: column; gap: 12px; }

.muted { color: var(--muted); font-size: 13px; }

#browse-list .card { margin-bottom: 10px; }

.practice-row {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 8px;
  overflow: hidden;
}

.practice-row.expanded { border-color: var(--accent); }

.row-summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  cursor: pointer;
}

.row-id {
  font-weight: 600;
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.row-tag {
  background: var(--tag-bg);
  color: var(--muted);
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 12px;
  white-space: nowrap;
}

.row-status {
  font-size: 12px;
  font-weight: 600;
  white-space: nowrap;
  margin-left: auto;
}

.row-status.status-due { color: var(--danger); }
.row-status.status-new { color: var(--accent); }
.row-status.status-upcoming { color: var(--muted); }

.row-detail {
  padding: 0 14px 16px;
  border-top: 1px solid var(--border);
  padding-top: 12px;
}

#mm-input { font-size: 18px; padding: 10px; width: 160px; }
#mm-form { display: flex; gap: 10px; align-items: center; }

button:disabled { opacity: 0.45; cursor: not-allowed; }
button:focus-visible, input:focus-visible, select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
.pagination {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 12px 0;
  margin-bottom: 8px;
}
.pagination label { flex-direction: row; align-items: center; }
.page-count { margin-right: auto; font-size: 13px; color: var(--muted); }
.page-number { width: 65px; }
.pagination button { font-size: 12px; padding: 7px 9px; }
.mark-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.mark-btn { --mark: var(--accent); background: transparent; color: var(--mark); border: 1px solid var(--mark); }
.mark-btn[aria-pressed="true"] { background: var(--mark); color: var(--card-bg); }
.mark-badge { --mark: var(--muted); font-size: 12px; font-weight: 600; color: var(--mark); white-space: nowrap; }
.mark-can { --mark: var(--success); }
.mark-partial { --mark: var(--warn); }
.mark-cannot { --mark: var(--danger); }
.browse-item h3 { margin: 0 0 8px; font-size: 16px; }
.meta { overflow-wrap: anywhere; }
#app-status:empty { display: none; }
#app-status.danger { color: var(--danger); }
@media (max-width: 600px) {
  .row-summary { flex-wrap: wrap; gap: 8px; }
  .row-id { flex-basis: 100%; }
  .page-count { flex-basis: 100%; }
  .pagination { gap: 6px; }
}

/* A file input styled as a button: the label is the visible control. */
.file-button {
  display: inline-block;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  padding: 7px 10px;
  border-radius: 6px;
  background: var(--border);
  color: var(--text);
}
.file-button input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.file-button:focus-within { outline: 2px solid var(--accent); outline-offset: 3px; }