/* Structural/layout rules only -- no colors, gradients, shadows, blur, or
   border-radius shape decisions. Those all live in the per-theme CSS files
   (theme-*.css) so a theme swap only needs to change stylesheet, not markup. */

* { box-sizing: border-box; }
html, body { height: 100%; }
body { margin: 0; min-height: 100vh; }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  position: sticky;
  top: 0;
  z-index: 10;
}
.topbar-actions { display: flex; align-items: center; gap: 14px; }
.brand {
  font-family: 'Orbitron', var(--font);
  font-weight: 600;
  font-size: 1.15rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  border-radius: 8px;
  border: 1px solid var(--border, rgba(127, 127, 127, 0.35));
  background: var(--panel-2, rgba(127, 127, 127, 0.08));
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  transition: transform 0.12s ease, box-shadow 0.12s ease, border-color 0.12s ease;
}
.brand:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  transform: translateY(-1px);
}
.brand:active { transform: translateY(1px) scale(0.98); }
.topbar-right { display: flex; align-items: center; gap: 14px; font-size: 0.9rem; }
.topbar-right .username { font-weight: 700; }
.nav-link { text-decoration: none; font-size: 0.9rem; font-weight: 600; }

.settings-wrap { position: relative; }
.settings-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  cursor: pointer;
  font-size: 1.05rem;
  line-height: 1;
}
.settings-panel {
  position: absolute;
  top: 44px;
  right: 0;
  min-width: 210px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  z-index: 20;
}
.settings-panel[hidden] { display: none; }
.settings-panel-title {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
  padding: 4px 8px 6px;
}
.theme-option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  border: none;
  text-align: left;
  width: 100%;
}
.theme-swatch { width: 16px; height: 16px; border-radius: 50%; flex-shrink: 0; }
.theme-option .check { margin-left: auto; opacity: 0; font-weight: 700; }
.theme-option.active .check { opacity: 1; }

.level-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 12px;
}
.level-bar { width: 60px; height: 7px; overflow: hidden; display: inline-block; }
.level-bar-fill { display: block; height: 100%; }
.xp-text { font-weight: 600; }

#app { max-width: 1200px; margin: 0 auto; padding: 24px; }

.btn {
  position: relative;
  overflow: hidden;
  padding: 9px 20px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  border-width: 1px;
  border-style: solid;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
}
.btn:active { transform: translateY(1px) scale(0.99); }
.btn-link { background: none; border: none; box-shadow: none; cursor: pointer; text-decoration: underline; font-weight: 600; padding: 0; }

.auth-card { max-width: 380px; margin: 60px auto; padding: 28px; }
.auth-tabs { display: flex; margin-bottom: 20px; overflow: hidden; padding: 4px; gap: 4px; }
.auth-tab { flex: 1; padding: 9px; border: none; cursor: pointer; font-weight: 600; }
.auth-tab.active { font-weight: 700; }
#auth-form { display: flex; flex-direction: column; gap: 14px; }
#auth-form label { display: flex; flex-direction: column; gap: 6px; font-size: 0.85rem; font-weight: 600; }
#auth-form input { padding: 10px 12px; font-size: 1rem; width: 100%; }
.auth-error { font-size: 0.85rem; min-height: 1em; font-weight: 600; }

.problems-page h1, .leaderboard-page h1, .notes-page h1 { margin-bottom: 4px; }
.subtitle { margin-top: 0; margin-bottom: 24px; }
.category-block { margin-bottom: 18px; overflow: hidden; }
.category-header {
  padding: 14px 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}
.category-header h3 { margin: 0; font-size: 1rem; }
.category-header .meta { font-size: 0.85rem; font-weight: 600; }
.problem-row { display: flex; align-items: center; gap: 12px; padding: 12px 18px; text-decoration: none; }
.problem-row .check { width: 18px; text-align: center; font-weight: 700; }
.problem-row .title { flex: 1; }
.badge { position: relative; overflow: hidden; font-size: 0.75rem; padding: 3px 10px; font-weight: 700; }

.solve-page { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; align-items: start; }
.solve-left, .solve-right { padding: 18px; }
.solve-header { margin-bottom: 12px; }
.back-link { font-size: 0.85rem; text-decoration: none; font-weight: 600; }
.solve-header h2 { margin: 8px 0 8px; }
.category-pill { margin-left: 8px; font-size: 0.8rem; font-weight: 600; padding: 2px 10px; }
.problem-description { line-height: 1.6; }
.problem-description code { padding: 1px 5px; font-size: 0.9em; }
.editor-toolbar { display: flex; gap: 8px; margin-bottom: 10px; }
#code-editor {
  width: 100%;
  min-height: 340px;
  font-family: "Cascadia Code", Consolas, Menlo, monospace;
  font-size: 0.9rem;
  padding: 14px;
  resize: vertical;
  tab-size: 2;
}
.results { margin-top: 14px; }
.result-summary { font-weight: 700; margin-bottom: 8px; }
.test-case { padding: 8px 12px; margin-bottom: 6px; font-size: 0.85rem; font-family: Consolas, Menlo, monospace; }
.test-case .label { font-weight: 700; margin-right: 6px; }

@media (max-width: 900px) {
  .solve-page { grid-template-columns: 1fr; }
}

.your-rank-card { padding: 14px 18px; margin-bottom: 20px; }
.your-rank-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.your-rank-label { font-size: 0.85rem; font-weight: 600; }
.your-rank-value { font-size: 1.5rem; font-weight: 800; }
.leaderboard-table { width: 100%; border-collapse: collapse; overflow: hidden; }
.leaderboard-table th { text-align: left; padding: 10px 16px; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.03em; }
.leaderboard-table td { padding: 10px 16px; }
.you-tag { font-size: 0.8rem; font-weight: 700; }

/* Notes */
.notes-block { margin-bottom: 18px; overflow: hidden; }
.notes-header {
  padding: 14px 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}
.notes-header h3 { margin: 0; font-size: 1rem; }
.notes-body { padding: 4px 22px 20px; line-height: 1.7; }
.notes-body[hidden] { display: none; }
.notes-body h4 { margin: 14px 0 6px; }
.notes-body ul { margin: 6px 0; padding-left: 22px; }
.notes-body code { padding: 1px 5px; font-size: 0.9em; }
.notes-body pre {
  padding: 12px 14px;
  overflow-x: auto;
  font-family: "Cascadia Code", Consolas, Menlo, monospace;
  font-size: 0.85rem;
}
.notes-toggle-icon { transition: transform 0.15s ease; }
.notes-header.open .notes-toggle-icon { transform: rotate(90deg); }
.notes-titlebar-left, .notes-titlebar-right { display: flex; align-items: center; gap: 8px; }
/* Fake window icon + minimize/maximize/close chrome -- decorative only,
   purely for the Windows XP/Vista "Aero" theme; every other theme hides
   these and keeps the plain header. */
.notes-win-icon, .win-btn { display: none; }

/* Notes: W3Schools-style callouts and example labels */
.notes-body .example-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-2);
  margin: 14px 0 4px;
}
.notes-body .note-callout,
.notes-body .tip-callout {
  margin: 10px 0;
  padding: 10px 14px;
  border-left: 4px solid var(--accent);
  background: var(--panel-2, rgba(127, 127, 127, 0.08));
  border-radius: 4px;
}
.notes-body .note-callout p,
.notes-body .tip-callout p { margin: 0; }
.notes-body .tip-callout { border-left-color: var(--accent-2); }
.notes-body .note-callout b, .notes-body .tip-callout b { color: var(--accent); }
.notes-body .tip-callout b { color: var(--accent-2); }
.notes-body .takeaways {
  margin: 14px 0;
  padding: 12px 16px;
  border: 1px solid var(--border, rgba(127, 127, 127, 0.25));
  border-radius: 6px;
  background: var(--panel-2, rgba(127, 127, 127, 0.05));
}
.notes-body .takeaways p { margin: 0 0 6px; font-weight: 700; }
.notes-body .takeaways ul { margin: 0; }