:root {
  --bg: #f5f6f8;
  --bg-alt: #ffffff;
  --text: #1c1f26;
  --text-dim: #5b6270;
  --border: #dde1e7;
  --accent: #4f5bd5;
  --accent-text: #ffffff;
  --good: #1f9d55;
  --bad: #d64545;
  --warn: #c98a12;
  --tag-seed: #4f5bd5;
  --tag-studon: #b3541e;
  --code-bg: #1e1e2e;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
}

[data-theme="dark"] {
  --bg: #14151a;
  --bg-alt: #1d1f27;
  --text: #e7e9ee;
  --text-dim: #9aa1b0;
  --border: #2c2f3a;
  --accent: #7c87f0;
  --accent-text: #10111a;
  --good: #3fcf76;
  --bad: #f06868;
  --warn: #e0a83f;
  --tag-seed: #7c87f0;
  --tag-studon: #e0955a;
  --code-bg: #0d0e14;
  --shadow: 0 1px 4px rgba(0,0,0,0.4);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.topbar {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.7rem 1.2rem;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
  flex-wrap: wrap;
}

.topbar h1 {
  font-size: 1.05rem;
  margin: 0;
  white-space: nowrap;
}

.tabs {
  display: flex;
  gap: 0.3rem;
  flex: 1;
  flex-wrap: wrap;
}

.tab-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-dim);
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.88rem;
}

.tab-btn:hover { background: var(--border); }

.tab-btn.active {
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 600;
}

.icon-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  width: 2.1rem;
  height: 2.1rem;
  cursor: pointer;
  font-size: 1rem;
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 1.2rem;
}

.view { display: none; }
.view.active { display: block; }

.card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow);
}

h2 { margin-top: 0; }

.row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  align-items: center;
}

label.field {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.82rem;
  color: var(--text-dim);
}

select, input[type="text"], input[type="number"], textarea {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.4rem 0.5rem;
  font-family: inherit;
  font-size: 0.9rem;
}

textarea { font-family: inherit; resize: vertical; }

button.btn {
  background: var(--accent);
  color: var(--accent-text);
  border: none;
  border-radius: 6px;
  padding: 0.5rem 1rem;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
}
button.btn:hover { filter: brightness(1.08); }
button.btn.secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  font-weight: 500;
}
button.btn.danger { background: var(--bad); color: white; }
button.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  color: white;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.tag.seed { background: var(--tag-seed); }
.tag.studon { background: var(--tag-studon); }
.tag.recall { background: var(--warn); color: #222; }
.tag.module { background: var(--border); color: var(--text); text-transform: none; }

.question-text { font-size: 1.05rem; font-weight: 600; margin: 0.4rem 0 0.8rem; line-height: 1.4; }

.question-image { margin: 0.6rem 0 1rem; }
.question-image img {
  max-width: 100%;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: white;
  display: block;
}

.inline-swatch {
  display: inline-block;
  width: 0.9em;
  height: 0.9em;
  border-radius: 3px;
  border: 1px solid rgba(0,0,0,0.25);
  vertical-align: -0.1em;
  margin-right: 0.4em;
}

.options-list { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 1rem; }

.option-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  background: var(--bg);
}
.option-row:hover { border-color: var(--accent); }
.option-row.selected { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 15%, var(--bg)); }
.option-row.correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 18%, var(--bg)); }
.option-row.incorrect { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 18%, var(--bg)); }
.option-row.disabled { cursor: default; }

.explanation {
  border-left: 3px solid var(--accent);
  padding: 0.6rem 0.9rem;
  background: var(--bg);
  border-radius: 0 8px 8px 0;
  font-size: 0.9rem;
  margin-top: 0.8rem;
}

.score-pill {
  font-weight: 700;
  padding: 0.3rem 0.7rem;
  border-radius: 20px;
  background: var(--bg);
  border: 1px solid var(--border);
}

table.manage-table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
table.manage-table th, table.manage-table td {
  text-align: left;
  padding: 0.5rem 0.6rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
table.manage-table tr:hover { background: var(--bg); }

.code-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
@media (max-width: 800px) {
  .code-layout { grid-template-columns: 1fr; }
}

.CodeMirror { height: 320px; border-radius: 8px; border: 1px solid var(--border); font-size: 0.85rem; }

.preview-pane {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: white;
  height: 320px;
  overflow: auto;
}
.preview-pane iframe { width: 100%; height: 100%; border: none; }

.console-pane {
  background: var(--code-bg);
  color: #d7dae0;
  font-family: "SF Mono", Menlo, monospace;
  font-size: 0.78rem;
  border-radius: 8px;
  padding: 0.5rem 0.7rem;
  height: 90px;
  overflow: auto;
  margin-top: 0.6rem;
  white-space: pre-wrap;
}
.console-pane .err { color: #f06868; }

.progress-bar-outer {
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
  margin: 0.6rem 0;
}
.progress-bar-inner { height: 100%; background: var(--accent); }

.muted { color: var(--text-dim); font-size: 0.85rem; }

.draft-card {
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 0.8rem;
  margin-bottom: 0.9rem;
}
.draft-card .opt-edit-row { display: flex; gap: 0.4rem; align-items: center; margin-bottom: 0.3rem; }
.draft-card .opt-edit-row input[type="text"] { flex: 1; }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.8rem;
}
.stat-box {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.8rem;
  text-align: center;
}
.stat-box .big { font-size: 1.6rem; font-weight: 700; }
.stat-box .lbl { font-size: 0.78rem; color: var(--text-dim); }

a { color: var(--accent); }

/* ===================== Coding view: layout + playground ===================== */

.prompt-text {
  font-size: 0.98rem;
  line-height: 1.55;
  color: var(--text);
  margin: 0.3rem 0 1rem;
}
.prompt-text code {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05rem 0.35rem;
  font-size: 0.88em;
}

.panel-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
}

.playground-panel {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem;
  margin-bottom: 1.1rem;
}

.pg-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.6rem;
  margin: 0.6rem 0 1.1rem;
}

.pg-param {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  min-width: 150px;
}
.pg-param-label {
  font-size: 0.82rem;
  color: var(--text-dim);
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
}
.pg-param-label b { color: var(--text); font-variant-numeric: tabular-nums; }
.pg-param input[type="range"] {
  width: 180px;
  accent-color: var(--accent);
}
.pg-param input[type="color"] {
  width: 60px;
  height: 32px;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-alt);
  cursor: pointer;
}

.pg-compare {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.4rem;
  flex-wrap: wrap;
}
.pg-swatch-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.45rem;
  flex: 1;
  min-width: 160px;
  max-width: 260px;
}
.pg-swatch-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-dim);
}
.pg-swatch {
  width: 100%;
  height: 80px;
  border-radius: 10px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: var(--border);
  transition: background 0.08s linear;
}
.pg-readout {
  font-family: "SF Mono", Menlo, monospace;
  font-size: 0.82rem;
  color: var(--text-dim);
  text-align: center;
  word-break: break-word;
}
.pg-readout.pg-error-text { color: var(--bad); }
.pg-vs {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-dim);
}

/* Custom CodeMirror theme matched to the site palette instead of a bolted-on editor theme */
.cm-s-infovis.CodeMirror { background: var(--code-bg); color: #d7dae0; }
.cm-s-infovis .CodeMirror-gutters { background: var(--code-bg); border-right: 1px solid rgba(255,255,255,0.08); }
.cm-s-infovis .CodeMirror-linenumber { color: #5b6270; }
.cm-s-infovis .CodeMirror-cursor { border-left: 1px solid #d7dae0; }
.cm-s-infovis .cm-keyword { color: #7c87f0; }
.cm-s-infovis .cm-def, .cm-s-infovis .cm-variable-2 { color: #6ec6ff; }
.cm-s-infovis .cm-string { color: #9fd88c; }
.cm-s-infovis .cm-number { color: #e0a83f; }
.cm-s-infovis .cm-comment { color: #7a8092; font-style: italic; }
.cm-s-infovis .cm-atom { color: #e0955a; }
.cm-s-infovis .cm-property { color: #d7dae0; }
.cm-s-infovis .cm-operator { color: #d7dae0; }

/* ===================== Quiz result banner (correct/incorrect) ===================== */

.result-banner {
  display: flex;
  align-items: flex-start;
  gap: 0.7rem;
  border-radius: 10px;
  padding: 0.8rem 1rem;
  margin-top: 0.8rem;
  font-size: 0.92rem;
  line-height: 1.5;
}
.result-banner.correct {
  background: color-mix(in srgb, var(--good) 14%, var(--bg-alt));
  border: 1px solid color-mix(in srgb, var(--good) 45%, var(--border));
}
.result-banner.incorrect {
  background: color-mix(in srgb, var(--bad) 14%, var(--bg-alt));
  border: 1px solid color-mix(in srgb, var(--bad) 45%, var(--border));
}
.result-banner .rb-icon {
  flex: none;
  width: 1.6rem;
  height: 1.6rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 700;
  color: white;
}
.result-banner.correct .rb-icon { background: var(--good); }
.result-banner.incorrect .rb-icon { background: var(--bad); }
.result-banner .rb-body strong { display: block; margin-bottom: 0.15rem; font-size: 0.98rem; }