:root {
  --bg: #0f1117;
  --bg-soft: #171a23;
  --panel: rgba(25, 28, 40, 0.9);
  --panel-strong: rgba(31, 35, 49, 0.96);
  --line: rgba(255, 255, 255, 0.09);
  --text: #f3f1ea;
  --muted: #b7b6c4;
  --gold: #f2c66d;
  --teal: #7fd7d0;
  --rose: #f29a8a;
  --violet: #a9a0ff;
  --green: #95dfa4;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Manrope', sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(127, 215, 208, 0.12), transparent 35%),
    radial-gradient(circle at top right, rgba(169, 160, 255, 0.16), transparent 32%),
    linear-gradient(160deg, #0c0e14 0%, #10131b 45%, #141925 100%);
  min-height: 100vh;
}

.page-shell {
  width: min(1240px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 40px;
  transition: width 220ms ease;
}

.hero,
.panel,
.top-tabs {
  backdrop-filter: blur(14px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.hero {
  padding: 28px;
  margin-bottom: 18px;
  background:
    linear-gradient(135deg, rgba(242, 198, 109, 0.08), rgba(127, 215, 208, 0.04)),
    var(--panel-strong);
}

.hero__badge,
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-size: 11px;
  color: var(--gold);
}

.hero h1,
.panel h2,
.flashcard h3 {
  font-family: 'DM Serif Display', serif;
  letter-spacing: 0.01em;
}

.hero h1 {
  margin: 14px 0 12px;
  font-size: clamp(2.2rem, 4vw, 4.2rem);
  line-height: 0.95;
}

.hero__text {
  max-width: 760px;
  color: var(--muted);
  line-height: 1.7;
  font-size: 1.02rem;
}

.hero__stats {
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.stat-chip,
.tag,
.list-tag {
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
}

.stat-chip {
  padding: 10px 14px;
  color: var(--muted);
  font-size: 0.94rem;
}

.stat-chip strong { color: var(--text); }

.top-tabs {
  display: inline-flex;
  gap: 10px;
  padding: 10px;
  margin-bottom: 22px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.top-tab {
  border: 1px solid transparent;
  background: transparent;
  color: var(--muted);
  padding: 10px 16px;
  border-radius: 14px;
  cursor: pointer;
}

.top-tab--active {
  color: var(--text);
  background: rgba(242, 198, 109, 0.1);
  border-color: rgba(242, 198, 109, 0.14);
}

.layout {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 22px;
  margin-bottom: 22px;
  transition: grid-template-columns 220ms ease, gap 220ms ease;
}

.panel {
  padding: 22px;
}

.panel__header {
  margin-bottom: 18px;
}

.panel__header--wide {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
}

.panel h2 {
  margin: 8px 0 0;
  font-size: 1.8rem;
}

.field {
  display: grid;
  gap: 8px;
  margin-bottom: 16px;
}

.field span,
.toggle span,
.list-note,
.session-meta,
.progress-labels,
.panel-note {
  color: var(--muted);
}

.panel-note {
  margin: 12px 0 0;
  line-height: 1.65;
  font-size: 0.94rem;
  max-width: 32ch;
}

select,
button {
  font: inherit;
}

select {
  width: 100%;
  padding: 12px 14px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(10, 12, 18, 0.75);
  color: var(--text);
}

.toggle-group {
  display: grid;
  gap: 10px;
  margin: 18px 0;
}

.toggle {
  display: flex;
  gap: 10px;
  align-items: center;
}

.button-grid,
.card-actions,
.rating-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.card-actions {
  align-items: center;
  margin-top: 6px;
}

.button-grid--stacked {
  display: grid;
  gap: 10px;
}

.card-actions .btn {
  min-width: 140px;
}

.card-actions .btn--ghost {
  min-width: 120px;
}

.rating-row {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.rating-row .rating {
  min-width: 110px;
  justify-content: center;
}

.btn,
.rating {
  border: 1px solid var(--line);
  color: var(--text);
  background: rgba(255, 255, 255, 0.04);
  padding: 12px 16px;
  border-radius: 16px;
  cursor: pointer;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease;
}

.btn:hover,
.rating:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.2);
}

.btn--primary {
  background: linear-gradient(135deg, rgba(242, 198, 109, 0.18), rgba(169, 160, 255, 0.18));
}

.btn--hero {
  width: 100%;
  justify-content: center;
  padding: 15px 18px;
  font-weight: 800;
  font-size: 1rem;
  background: linear-gradient(135deg, rgba(242, 198, 109, 0.28), rgba(127, 215, 208, 0.22));
  border-color: rgba(242, 198, 109, 0.22);
  box-shadow: 0 12px 30px rgba(242, 198, 109, 0.08);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.03);
}

.progress-block {
  margin: 20px 0 22px;
}

.progress-labels {
  display: flex;
  justify-content: space-between;
  margin-bottom: 10px;
}

.progress-bar {
  width: 100%;
  height: 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  overflow: hidden;
}

.progress-bar__fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--teal), var(--gold));
  border-radius: inherit;
}

.mini-list {
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

.mini-list h3 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.formula-item {
  padding: 12px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.formula-item:last-child { border-bottom: 0; }
.formula-item strong { display: block; margin-bottom: 5px; color: var(--gold); }
.formula-item span { color: var(--muted); font-size: 0.95rem; line-height: 1.5; }

.context-strip {
  margin: 0 0 12px;
  padding: 10px 14px;
  border: 1px solid rgba(242, 198, 109, 0.14);
  border-radius: 14px;
  background: rgba(242, 198, 109, 0.06);
  color: var(--gold);
  font-size: 0.9rem;
}

.flashcard {
  min-height: 340px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    radial-gradient(circle at top right, rgba(242, 198, 109, 0.1), transparent 30%),
    rgba(9, 10, 16, 0.6);
  padding: 24px;
  display: grid;
  gap: 18px;
  margin-bottom: 16px;
  transition: min-height 220ms ease, padding 220ms ease;
}

.flashcard__face {
  display: grid;
  align-content: start;
  gap: 14px;
}

.card-label {
  color: var(--gold);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 11px;
  margin: 0;
}

.flashcard h3 {
  margin: 0;
  font-size: clamp(1.6rem, 2vw, 2.3rem);
  line-height: 1.2;
}

.card-answer {
  color: var(--muted);
  line-height: 1.8;
  font-size: 1.02rem;
}

.card-answer strong { color: var(--text); }
.card-answer code {
  color: var(--teal);
  background: rgba(127, 215, 208, 0.08);
  padding: 2px 8px;
  border-radius: 999px;
}

.card-tags,
.list-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag,
.list-tag {
  padding: 8px 11px;
  font-size: 0.8rem;
  color: var(--muted);
}

.tag--formula,
.list-tag--formula {
  color: var(--gold);
  border-color: rgba(242, 198, 109, 0.22);
  background: rgba(242, 198, 109, 0.08);
}

.rating { min-width: 92px; }
.rating--again { background: rgba(242, 154, 138, 0.12); }
.rating--hard { background: rgba(242, 198, 109, 0.12); }
.rating--good { background: rgba(127, 215, 208, 0.12); }
.rating--easy { background: rgba(149, 223, 164, 0.12); }

.hidden { display: none !important; }

body.focus-mode .hero,
body.focus-mode .top-tabs,
body.focus-mode .controls-panel,
body.focus-mode .list-panel {
  display: none;
}

body.focus-mode .page-shell {
  width: min(1100px, calc(100% - 20px));
  padding-top: 18px;
}

body.focus-mode .layout {
  grid-template-columns: 1fr;
  gap: 0;
  margin-bottom: 0;
}

body.focus-mode .card-panel {
  min-height: calc(100vh - 36px);
  padding: 28px;
}

body.focus-mode .context-strip {
  margin-bottom: 16px;
}

body.focus-mode .flashcard {
  min-height: 58vh;
  padding: 32px;
}

body.focus-mode .card-actions,
body.focus-mode .rating-row {
  justify-content: center;
}

body.focus-mode .session-meta::after {
  content: ' · Focus mode';
  color: var(--gold);
}

.card-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 14px;
}

.card-list-item {
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.025);
  display: grid;
  gap: 12px;
}

.card-list-item h3 {
  margin: 0;
  font-size: 1rem;
  line-height: 1.5;
}

.card-list-item p {
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
  font-size: 0.94rem;
}

.card-list-item footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
}

.score-chip {
  padding: 8px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font-size: 0.82rem;
}

@media (max-width: 980px) {
  .layout { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .page-shell { width: min(100% - 18px, 1240px); }
  .hero, .panel { border-radius: 22px; }
  .flashcard { min-height: 300px; padding: 18px; }
  .panel__header--wide { flex-direction: column; }
  .card-actions,
  .rating-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }
  .card-actions .btn,
  .rating-row .rating {
    width: 100%;
    min-width: 0;
  }
}