:root {
  color-scheme: light dark;
  --bg: #eef2f7;
  --surface: #ffffff;
  --surface-soft: #f7f9fc;
  --text: #172033;
  --muted: #667085;
  --border: #d8dee9;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #e8efff;
  --success: #178447;
  --success-soft: #e8f7ef;
  --danger: #c53939;
  --danger-soft: #fdecec;
  --shadow: 0 20px 60px rgba(15, 23, 42, .12);
  --radius: 18px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #08101d;
    --surface: #111a2a;
    --surface-soft: #0d1524;
    --text: #edf3ff;
    --muted: #a8b3c7;
    --border: #2a3850;
    --accent: #78a7ff;
    --accent-hover: #9bbcff;
    --accent-soft: #1b2b49;
    --success: #72d69a;
    --success-soft: #113321;
    --danger: #ff9292;
    --danger-soft: #3a171b;
    --shadow: 0 22px 60px rgba(0, 0, 0, .34);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at top, rgba(37,99,235,.11), transparent 34%), var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button, input, select { font: inherit; }
button { cursor: pointer; }

.page-shell {
  width: min(980px, calc(100% - 28px));
  margin: 0 auto;
  padding: 34px 0 56px;
}

.page-header {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 20px;
  align-items: start;
  margin-bottom: 24px;
}

.brand {
  display: inline-grid;
  place-items: center;
  width: 54px;
  height: 54px;
  border-radius: 14px;
  background: var(--text);
  color: var(--surface);
  text-decoration: none;
  font-weight: 800;
  letter-spacing: -.04em;
}

.eyebrow, .card-kicker {
  margin: 0 0 5px;
  color: var(--accent);
  font-size: .8rem;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
}

h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 8px; font-size: clamp(1.8rem, 4vw, 2.75rem); letter-spacing: -.04em; }
.intro { max-width: 720px; margin-bottom: 0; color: var(--muted); line-height: 1.55; }

.toolbar {
  display: grid;
  grid-template-columns: 1fr 1.35fr auto;
  gap: 14px;
  padding: 16px;
  margin-bottom: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 28px rgba(15,23,42,.05);
}

.control-group { display: grid; gap: 7px; }
.control-group > span, .toggle-control > span { font-size: .82rem; font-weight: 750; color: var(--muted); }

select, input[type="search"] {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: var(--surface-soft);
  color: var(--text);
  padding: 0 12px;
  outline: none;
}

select:focus, input[type="search"]:focus { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent); }

.toggle-control {
  display: flex;
  gap: 9px;
  align-items: end;
  padding-bottom: 11px;
  white-space: nowrap;
}
.toggle-control input { width: 18px; height: 18px; accent-color: var(--accent); }

.mode-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 14px;
  padding: 6px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.mode-tab {
  min-height: 44px;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: var(--muted);
  font-weight: 800;
}

.mode-tab:hover { background: var(--surface-soft); color: var(--text); }
.mode-tab.active { background: var(--accent-soft); color: var(--accent); }
.mode-tab:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 28%, transparent); outline-offset: 2px; }

.study-panel,
.quiz-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: clamp(18px, 4vw, 32px);
  box-shadow: var(--shadow);
}

.study-panel[hidden], .quiz-panel[hidden] { display: none; }

.progress-row,
.quiz-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  color: var(--muted);
  font-size: .9rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 11px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 800;
}

.flash-card {
  height: clamp(650px, 70dvh, 780px);
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
  padding: clamp(22px, 5vw, 42px);
  border-radius: 20px;
  background: linear-gradient(145deg, var(--surface-soft), var(--surface));
  border: 1px solid var(--border);
}

.card-heading { padding-bottom: 18px; border-bottom: 1px solid var(--border); }
.card-heading h2 { margin-bottom: 0; font-size: clamp(2rem, 6vw, 3.7rem); line-height: 1.04; letter-spacing: -.05em; }

.card-details { display: grid; gap: 22px; padding-top: 24px; }
.card-details h3 { margin-bottom: 8px; font-size: .92rem; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }
.card-details p { margin-bottom: 0; font-size: 1.04rem; line-height: 1.65; }

.term-list { display: flex; flex-wrap: wrap; gap: 8px; }
.term {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 5px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  font-size: .9rem;
  font-weight: 700;
}

.recall-prompt {
  min-height: 420px;
  display: grid;
  place-items: center;
  align-content: center;
  text-align: center;
  gap: 18px;
  padding: 28px 0;
}
.recall-prompt[hidden] { display: none; }
.recall-prompt p { max-width: 560px; margin: 0; font-size: 1.15rem; color: var(--muted); line-height: 1.6; }

.nav-row { display: grid; grid-template-columns: 1fr auto 1fr; gap: 12px; margin-top: 18px; min-height: 48px; }
.button {
  min-height: 48px;
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 0 18px;
  font-weight: 800;
  transition: transform .12s ease, background .12s ease, border-color .12s ease;
}
.button:hover { transform: translateY(-1px); }
.button:active { transform: translateY(0); }
.button.primary { background: var(--accent); color: #fff; }
.button.primary:hover { background: var(--accent-hover); }
.button.secondary { background: var(--surface-soft); border-color: var(--border); color: var(--text); }
.button.ghost { background: transparent; border-color: var(--border); color: var(--muted); }
.button:disabled { opacity: .45; cursor: not-allowed; transform: none; }

.keyboard-note { margin: 14px 0 0; color: var(--muted); text-align: center; font-size: .84rem; }
.empty-state { text-align: center; color: var(--muted); padding: 80px 10px; }

.term-hint {
  margin: -2px 0 9px !important;
  color: var(--muted);
  font-size: .82rem !important;
  line-height: 1.4 !important;
}

.term {
  appearance: none;
  color: var(--text);
  cursor: pointer;
  transition: border-color .12s ease, background .12s ease, color .12s ease, transform .12s ease;
}

.term:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
  transform: translateY(-1px);
}

.term:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent);
}

.term.active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.term-definition {
  margin-top: 12px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 12px;
  background: var(--accent-soft);
}

.term-definition[hidden] { display: none; }
.term-definition strong { display: block; margin-bottom: 4px; color: var(--accent); }
.term-definition p { margin: 0; font-size: .94rem !important; line-height: 1.55 !important; }

/* Quiz */
.quiz-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, .75fr);
  gap: 28px;
  align-items: end;
  padding-bottom: 22px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--border);
}

.quiz-header h2 { margin-bottom: 8px; font-size: clamp(1.6rem, 4vw, 2.35rem); letter-spacing: -.035em; }
.quiz-header p:not(.eyebrow) { margin-bottom: 0; color: var(--muted); line-height: 1.55; }

.quiz-settings {
  display: grid;
  grid-template-columns: 1.3fr .85fr;
  gap: 10px;
  align-items: end;
}

.quiz-settings .button { grid-column: 1 / -1; }

.quiz-welcome {
  display: grid;
  place-items: center;
  min-height: 360px;
  text-align: center;
  padding: 40px 20px;
  border: 1px dashed var(--border);
  border-radius: 18px;
  background: var(--surface-soft);
}

.quiz-welcome h3 { margin-bottom: 8px; font-size: 1.45rem; }
.quiz-welcome p { max-width: 570px; margin-bottom: 0; color: var(--muted); line-height: 1.6; }

.quiz-card {
  min-height: 480px;
  padding: clamp(22px, 5vw, 38px);
  border: 1px solid var(--border);
  border-radius: 20px;
  background: linear-gradient(145deg, var(--surface-soft), var(--surface));
}

.quiz-card h3 {
  margin-bottom: 12px;
  font-size: clamp(1.35rem, 4vw, 2rem);
  line-height: 1.25;
  letter-spacing: -.025em;
}

.quiz-clue {
  margin-bottom: 24px;
  padding: 15px 17px;
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  background: var(--accent-soft);
  font-size: 1rem;
  line-height: 1.6;
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.quiz-option {
  min-height: 64px;
  padding: 12px 15px;
  border: 1px solid var(--border);
  border-radius: 13px;
  background: var(--surface);
  color: var(--text);
  text-align: left;
  font-weight: 750;
  line-height: 1.35;
  transition: border-color .12s ease, background .12s ease, transform .12s ease;
}

.quiz-option:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); transform: translateY(-1px); }
.quiz-option:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 24%, transparent); outline-offset: 2px; }
.quiz-option.correct { border-color: var(--success); background: var(--success-soft); }
.quiz-option.wrong { border-color: var(--danger); background: var(--danger-soft); }
.quiz-option:disabled { cursor: default; }

.quiz-feedback {
  margin-top: 18px;
  padding: 15px 17px;
  border: 1px solid var(--border);
  border-radius: 12px;
  line-height: 1.55;
}
.quiz-feedback[hidden] { display: none; }
.quiz-feedback.success { border-color: var(--success); background: var(--success-soft); }
.quiz-feedback.error { border-color: var(--danger); background: var(--danger-soft); }
.quiz-feedback strong { display: block; margin-bottom: 4px; }
.quiz-feedback p { margin: 0; }

.quiz-actions { display: flex; justify-content: flex-end; margin-top: 16px; }
.quiz-actions .button { min-width: 190px; }

.quiz-results {
  padding: clamp(26px, 5vw, 44px);
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface-soft);
  text-align: center;
}
.quiz-results[hidden] { display: none; }
.quiz-results h3 { margin-bottom: 8px; font-size: clamp(1.6rem, 4vw, 2.25rem); }
.quiz-score { margin-bottom: 8px; font-size: clamp(2rem, 8vw, 4rem); font-weight: 850; letter-spacing: -.05em; }
.quiz-results > p:not(.eyebrow):not(.quiz-score) { color: var(--muted); line-height: 1.55; }

.missed-technologies {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin: 20px 0 0;
}

.missed-chip {
  min-height: 36px;
  padding: 6px 11px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-weight: 700;
}
.missed-chip:hover { border-color: var(--accent); color: var(--accent); }

.quiz-result-actions {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 24px;
}

@media (max-width: 720px) {
  .page-shell { width: min(100% - 20px, 980px); padding-top: 20px; }
  .page-header { grid-template-columns: 1fr; gap: 12px; }
  .brand { width: 46px; height: 46px; }
  .toolbar { grid-template-columns: 1fr; }
  .toggle-control { align-items: center; padding: 3px 0 0; }

  /* Taller card reduces internal scrolling while keeping navigation stationary. */
  .flash-card { height: clamp(660px, 76dvh, 780px); min-height: 0; }
  .term { min-height: 38px; padding: 7px 11px; }

  .nav-row { grid-template-columns: 1fr 1fr; }
  .button.ghost { grid-column: 1 / -1; grid-row: 2; }

  .quiz-header { grid-template-columns: 1fr; gap: 18px; }
  .quiz-settings { grid-template-columns: 1fr 1fr; }
  .quiz-options { grid-template-columns: 1fr; }
  .quiz-card { min-height: 520px; }
}

@media (max-width: 460px) {
  .study-panel, .quiz-panel { padding: 14px; border-radius: 20px; }
  .flash-card { height: clamp(680px, 78dvh, 800px); padding: 22px; }
  .card-heading h2 { font-size: clamp(2rem, 11vw, 3rem); }
  .quiz-settings { grid-template-columns: 1fr; }
  .quiz-settings .button { grid-column: auto; }
  .quiz-meta { align-items: flex-start; }
  .quiz-actions .button { width: 100%; }
}

/* Title bar replaces the old page header */
.page-shell { padding-top: 18px; }
.title-bar { margin-bottom: 12px; }
.title-bar h1 { margin: 0; font-size: clamp(1.8rem, 5vw, 3rem); line-height: 1.08; letter-spacing: -.04em; }
.tech-link { color: var(--text); text-decoration: none; border-bottom: 2px solid color-mix(in srgb, var(--accent) 45%, transparent); }
.tech-link:hover, .tech-link:focus-visible { color: var(--accent); border-bottom-color: var(--accent); outline: none; }
.tech-link[href="#"], .tech-link:not([href]) { border-bottom: 0; }
.card-details { padding-top: 0; }
.flow { margin-top: 16px; padding: 14px 16px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); }
.flow[hidden] { display: none; }
.flow h4 { margin: 0 0 8px; font-size: .78rem; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }
.flow h4:not(:first-child) { margin-top: 14px; }
.flow-steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; counter-reset: step; }
.flow-steps li { position: relative; padding: 9px 12px 9px 40px; border-radius: 10px; background: var(--accent-soft); font-size: .95rem; line-height: 1.4; counter-increment: step; }
.flow-steps li::before { content: counter(step); position: absolute; left: 11px; top: 50%; transform: translateY(-50%); width: 20px; height: 20px; border-radius: 50%; background: var(--accent); color: #fff; font-size: .75rem; font-weight: 800; display: grid; place-items: center; }
.flow-steps li:not(:last-child)::after { content: "\2193"; position: absolute; left: 15px; bottom: -11px; color: var(--accent); font-size: .8rem; z-index: 1; }
.term.static { cursor: default; }
.term.static:hover { transform: none; background: var(--surface); border-color: var(--border); color: var(--text); }

/* Compact top-right tabs, no category filter */
.title-bar { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.title-text { min-width: 0; }
.title-bar .mode-tabs { display: inline-flex; flex: none; gap: 2px; margin: 0; padding: 3px; border-radius: 10px; }
.title-bar .mode-tab { min-height: 32px; padding: 0 12px; border-radius: 8px; font-size: .84rem; }
.toolbar { grid-template-columns: 1fr auto; }
@media (max-width: 720px) { .toolbar { grid-template-columns: 1fr; } }

/* Step descriptions beside each step */
.flow-steps li strong { font-weight: 700; }
.flow-steps li.has-note { display: grid; grid-template-columns: minmax(130px, 34%) 1fr; gap: 6px 14px; align-items: center; }
.step-note { color: var(--muted); font-size: .88rem; line-height: 1.4; }
@media (max-width: 620px) { .flow-steps li.has-note { grid-template-columns: 1fr; } }

.search-results p{color:var(--muted)}.search-results{padding-bottom:18px}.search-results button{margin:4px}.grocery-note{border-left:3px solid var(--accent);padding-left:15px;margin-top:18px}
/* Keep mobile space focused on the technology content. */
@media(max-width:720px){.page-shell{padding-top:8px}.title-bar{margin-bottom:8px}.search-results{padding-bottom:8px}.search-results:empty{display:none}.keyboard-note{display:none}}

/* Compact review header: reserve screen space for the entry. */
.page-shell{padding-top:8px}
.title-bar{align-items:center;gap:8px;margin-bottom:8px}
.title-bar h1{font-size:clamp(1.25rem,3.4vw,1.75rem);line-height:1.15;letter-spacing:-.02em;overflow-wrap:anywhere}
.title-bar .card-kicker{font-size:.65rem;margin-bottom:2px;letter-spacing:.04em}
.title-bar .mode-tabs{padding:2px}
.title-bar .mode-tab{min-height:36px;padding:0 9px;font-size:.78rem}
.toolbar{grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:10px;padding:0;margin-bottom:8px;border:0;border-radius:0;background:transparent;box-shadow:none}
.search-group{min-width:0;gap:0}
.search-group>span{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
.search-group input{min-height:40px;font-size:16px;border-radius:8px}
.toggle-control{align-items:center;padding:0;gap:5px;min-height:40px}
.toggle-control>span{font-size:.75rem}
.search-results{padding-bottom:6px}
.search-results[hidden]{display:none}
.search-results p{margin:0 0 4px;font-size:.75rem}
.study-panel{padding:10px;border-radius:12px}
.progress-row{margin-bottom:6px;gap:8px;font-size:.78rem}
.progress-row .badge{min-height:24px;padding:0 8px;font-size:.75rem}
.flash-card{padding:14px;border-radius:10px}
.card-details{gap:16px}
.card-details h3{margin-bottom:6px}
@media(max-width:460px){
.page-shell{width:calc(100% - 16px)}
.title-bar .mode-tab{padding:0 7px}
.toolbar{gap:6px}
.study-panel{padding:8px}
.flash-card{padding:12px}
.toggle-control>span{font-size:.7rem}
}