/* ================================================================
   QuizForge · BEM Refactored Stylesheet
   ================================================================ */

/* ── RESET ── */

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ── CUSTOM PROPERTIES ── */

:root {
  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Outfit', system-ui, -apple-system, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --nav-h: 52px;
  --max-w: 1140px;
  --card-h: 400px;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-pill: 100px;
  --focus-ring: 0 0 0 3px var(--accent-focus);
}

/* ── DARK THEME — deep ink with cool blue undertones ── */

[data-theme="dark"] {
  --bg-0: #08090E;
  --bg-1: #0F1118;
  --bg-2: #171A25;
  --bg-3: #1F2333;
  --bg-card: rgba(15, 17, 24, 0.90);
  --bg-card-h: rgba(23, 26, 37, 0.95);
  --bg-glass: rgba(8, 9, 14, 0.72);
  --bg-elevated: rgba(20, 22, 32, 0.96);
  --tx-0: #E8ECF4;
  --tx-1: #9BA3B8;
  --tx-2: #636D84;
  --tx-3: #3E4660;
  /* Hero blue */
  --blue: #3B82F6;
  --blue-d: rgba(59, 130, 246, 0.10);
  --blue-b: rgba(59, 130, 246, 0.22);
  /* Emerald — mastery/success */
  --teal: #34D399;
  --teal-d: rgba(52, 211, 153, 0.10);
  --teal-b: rgba(52, 211, 153, 0.22);
  /* Warm amber */
  --amber: #F59E0B;
  --amber-d: rgba(245, 158, 11, 0.10);
  --amber-b: rgba(245, 158, 11, 0.22);
  /* Soft indigo */
  --violet: #8B5CF6;
  --violet-d: rgba(139, 92, 246, 0.10);
  --violet-b: rgba(139, 92, 246, 0.22);
  /* Coral pink */
  --rose: #F472B6;
  --rose-d: rgba(244, 114, 182, 0.10);
  --rose-b: rgba(244, 114, 182, 0.22);
  /* Steel */
  --slate: #94A3B8;
  --slate-d: rgba(148, 163, 184, 0.08);
  --slate-b: rgba(148, 163, 184, 0.18);
  /* Sky cyan */
  --green: #38BDF8;
  --green-d: rgba(56, 189, 248, 0.10);
  --green-b: rgba(56, 189, 248, 0.22);
  /* Danger */
  --red: #EF4444;
  --red-d: rgba(239, 68, 68, 0.08);
  --red-b: rgba(239, 68, 68, 0.20);
  --border: rgba(255, 255, 255, 0.06);
  --border-h: rgba(255, 255, 255, 0.12);
  --shadow-card: 0 2px 20px rgba(0, 0, 0, 0.35), 0 0 0 1px rgba(255, 255, 255, 0.03);
  --shadow-lg: 0 16px 56px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.04);
  --accent-focus: rgba(59, 130, 246, 0.45);
  --grain-o: 0.018;
}

/* ── LIGHT THEME — crisp Apple-white with cool undertones ── */

[data-theme="light"] {
  --bg-0: #F8F9FC;
  --bg-1: #EFF1F7;
  --bg-2: #E4E7F0;
  --bg-3: #D4D8E4;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-card-h: rgba(255, 255, 255, 0.98);
  --bg-glass: rgba(248, 249, 252, 0.82);
  --bg-elevated: rgba(255, 255, 255, 0.98);
  --tx-0: #0F172A;
  --tx-1: #334155;
  --tx-2: #64748B;
  --tx-3: #94A3B8;
  --blue: #2563EB;
  --blue-d: rgba(37, 99, 235, 0.07);
  --blue-b: rgba(37, 99, 235, 0.18);
  --teal: #059669;
  --teal-d: rgba(5, 150, 105, 0.07);
  --teal-b: rgba(5, 150, 105, 0.18);
  --amber: #D97706;
  --amber-d: rgba(217, 119, 6, 0.07);
  --amber-b: rgba(217, 119, 6, 0.16);
  --violet: #7C3AED;
  --violet-d: rgba(124, 58, 237, 0.07);
  --violet-b: rgba(124, 58, 237, 0.16);
  --rose: #DB2777;
  --rose-d: rgba(219, 39, 119, 0.07);
  --rose-b: rgba(219, 39, 119, 0.16);
  --slate: #64748B;
  --slate-d: rgba(100, 116, 139, 0.07);
  --slate-b: rgba(100, 116, 139, 0.16);
  --green: #0284C7;
  --green-d: rgba(2, 132, 199, 0.07);
  --green-b: rgba(2, 132, 199, 0.18);
  --red: #DC2626;
  --red-d: rgba(220, 38, 38, 0.06);
  --red-b: rgba(220, 38, 38, 0.16);
  --border: rgba(0, 0, 0, 0.08);
  --border-h: rgba(0, 0, 0, 0.14);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.06), 0 6px 24px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.10), 0 1px 3px rgba(0, 0, 0, 0.05);
  --accent-focus: rgba(37, 99, 235, 0.4);
  --grain-o: 0.012;
}

/* ── BASE ── */

html {
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--bg-3) var(--bg-0);
}

body {
  background: var(--bg-0);
  color: var(--tx-0);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.65;
  overflow-x: hidden;
  transition: background .4s ease, color .3s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

::selection {
  background: var(--blue);
  color: #fff;
}

/* ── SKIP LINK ── */

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 9999;
  padding: .6rem 1.2rem;
  border-radius: var(--radius-sm);
  background: var(--blue);
  color: #fff;
  font-size: .82rem;
  font-weight: 600;
  text-decoration: none;
  transition: top .2s;
}

.skip-link:focus {
  top: .5rem;
}

/* ── FOCUS VISIBLE ── */

:focus {
  outline: none;
}

:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

button:focus-visible,
a:focus-visible,
.mode-group__btn:focus-visible,
.cat-pills__item:focus-visible,
.quiz-options__item:focus-visible,
.grid-card:focus-visible,
.quiz-card:focus-visible,
.card-stage__arrow:focus-visible,
.icon-btn:focus-visible,
.mastery-btn:focus-visible,
.btn:focus-visible,
.card-actions__btn:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
  box-shadow: none;
}

input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  border-color: var(--blue) !important;
  box-shadow: var(--focus-ring);
}

/* ── REDUCED MOTION ── */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ── GRAIN OVERLAY ── */

.grain {
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: var(--grain-o);
  background: url("data:image/svg+xml,%3Csvg viewBox='0 0 512 512' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.7' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ================================================================
   NAVIGATION
   ================================================================ */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(1.2rem, 4vw, 3rem);
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
}

.nav__brand {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--tx-0);
  text-decoration: none;
  letter-spacing: .01em;
  cursor: pointer;
}

.nav__brand-accent {
  color: var(--blue);
  font-style: italic;
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: .6rem;
}

.icon-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: var(--bg-2);
  color: var(--tx-1);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .85rem;
  transition: all .2s ease;
  flex-shrink: 0;
}

.icon-btn:hover {
  background: var(--blue-d);
  color: var(--blue);
}

/* ================================================================
   BUTTONS
   ================================================================ */

.btn {
  font-family: var(--font-body);
  font-size: .78rem;
  font-weight: 500;
  padding: .55rem 1.2rem;
  border-radius: var(--radius-sm);
  border: none;
  background: var(--bg-2);
  color: var(--tx-1);
  cursor: pointer;
  transition: all .2s ease;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  letter-spacing: .01em;
}

.btn:hover {
  color: var(--tx-0);
  background: var(--bg-3);
}

.btn--primary {
  color: #fff;
  background: var(--blue);
}

.btn--primary:hover {
  filter: brightness(1.12);
  background: var(--blue);
}

.btn--danger {
  color: var(--red);
  background: var(--red-d);
}

.btn--danger:hover {
  background: var(--red);
  color: #fff;
}

.btn--teal {
  color: var(--teal);
  background: var(--teal-d);
}

.btn--teal:hover {
  background: var(--teal);
  color: #fff;
}

.btn--sm {
  padding: .45rem .9rem;
  font-size: .72rem;
  border-radius: var(--radius-sm);
  min-height: 36px;
}

.btn--lg {
  padding: .75rem 1.8rem;
  font-size: .85rem;
  border-radius: var(--radius);
  min-height: 44px;
}

/* ── TAG ── */

.tag {
  font-family: var(--font-mono);
  font-size: .55rem;
  font-weight: 500;
  letter-spacing: .08em;
  text-transform: uppercase;
  padding: .2rem .6rem;
  border-radius: var(--radius-sm);
  color: var(--tx-2);
  background: var(--bg-2);
}

/* ================================================================
   PROGRESS
   ================================================================ */

.progress {
  height: 3px;
  background: var(--bg-2);
  max-width: var(--max-w);
  margin: 0 auto;
  border-radius: 2px;
}

.progress__fill {
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--teal));
  transition: width .6s var(--ease-out-expo);
  border-radius: 2px;
}

/* ── CONTENT WRAPPER ── */

.content {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 clamp(1.2rem, 4vw, 3rem);
  min-height: calc(100vh - var(--nav-h) - 80px);
}

/* ================================================================
   DASHBOARD — HERO
   ================================================================ */

.hero {
  padding: clamp(2.5rem, 5vw, 4rem) 0 clamp(2rem, 3vw, 2.5rem);
}

.hero__eyebrow {
  font-family: var(--font-mono);
  font-size: .6rem;
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: .7rem;
  animation: fadeUp .8s var(--ease-out-expo) both;
}

.hero__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -.02em;
  margin-bottom: .6rem;
  animation: fadeUp .8s .08s var(--ease-out-expo) both;
}

.hero__title-accent {
  color: var(--blue);
  font-style: italic;
}

.hero__description {
  font-size: .92rem;
  color: var(--tx-1);
  font-weight: 300;
  max-width: 520px;
  line-height: 1.7;
  animation: fadeUp .8s .15s var(--ease-out-expo) both;
}

.hero__actions {
  display: flex;
  gap: .6rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
  animation: fadeUp .8s .22s var(--ease-out-expo) both;
}

/* ================================================================
   DASHBOARD — QUIZ LIST
   ================================================================ */

.quiz-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1rem;
  padding-bottom: 3rem;
}

.quiz-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem 1.7rem;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: all .3s var(--ease-out-expo);
  display: flex;
  flex-direction: column;
  animation: fadeUp .5s var(--ease-out-expo) both;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.quiz-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 3px;
  background: var(--blue);
  opacity: 0;
  transition: opacity .3s;
  border-radius: 0 2px 2px 0;
}

.quiz-card:hover {
  background: var(--bg-card-h);
  border-color: var(--border-h);
  box-shadow: var(--shadow-card);
  transform: translateY(-3px);
}

.quiz-card:hover::before {
  opacity: 1;
}

.quiz-card__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: .5rem;
}

.quiz-card__title {
  font-family: var(--font-display);
  font-size: 1.3rem;
  line-height: 1.2;
}

.quiz-card__count {
  font-family: var(--font-mono);
  font-size: .6rem;
  color: var(--tx-3);
  letter-spacing: .06em;
}

.quiz-card__description {
  font-size: .8rem;
  color: var(--tx-2);
  font-weight: 300;
  line-height: 1.6;
  margin-bottom: .8rem;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.quiz-card__categories {
  display: flex;
  gap: .35rem;
  flex-wrap: wrap;
  margin-bottom: .8rem;
}

.quiz-card__category {
  font-family: var(--font-mono);
  font-size: .48rem;
  font-weight: 500;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: .18rem .5rem;
  border-radius: var(--radius-sm);
  color: var(--tx-3);
  background: var(--bg-2);
}

.quiz-card__footer {
  display: flex;
  gap: .5rem;
  padding-top: .8rem;
  border-top: 1px solid var(--border);
  align-items: center;
  flex-wrap: wrap;
}

.quiz-card__footer .btn--danger {
  margin-left: auto;
}

/* ── EMPTY STATE ── */

.empty-state {
  text-align: center;
  padding: 6rem 2rem;
  animation: fadeUp .6s var(--ease-out-expo) both;
}

.empty-state__icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  opacity: .2;
}

.empty-state h3 {
  font-family: var(--font-display);
  font-size: 1.6rem;
  margin-bottom: .5rem;
}

.empty-state p {
  color: var(--tx-2);
  font-size: .88rem;
  font-weight: 300;
  margin-bottom: 1.5rem;
}

/* ================================================================
   EDITOR
   ================================================================ */

.editor__header {
  padding: clamp(1.5rem, 3vw, 2.5rem) 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.editor__title {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  font-weight: 400;
}

/* ── FORM ── */

.form__group {
  margin-bottom: 1.1rem;
}

.form__label {
  display: block;
  font-family: var(--font-mono);
  font-size: .6rem;
  font-weight: 500;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--tx-2);
  margin-bottom: .45rem;
}

.form__input,
.form__textarea,
.form__select {
  width: 100%;
  font-family: var(--font-body);
  font-size: max(.85rem, 16px);
  font-weight: 400;
  padding: .7rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-1);
  color: var(--tx-0);
  outline: none;
  transition: all .2s ease;
}

.form__input:focus,
.form__textarea:focus,
.form__select:focus {
  border-color: var(--blue);
  background: var(--bg-0);
}

.form__input::placeholder,
.form__textarea::placeholder {
  color: var(--tx-3);
}

.form__textarea {
  resize: vertical;
  min-height: 80px;
  line-height: 1.7;
}

.form__select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%236E6E82' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .8rem center;
  padding-right: 2rem;
}

.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .8rem;
}

/* ── EDITOR SECTIONS ── */

.editor__section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem;
  margin-bottom: 1rem;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.editor__section-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ── CATEGORY EDITOR ── */

.cat-editor {
  display: flex;
  flex-direction: column;
  gap: .5rem;
}

.cat-editor__row {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .55rem .8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-1);
}

.cat-editor__row .cat-editor__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.cat-editor__row input {
  flex: 1;
  font-family: var(--font-body);
  font-size: .8rem;
  background: transparent;
  border: none;
  color: var(--tx-0);
  outline: none;
  min-width: 0;
}

.cat-editor__row select {
  font-family: var(--font-mono);
  font-size: .65rem;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--tx-1);
  padding: .2rem .4rem;
  cursor: pointer;
  outline: none;
}

/* ── CARD LIST (editor) ── */

.card-list {
  display: flex;
  flex-direction: column;
  gap: .5rem;
}

.card-list__item {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  gap: .6rem;
  align-items: center;
  padding: .7rem .9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-1);
  transition: all .2s;
}

.card-list__item:hover {
  border-color: var(--border-h);
  background: var(--bg-2);
}

.card-list__number {
  font-family: var(--font-mono);
  font-size: .58rem;
  color: var(--tx-3);
  width: 2rem;
  text-align: center;
}

.card-list__term {
  font-weight: 500;
  font-size: .84rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-list__category {
  font-family: var(--font-mono);
  font-size: .48rem;
  font-weight: 500;
  letter-spacing: .05em;
  text-transform: uppercase;
  padding: .18rem .45rem;
  border-radius: 6px;
  color: var(--tx-3);
  background: var(--bg-2);
}

.card-list__actions {
  display: flex;
  gap: .3rem;
}

.card-edit-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ================================================================
   PLAYER
   ================================================================ */

.player__header {
  padding: clamp(2rem, 4vw, 3rem) 0 1.2rem;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.player__info {
  flex: 1;
  min-width: 200px;
}

.player__eyebrow {
  font-family: var(--font-mono);
  font-size: .58rem;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: .5rem;
}

.player__title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  line-height: 1.1;
  margin-bottom: .35rem;
}

.player__subtitle {
  font-size: .85rem;
  color: var(--tx-2);
  font-weight: 300;
}

.player__stats {
  display: flex;
  gap: .8rem;
  flex-wrap: wrap;
  align-items: center;
}

/* ── STAT RING ── */

.stat-ring {
  text-align: center;
  position: relative;
  width: 76px;
  height: 76px;
}

.stat-ring svg {
  width: 76px;
  height: 76px;
  transform: rotate(-90deg);
}

.stat-ring .track {
  fill: none;
  stroke: var(--bg-2);
  stroke-width: 5;
}

.stat-ring .fill {
  fill: none;
  stroke-width: 5;
  stroke-linecap: round;
  transition: stroke-dasharray .8s var(--ease-out-expo);
}

.stat-ring__inner {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.stat-ring__number {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1;
}

.stat-ring__label {
  font-family: var(--font-mono);
  font-size: .42rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--tx-2);
  margin-top: .15rem;
}

/* ── TOOLBAR ── */

.toolbar {
  padding: 0 0 1.2rem;
  display: flex;
  flex-direction: column;
  gap: .7rem;
}

.toolbar__row {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
  align-items: center;
}

.toolbar__row--between {
  justify-content: space-between;
}

/* ── MODE GROUP ── */

.mode-group {
  display: flex;
  gap: 2px;
  background: var(--bg-2);
  border-radius: var(--radius-sm);
  padding: 2px;
  overflow: hidden;
}

.mode-group__btn {
  font-family: var(--font-body);
  font-size: .76rem;
  font-weight: 500;
  padding: .5rem 1.1rem;
  border: none;
  background: transparent;
  color: var(--tx-2);
  min-height: 38px;
  cursor: pointer;
  transition: all .2s ease;
  white-space: nowrap;
  border-radius: calc(var(--radius-sm) - 2px);
}

.mode-group__btn:hover {
  color: var(--tx-0);
}

.mode-group__btn--active {
  color: var(--tx-0);
  background: var(--bg-card);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.12);
}

/* ── SEARCH ── */

.search {
  flex: 1;
  min-width: 160px;
  max-width: 320px;
  position: relative;
}

.search__input {
  width: 100%;
  font-family: var(--font-mono);
  font-size: max(.76rem, 16px);
  font-weight: 400;
  padding: .55rem .9rem .55rem 2.1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-1);
  color: var(--tx-0);
  outline: none;
  transition: all .2s ease;
  min-height: 38px;
}

.search__input:focus {
  border-color: var(--blue);
  background: var(--bg-0);
}

.search__input::placeholder {
  color: var(--tx-3);
}

.search__icon {
  position: absolute;
  left: .7rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--tx-3);
  font-size: .72rem;
  pointer-events: none;
}

/* ── CATEGORY PILLS ── */

.cat-pills {
  display: flex;
  gap: .4rem;
  flex-wrap: wrap;
}

.cat-pills__item {
  font-family: var(--font-mono);
  font-size: .6rem;
  font-weight: 500;
  letter-spacing: .04em;
  padding: .4rem .85rem;
  border: none;
  border-radius: var(--radius-sm);
  min-height: 34px;
  background: var(--bg-2);
  color: var(--tx-1);
  cursor: pointer;
  transition: all .2s ease;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: .3rem;
}

.cat-pills__item:hover {
  color: var(--tx-0);
  background: var(--bg-3);
}

.cat-pills__item--active {
  color: #fff;
  background: var(--_c, var(--blue));
}

/* ================================================================
   GRID VIEW
   ================================================================ */

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
  padding-bottom: 2rem;
}

.grid-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: all .3s var(--ease-out-expo);
  display: flex;
  flex-direction: column;
  min-height: 170px;
  animation: fadeUp .5s var(--ease-out-expo) both;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.grid-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 3px;
  background: var(--_c, var(--blue));
  opacity: 0;
  transition: opacity .3s;
  border-radius: 0 2px 2px 0;
}

.grid-card:hover {
  background: var(--bg-card-h);
  border-color: var(--border-h);
  box-shadow: var(--shadow-card);
  transform: translateY(-3px);
}

.grid-card:hover::before {
  opacity: 1;
}

.grid-card__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: .6rem;
}

.grid-card__number {
  font-family: var(--font-mono);
  font-size: .55rem;
  color: var(--tx-3);
  letter-spacing: .05em;
}

.grid-card__category {
  font-family: var(--font-mono);
  font-size: .5rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: .2rem .55rem;
  border-radius: 6px;
  color: var(--_c, var(--blue));
  background: var(--_c-bg, var(--blue-d));
}

.grid-card__term {
  font-family: var(--font-display);
  font-size: 1.2rem;
  line-height: 1.2;
  margin-bottom: .5rem;
  flex-shrink: 0;
}

.grid-card__definition {
  font-size: .8rem;
  font-weight: 300;
  color: var(--tx-2);
  line-height: 1.65;
  flex: 1;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  line-clamp: 3;
  -webkit-box-orient: vertical;
}

.grid-card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: .9rem;
  padding-top: .65rem;
  border-top: 1px solid var(--border);
}

/* ── MASTERY BUTTON ── */

.mastery-btn {
  font-family: var(--font-mono);
  font-size: .58rem;
  font-weight: 600;
  letter-spacing: .06em;
  padding: .35rem .7rem;
  border: none;
  border-radius: 6px;
  min-height: 30px;
  background: var(--bg-2);
  color: var(--tx-2);
  cursor: pointer;
  transition: all .2s;
  display: inline-flex;
  align-items: center;
  gap: .25rem;
}

.mastery-btn:hover {
  background: var(--teal-d);
  color: var(--teal);
}

.mastery-btn--known {
  color: #fff;
  background: var(--teal);
}

/* ================================================================
   FOCUSED CARD VIEW
   ================================================================ */

.focused {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  padding-bottom: 2rem;
}

.focused__counter {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--tx-2);
  letter-spacing: .08em;
}

.focused__counter b {
  color: var(--blue);
  font-weight: 600;
}

.focused__score {
  color: var(--teal);
  margin-left: 1.5rem;
}

/* ── CARD STAGE ── */

.card-stage {
  display: flex;
  align-items: center;
  gap: clamp(.6rem, 2vw, 1.5rem);
  width: 100%;
  justify-content: center;
}

.card-stage__arrow {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: none;
  background: var(--bg-2);
  color: var(--tx-2);
  font-size: 1.3rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all .2s ease;
  flex-shrink: 0;
}

.card-stage__arrow:hover {
  background: var(--blue-d);
  color: var(--blue);
}

/* ── FLIP CARD ── */

.flip {
  perspective: 1200px;
  width: 100%;
  max-width: 600px;
  height: var(--card-h);
  cursor: pointer;
  touch-action: pan-y;
}

.flip__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform .55s cubic-bezier(.4, 0, .2, 1);
}

.flip__inner--flipped {
  transform: rotateY(180deg);
}

.flip__face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.flip__front {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 2.5rem 3rem;
  justify-content: center;
  align-items: center;
  text-align: center;
  position: relative;
  box-shadow: var(--shadow-card);
}

.flip__front::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--_c, var(--blue));
  opacity: .7;
  border-radius: 0 0 2px 2px;
}

.flip__front .flip__category {
  font-family: var(--font-mono);
  font-size: .55rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: .28rem .75rem;
  border-radius: 6px;
  color: var(--_c, var(--blue));
  background: var(--_c-bg, var(--blue-d));
  margin-bottom: .8rem;
}

.flip__front .flip__id {
  font-family: var(--font-mono);
  font-size: .55rem;
  color: var(--tx-3);
  letter-spacing: .1em;
  margin-bottom: .5rem;
}

.flip__front .flip__term {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  line-height: 1.1;
  letter-spacing: -.01em;
}

.flip__front .flip__hint {
  font-family: var(--font-mono);
  font-size: .55rem;
  color: var(--tx-3);
  margin-top: 1.5rem;
  opacity: .4;
}

.flip__back {
  transform: rotateY(180deg);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  padding: 2rem 2.5rem;
  box-shadow: var(--shadow-card);
}

.flip__back .flip__category {
  font-family: var(--font-mono);
  font-size: .55rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: .28rem .75rem;
  border-radius: 6px;
  color: var(--_c, var(--blue));
  background: var(--_c-bg, var(--blue-d));
  margin-bottom: .6rem;
  align-self: flex-start;
}

.flip__back .flip__term--small {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--_c, var(--blue));
  margin-bottom: .8rem;
}

.flip__back .flip__definition {
  font-size: .86rem;
  font-weight: 300;
  color: var(--tx-1);
  line-height: 1.85;
  flex: 1;
  overflow-y: auto;
}

.flip__back .flip__definition code {
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 500;
  background: var(--bg-3);
  padding: .15rem .4rem;
  border-radius: 5px;
  color: var(--_c, var(--blue));
}

/* ── CARD ACTIONS ── */

.card-actions {
  display: flex;
  gap: .6rem;
  justify-content: center;
  flex-wrap: wrap;
}

.card-actions__btn {
  font-family: var(--font-body);
  font-size: .78rem;
  font-weight: 500;
  padding: .6rem 1.4rem;
  border: none;
  border-radius: var(--radius-sm);
  min-height: 40px;
  background: var(--bg-2);
  color: var(--tx-1);
  cursor: pointer;
  transition: all .2s ease;
}

.card-actions__btn:hover {
  color: var(--tx-0);
  background: var(--bg-3);
}

.card-actions__btn--mastered {
  color: #fff;
  background: var(--teal);
}

.card-actions__btn--next {
  color: #fff;
  background: var(--blue);
}

.card-actions__btn--next:hover {
  filter: brightness(1.1);
}

/* ================================================================
   QUIZ OPTIONS
   ================================================================ */

.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .7rem;
  width: 100%;
  max-width: 600px;
}

.quiz-options__item {
  padding: 1rem 1.1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
  cursor: pointer;
  text-align: left;
  transition: all .2s ease;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.quiz-options__item:hover:not(.quiz-options__item--answered) {
  border-color: var(--border-h);
  background: var(--bg-card-h);
  transform: translateY(-1px);
}

.quiz-options__text {
  font-weight: 500;
  font-size: .88rem;
  color: var(--tx-0);
}

.quiz-options__hint {
  font-size: .7rem;
  font-weight: 300;
  color: var(--tx-2);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.quiz-options__item--correct {
  border-color: var(--teal);
  background: var(--teal-d);
}

.quiz-options__item--wrong {
  border-color: var(--red);
  background: var(--red-d);
}

.quiz-options__item--answered {
  cursor: default;
}

/* ================================================================
   MODAL
   ================================================================ */

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 500;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  transition: opacity .3s ease;
}

.modal-overlay--open {
  display: flex;
  opacity: 1;
}

.modal {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 620px;
  width: 100%;
  max-height: 88vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  position: relative;
  padding: 2rem;
  animation: modalIn .35s var(--ease-out-expo) both;
}

.modal__close {
  position: absolute;
  top: .8rem;
  right: .8rem;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: none;
  background: var(--bg-2);
  color: var(--tx-2);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .75rem;
  transition: all .2s;
  z-index: 1;
}

.modal__close:hover {
  background: var(--blue-d);
  color: var(--blue);
}

.modal__title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin-bottom: 1rem;
  padding-right: 2rem;
}

/* ── MODAL DETAIL (player card modal) ── */

.modal__category {
  font-family: var(--font-mono);
  font-size: .55rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: .28rem .75rem;
  border-radius: 6px;
  color: var(--_c, var(--blue));
  background: var(--_c-bg, var(--blue-d));
  display: inline-block;
  margin-bottom: .8rem;
}

.modal__card-number {
  font-family: var(--font-mono);
  font-size: .6rem;
  color: var(--tx-3);
  letter-spacing: .08em;
  margin-bottom: .3rem;
}

.modal__card-term {
  font-family: var(--font-display);
  font-size: 1.9rem;
  line-height: 1.2;
  margin-bottom: 1.2rem;
}

.modal__card-definition {
  font-size: .92rem;
  font-weight: 300;
  color: var(--tx-1);
  line-height: 1.9;
}

.modal__card-definition code {
  font-family: var(--font-mono);
  font-size: .82rem;
  font-weight: 500;
  background: var(--bg-3);
  padding: .12rem .45rem;
  border-radius: 5px;
  color: var(--_c, var(--blue));
}

.modal__footer {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
}

/* ── PROMPT MODAL ── */

.modal--prompt {
  max-width: 720px;
}

.prompt__section {
  margin-bottom: 1.4rem;
}

.prompt__title {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: .82rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--tx-2);
  margin-bottom: .5rem;
}

.prompt__table {
  width: 100%;
  border-collapse: collapse;
  font-size: .82rem;
  margin-bottom: .5rem;
}

.prompt__table th {
  text-align: left;
  font-weight: 600;
  color: var(--tx-1);
  padding: .35rem .6rem;
  border-bottom: 1px solid var(--border);
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .05em;
}

.prompt__table td {
  padding: .35rem .6rem;
  border-bottom: 1px solid var(--border);
  color: var(--tx-1);
  font-weight: 300;
}

.prompt__table td:first-child {
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--tx-0);
  font-size: .78rem;
}

.prompt__copyable {
  position: relative;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  line-height: 1.7;
  color: var(--tx-1);
  white-space: pre-wrap;
  word-break: break-word;
  cursor: pointer;
  transition: border-color .2s;
}

.prompt__copyable:hover {
  border-color: var(--blue);
}

.prompt__copyable::after {
  content: 'Click to copy';
  position: absolute;
  top: .5rem;
  right: .6rem;
  font-family: var(--font-body);
  font-size: .65rem;
  font-weight: 500;
  color: var(--tx-3);
  text-transform: uppercase;
  letter-spacing: .06em;
  transition: color .2s;
}

.prompt__copyable:hover::after {
  color: var(--blue);
}

.prompt__copyable--copied::after {
  content: 'Copied!';
  color: var(--teal);
}

.prompt__rule {
  font-size: .85rem;
  color: var(--tx-1);
  font-weight: 300;
  line-height: 1.7;
  padding-left: .2rem;
}

.prompt__rule strong {
  font-weight: 600;
  color: var(--tx-0);
}

/* ================================================================
   KEYBOARD HINTS
   ================================================================ */

.kbd-hints {
  text-align: center;
  margin-top: 1rem;
  font-family: var(--font-mono);
  font-size: .55rem;
  color: var(--tx-3);
}

.kbd-hints__key {
  display: inline-block;
  padding: .14rem .45rem;
  border-radius: 5px;
  font-size: .5rem;
  margin: 0 .15rem;
  color: var(--tx-2);
  background: var(--bg-2);
}

/* ================================================================
   FOOTER
   ================================================================ */

.footer {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2.5rem clamp(1.2rem, 4vw, 3rem);
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: .74rem;
  color: var(--tx-3);
}

.footer a {
  color: var(--blue);
  text-decoration: none;
}

/* ================================================================
   TOAST
   ================================================================ */

.toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 600;
  display: flex;
  flex-direction: column;
  gap: .5rem;
}

.toast {
  padding: .75rem 1.3rem;
  border-radius: var(--radius-sm);
  font-size: .8rem;
  font-weight: 500;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--tx-0);
  box-shadow: var(--shadow-lg);
  animation: slideInRight .4s var(--ease-out-expo) both;
  max-width: 340px;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.toast--success {
  border-color: var(--teal-b);
  background: var(--teal-d);
  color: var(--teal);
}

.toast--error {
  border-color: var(--red-b);
  background: var(--red-d);
  color: var(--red);
}

/* ================================================================
   ANIMATIONS
   ================================================================ */

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: scale(.97) translateY(8px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* ── STAGGERED ANIMATION DELAYS ── */

.grid-card:nth-child(1) { animation-delay: .02s; }
.grid-card:nth-child(2) { animation-delay: .04s; }
.grid-card:nth-child(3) { animation-delay: .06s; }
.grid-card:nth-child(4) { animation-delay: .08s; }
.grid-card:nth-child(5) { animation-delay: .10s; }
.grid-card:nth-child(6) { animation-delay: .12s; }
.grid-card:nth-child(7) { animation-delay: .14s; }
.grid-card:nth-child(8) { animation-delay: .16s; }
.grid-card:nth-child(9) { animation-delay: .18s; }
.grid-card:nth-child(10) { animation-delay: .20s; }

.quiz-card:nth-child(1) { animation-delay: .03s; }
.quiz-card:nth-child(2) { animation-delay: .06s; }
.quiz-card:nth-child(3) { animation-delay: .09s; }
.quiz-card:nth-child(4) { animation-delay: .12s; }
.quiz-card:nth-child(5) { animation-delay: .15s; }
.quiz-card:nth-child(6) { animation-delay: .18s; }

/* ================================================================
   RESPONSIVE
   ================================================================ */

@media (max-width: 768px) {
  .quiz-list {
    grid-template-columns: 1fr;
  }

  .grid {
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  }

  .quiz-options {
    grid-template-columns: 1fr;
  }

  .flip {
    height: 340px;
  }

  .flip__front,
  .flip__back {
    padding: 1.5rem 1.2rem;
  }

  .modal {
    padding: 1.5rem;
    margin: .5rem;
    max-height: 92vh;
  }

  .toolbar__row {
    flex-direction: column;
    align-items: stretch;
  }

  .search {
    max-width: none;
  }

  .card-stage__arrow {
    width: 44px;
    height: 44px;
    font-size: 1.1rem;
  }

  .form__row {
    grid-template-columns: 1fr;
  }

  .player__header {
    flex-direction: column;
  }

  .editor__header {
    flex-direction: column;
    align-items: flex-start;
  }

  .card-list__item {
    grid-template-columns: auto 1fr auto;
    gap: .4rem;
  }

  .card-list__category {
    display: none;
  }

  .quiz-card__footer {
    gap: .4rem;
  }

  .quiz-card__footer .btn--sm {
    padding: .45rem .7rem;
    font-size: .68rem;
    min-height: 38px;
  }

  .mode-group {
    width: 100%;
  }

  .mode-group__btn {
    flex: 1;
    justify-content: center;
    text-align: center;
  }

  .nav {
    padding: 0 clamp(.8rem, 3vw, 2rem);
  }

  .content {
    padding: 0 clamp(.8rem, 3vw, 2rem);
  }

  .stat-ring {
    width: 68px;
    height: 68px;
  }

  .stat-ring svg {
    width: 68px;
    height: 68px;
  }

  .btn--lg {
    width: 100%;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .flip {
    height: 280px;
  }

  .cat-pills {
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: .5rem;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
  }

  .cat-pills::-webkit-scrollbar {
    display: none;
  }

  .hero__actions {
    flex-direction: column;
  }

  .hero__actions .btn {
    width: 100%;
    justify-content: center;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .player__stats {
    width: 100%;
    justify-content: center;
  }

  .hero__title {
    font-size: clamp(1.8rem, 8vw, 2.6rem);
  }

  .player__title {
    font-size: clamp(1.3rem, 6vw, 1.8rem);
  }

  .quiz-card {
    padding: 1.2rem 1.3rem;
  }

  .grid-card {
    padding: 1.1rem 1.2rem;
    min-height: 150px;
  }

  .footer {
    flex-direction: column;
    text-align: center;
    gap: .5rem;
  }
}

/* ── TOUCH-FRIENDLY: ensure all interactive elements meet 44px minimum ── */

@media (pointer: coarse) {
  .btn {
    min-height: 44px;
  }

  .btn--sm {
    min-height: 40px;
  }

  .icon-btn {
    width: 44px;
    height: 44px;
  }

  .cat-pills__item {
    min-height: 38px;
    padding: .45rem .9rem;
  }

  .mastery-btn {
    min-height: 36px;
    padding: .4rem .8rem;
  }

  .card-stage__arrow {
    width: 48px;
    height: 48px;
  }

  .mode-group__btn {
    min-height: 44px;
  }

  .quiz-options__item {
    padding: 1rem 1.1rem;
  }

  .card-actions__btn {
    min-height: 44px;
  }

  .modal__close {
    width: 36px;
    height: 36px;
  }
}