/* ============================================================
   Vocabulario — Spanish flashcard app
   Design: study notebook / library card-catalog motif
   ============================================================ */

:root {
  --paper: #F5F6F3;
  --paper-line: #D7DEE4;
  --ink: #1D2A3A;
  --ink-soft: #5B6B7C;
  --ink-faint: #93A1AE;

  --coral: #E85D4C;
  --teal: #2F9E8F;
  --marigold: #E8A93B;
  --plum: #8858A8;
  --sky: #3E8FD0;
  --moss: #6B9E4A;

  --card-front: #FFFFFF;
  --card-back: #EEF2F5;
  --shadow-sm: 0 2px 8px rgba(29, 42, 58, 0.08);
  --shadow-md: 0 8px 24px rgba(29, 42, 58, 0.14);
  --shadow-lg: 0 18px 40px rgba(29, 42, 58, 0.20);

  --radius: 18px;
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--ink);
  background:
    linear-gradient(var(--paper-line) 1px, transparent 1px) 0 0 / 100% 32px,
    var(--paper);
  min-height: 100vh;
  -webkit-tap-highlight-color: transparent;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

.app {
  max-width: 900px;
  margin: 0 auto;
  padding: calc(20px + env(safe-area-inset-top)) 20px 60px;
  min-height: 100vh;
}

/* ---------- Header ---------- */

.app-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 14px 4px 26px;
}

.hub-back {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-soft);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 8px;
  order: -1;
  margin-right: auto;
}
.hub-back:hover { background: rgba(29,42,58,0.06); color: var(--ink); }

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.brand-mark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.6rem;
  letter-spacing: -0.01em;
}

.brand-mark .accent { color: var(--coral); }

.brand-sub {
  font-size: 0.8rem;
  color: var(--ink-soft);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ---------- Home: category catalog ---------- */

.catalog-intro {
  margin: 0 4px 20px;
  color: var(--ink-soft);
  font-size: 0.98rem;
  line-height: 1.5;
  max-width: 60ch;
}

.catalog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 14px;
}

.tab-card {
  position: relative;
  background: var(--card-front);
  border-radius: 14px;
  padding: 18px 16px 16px;
  box-shadow: var(--shadow-sm);
  text-align: left;
  overflow: hidden;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  border: 1px solid rgba(29,42,58,0.05);
}

.tab-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 6px;
  height: 100%;
  background: var(--tab-color, var(--coral));
}

.tab-card:hover, .tab-card:focus-visible {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  outline: none;
}

.tab-card:active { transform: translateY(-1px) scale(0.99); }

.tab-icon {
  font-size: 1.7rem;
  display: inline-block;
  margin-bottom: 10px;
}

.tab-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.03rem;
  margin: 0 0 4px;
  line-height: 1.25;
}

.tab-count {
  font-size: 0.8rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}

.tab-card.all-words {
  background: var(--ink);
  color: #fff;
}
.tab-card.all-words .tab-count { color: rgba(255,255,255,0.65); }
.tab-card.all-words::before { background: var(--coral); }

/* ---------- Deck view ---------- */

.deck-view { display: none; }
.deck-view.active { display: block; }
.home-view.hidden { display: none; }

.deck-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 4px 2px 18px;
}

.back-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ink-soft);
  padding: 8px 10px;
  border-radius: 10px;
}
.back-btn:hover { background: rgba(29,42,58,0.06); color: var(--ink); }

.deck-title-wrap { flex: 1; min-width: 0; }

.deck-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  margin: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.deck-progress-text {
  font-size: 0.78rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}

.shuffle-btn {
  width: 38px; height: 38px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.05rem;
  color: var(--ink-soft);
  flex-shrink: 0;
}
.shuffle-btn:hover { background: rgba(29,42,58,0.06); }
.shuffle-btn.active { background: var(--coral); color: #fff; }

.progress-track {
  height: 4px;
  background: rgba(29,42,58,0.08);
  border-radius: 4px;
  overflow: hidden;
  margin: 0 2px 28px;
}
.progress-fill {
  height: 100%;
  background: var(--tab-color, var(--coral));
  border-radius: 4px;
  transition: width 0.25s ease;
}

/* ---------- The flashcard ---------- */

.stage {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 6px 0 24px;
}

.nav-arrow {
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--card-front);
  box-shadow: var(--shadow-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem;
  color: var(--ink-soft);
  flex-shrink: 0;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}
.nav-arrow:hover { box-shadow: var(--shadow-md); color: var(--ink); }
.nav-arrow:active { transform: scale(0.93); }
.nav-arrow:disabled { opacity: 0.3; cursor: default; box-shadow: none; }
.nav-arrow:disabled:hover { transform: none; }

.card-frame {
  perspective: 1600px;
  width: 100%;
  max-width: 380px;
  height: 460px;
}

.flashcard {
  position: relative;
  width: 100%;
  height: 100%;
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.5s cubic-bezier(.4,.2,.2,1);
}

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

.card-face {
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  backface-visibility: hidden;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  padding: 26px 24px 22px;
}

.card-face.front {
  background: var(--card-front);
  border-top: 8px solid var(--tab-color, var(--coral));
}

.card-face.back {
  background: var(--card-back);
  transform: rotateY(180deg);
  border-top: 8px solid var(--ink-soft);
  align-items: center;
  justify-content: center;
}

.card-ring {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid rgba(29,42,58,0.18);
  z-index: 2;
}

.card-top-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.card-category-pill {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--tab-color, var(--coral));
  background: color-mix(in srgb, var(--tab-color, var(--coral)) 12%, white);
  padding: 4px 10px;
  border-radius: 20px;
}

.speak-btn {
  width: 40px; height: 40px;
  border-radius: 50%;
  background: rgba(29,42,58,0.05);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.05rem;
  color: var(--ink);
  transition: background 0.15s ease, transform 0.1s ease;
}
.speak-btn:hover { background: rgba(29,42,58,0.1); }
.speak-btn:active { transform: scale(0.9); }
.speak-btn.speaking { background: var(--coral); color: #fff; }

.card-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 14px;
}

.card-emoji {
  font-size: 3.4rem;
  line-height: 1;
}

.card-word-es {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.9rem;
  line-height: 1.15;
  word-break: break-word;
}

.card-hint {
  font-size: 0.78rem;
  color: var(--ink-faint);
  letter-spacing: 0.03em;
}

.card-word-en {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 2rem;
  color: var(--ink);
  text-align: center;
}

.card-back-label {
  position: absolute;
  top: 20px;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.rule-line {
  position: absolute;
  left: 24px; right: 24px;
  top: 64px;
  height: 1px;
  background: rgba(232, 93, 76, 0.25);
}

.deck-footer {
  text-align: center;
  color: var(--ink-faint);
  font-size: 0.8rem;
  padding-top: 4px;
}

.deck-footer kbd {
  font-family: var(--font-body);
  background: rgba(29,42,58,0.06);
  padding: 2px 6px;
  border-radius: 5px;
  font-size: 0.75rem;
}

/* ---------- Responsive ---------- */

@media (max-width: 480px) {
  .app { padding: 14px 14px 40px; }
  .card-frame { height: 420px; }
  .card-word-es { font-size: 1.6rem; }
  .card-emoji { font-size: 3rem; }
  .nav-arrow { width: 40px; height: 40px; font-size: 1rem; }
  .catalog-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
}

@media (prefers-reduced-motion: reduce) {
  .flashcard, .tab-card, .progress-fill { transition: none !important; }
}