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

:root {
  --bg: #f5f3ef;
  --surface: #ffffff;
  --surface-2: #f0ede8;
  --border: #e2ddd6;
  --text: #1a1916;
  --text-2: #6b6760;
  --text-3: #9e9b96;
  --accent: #2d5a3d;
  --accent-light: #e8f0eb;
  --accent-hover: #234a31;
  --danger: #c0392b;
  --danger-light: #fdf0ef;
  --success: #2d5a3d;
  --success-light: #e8f0eb;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-card: 0 2px 8px rgba(0,0,0,.08), 0 8px 32px rgba(0,0,0,.08);
}

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  font-size: 15px;
  line-height: 1.5;
}

/* ── ÉCRANS CENTRÉS ── */
.screen-center {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 24px;
}

.auth-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 48px 40px;
  max-width: 440px;
  width: 100%;
  box-shadow: var(--shadow-card);
}

.auth-logo {
  font-family: 'Instrument Serif', serif;
  font-size: 2.2rem;
  font-weight: 400;
  color: var(--text);
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.auth-logo span { font-style: italic; color: var(--accent); }

.auth-subtitle {
  color: var(--text-2);
  font-size: 13px;
  margin-bottom: 36px;
}

.field-group {
  margin-bottom: 16px;
}

.field-group label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-2);
  margin-bottom: 8px;
}

.field-row {
  display: flex;
  gap: 8px;
}

input[type="text"], input[type="password"] {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 14px;
  color: var(--text);
  background: var(--surface);
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}
input[type="text"]:focus, input[type="password"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(45,90,61,.1);
}

.btn {
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  border: none;
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background .15s, transform .1s;
  white-space: nowrap;
}
.btn:active { transform: scale(.98); }
.btn:disabled { opacity: .45; cursor: not-allowed; transition: opacity .2s; }

.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--accent-hover); }

.btn-ghost {
  background: transparent;
  color: var(--text-2);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--surface-2); color: var(--text); }

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

.btn-sm {
  padding: 5px 12px;
  font-size: 13px;
}

.btn-danger {
  color: var(--danger);
  border-color: #f0c0bb;
}

.error-msg {
  color: var(--danger);
  font-size: 12px;
  margin-top: 8px;
  min-height: 18px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Deck preview dans l'écran code */
.deck-preview {
  background: var(--accent-light);
  border: 1px solid #b2d4bd;
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  margin-bottom: 20px;
  display: none;
}

.deck-preview-title {
  font-weight: 600;
  font-size: 14px;
  color: var(--accent);
  margin-bottom: 2px;
}

.deck-preview-desc {
  font-size: 12px;
  color: var(--text-2);
}

/* ── APP ── */
#screen-app { display: none; min-height: 100vh; }

.app-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.app-title {
  font-family: 'Instrument Serif', serif;
  font-size: 1.15rem;
  font-weight: 400;
}

.deck-chip {
  font-size: 12px;
  color: var(--text-3);
  padding: 3px 10px;
  background: var(--surface-2);
  border-radius: 20px;
  font-weight: 500;
}

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

.app-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  padding: 0 24px;
  overflow-x: auto;
}

.tab-btn {
  padding: 12px 16px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  white-space: nowrap;
  transition: color .15s;
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }

.app-main {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 24px;
}

/* ── FLASHCARD ── */
#view-study { display: none; }

.session-controls {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.session-controls h2 { font-size: 14px; font-weight: 600; margin-bottom: 16px; }

.controls-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 16px;
}

.control-group label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-2);
  margin-bottom: 6px;
}

select {
  width: 100%;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 13px;
  color: var(--text);
  background: var(--surface);
  outline: none;
  cursor: pointer;
  transition: border-color .15s;
}
select:focus { border-color: var(--accent); }

.session-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.card-count-label {
  font-size: 13px;
  color: var(--text-2);
}

.study-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.study-header-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

.study-progress { font-size: 13px; color: var(--text-2); }
.study-progress strong { color: var(--text); }

.progress-bar {
  width: 100%;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  margin-bottom: 24px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width .3s ease;
}

.flashcard-scene { perspective: 1000px; margin-bottom: 20px; }

.flashcard {
  position: relative;
  width: 100%;
  min-height: 300px;
  transform-style: preserve-3d;
  transition: transform .45s cubic-bezier(.4,0,.2,1);
  cursor: pointer;
}
.flashcard.flipped { transform: rotateX(180deg); }

.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 48px;
  text-align: center;
}

.flashcard-face.back {
  transform: rotateX(180deg);
}

.flashcard-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 16px;
}

.flashcard-question {
  font-family: 'Instrument Serif', serif;
  font-size: 1.35rem;
  line-height: 1.45;
}

.flashcard-answer {
  font-size: 14px;
  line-height: 1.75;
}
.flashcard-answer b { color: var(--accent); }

.flip-hint {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-3);
  margin-top: 20px;
}
.flip-hint kbd {
  padding: 2px 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: inherit;
  font-size: 11px;
}

.card-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 12px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease .35s;
}
.card-actions.visible {
  opacity: 1;
  pointer-events: auto;
}

.btn-knew {
  padding: 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background .15s, border-color .15s, transform .1s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.btn-knew:active { transform: scale(.97); }

.btn-knew.yes { background: var(--success-light); border-color: #b2d4bd; color: var(--success); }
.btn-knew.yes:hover { background: #d0e8d8; border-color: var(--accent); }
.btn-knew.no { background: var(--danger-light); border-color: #f0c0bb; color: var(--danger); }
.btn-knew.no:hover { background: #fad8d5; border-color: var(--danger); }

.keyboard-hint { text-align: center; font-size: 12px; color: var(--text-3); }
.keyboard-hint kbd {
  padding: 2px 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: inherit;
  font-size: 11px;
}

/* Session end */
.session-end {
  text-align: center;
  padding: 48px 32px;
  display: none;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  margin-bottom: 24px;
}
.session-end h2 { font-family: 'Instrument Serif', serif; font-size: 1.8rem; margin-bottom: 8px; }
.session-end p { color: var(--text-2); margin-bottom: 24px; }

.end-stats { display: flex; gap: 24px; justify-content: center; margin-bottom: 32px; flex-wrap: wrap; }
.end-stat { text-align: center; }
.end-stat-value { font-family: 'Instrument Serif', serif; font-size: 2.5rem; }
.end-stat-value--success { color: var(--accent); }
.end-stat-value--danger  { color: var(--danger); }
.end-stat-value--neutral { color: var(--text); }
.end-stat-label { font-size: 13px; color: var(--text-2); }

.action-row {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── PROGRESSION ── */
#view-progress { display: none; }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.stat-value { font-family: 'Instrument Serif', serif; font-size: 2rem; line-height: 1; margin-bottom: 4px; }
.stat-value--success { color: var(--accent); }
.stat-value--danger  { color: var(--danger); }
.stat-value--neutral { color: var(--text-3); }
.stat-label { font-size: 12px; color: var(--text-2); font-weight: 500; }

.deck-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 12px;
}
.deck-section-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
.deck-section-title { font-size: 14px; font-weight: 600; }
.deck-section-count { font-size: 12px; color: var(--text-2); }

.deck-bar { height: 8px; background: var(--surface-2); border-radius: 4px; overflow: hidden; }
.deck-bar-fill { height: 100%; background: var(--accent); border-radius: 4px; transition: width .5s ease; }

.deck-detail { display: flex; gap: 16px; margin-top: 10px; flex-wrap: wrap; }
.detail-item { display: flex; align-items: center; gap: 6px; font-size: 12px; color: var(--text-2); }
.dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
.dot-green { background: var(--accent); }
.dot-red { background: var(--danger); }
.dot-gray { background: var(--border); }

.reset-zone {
  margin-top: 24px;
  padding: 16px;
  background: var(--danger-light);
  border: 1px solid #f0c0bb;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.reset-zone p { font-size: 13px; color: var(--text-2); }

/* ── LOADING ── */
.loading-state { text-align: center; padding: 64px; color: var(--text-2); font-size: 14px; }
.spinner {
  width: 32px; height: 32px;
  border: 2px solid var(--border); border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin .8s linear infinite;
  margin: 0 auto 16px;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── BADGE ── */
.badge { display: inline-flex; align-items: center; padding: 3px 10px; border-radius: 12px; font-size: 11px; font-weight: 600; }
.badge-green { background: var(--success-light); color: var(--success); }
.badge-red { background: var(--danger-light); color: var(--danger); }

/* ── TOAST ── */
.toast-container { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); z-index: 100; display: flex; flex-direction: column; gap: 8px; pointer-events: none; }
.toast {
  padding: 10px 16px; border-radius: var(--radius-sm);
  font-size: 13px; font-weight: 500;
  background: var(--text); color: #fff;
  box-shadow: 0 4px 16px rgba(0,0,0,.15);
  animation: toast-in .2s ease, toast-out .2s ease 3.8s forwards;
  white-space: nowrap;
}
@keyframes toast-in { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
@keyframes toast-out { from { opacity:1; } to { opacity:0; } }

.hidden { display: none !important; }

/* ── FOCUS VISIBLE (accessibilité) ── */
.btn:focus-visible,
.btn-knew:focus-visible,
.tab-btn:focus-visible,
input[type="text"]:focus-visible,
select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

@media (max-width: 600px) {
  .auth-card { padding: 32px 24px; }
  .app-main { padding: 20px 16px; }
  .controls-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .flashcard-face { padding: 28px 24px; }
  .deck-chip { display: none; }
  select { appearance: auto; }
}