/* ============================================================
   RESET & VARIABLES
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --red:       #c0392b;
  --red-dark:  #96281b;
  --blue:      #2c5f8a;
  --purple:    #6d28d9;
  --green:     #16a34a;
  --error:     #dc2626;
  --bg:        #f4f3ee;
  --surface:   #ffffff;
  --text:      #1a1a1a;
  --muted:     #6b7280;
  --border:    #e5e7eb;
  --radius:    12px;
  --shadow-sm: 0 1px 4px rgba(0,0,0,.08);
  --shadow-md: 0 4px 14px rgba(0,0,0,.10);
}

body {
  font-family: 'Noto Sans JP', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  font-size: 15px;
}

/* ============================================================
   VIEWS (single-page routing)
   ============================================================ */
.view { display: none; min-height: 100vh; flex-direction: column; }
.view.active { display: flex; }

/* ============================================================
   SHARED HEADER
   ============================================================ */
.app-header {
  background: var(--red);
  color: #fff;
  padding: .9rem 1.25rem;
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-shrink: 0;
}
.app-header h1 { font-size: 1.15rem; font-weight: 700; }

.back-btn {
  background: none;
  border: none;
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  padding: .25rem .5rem;
  border-radius: 6px;
  white-space: nowrap;
  transition: background .15s;
}
.back-btn:hover { background: rgba(255,255,255,.2); }

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .4rem;
  padding: .6rem 1.2rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-size: .9rem;
  font-family: inherit;
  font-weight: 500;
  transition: opacity .15s, transform .1s;
}
.btn:active { transform: scale(.97); }

.btn-primary  { background: var(--red);    color: #fff; }
.btn-primary:hover  { background: var(--red-dark); }
.btn-blue     { background: var(--blue);   color: #fff; }
.btn-blue:hover { opacity: .88; }
.btn-srs      { background: var(--purple); color: #fff; }
.btn-srs:hover  { opacity: .88; }
.btn-ghost {
  background: var(--surface);
  color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-ghost:hover { background: var(--bg); }
.btn-sm { padding: .4rem .85rem; font-size: .8rem; }

/* ============================================================
   HOME — Collections grid
   ============================================================ */
.home-body {
  flex: 1;
  padding: 1.25rem;
  overflow-y: auto;
}

.collections-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 1rem;
}

.coll-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  border: 2px solid transparent;
  transition: border-color .15s, box-shadow .15s;
}
.coll-card:hover {
  border-color: var(--red);
  box-shadow: var(--shadow-md);
}
.coll-card h2 { font-size: 1.05rem; margin-bottom: .55rem; }

.coll-badges { display: flex; gap: .5rem; flex-wrap: wrap; }
.badge {
  font-size: .72rem;
  padding: .18rem .5rem;
  border-radius: 4px;
  background: var(--bg);
  color: var(--muted);
}
.badge-due { color: var(--purple); font-weight: 600; }

/* ============================================================
   HOME — Bottom bar
   ============================================================ */
.home-bar {
  display: flex;
  gap: .65rem;
  padding: .85rem 1.25rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

/* ============================================================
   COLLECTION VIEW
   ============================================================ */
.coll-body {
  flex: 1;
  padding: 1.25rem;
  overflow-y: auto;
}

.coll-info-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  box-shadow: var(--shadow-sm);
  margin-bottom: 1rem;
}

.srs-status {
  font-size: .82rem;
  color: var(--muted);
  margin-bottom: .85rem;
}
.due-count { color: var(--purple); font-weight: 600; }

.mode-btns { display: flex; gap: .65rem; margin-bottom: .75rem; }
.mode-btns .btn { flex: 1; font-size: .95rem; padding: .75rem; }

/* ============================================================
   COLLECTION — Preview list
   ============================================================ */
.preview-section { margin-top: 1.25rem; }
.preview-section h3 {
  font-size: .8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .05em;
  margin-bottom: .5rem;
}

.preview-row {
  background: var(--surface);
  border-radius: 8px;
  padding: .65rem .9rem;
  margin-bottom: .4rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-sm);
  gap: .5rem;
}
.preview-row .jp        { font-size: 1.05rem; font-weight: 500; }
.preview-row .reading   { font-size: .78rem; color: var(--muted); margin-top: .1rem; }
.preview-row .trans     { font-size: .78rem; color: var(--muted); text-align: right; max-width: 45%; }

/* ============================================================
   SESSION — Header
   ============================================================ */
#view-session { background: var(--bg); }

.session-header {
  background: var(--red);
  color: #fff;
  padding: .85rem 1.25rem .75rem;
  flex-shrink: 0;
}
.session-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: .5rem;
}
.phase-label {
  font-size: .82rem;
  opacity: .9;
  font-weight: 500;
  flex: 1;
  text-align: center;
}
.phase-dots { display: flex; gap: .4rem; }
.phase-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: rgba(255,255,255,.3);
  transition: background .2s;
}
.phase-dot.active { background: #fff; }
.phase-dot.done   { background: rgba(255,255,255,.55); }

.progress-bar {
  height: 4px;
  background: rgba(255,255,255,.25);
  border-radius: 2px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: #fff;
  border-radius: 2px;
  transition: width .3s ease;
}
.progress-text {
  font-size: .75rem;
  opacity: .8;
  text-align: right;
  margin-top: .3rem;
}

/* ============================================================
   SESSION — Card area
   ============================================================ */
.card-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.75rem 1.5rem;
  text-align: center;
  overflow-y: auto;
}

.card-type-badge {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  padding: .28rem .75rem;
  border-radius: 20px;
  margin-bottom: 1rem;
}
.badge-sentence { background: #fef3c7; color: #92400e; }
.badge-word     { background: #dbeafe; color: #1e40af; }
.badge-kanji    { background: #fce7f3; color: #9d174d; }

.card-display {
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: .6rem;
  /* size set dynamically via JS class */
}
.card-display.size-xl  { font-size: 5rem; }
.card-display.size-lg  { font-size: 3.25rem; }
.card-display.size-md  { font-size: 2rem; }
.card-display.size-sm  { font-size: 1.35rem; }

.card-context {
  font-size: .95rem;
  color: var(--muted);
  margin-bottom: .5rem;
}
.card-translation {
  font-size: .88rem;
  color: var(--muted);
  max-width: 360px;
  line-height: 1.4;
}

/* ============================================================
   SESSION — Input / Feedback
   ============================================================ */
.input-area {
  display: flex;
  gap: .6rem;
  padding: .9rem 1.25rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

#answer-input {
  flex: 1;
  padding: .65rem 1rem;
  border: 2px solid var(--border);
  border-radius: 10px;
  font-size: 1.15rem;
  font-family: inherit;
  outline: none;
  transition: border-color .15s, background .15s;
  background: var(--bg);
}
#answer-input::placeholder { color: #bbb; }
#answer-input:focus        { border-color: var(--red); background: #fff; }
#answer-input.correct      { border-color: var(--green); background: #f0fdf4; }
#answer-input.correct:focus { border-color: var(--green); background: #f0fdf4; }
#answer-input.wrong        { border-color: var(--error);  background: #fef2f2; }
#answer-input.wrong:focus  { border-color: var(--error);  background: #fef2f2; }
#answer-input[readonly]    { cursor: default; }

.answer-feedback {
  display: flex;
  align-items: flex-start;
  gap: .75rem;
  padding: .85rem 1.25rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  flex-wrap: wrap;
}
.answer-feedback.hidden { display: none; }

.feedback-icon { font-size: 1.4rem; line-height: 1; margin-top: .1rem; }

.feedback-body { flex: 1; min-width: 0; }
.feedback-label { font-size: .75rem; color: var(--muted); margin-bottom: .15rem; }
.feedback-value { font-size: 1.1rem; font-weight: 600; }
.feedback-value.ok    { color: var(--green); }
.feedback-value.fail  { color: var(--error); }
.feedback-typed { font-size: .8rem; color: var(--muted); margin-top: .2rem; }
.feedback-all   { font-size: .8rem; color: var(--muted); margin-top: .15rem; }

.srs-quality-bar {
  display: none;
  align-items: center;
  gap: .45rem;
  padding: .7rem 1.25rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  flex-wrap: wrap;
}
.srs-quality-bar.visible { display: flex; }
.srs-quality-bar .label { font-size: .78rem; color: var(--muted); margin-right: .1rem; }
.srs-quality-bar .btn { flex: 1; min-width: 70px; font-size: .78rem; padding: .4rem .5rem; }

/* ============================================================
   RESULTS VIEW
   ============================================================ */
.results-body {
  flex: 1;
  padding: 2rem 1.25rem 1.25rem;
  max-width: 480px;
  width: 100%;
  margin: 0 auto;
}

.results-title    { font-size: 1.75rem; font-weight: 700; text-align: center; margin-bottom: .3rem; }
.results-subtitle { font-size: 1rem; color: var(--muted); text-align: center; margin-bottom: 1.75rem; }

.results-phase {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin-bottom: .75rem;
  box-shadow: var(--shadow-sm);
}
.results-phase h3 { font-size: .82rem; color: var(--muted); margin-bottom: .6rem; text-transform: uppercase; letter-spacing: .04em; }

.score-row { display: flex; align-items: center; gap: .75rem; }
.score-bar {
  flex: 1;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}
.score-fill { height: 100%; background: var(--green); border-radius: 4px; transition: width .4s ease; }
.score-text { font-size: .85rem; color: var(--muted); min-width: 2.75rem; text-align: right; font-weight: 600; }

.results-actions {
  display: flex;
  gap: .65rem;
  padding: .75rem 1.25rem 1.25rem;
  justify-content: center;
  flex-shrink: 0;
}
.results-actions .btn { flex: 1; max-width: 190px; padding: .75rem; font-size: .95rem; }

/* ============================================================
   TOAST
   ============================================================ */
.toast {
  position: fixed;
  bottom: 90px;
  left: 50%;
  transform: translateX(-50%) translateY(12px);
  background: rgba(26,26,26,.88);
  color: #fff;
  padding: .65rem 1.4rem;
  border-radius: 24px;
  font-size: .88rem;
  opacity: 0;
  pointer-events: none;
  z-index: 200;
  transition: opacity .25s, transform .25s;
  white-space: nowrap;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ============================================================
   EMPTY STATE
   ============================================================ */
.empty-state {
  text-align: center;
  padding: 3rem 1.5rem;
  color: var(--muted);
  grid-column: 1/-1;
}
.empty-state .icon { font-size: 2.5rem; margin-bottom: .75rem; }

/* ============================================================
   UTILITY
   ============================================================ */
.hidden { display: none !important; }

#file-import { display: none; }

@media (max-width: 480px) {
  .card-display.size-xl { font-size: 4rem; }
  .card-display.size-lg { font-size: 2.5rem; }
  .collections-grid { grid-template-columns: 1fr; }
  .mode-btns .btn { font-size: .85rem; }
}