:root {
  --bg:        #1a2233;
  --surface:   #1e2a3a;
  --green:     #507844;
  --rust:      #ae4f2f;
  --white:     #ffffff;
  --muted:     rgba(255,255,255,0.6);
  --overlay:   rgba(80,120,68,0.25);
  --white-12:  rgba(255,255,255,0.12);
  --rust-20:   rgba(174,79,47,0.2);
  --rust-30:   rgba(174,79,47,0.3);
  --overlay-hover: rgba(80,120,68,0.4);
  --option-hover:  rgba(80,120,68,0.35);
  --error-text:   #fca5a5;
  --success-text: #a7f3d0;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 40px 20px;
  color: var(--white);
}

.app-wrapper {
  width: 100%;
  max-width: 560px;
}

.screen { width: 100%; }
.hidden { display: none; }

.card {
  background: var(--surface);
  border: 1px solid var(--green);
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
}

/* ── Setup screen ─────────────────────────────── */
.setup-title {
  font-size: 22px; font-weight: 700;
  text-align: center; margin-bottom: 4px;
}
.setup-sub {
  color: var(--rust); font-size: 13px; letter-spacing: 1px;
  text-align: center; margin-bottom: 24px;
}
.upload-zone {
  border: 2px dashed var(--green);
  border-radius: 10px; padding: 24px;
  text-align: center; margin-bottom: 20px;
  cursor: pointer; position: relative;
}
.upload-zone input[type="file"] {
  position: absolute; inset: 0; opacity: 0; cursor: pointer; width: 100%; height: 100%;
}
.upload-icon { font-size: 28px; margin-bottom: 6px; }
.upload-text { font-size: 14px; }
.upload-hint { color: var(--rust); font-size: 12px; margin-top: 4px; }

.setting-label {
  color: var(--muted); font-size: 11px;
  letter-spacing: 1px; text-transform: uppercase; margin-bottom: 8px;
}
.chips { display: flex; gap: 8px; margin-bottom: 20px; flex-wrap: wrap; }
.chip {
  background: var(--overlay); border: 1px solid var(--green);
  border-radius: 20px; padding: 6px 14px;
  color: var(--muted); font-size: 13px; cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.chip.active { background: var(--green); color: var(--white); font-weight: 600; }
.chip:hover:not(.active) { background: var(--overlay-hover); color: var(--white); }

.start-btn {
  width: 100%; background: var(--green); border: none;
  border-radius: 10px; padding: 14px; color: var(--white);
  font-size: 15px; font-weight: 600; cursor: pointer; letter-spacing: 1px;
  transition: opacity 0.2s;
}
.start-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.start-btn:not(:disabled):hover { opacity: 0.85; }

.format-hint {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--white-12);
  border-radius: 8px;
  padding: 12px 14px;
  margin-bottom: 16px;
  font-size: 12px;
}
.format-hint-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}
.format-hint-title {
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.5px;
}
.use-example-btn {
  background: var(--overlay);
  border: 1px solid var(--green);
  border-radius: 6px;
  padding: 4px 10px;
  color: var(--white);
  font-size: 11px;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s;
  white-space: nowrap;
}
.use-example-btn:hover { background: var(--overlay-hover); }
.format-code {
  display: block;
  background: rgba(0,0,0,0.3);
  border-radius: 4px;
  padding: 6px 8px;
  color: var(--success-text);
  font-family: 'Courier New', Courier, monospace;
  font-size: 11px;
  margin-bottom: 6px;
  word-break: break-all;
}
.format-labels {
  display: flex;
  gap: 0;
  margin-bottom: 8px;
  padding: 0 2px;
}
.format-labels span {
  flex: 1;
  font-size: 10px;
  color: rgba(255,255,255,0.3);
  text-align: center;
}
.format-labels span:first-child { text-align: left; }
.format-labels span:last-child  { text-align: right; }
.format-examples {
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.format-example {
  color: rgba(255,255,255,0.35);
  font-size: 11px;
  font-family: 'Courier New', Courier, monospace;
  word-break: break-all;
}

.status-msg {
  margin-top: 12px; padding: 10px 14px; border-radius: 8px; font-size: 13px;
}
.status-msg.error   { background: var(--rust-20);  color: var(--error-text);   border: 1px solid var(--rust); }
.status-msg.success { background: rgba(80,120,68,0.2); color: var(--success-text); border: 1px solid var(--green); }

/* ── Quiz screen ──────────────────────────────── */
.quiz-header {
  display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px;
}
.quiz-label { font-size: 12px; font-weight: 600; }
.quiz-score { color: var(--rust); font-size: 12px; flex: 1; text-align: right; }
.quiz-exit-btn {
  background: none;
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 6px;
  color: var(--muted);
  font-size: 12px;
  padding: 2px 7px;
  cursor: pointer;
  margin-left: 10px;
  transition: border-color 0.15s, color 0.15s;
}
.quiz-exit-btn:hover { border-color: var(--rust); color: var(--error-text); }

.progress-bar-bg { background: var(--white-12); border-radius: 4px; height: 4px; margin-bottom: 18px; }
.progress-bar-fill {
  background: linear-gradient(90deg, var(--green), var(--rust));
  height: 4px; border-radius: 4px; transition: width 0.3s ease;
}

.word-card {
  background: var(--overlay); border: 1px solid var(--green);
  border-radius: 14px; padding: 28px 20px; text-align: center; margin-bottom: 16px;
}
.word-pronunciation { color: var(--rust); font-size: 13px; margin-bottom: 10px; font-style: italic; }
.word-text { color: var(--white); font-size: 30px; font-weight: 700; letter-spacing: 1px; }

.options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.option-btn {
  background: var(--white-12); border: 1px solid var(--green);
  border-radius: 10px; padding: 16px 10px; text-align: center;
  cursor: pointer; transition: background 0.15s, border-color 0.15s;
  color: var(--white);
}
.option-btn:hover:not(:disabled) { background: var(--option-hover); }
.option-btn:disabled { cursor: not-allowed; }
.option-btn.selected-correct { background: var(--green) !important; border-color: var(--green); }
.option-btn.selected-wrong   { background: var(--rust)  !important; border-color: var(--rust); }
.option-meaning { font-size: 14px; display: block; }

/* ── Results screen ───────────────────────────── */
.score-wrap { text-align: center; margin-bottom: 20px; }
.score-num  { color: var(--green); font-size: 52px; font-weight: 700; line-height: 1; }
.score-den  { color: var(--muted); font-size: 22px; }
.score-msg  { color: var(--muted); font-size: 13px; margin-top: 8px; }

.wrong-label {
  color: var(--rust); font-size: 11px;
  letter-spacing: 1px; text-transform: uppercase; margin-bottom: 10px;
}
.wrong-list { margin-bottom: 16px; max-height: 200px; overflow-y: auto; }
.wrong-item {
  background: var(--white-12); border: 1px solid var(--rust-30);
  border-radius: 8px; padding: 10px 12px; margin-bottom: 6px;
}
.wrong-word    { color: var(--error-text); font-size: 14px; font-weight: 600; }
.wrong-meaning { color: var(--muted); font-size: 12px; margin-top: 2px; }

.review-insufficient {
  color: var(--muted); font-size: 12px; text-align: center;
  margin-bottom: 12px; font-style: italic;
}

.btn-review {
  width: 100%; background: var(--rust); border: none;
  border-radius: 10px; padding: 13px; color: var(--white);
  font-size: 14px; font-weight: 600; cursor: pointer; margin-bottom: 8px;
  transition: opacity 0.2s;
}
.btn-review:hover { opacity: 0.85; }
.btn-restart {
  width: 100%; background: var(--overlay); border: 1px solid var(--green);
  border-radius: 10px; padding: 13px; color: var(--white);
  font-size: 14px; cursor: pointer; transition: opacity 0.2s;
}
.btn-restart:hover { opacity: 0.85; }

/* ── Tab Bar ──────────────────────────────────── */
.tab-bar {
  display: flex;
  background: var(--surface);
  border: 1px solid var(--green);
  border-bottom: none;
  border-radius: 16px 16px 0 0;
  overflow: hidden;
  margin-bottom: -1px;
}
.tab-bar.hidden { display: none; }
.tab {
  flex: 1;
  padding: 12px 8px;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--muted);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}
.tab:hover:not(:disabled):not(.active) {
  color: var(--white);
  background: var(--overlay);
}
.tab.active {
  color: var(--white);
  border-bottom-color: var(--green);
  font-weight: 600;
}
.tab:disabled {
  color: rgba(255,255,255,0.2);
  cursor: not-allowed;
}

/* When tab-bar is visible, square the top corners of every screen's card */
.tab-bar:not(.hidden) ~ .screen .card {
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

/* ── Vocab screen ─────────────────────────────── */
.vocab-controls {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}
.vocab-search {
  flex: 1;
  background: var(--white-12);
  border: 1px solid var(--green);
  border-radius: 8px;
  padding: 8px 12px;
  color: var(--white);
  font-size: 13px;
  font-family: inherit;
  outline: none;
}
.vocab-search::placeholder { color: rgba(255,255,255,0.3); }
.vocab-sort-btn {
  background: var(--rust-20);
  border: 1px solid var(--rust);
  border-radius: 8px;
  padding: 8px 12px;
  color: var(--white);
  font-size: 12px;
  font-family: inherit;
  cursor: pointer;
  white-space: nowrap;
  transition: opacity 0.2s;
}
.vocab-sort-btn:hover { opacity: 0.85; }
.vocab-view-btn {
  background: var(--white-12);
  border: 1px solid var(--green);
  border-radius: 8px;
  padding: 8px 12px;
  color: var(--white);
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s;
}
.vocab-view-btn:hover { background: var(--overlay-hover); }

.vocab-filters {
  display: flex;
  gap: 6px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}
.vocab-count {
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 10px;
}

.vocab-empty {
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  padding: 24px 0;
  font-style: italic;
}

/* List view */
.vocab-list {
  display: flex;
  flex-direction: column;
  gap: 5px;
  max-height: 400px;
  overflow-y: auto;
  scrollbar-gutter: stable;
}
.vocab-row {
  display: flex;
  align-items: center;
  background: var(--white-12);
  border: 1px solid rgba(80,120,68,0.3);
  border-radius: 8px;
  padding: 8px 10px;
  gap: 10px;
}
.vr-word { font-weight: 700; font-size: 14px; min-width: 90px; color: var(--white); }
.vr-pron { color: var(--rust); font-size: 11px; font-style: italic; min-width: 90px; }
.vr-part {
  background: rgba(80,120,68,0.4);
  border-radius: 4px;
  padding: 2px 6px;
  font-size: 10px;
  color: rgba(255,255,255,0.85);
  white-space: nowrap;
}
.vr-meaning { color: var(--muted); font-size: 12px; flex: 1; }

/* Grid view */
.vocab-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  max-height: 400px;
  overflow-y: auto;
  scrollbar-gutter: stable;
}
.vocab-card {
  background: var(--overlay);
  border: 1px solid var(--green);
  border-radius: 10px;
  padding: 14px 10px;
  text-align: center;
}
.vc-word { font-size: 16px; font-weight: 700; color: var(--white); margin-bottom: 4px; }
.vc-pron { color: var(--rust); font-size: 11px; font-style: italic; margin-bottom: 6px; }
.vc-part {
  background: rgba(80,120,68,0.4);
  border-radius: 4px;
  padding: 2px 7px;
  font-size: 10px;
  color: rgba(255,255,255,0.85);
  display: inline-block;
  margin-bottom: 6px;
}
.vc-meaning { color: var(--muted); font-size: 12px; line-height: 1.4; }