:root {
  color-scheme: light;
  --ink: #1f2933;
  --muted: #6b7280;
  --line: #d8dee7;
  --paper: #ffffff;
  --page: #f2f5f3;
  --green: #2f855a;
  --blue: #2563eb;
  --amber: #b7791f;
  --red: #c2413a;
  --shadow: 0 16px 40px rgba(31, 41, 51, 0.10);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--page);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding: 14px max(18px, env(safe-area-inset-left)) 12px max(18px, env(safe-area-inset-right));
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.topbar-main {
  min-width: 0;
  flex: 1 1 auto;
}

.brand {
  font-size: 20px;
  font-weight: 800;
}

.subtle {
  color: var(--muted);
  font-size: 13px;
}

.account-code {
  margin-top: 3px;
  color: var(--muted);
  font-size: 12px;
}

.account-code strong {
  margin-left: 6px;
  color: var(--ink);
  letter-spacing: 0.08em;
}

.topbar-actions {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  flex-shrink: 0;
}

.visible-learning-code {
  margin-top: 2px;
  color: var(--ink);
  font-size: 17px;
  line-height: 1.2;
  font-weight: 850;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.app-shell {
  width: min(760px, 100%);
  margin: 0 auto;
  padding: 14px 16px 28px;
}

.stats-grid,
.home-stats-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 14px;
}

.home-stats-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.data-details {
  margin-bottom: 12px;
  color: var(--muted);
  font-size: 13px;
}

.data-details summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  font-weight: 700;
  color: var(--muted);
}

.data-details summary::before {
  content: "▶";
  font-size: 10px;
  transition: transform 200ms ease;
}

.data-details[open] summary::before {
  transform: rotate(90deg);
}

.data-details summary::-webkit-details-marker {
  display: none;
}

.detail-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 8px;
}

.stat-card {
  min-height: 62px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.stat-value {
  font-size: 25px;
  line-height: 1;
  font-weight: 850;
}

.stat-label {
  margin-top: 6px;
  color: #555;
  font-size: 14px;
}

.study-summary {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}

#sessionProgress {
  display: block;
  min-width: 64px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.progress-track {
  height: 10px;
  background: #e7ebef;
  border-radius: 999px;
  overflow: hidden;
}

.progress-fill {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--green), var(--blue));
  transition: width 180ms ease;
}

.bottom-action-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}

.bottom-action-pair .ghost-button {
  width: 100%;
  min-height: 44px;
  margin-top: 0;
}

.custom-pack-panel {
  margin-bottom: 12px;
  padding: 14px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.custom-pack-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.custom-pack-name {
  display: block;
  font-size: 15px;
  font-weight: 800;
}

.custom-pack-info .ghost-button {
  flex-shrink: 0;
  min-height: 36px;
  margin-top: 0;
  padding: 0 16px;
  font-size: 13px;
}

.custom-pack-progress-track {
  height: 6px;
  margin-top: 10px;
}

.custom-pack-bottom {
  display: flex;
  justify-content: space-between;
  margin-top: 10px;
}

.custom-pack-reimport,
.custom-pack-reimport-style {
  color: var(--muted);
  font-size: 12px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
}

.custom-pack-reimport:hover,
.custom-pack-reimport-style:hover {
  color: var(--ink);
}

.file-import-button {
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.file-input-native {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
  white-space: nowrap;
}

.tool-status {
  min-height: 18px;
  margin: 8px 0 0;
}

.stage-panel {
  margin-bottom: 12px;
  padding: 12px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
}

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

.stage-header {
  margin-bottom: 10px;
}

.stage-label {
  display: block;
  font-size: 16px;
  font-weight: 850;
}

.stage-count {
  font-size: 24px;
  line-height: 1;
}

.stage-footer {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
}

.stage-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
}

.stage-actions .ghost-button,
.stage-actions .primary-button {
  width: auto;
  min-height: 36px;
  margin-top: 0;
  padding: 0 12px;
  font-size: 13px;
}

.flashcard-tool {
  margin-bottom: 14px;
  padding: 0;
  background: transparent;
  border: 0;
  border-radius: 8px;
  box-shadow: none;
}

.english-signal {
  width: 100%;
  margin: 12px 0 10px;
  color: #9a5a10;
  font-size: clamp(10px, 2.8vw, 12px);
  font-weight: 800;
  line-height: 1.2;
  text-align: center;
  white-space: nowrap;
}

.topbar .english-signal {
  margin: 4px 0 0;
  text-align: left;
}

.session-panel {
  position: fixed;
  inset: 0;
  z-index: 20;
  min-height: 100vh;
  padding: max(12px, env(safe-area-inset-top)) 12px max(12px, env(safe-area-inset-bottom));
  background: #f7f8fa;
}

.session-shell {
  width: min(760px, 100%);
  height: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
}

.session-header {
  display: grid;
  grid-template-columns: minmax(64px, 1fr) auto minmax(64px, 1fr);
  align-items: center;
  gap: 8px;
  min-height: 44px;
}

.session-back-button {
  width: fit-content;
  min-height: 36px;
  border: 0;
  background: transparent;
  color: var(--blue);
  font-weight: 800;
}

.session-title {
  text-align: center;
  font-size: 17px;
}

.session-counter {
  justify-self: end;
  color: var(--muted);
  font-weight: 750;
}

.session-progress-track {
  margin: 6px 0 10px;
}

.session-status-line {
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 10px;
  min-height: 36px;
  color: var(--muted);
  font-size: 14px;
}

.countdown-track {
  height: 6px;
  margin: 0 0 8px;
  overflow: hidden;
  border-radius: 999px;
  background: #e7ebef;
  opacity: 1;
  transition: opacity 120ms ease;
}

.countdown-track.countdown-idle {
  opacity: 0;
}

.countdown-fill {
  width: 100%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--green), #f2b544);
  transform: scaleX(1);
  transform-origin: left center;
  will-change: transform;
}

.session-card-area {
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: stretch;
  padding: 8px 0 10px;
  contain: layout paint;
}

.session-complete {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
  gap: 32px;
}

.complete-icon {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: #e8f5e9;
  color: #2e7d32;
  font-size: 36px;
  font-weight: bold;
  display: flex;
  align-items: center;
  justify-content: center;
}

.complete-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  width: 100%;
  max-width: 320px;
}

.session-panel .word-card {
  min-height: 0;
  flex: 1;
  border-radius: 10px;
}

.response-dock {
  position: sticky;
  bottom: max(40px, calc(env(safe-area-inset-bottom) + 24px));
  z-index: 2;
  margin-top: 0;
  padding: 10px 0 0;
  background: #f7f8fa;
}

.response-dock .response {
  min-height: 72px;
  border-radius: 10px;
  font-size: 18px;
  font-weight: 850;
}

.countdown-toggle {
  display: inline-block;
  margin-left: 6px;
  padding: 2px 8px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper);
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  vertical-align: middle;
}

.hunt-actions {
  display: grid;
  grid-template-columns: minmax(180px, 240px) 1fr;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}

.hunt-actions .primary-button {
  margin-top: 0;
}

.hunt-status {
  min-height: 24px;
  color: var(--green);
  font-size: 18px;
  font-weight: 800;
}

.card-topline {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 8px;
}

.word-card {
  width: 100%;
  min-height: 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 20px;
  background: #fbfcfd;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: inherit;
}

.word-card:focus-visible,
.response:focus-visible,
.primary-button:focus-visible,
.ghost-button:focus-visible,
.icon-button:focus-visible,
.mode-button:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.35);
  outline-offset: 2px;
}

.word-text {
  max-width: 100%;
  overflow-wrap: anywhere;
  text-align: center;
  font-size: clamp(36px, 10svh, 86px);
  line-height: 1;
  font-weight: 900;
}

.word-text.word-text-md {
  font-size: clamp(32px, 8svh, 64px);
}

.word-text.word-text-sm {
  font-size: clamp(24px, 6svh, 48px);
}

.meaning-text {
  max-width: 100%;
  text-align: center;
  color: var(--green);
  font-size: clamp(24px, 4.8vw, 34px);
  line-height: 1.18;
  font-weight: 750;
}

.response-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin-top: 12px;
}

.response-grid.hunt-choice {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.response,
.primary-button,
.ghost-button,
.icon-button {
  min-height: 44px;
  border-radius: 8px;
  border: 1px solid transparent;
  font-weight: 750;
}

.response {
  padding: 12px 8px;
}

.response.known {
  background: #e5f4eb;
  color: var(--green);
  border-color: #b9dfc8;
}

.response.vague {
  background: #fff4d8;
  color: var(--amber);
  border-color: #f2d48b;
}

.response.new {
  background: #fbe8e6;
  color: var(--red);
  border-color: #eeb7b3;
}

.primary-button {
  width: 100%;
  margin-top: 14px;
  background: var(--ink);
  color: white;
}

.home-action-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 10px;
  margin-bottom: 14px;
}

.home-action-button {
  min-height: 64px;
  border: 0;
  border-radius: 16px;
  font-size: 18px;
  font-weight: 900;
  cursor: pointer;
}

.home-action-primary {
  background: linear-gradient(135deg, #ff9f1c, #ff6b35);
  color: #fff;
  box-shadow: 0 10px 24px rgba(255, 111, 53, 0.22);
}

.home-action-secondary {
  background: #fff3e8;
  color: #d4600a;
  border: 1.5px solid #fdd9b8;
}

.ghost-button,
.icon-button {
  background: white;
  color: var(--ink);
  border-color: var(--line);
  padding: 0 14px;
}

.ghost-button:disabled {
  cursor: not-allowed;
  color: var(--muted);
  background: #f5f7f9;
}

.export-button {
  width: 100%;
  margin-top: 10px;
}

.export-status {
  min-height: 18px;
  margin: 6px 0 0;
  text-align: center;
}

.dialog {
  width: min(420px, calc(100% - 32px));
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.dialog::backdrop {
  background: rgba(15, 23, 42, 0.32);
}

.dialog h2 {
  margin: 0 0 8px;
}

.dialog label {
  display: block;
  margin-top: 16px;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 14px;
}

.dialog input {
  width: 100%;
  height: 46px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.dialog-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.error-text {
  min-height: 20px;
  color: var(--red);
  font-size: 13px;
}

.site-footer {
  width: min(760px, 100%);
  margin: 0 auto;
  padding: 0 16px 24px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: 12px;
}

.site-footer a {
  color: var(--muted);
}

.hidden {
  display: none !important;
}

.content-page {
  width: min(760px, 100%);
  margin: 0 auto;
  padding: 22px 16px 40px;
  line-height: 1.75;
}

.content-page h1 {
  font-size: 28px;
  margin: 0 0 16px;
}

.content-page h2 {
  font-size: 18px;
  margin-top: 28px;
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border: 1px solid var(--line);
  margin-bottom: 20px;
}

.admin-table th,
.admin-table td {
  padding: 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.admin-panel,
.login-panel {
  margin-bottom: 18px;
  padding: 18px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.admin-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
  padding: 14px 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  font-weight: 750;
}

.login-panel h1,
.admin-panel h2 {
  margin: 0 0 16px;
}

.login-panel label,
.admin-form label {
  display: block;
  margin: 12px 0 6px;
  color: var(--muted);
  font-size: 14px;
}

.login-panel input,
.admin-form input {
  width: 100%;
  height: 44px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.copy-result {
  min-height: 24px;
  color: var(--green);
  font-weight: 750;
}

.admin-actions {
  min-width: 280px;
}

.admin-actions button {
  min-height: 34px;
  margin: 3px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-size: 13px;
  font-weight: 700;
}

.export-output {
  max-height: 360px;
  overflow: auto;
  padding: 12px;
  background: #0f172a;
  color: #e5e7eb;
  border-radius: 8px;
  white-space: pre-wrap;
}

@media (max-width: 640px) {
  .topbar {
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .brand {
    font-size: 18px;
  }

  .topbar .subtle {
    display: none;
  }

  .app-shell {
    padding: 10px 12px 24px;
  }

  .stats-grid,
  .home-stats-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
    margin-bottom: 10px;
  }

  .home-stats-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .detail-stats-grid {
    gap: 6px;
  }

  .stat-card {
    min-height: 54px;
  }

  .stat-value {
    font-size: 22px;
  }

  .stat-label {
    font-size: 12px;
  }

  .study-summary {
    grid-template-columns: auto 1fr;
  }

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

  .response-grid.hunt-choice {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .response-dock {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .response-dock.hunt-choice {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hunt-actions {
    grid-template-columns: minmax(130px, 180px) 1fr;
  }

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

  .stage-actions {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .stage-actions .primary-button {
    grid-column: 1 / -1;
  }

  .stage-actions .ghost-button,
  .stage-actions .primary-button {
    width: 100%;
  }

  .word-card {
    min-height: 180px;
  }

  .session-panel .word-card {
    min-height: 0;
  }

  .session-title {
    font-size: 16px;
  }

  .session-card-area {
    padding-top: 4px;
  }

  .site-footer {
    flex-direction: column;
  }
}

/* Vocab Test */
.login-divider {
  text-align: center;
  color: var(--muted);
  margin: 16px 0;
  font-size: 14px;
}

.vocab-test-entry {
  width: 100%;
  font-size: 15px;
}

.vocab-test-card {
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: default;
}

.vocab-test-buttons {
  grid-template-columns: 1fr 1fr;
}

.word-map {
  margin: 16px 0;
}

.word-map-section-label {
  font-weight: 700;
  font-size: 15px;
  color: #333;
  margin: 20px 0 8px;
  padding-top: 12px;
  border-top: 1px solid #e0e0e0;
}

.word-map-group {
  margin-bottom: 16px;
}

.word-map-label {
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.word-map-label .map-icon {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.word-map-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.word-tag {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  line-height: 1.4;
}

.word-tag-known {
  background: #e8f5e9;
  color: #2e7d32;
  border: 1px solid #c8e6c9;
}

.word-tag-vague {
  background: #fff3e0;
  color: #e65100;
  border: 1px solid #ffe0b2;
}

.word-tag-new {
  background: #f5f5f5;
  color: #757575;
  border: 1px solid #e0e0e0;
}

.vocab-result-title {
  text-align: center;
  margin: 0 0 20px;
  font-size: 20px;
}

.vocab-result-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 24px 0 16px;
}

.vocab-test-exit {
  width: 100%;
  margin-top: 8px;
}