:root {
  --forest: #4056d6;
  --forest-deep: #17204f;
  --mint: #e8ecff;
  --mint-soft: #f4f6ff;
  --gold: #ffb000;
  --coral: #f05263;
  --coral-soft: #fff0f1;
  --ink: #1b2140;
  --muted: #5f6884;
  --line: #dbe0f0;
  --surface: #ffffff;
  --canvas: #f4f6fb;
  --shadow: 0 22px 60px rgba(23, 32, 79, 0.13);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--canvas);
}

body {
  min-width: 320px;
  min-height: 100vh;
  min-height: 100dvh;
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(rgba(21, 29, 60, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21, 29, 60, 0.035) 1px, transparent 1px),
    var(--canvas);
  background-size: 32px 32px;
  font-family:
    "Segoe UI",
    "Microsoft YaHei",
    system-ui,
    sans-serif;
}

button,
select {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible,
select:focus-visible,
.review-card:focus-visible {
  outline: 3px solid rgba(77, 90, 143, 0.35);
  outline-offset: 2px;
}

[hidden] {
  display: none !important;
}

.review-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: 64px;
  padding:
    max(8px, env(safe-area-inset-top))
    max(14px, env(safe-area-inset-right))
    8px
    max(14px, env(safe-area-inset-left));
  display: grid;
  grid-template-columns: minmax(76px, 1fr) auto minmax(76px, 1fr);
  align-items: center;
  gap: 12px;
  color: #ffffff;
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.04), transparent 58%),
    var(--forest-deep);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.back-link,
.topbar-button {
  color: #d9dce8;
  font-size: 12px;
  font-weight: 800;
  text-decoration: none;
}

.back-link {
  justify-self: start;
}

.review-topbar .topbar-links {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  justify-self: start;
}

.topbar-button {
  min-height: 38px;
  padding: 0 12px;
  justify-self: end;
  color: #ffffff;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 7px;
  cursor: pointer;
}

.topbar-button:hover {
  background: rgba(255, 255, 255, 0.14);
}

.review-brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: #ffffff;
  text-decoration: none;
}

.brand-mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  color: #ffffff;
  background: var(--gold);
  border-radius: 8px;
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 800;
}

.review-brand > span:last-child {
  display: grid;
  gap: 1px;
}

.review-brand strong {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 17px;
  line-height: 1.1;
}

.review-brand small {
  color: #a9aec3;
  font-size: 8px;
  line-height: 1.2;
}

.review-shell {
  width: min(760px, calc(100% - 28px));
  margin: 0 auto;
  padding: 18px 0 max(22px, env(safe-area-inset-bottom));
  display: grid;
  gap: 12px;
}

.scope-panel {
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 10px 32px rgba(14, 21, 49, 0.055);
}

.scope-head {
  min-height: 78px;
  padding: 15px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.scope-label {
  display: block;
  margin-bottom: 2px;
  color: #8a8d98;
  font-size: 10px;
  font-weight: 800;
  text-transform: uppercase;
}

.scope-head h1 {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 23px;
  line-height: 1.2;
}

.scope-head p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.5;
}

.scope-toggle-button {
  min-height: 38px;
  padding: 0 13px;
  flex: 0 0 auto;
  color: var(--forest);
  background: var(--mint-soft);
  border: 1px solid #c8ccdb;
  border-radius: 7px;
  font-size: 12px;
  font-weight: 800;
  cursor: pointer;
}

.scope-controls {
  padding: 0 16px 16px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  border-top: 1px solid var(--line);
}

.scope-controls[hidden] {
  display: none;
}

.scope-field {
  min-width: 0;
  padding-top: 13px;
  display: grid;
  gap: 6px;
}

.scope-field:last-child {
  grid-column: 1 / -1;
}

.scope-field span {
  color: #646876;
  font-size: 11px;
  font-weight: 800;
}

.scope-field select {
  width: 100%;
  min-width: 0;
  min-height: 42px;
  padding: 0 34px 0 11px;
  color: var(--ink);
  background: #f7f8fa;
  border: 1px solid #cfd2de;
  border-radius: 7px;
  font-size: 12px;
}

.scope-field select:disabled {
  color: #989aa4;
  background: #f0f1f3;
}

.review-progress {
  padding: 0 3px;
  display: grid;
  gap: 7px;
}

.review-progress-copy {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font-size: 11px;
}

.review-progress-copy strong {
  color: var(--forest);
  font-size: 12px;
}

.review-progress-track {
  height: 4px;
  overflow: hidden;
  background: #d8dae4;
  border-radius: 4px;
}

.review-progress-track span {
  width: 0;
  height: 100%;
  display: block;
  background: linear-gradient(90deg, var(--forest), #4f5c90);
  border-radius: inherit;
  transition: width 220ms ease;
}

.review-stage {
  position: relative;
  min-height: 440px;
  display: grid;
  align-items: stretch;
  touch-action: pan-x;
  user-select: none;
}

.review-card {
  position: relative;
  min-height: 440px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 20px;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(248, 249, 251, 0.97)),
    var(--surface);
  border: 1px solid #ced1dd;
  border-radius: 8px;
  box-shadow: var(--shadow);
  cursor: grab;
  will-change: transform;
}

.review-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: linear-gradient(
    180deg,
    var(--gold),
    var(--coral) 54%,
    #727ead
  );
}

.review-card.is-dragging {
  cursor: grabbing;
  transition: none;
}

.review-card.is-settling {
  transition: transform 190ms ease;
}

.review-card.is-entering-next {
  animation: card-enter-next 220ms ease both;
}

.review-card.is-entering-previous {
  animation: card-enter-previous 220ms ease both;
}

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

.card-deck {
  min-width: 0;
  overflow: hidden;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.speak-button {
  min-height: 36px;
  padding: 0 13px;
  flex: 0 0 auto;
  color: var(--forest);
  background: var(--mint-soft);
  border: 1px solid #c8ccdb;
  border-radius: 7px;
  font-size: 12px;
  font-weight: 800;
  cursor: pointer;
}

.card-word-block {
  margin: auto 0;
  padding: 18px 0;
  text-align: center;
}

.card-word-block h2 {
  margin: 0;
  color: var(--forest);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 52px;
  line-height: 1.12;
  overflow-wrap: anywhere;
}

.card-phonetic {
  min-height: 20px;
  margin: 10px 0 0;
  color: #6d7181;
  font-size: 16px;
  line-height: 1.4;
}

.card-answer {
  padding: 15px 16px;
  display: grid;
  gap: 12px;
  background: #f4f5f8;
  border: 1px solid #d7dae5;
  border-radius: 8px;
  animation: answer-in 180ms ease both;
}

.card-meaning {
  margin: 0;
  color: #292f46;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.6;
}

.example-block {
  display: grid;
  gap: 5px;
}

.card-sentence,
.card-translation {
  margin: 0;
  line-height: 1.55;
}

.card-sentence {
  color: #40465c;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 14px;
}

.card-translation {
  color: #7a7d89;
  font-size: 12px;
}

.reveal-button {
  min-height: 44px;
  padding: 0 18px;
  color: #ffffff;
  background: var(--forest);
  border: 1px solid var(--forest);
  border-radius: 7px;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
}

.reveal-button:hover {
  background: var(--forest-deep);
}

.review-actions {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.15fr) minmax(0, 1.15fr) minmax(0, 0.8fr);
  gap: 8px;
}

.direction-button,
.mark-button,
.primary-button {
  min-height: 48px;
  padding: 0 12px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
}

.direction-button {
  color: #535766;
  background: #ffffff;
  border: 1px solid #cfd2de;
}

.direction-button:hover {
  border-color: #a8adc1;
}

.mark-button.is-unknown {
  color: #9a3f39;
  background: var(--coral-soft);
  border: 1px solid #e8b8b3;
}

.mark-button.is-known {
  color: #1d2a5c;
  background: #eef0f8;
  border: 1px solid #b8bed8;
}

.mark-button.is-active {
  color: #ffffff;
  background: var(--forest);
  border-color: var(--forest);
  box-shadow: 0 7px 18px rgba(13, 21, 52, 0.17);
}

.mark-button.is-unknown.is-active {
  background: var(--coral);
  border-color: var(--coral);
  box-shadow: 0 7px 18px rgba(167, 60, 53, 0.17);
}

.direction-button:disabled,
.mark-button:disabled,
.speak-button:disabled,
.reveal-button:disabled {
  opacity: 0.42;
  cursor: default;
}

.review-message {
  min-height: 18px;
  margin: 0;
  color: #595f76;
  font-size: 11px;
  text-align: center;
}

.completion-view,
.empty-view {
  min-height: 440px;
  padding: 34px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  text-align: center;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid #ced1dd;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.completion-mark {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  color: #ffffff;
  background: var(--forest);
  border-radius: 50%;
  font-size: 28px;
  font-weight: 800;
}

.completion-view h2,
.empty-view strong {
  margin: 0;
  color: var(--forest);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 28px;
  line-height: 1.25;
}

.completion-view p,
.empty-view p {
  max-width: 440px;
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.65;
}

.primary-button {
  min-width: 138px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  background: var(--forest);
  border: 1px solid var(--forest);
  text-decoration: none;
}

.primary-button:hover {
  background: var(--forest-deep);
}

.toast {
  position: fixed;
  left: 50%;
  bottom: max(20px, env(safe-area-inset-bottom));
  z-index: 40;
  max-width: min(86vw, 420px);
  padding: 10px 15px;
  color: #ffffff;
  background: rgba(11, 17, 41, 0.94);
  border-radius: 8px;
  box-shadow: 0 12px 30px rgba(7, 11, 28, 0.22);
  font-size: 12px;
  font-weight: 700;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 12px);
  transition:
    opacity 160ms ease,
    transform 160ms ease;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@keyframes answer-in {
  from {
    opacity: 0;
    transform: translateY(7px);
  }
}

@keyframes card-enter-next {
  from {
    opacity: 0;
    transform: translateY(42px) scale(0.985);
  }
}

@keyframes card-enter-previous {
  from {
    opacity: 0;
    transform: translateY(-42px) scale(0.985);
  }
}

@media (max-width: 640px) {
  .review-topbar {
    grid-template-columns: 74px 1fr 78px;
    gap: 8px;
  }

  .review-topbar .topbar-links {
    gap: 6px;
  }

  .review-topbar .topbar-back {
    font-size: 0;
  }

  .review-topbar .topbar-back::before {
    content: "←";
    font-size: 11px;
  }

  .review-brand {
    justify-content: center;
  }

  .review-brand small {
    display: none;
  }

  .review-shell {
    width: min(100% - 20px, 760px);
    padding-top: 12px;
    gap: 10px;
  }

  .scope-head {
    min-height: 70px;
    padding: 12px 13px;
  }

  .scope-head h1 {
    font-size: 20px;
  }

  .scope-toggle-button {
    min-height: 36px;
    padding: 0 10px;
  }

  .scope-controls {
    padding: 0 13px 13px;
    grid-template-columns: minmax(0, 1fr);
  }

  .scope-field:last-child {
    grid-column: auto;
  }

  .review-stage,
  .review-card {
    min-height: min(520px, calc(100dvh - 330px));
  }

  .review-stage,
  .completion-view,
  .empty-view {
    min-height: max(400px, calc(100dvh - 330px));
  }

  .review-card {
    padding: 18px;
  }

  .card-word-block h2 {
    font-size: 42px;
  }

  .card-phonetic {
    font-size: 14px;
  }

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

  .mark-button {
    order: -1;
  }

  .direction-button {
    min-height: 42px;
    font-size: 12px;
  }
}

@media (max-width: 370px) {
  .review-topbar {
    grid-template-columns: 64px 1fr 70px;
  }

  .back-link,
  .topbar-button {
    font-size: 11px;
  }

  .topbar-button {
    padding: 0 8px;
  }

  .review-brand .brand-mark {
    width: 32px;
    height: 32px;
  }

  .review-brand strong {
    font-size: 15px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 1ms !important;
    transition-duration: 1ms !important;
  }
}