:root {
  --bg: #111318;
  --panel: rgba(255, 255, 255, 0.93);
  --panel-strong: #ffffff;
  --ink: #171b22;
  --muted: #667085;
  --line: rgba(23, 27, 34, 0.12);
  --primary: #1f6feb;
  --primary-deep: #164ea6;
  --accent: #00a884;
  --warn: #c77900;
  --danger: #c43d4b;
  --ok: #168a55;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.22);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: Inter, "Avenir Next", "Hiragino Sans", "Yu Gothic", sans-serif;
  letter-spacing: 0;
  background:
    linear-gradient(120deg, rgba(31, 111, 235, 0.24), transparent 34%),
    linear-gradient(210deg, rgba(0, 168, 132, 0.2), transparent 40%),
    #111318;
}

button,
input {
  font: inherit;
}

button {
  border: 0;
}

.app-shell {
  width: min(1500px, calc(100% - 28px));
  min-height: calc(100vh - 28px);
  margin: 14px auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 380px;
  gap: 14px;
}

.practice-panel,
.side-rail,
.control-block,
.metric-card,
.quiz-surface,
.console-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
}

.practice-panel {
  min-width: 0;
  padding: 18px;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 14px;
}

.topbar,
.question-head,
.feedback-row,
.section-head.inline,
.top-actions,
.action-cluster,
.brand-lockup {
  display: flex;
  align-items: center;
}

.topbar,
.question-head,
.feedback-row,
.section-head.inline {
  justify-content: space-between;
  gap: 16px;
}

.brand-lockup {
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  color: #ffffff;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), var(--accent));
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--primary);
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
}

h1,
h2 {
  margin: 0;
  line-height: 1.15;
}

h1 {
  font-size: 24px;
}

h2 {
  font-size: 17px;
}

.top-actions {
  gap: 8px;
}

.icon-button,
.mini-button,
.tool-button,
.primary-button,
.segmented button {
  min-height: 40px;
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--ink);
  background: #edf1f7;
  transition: transform 0.12s ease, background 0.12s ease, box-shadow 0.12s ease;
}

.icon-button {
  width: 42px;
  display: grid;
  place-items: center;
  font-size: 19px;
  font-weight: 800;
}

.file-button {
  position: relative;
}

.danger {
  color: #ffffff;
  background: var(--danger);
}

.icon-button:hover,
.mini-button:hover,
.tool-button:hover,
.primary-button:hover,
.segmented button:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 24px rgba(31, 111, 235, 0.16);
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.metric-card {
  padding: 12px;
  box-shadow: none;
}

.metric-card span,
.console-card span,
.answer-glance span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.metric-card strong,
.console-card strong {
  font-size: 24px;
}

.meter {
  height: 7px;
  overflow: hidden;
  margin-top: 10px;
  border-radius: 999px;
  background: #e5eaf1;
}

.meter i {
  display: block;
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 0.24s ease;
}

.quiz-surface {
  min-height: 480px;
  padding: 24px;
  display: grid;
  grid-template-rows: auto auto auto auto;
  align-content: center;
  gap: 22px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(246, 249, 252, 0.96)),
    var(--panel-strong);
}

.meaning-prompt {
  max-width: 920px;
  min-height: 138px;
  display: flex;
  align-items: center;
  font-size: clamp(32px, 5vw, 64px);
  font-weight: 900;
  line-height: 1.16;
  word-break: keep-all;
  overflow-wrap: anywhere;
}

.round-gauge {
  width: 112px;
  height: 112px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  align-content: center;
  border-radius: 50%;
  color: #ffffff;
  background: conic-gradient(from 210deg, var(--primary), var(--accent), var(--primary));
}

.round-gauge strong {
  font-size: 30px;
}

.round-gauge span {
  font-size: 12px;
  font-weight: 800;
  opacity: 0.86;
  text-transform: uppercase;
}

.answer-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 132px;
  gap: 10px;
}

.answer-form input,
.search-input {
  width: 100%;
  min-height: 58px;
  border: 2px solid #d8dee8;
  border-radius: var(--radius);
  padding: 0 16px;
  color: var(--ink);
  background: #ffffff;
  outline: none;
}

.answer-form input {
  font-size: 28px;
  font-weight: 800;
}

.answer-form input:focus,
.search-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(31, 111, 235, 0.12);
}

.primary-button {
  color: #ffffff;
  background: var(--primary);
  font-weight: 900;
}

.feedback-panel {
  min-height: 62px;
  flex: 1;
  padding: 12px 14px;
  border-radius: var(--radius);
  border: 1px solid #d8dee8;
  background: #f6f8fb;
}

.feedback-panel strong,
.feedback-panel span {
  display: block;
}

.feedback-panel strong {
  margin-bottom: 4px;
}

.feedback-panel span {
  color: var(--muted);
}

.feedback-panel.correct {
  border-color: rgba(22, 138, 85, 0.36);
  background: rgba(22, 138, 85, 0.1);
}

.feedback-panel.wrong {
  border-color: rgba(196, 61, 75, 0.36);
  background: rgba(196, 61, 75, 0.1);
}

.feedback-panel.neutral {
  border-color: #d8dee8;
}

.action-cluster {
  gap: 8px;
}

.tool-button,
.mini-button {
  padding: 0 13px;
  font-weight: 800;
}

.tool-button.strong {
  color: #ffffff;
  background: var(--accent);
}

.tool-button:disabled,
.primary-button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
  transform: none;
  box-shadow: none;
}

.answer-glance {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 0.5fr);
  gap: 10px;
}

.answer-glance div {
  min-height: 70px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.answer-glance strong {
  display: block;
  min-height: 26px;
  font-size: 20px;
  overflow-wrap: anywhere;
}

.session-console {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.console-card {
  padding: 12px;
  box-shadow: none;
}

.side-rail {
  min-width: 0;
  padding: 12px;
  display: grid;
  gap: 12px;
  align-content: start;
  overflow: auto;
  max-height: calc(100vh - 28px);
}

.control-block {
  padding: 14px;
  box-shadow: none;
}

.section-head {
  margin-bottom: 12px;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  padding: 5px;
  border-radius: var(--radius);
  background: #edf1f7;
}

.segmented button {
  min-height: 36px;
  background: transparent;
  font-size: 13px;
  font-weight: 800;
}

.segmented button.active {
  color: #ffffff;
  background: var(--primary);
}

.slider-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) 44px;
  align-items: center;
  gap: 10px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.slider-row input {
  width: 100%;
}

.queue-list,
.word-list,
.log-list,
.search-results {
  display: grid;
  gap: 8px;
}

.queue-item,
.word-item,
.log-item,
.search-item {
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.queue-item strong,
.word-item strong,
.search-item strong {
  display: block;
  margin-bottom: 3px;
}

.queue-item span,
.word-item span,
.log-item span,
.search-item span {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.45;
}

.log-item {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 8px;
}

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 28px;
  border-radius: var(--radius);
  color: #ffffff;
  font-size: 12px;
  font-weight: 900;
}

.badge.ok {
  background: var(--ok);
}

.badge.ng {
  background: var(--danger);
}

.badge.show {
  background: var(--warn);
}

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

.shake {
  animation: shake 0.24s ease;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-6px);
  }
  75% {
    transform: translateX(6px);
  }
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .side-rail {
    max-height: none;
    overflow: visible;
  }

  .meaning-prompt {
    min-height: 110px;
  }
}

@media (max-width: 680px) {
  .app-shell {
    width: min(100% - 16px, 1500px);
    margin: 8px auto;
  }

  .practice-panel {
    padding: 12px;
  }

  .topbar,
  .question-head,
  .feedback-row {
    align-items: stretch;
    flex-direction: column;
  }

  .top-actions,
  .action-cluster {
    width: 100%;
  }

  .icon-button,
  .tool-button {
    flex: 1;
  }

  .metric-strip,
  .session-console,
  .answer-glance {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .answer-form {
    grid-template-columns: 1fr;
  }

  .answer-form input {
    font-size: 22px;
  }

  .meaning-prompt {
    min-height: 132px;
    font-size: 32px;
  }

  .round-gauge {
    width: 86px;
    height: 86px;
  }
}