:root {
  color-scheme: light;
  font-family:
    Pretendard, -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Noto Sans KR",
    "Segoe UI", sans-serif;
  font-synthesis: none;
  --bg: #eef2f3;
  --surface: #ffffff;
  --surface-muted: #f5f7f8;
  --text: #172124;
  --muted: #5f6c70;
  --line: #cfd8da;
  --primary: #147d78;
  --primary-dark: #0d625e;
  --primary-soft: #e3f3f1;
  --accent: #c47a18;
  --correct: #237a4b;
  --correct-soft: #e5f4eb;
  --wrong: #b13b43;
  --wrong-soft: #fbe9ea;
  --focus: #0b67c2;
  --shadow: 0 12px 32px rgb(30 54 60 / 9%);
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  background: var(--bg);
  color: var(--text);
}

button,
select,
input {
  font: inherit;
}

button,
select {
  min-height: 44px;
}

button:focus-visible,
select:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.topbar {
  position: sticky;
  z-index: 10;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 58px;
  padding: 8px max(18px, calc((100vw - 1180px) / 2));
  border-bottom: 1px solid var(--line);
  background: rgb(255 255 255 / 96%);
}

.brand {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 750;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 30px;
  height: 30px;
  place-items: center;
  border-radius: 7px;
  background: var(--primary);
  color: white;
  font-weight: 850;
}

.save-status {
  color: var(--muted);
  font-size: 0.82rem;
}

.topbar-actions {
  display: flex;
  gap: 14px;
  align-items: center;
}

.app-switch {
  color: var(--primary-dark);
  font-size: 0.82rem;
  font-weight: 750;
  text-decoration: none;
}

.app-switch:hover {
  text-decoration: underline;
}

.app-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 28px;
  width: min(1180px, calc(100% - 36px));
  margin: 28px auto 52px;
}

.course-panel {
  align-self: start;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.course-cover {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 8;
  border-bottom: 1px solid var(--line);
  object-fit: cover;
  object-position: top;
}

.course-heading {
  padding: 18px 18px 14px;
}

.course-code,
.result-kicker {
  margin: 0 0 5px;
  color: var(--primary-dark);
  font-size: 0.76rem;
  font-weight: 800;
}

.course-heading h1 {
  margin: 0;
  font-size: 1.12rem;
  line-height: 1.35;
  letter-spacing: 0;
}

.course-heading p:last-child {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.settings-disclosure {
  border-top: 1px solid var(--line);
}

.settings-disclosure summary {
  display: none;
}

.settings-disclosure:not([open]) > .settings,
.settings {
  display: grid;
  gap: 7px;
  padding: 16px 18px 18px;
}

.settings-summary-hint {
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 600;
}

.settings label:not(.check-setting) {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
}

.settings select {
  width: 100%;
  padding: 0 38px 0 12px;
  border: 1px solid #aebbbe;
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
}

.check-setting {
  display: flex;
  gap: 9px;
  align-items: center;
  min-height: 44px;
  margin-top: 5px;
  color: var(--text);
  font-size: 0.87rem;
  font-weight: 650;
}

.check-setting input {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
}

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  margin: 0;
  border-top: 1px solid var(--line);
  background: var(--surface-muted);
}

.stats div {
  padding: 14px 18px;
}

.stats div + div {
  border-left: 1px solid var(--line);
}

.stats dt {
  color: var(--muted);
  font-size: 0.75rem;
}

.stats dd {
  margin: 4px 0 0;
  font-size: 1.08rem;
  font-weight: 800;
}

.quiz-panel {
  min-width: 0;
}

.quiz-progress {
  margin-bottom: 14px;
}

.progress-copy {
  display: flex;
  gap: 12px;
  justify-content: space-between;
  min-height: 22px;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 650;
}

.progress-track {
  overflow: hidden;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: #d9e1e2;
}

.progress-track span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--primary);
  transition: width 180ms ease;
}

.question-card {
  min-height: 505px;
  padding: clamp(22px, 4vw, 42px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.question-meta span {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 3px 9px;
  border-radius: 4px;
  background: var(--primary-soft);
  color: var(--primary-dark);
  font-size: 0.73rem;
  font-weight: 750;
}

.question-meta span:last-child {
  background: #f7eddd;
  color: #845314;
}

.question-card h2 {
  max-width: 760px;
  margin: 0 0 26px;
  font-size: clamp(1.18rem, 1.8vw, 1.55rem);
  line-height: 1.55;
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

.options {
  display: grid;
  gap: 10px;
}

.option-button {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 11px;
  align-items: center;
  width: 100%;
  min-height: 58px;
  padding: 10px 14px;
  border: 1px solid #b6c2c4;
  border-radius: 7px;
  background: white;
  color: var(--text);
  text-align: left;
  cursor: pointer;
}

.option-button:hover:not(:disabled) {
  border-color: var(--primary);
  background: #f7fbfa;
}

.option-button:disabled {
  cursor: default;
  opacity: 1;
}

.option-key {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--surface-muted);
  font-size: 0.82rem;
  font-weight: 800;
}

.option-text {
  min-width: 0;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.option-button.is-correct {
  border-color: var(--correct);
  background: var(--correct-soft);
}

.option-button.is-correct .option-key {
  border-color: var(--correct);
  background: var(--correct);
  color: white;
}

.option-button.is-wrong {
  border-color: var(--wrong);
  background: var(--wrong-soft);
}

.option-button.is-wrong .option-key {
  border-color: var(--wrong);
  background: var(--wrong);
  color: white;
}

.feedback {
  margin-top: 20px;
  padding: 16px 18px;
  border-left: 4px solid var(--primary);
  background: var(--surface-muted);
}

.feedback.is-correct {
  border-color: var(--correct);
  background: var(--correct-soft);
}

.feedback.is-wrong {
  border-color: var(--wrong);
  background: var(--wrong-soft);
}

.feedback p {
  margin: 0;
  line-height: 1.55;
}

.feedback p + p {
  margin-top: 7px;
}

.feedback-title {
  font-weight: 850;
}

.feedback-source {
  color: var(--muted);
  font-size: 0.78rem;
}

.question-nav,
.result-actions {
  display: flex;
  gap: 10px;
  justify-content: space-between;
  margin-top: 16px;
}

.button {
  min-width: 116px;
  padding: 0 18px;
  border-radius: 6px;
  font-weight: 750;
  cursor: pointer;
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.button-primary {
  border: 1px solid var(--primary);
  background: var(--primary);
  color: white;
}

.button-primary:hover:not(:disabled) {
  border-color: var(--primary-dark);
  background: var(--primary-dark);
}

.button-secondary {
  border: 1px solid #aebbbe;
  background: var(--surface);
  color: var(--text);
}

.button-secondary:hover:not(:disabled) {
  background: var(--surface-muted);
}

.result-view {
  min-height: 505px;
  padding: clamp(28px, 6vw, 68px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.result-view h2 {
  margin: 0;
  font-size: clamp(1.45rem, 3vw, 2.25rem);
  letter-spacing: 0;
}

.result-score {
  margin: 28px 0 6px;
  color: var(--primary-dark);
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  font-weight: 850;
  line-height: 1;
}

.result-message {
  max-width: 560px;
  margin: 18px 0 28px;
  color: var(--muted);
  line-height: 1.65;
}

.result-actions {
  justify-content: flex-start;
  flex-wrap: wrap;
}

.keyboard-hint {
  margin: 14px 2px 0;
  color: var(--muted);
  font-size: 0.76rem;
  text-align: right;
}

noscript {
  display: block;
  padding: 20px;
  text-align: center;
}

@media (max-width: 800px) {
  body {
    padding-bottom: calc(78px + env(safe-area-inset-bottom));
  }

  .app-shell {
    grid-template-columns: 1fr;
    gap: 18px;
    width: min(100% - 24px, 680px);
    margin-top: 14px;
  }

  .course-panel {
    display: grid;
    grid-template-columns: 110px minmax(0, 1fr);
  }

  .course-cover {
    grid-row: 1 / 3;
    height: 100%;
    aspect-ratio: auto;
    border-right: 1px solid var(--line);
    border-bottom: 0;
  }

  .course-heading {
    padding: 14px 15px 10px;
  }

  .settings-disclosure {
    grid-column: 2;
  }

  .settings-disclosure summary {
    display: flex;
    gap: 12px;
    align-items: center;
    justify-content: space-between;
    min-height: 48px;
    padding: 8px 15px;
    color: var(--primary-dark);
    font-size: 0.86rem;
    font-weight: 800;
    cursor: pointer;
    list-style: none;
  }

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

  .settings-disclosure summary::after {
    width: 8px;
    height: 8px;
    margin-left: auto;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    content: "";
    transform: rotate(45deg) translateY(-2px);
    transition: transform 160ms ease;
  }

  .settings-disclosure[open] summary::after {
    transform: rotate(225deg) translate(-2px, -2px);
  }

  .settings-disclosure:not([open]) > .settings {
    display: none;
  }

  .settings-disclosure[open] summary {
    border-bottom: 1px solid var(--line);
  }

  .settings {
    grid-template-columns: 74px minmax(0, 1fr);
    padding: 10px 15px 14px;
  }

  .settings label:not(.check-setting) {
    align-self: center;
    margin: 0;
  }

  .check-setting {
    grid-column: 1 / -1;
    min-height: 36px;
    margin: 0;
  }

  .stats {
    display: none;
  }

  .question-card,
  .result-view {
    min-height: 0;
  }

  .question-nav,
  .result-actions {
    position: fixed;
    z-index: 20;
    right: 0;
    bottom: 0;
    left: 0;
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 10px;
    margin: 0;
    padding: 10px max(12px, calc((100vw - 680px) / 2))
      calc(10px + env(safe-area-inset-bottom));
    border-top: 1px solid var(--line);
    background: rgb(255 255 255 / 96%);
    box-shadow: 0 -8px 24px rgb(30 54 60 / 12%);
    backdrop-filter: blur(12px);
  }

  .question-nav .button,
  .result-actions .button {
    width: 100%;
    min-width: 0;
  }
}

@media (max-width: 500px) {
  .topbar {
    min-height: 52px;
    padding: 7px 12px;
  }

  .brand {
    font-size: 0.88rem;
  }

  .brand-mark {
    width: 28px;
    height: 28px;
  }

  .save-status {
    font-size: 0.73rem;
  }

  .topbar-actions {
    gap: 9px;
  }

  .app-switch {
    font-size: 0.75rem;
  }

  .app-shell {
    width: calc(100% - 20px);
    margin-bottom: 18px;
  }

  .course-panel {
    grid-template-columns: 78px minmax(0, 1fr);
  }

  .course-heading h1 {
    font-size: 1rem;
  }

  .course-heading p:last-child {
    font-size: 0.8rem;
  }

  .settings {
    grid-template-columns: 58px minmax(0, 1fr);
    padding: 10px 12px 12px;
  }

  .question-card {
    padding: 21px 16px;
  }

  .question-card h2 {
    margin-bottom: 20px;
    font-size: 1.12rem;
  }

  .option-button {
    grid-template-columns: 30px minmax(0, 1fr);
    min-height: 56px;
    padding: 9px 10px;
  }

  .option-key {
    width: 29px;
    height: 29px;
  }

  .keyboard-hint {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}