:root {
  --bg-top: #f8f2dc;
  --bg-bottom: #f3d8b5;
  --panel: rgba(255, 250, 241, 0.78);
  --panel-strong: rgba(255, 248, 236, 0.92);
  --line: rgba(110, 75, 28, 0.14);
  --text: #2f2418;
  --muted: #6b5741;
  --accent: #d95d39;
  --accent-deep: #9f3417;
  --success: #2f8f5b;
  --error: #c44536;
  --shadow: 0 20px 60px rgba(101, 66, 22, 0.16);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Noto Sans KR", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.72), transparent 30%),
    radial-gradient(circle at bottom right, rgba(217, 93, 57, 0.18), transparent 26%),
    linear-gradient(160deg, var(--bg-top), var(--bg-bottom));
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.18) 1px, transparent 1px);
  background-size: 36px 36px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.44), transparent 85%);
}

.app-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 40px 0 56px;
}

.hero-card,
.quiz-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--panel);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
}

.hero-card {
  padding: 36px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.65), rgba(255, 246, 231, 0.92)),
    var(--panel-strong);
}

.hero-card::after,
.quiz-card::after {
  content: "";
  position: absolute;
  right: -36px;
  top: -36px;
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(217, 93, 57, 0.18), transparent 68%);
}

.eyebrow,
.card-label {
  margin: 0 0 10px;
  color: var(--accent-deep);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-family: "Black Han Sans", sans-serif;
  font-size: clamp(2.2rem, 4vw, 4.1rem);
  line-height: 1.04;
  letter-spacing: 0.01em;
}

.hero-copy {
  max-width: 720px;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.7;
}

.hero-actions,
.form-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-actions {
  margin-top: 24px;
}

button,
input {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
  transition:
    transform 140ms ease,
    opacity 140ms ease,
    box-shadow 140ms ease,
    background-color 140ms ease;
}

button:hover:not(:disabled) {
  transform: translateY(-1px);
}

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

.primary-button,
.ghost-button {
  min-width: 132px;
  border-radius: 999px;
  padding: 14px 22px;
  font-weight: 700;
}

.primary-button {
  color: #fff9f0;
  background: linear-gradient(135deg, var(--accent), var(--accent-deep));
  box-shadow: 0 12px 26px rgba(159, 52, 23, 0.25);
}

.ghost-button {
  color: var(--accent-deep);
  background: rgba(255, 255, 255, 0.64);
  border: 1px solid rgba(159, 52, 23, 0.18);
}

.quiz-grid {
  display: grid;
  grid-template-columns: 1.1fr 1.2fr;
  gap: 18px;
  margin-top: 18px;
}

.quiz-card {
  padding: 28px;
}

.kana-card,
.control-card {
  min-height: 320px;
}

.status-card,
.note-card {
  min-height: 240px;
}

.kana-display {
  display: grid;
  place-items: center;
  min-height: 170px;
  margin-top: 10px;
  border-radius: 24px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.72), rgba(255, 246, 232, 0.9)),
    rgba(255, 255, 255, 0.6);
  border: 1px solid rgba(110, 75, 28, 0.08);
  font-family: "Black Han Sans", sans-serif;
  font-size: clamp(5rem, 12vw, 8rem);
  letter-spacing: 0.04em;
}

.question-hint {
  margin: 16px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.answer-form {
  display: grid;
  gap: 14px;
  margin-top: 14px;
}

.answer-input {
  width: 100%;
  border: 1px solid rgba(110, 75, 28, 0.14);
  border-radius: 18px;
  padding: 16px 18px;
  background: rgba(255, 255, 255, 0.82);
  color: var(--text);
  font-size: 1rem;
  outline: none;
}

.answer-input:focus {
  border-color: rgba(217, 93, 57, 0.6);
  box-shadow: 0 0 0 4px rgba(217, 93, 57, 0.12);
}

.feedback-panel {
  margin-top: 18px;
  padding: 18px;
  border-radius: 22px;
  line-height: 1.7;
  border: 1px solid transparent;
}

.feedback-panel.neutral {
  color: var(--muted);
  background: rgba(255, 255, 255, 0.56);
}

.feedback-panel.correct {
  color: #184f32;
  background: rgba(47, 143, 91, 0.12);
  border-color: rgba(47, 143, 91, 0.18);
}

.feedback-panel.wrong {
  color: #6e1f16;
  background: rgba(196, 69, 54, 0.12);
  border-color: rgba(196, 69, 54, 0.18);
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 14px;
}

.stat-item {
  padding: 16px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.66);
  border: 1px solid rgba(110, 75, 28, 0.08);
}

.stat-name {
  display: block;
  color: var(--muted);
  font-size: 0.9rem;
}

.stat-item strong {
  display: block;
  margin-top: 8px;
  font-size: 1.9rem;
}

.progress-area {
  margin-top: 22px;
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
  font-size: 0.95rem;
}

.progress-bar {
  height: 14px;
  margin-top: 10px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid rgba(110, 75, 28, 0.08);
}

.progress-fill {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), #f39b6d);
  transition: width 220ms ease;
}

.note-list {
  margin: 14px 0 0;
  padding-left: 18px;
  color: var(--muted);
  line-height: 1.8;
}

.note-list span,
.note-list strong {
  color: var(--text);
}

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

@media (max-width: 860px) {
  .app-shell {
    width: min(100% - 24px, 720px);
    padding-top: 24px;
  }

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

  .hero-card,
  .quiz-card {
    padding: 22px;
    border-radius: 24px;
  }

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

  .kana-display {
    min-height: 150px;
    font-size: clamp(4rem, 24vw, 6.4rem);
  }
}