:root {
  --red:    #dc2626;
  --red2:   #b91c1c;
  --gold:   #d97706;
  --bg:     #fffbf7;
  --card:   #ffffff;
  --ink:    #1a0808;
  --muted:  #6b5a4a;
  --line:   #f3e0cc;
  --shadow: 0 8px 28px rgba(180,60,0,.10);
  --radius: 16px;
  --radius2:12px;
  --focus:  0 0 0 4px rgba(220,38,38,.18);
}

* { box-sizing: border-box }

body {
  margin-top: 70px;
  font-family: 'Pretendard', ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(1000px 500px at 20% -10%, rgba(220,38,38,.10), transparent 60%),
    radial-gradient(800px 400px at 85% 5%, rgba(217,119,6,.08), transparent 55%),
    var(--bg);
}

/* ── 전체 래퍼 ── */
.wrap { max-width: 100%; padding: 0 0 60px }

/* ── 헤더 브랜드 ── */
.top { padding: 16px 0 20px }
.brand {
  display: flex;
  align-items: center;
  gap: 16px;
}
.logo {
  width: 48px; height: 48px;
  border-radius: 13px;
  background: linear-gradient(135deg, var(--red) 0%, var(--gold) 100%);
  display: flex; align-items: center; justify-content: center;
  font-size: 24px; font-weight: 900;
  color: #fff;
  flex-shrink: 0;
  box-shadow: 0 4px 14px rgba(220,38,38,.35);
}
.brand h1 { margin: 0; font-size: 22px; font-weight: 800; letter-spacing: -.03em }
.brand .sub { margin: 4px 0 0; font-size: 13px; color: var(--muted) }

/* ── 레벨 탭 ── */
.level-tabs {
  display: flex; gap: 8px; flex-wrap: wrap;
  margin: 0 0 14px;
}
.lvl-btn {
  padding: 8px 18px;
  border: 1.5px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  font-size: 14px; font-weight: 700;
  cursor: pointer; color: var(--muted);
  transition: all .18s;
}
.lvl-btn:hover { border-color: var(--red); color: var(--red) }
.lvl-btn.active {
  background: var(--red); border-color: var(--red);
  color: #fff;
}

/* ── 통계 바 ── */
.stats-bar {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius2);
  padding: 10px 16px;
  font-size: 13px; font-weight: 600;
  margin: 0 0 14px;
}
.stats-bar span { color: var(--muted) }
.reset-btn {
  margin-left: auto;
  background: none; border: 1.5px solid #e5e7eb;
  border-radius: 8px; padding: 4px 12px;
  font-size: 12px; cursor: pointer; color: var(--muted);
  transition: all .15s;
}
.reset-btn:hover { border-color: var(--red); color: var(--red) }

/* ── 모드 탭 ── */
.mode-tabs {
  display: flex; gap: 6px; flex-wrap: wrap;
  margin: 0 0 18px;
}
.mode-btn {
  padding: 8px 16px;
  border: 1.5px solid var(--line);
  background: var(--card);
  border-radius: 10px;
  font-size: 13px; font-weight: 600;
  cursor: pointer; color: var(--muted);
  transition: all .18s;
}
.mode-btn:hover { border-color: var(--gold); color: var(--gold) }
.mode-btn.active {
  background: var(--gold); border-color: var(--gold);
  color: #fff;
}

/* ── 단어 카드 그리드 ── */
.word-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
}
.word-card {
  background: var(--card);
  border: 1.5px solid var(--line);
  border-radius: var(--radius2);
  padding: 14px 12px;
  text-align: center;
  transition: border-color .15s;
}
.word-card:hover { border-color: var(--red) }
.word-card.correct { border-color: #22c55e; background: #f0fdf4 }
.word-card.wrong   { border-color: #ef4444; background: #fef2f2 }

.wc-char   { font-size: 22px; font-weight: 800; margin: 0 0 4px; color: var(--ink) }
.wc-pinyin { font-size: 12px; color: var(--red); margin: 0 0 4px; font-weight: 600 }
.wc-mean   { font-size: 12px; color: var(--muted) }

/* ── 플래시카드 ── */
.flash-nav {
  display: flex; justify-content: space-between; align-items: center;
  margin: 0 0 14px; font-size: 14px; font-weight: 600; color: var(--muted);
}
.flash-nav div { display: flex; gap: 8px }
.flash-nav button {
  padding: 7px 14px; border: 1.5px solid var(--line);
  background: var(--card); border-radius: 8px;
  font-size: 13px; cursor: pointer; font-weight: 600; color: var(--ink);
  transition: all .15s;
}
.flash-nav button:hover { border-color: var(--red); color: var(--red) }

.flash-card {
  background: var(--card);
  border: 2px solid var(--line);
  border-radius: 20px;
  min-height: 200px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  text-align: center;
  padding: 32px 24px;
  box-shadow: var(--shadow);
  transition: box-shadow .2s, transform .15s;
  margin: 0 0 16px;
  user-select: none;
}
.flash-card:hover { box-shadow: 0 12px 36px rgba(180,60,0,.15); transform: translateY(-2px) }
.flash-card.flipped { border-color: var(--red) }

.flash-front, .flash-back { width: 100% }
.flash-char   { font-size: 60px; font-weight: 900; color: var(--ink); margin: 0 0 8px }
.flash-hint   { font-size: 13px; color: var(--muted); margin: 0 }
.flash-pinyin { font-size: 18px; font-weight: 700; color: var(--red); margin: 0 0 10px }
.flash-meaning{ font-size: 28px; font-weight: 800; color: var(--ink) }

.flash-btns {
  display: flex; gap: 12px; justify-content: center;
}
.btn-wrong, .btn-correct {
  flex: 1; max-width: 180px;
  padding: 12px 0;
  border: none; border-radius: var(--radius2);
  font-size: 15px; font-weight: 700;
  cursor: pointer; transition: opacity .15s;
}
.btn-wrong   { background: #fef2f2; color: #dc2626 }
.btn-correct { background: #f0fdf4; color: #16a34a }
.btn-wrong:hover   { opacity: .8 }
.btn-correct:hover { opacity: .8 }

/* ── 퀴즈 ── */
.quiz-progress {
  display: flex; align-items: center; gap: 12px;
  margin: 0 0 14px;
}
.quiz-bar {
  flex: 1; height: 8px;
  background: var(--line); border-radius: 999px; overflow: hidden;
}
#quizBarFill {
  height: 100%; width: 0;
  background: linear-gradient(90deg, var(--red), var(--gold));
  border-radius: 999px;
  transition: width .3s;
}
.quiz-card {
  background: var(--card); border: 2px solid var(--line);
  border-radius: 20px; padding: 28px 24px;
  box-shadow: var(--shadow); margin: 0 0 14px;
  text-align: center;
}
.qchar   { font-size: 54px; font-weight: 900; margin: 0 0 8px }
.qpinyin { font-size: 16px; font-weight: 600; color: var(--red) }

.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px; margin-top: 20px;
}
.opt-btn {
  padding: 12px 8px;
  border: 1.5px solid var(--line);
  background: var(--card); border-radius: 12px;
  font-size: 14px; font-weight: 600;
  cursor: pointer; transition: all .15s;
}
.opt-btn:hover:not(:disabled) { border-color: var(--gold); background: #fffbf0 }
.opt-btn.opt-correct { background: #f0fdf4; border-color: #22c55e; color: #16a34a }
.opt-btn.opt-wrong   { background: #fef2f2; border-color: #ef4444; color: #dc2626 }
.opt-btn:disabled    { cursor: default }

.quiz-result {
  margin-top: 14px; padding: 10px 16px;
  border-radius: 10px; font-size: 14px; font-weight: 700;
}
.quiz-result.correct { background: #f0fdf4; color: #16a34a }
.quiz-result.wrong   { background: #fef2f2; color: #dc2626 }

.btn-next-quiz, .btn-restart-quiz {
  width: 100%; padding: 13px;
  border: none; border-radius: var(--radius2);
  font-size: 15px; font-weight: 700;
  cursor: pointer; margin-top: 4px;
  transition: opacity .15s;
}
.btn-next-quiz    { background: var(--red);  color: #fff }
.btn-restart-quiz { background: var(--gold); color: #fff }
.btn-next-quiz:hover, .btn-restart-quiz:hover { opacity: .85 }

/* ── 오답 노트 ── */
.wrong-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
}
.wrong-card {
  background: #fef2f2; border: 1.5px solid #fca5a5;
  border-radius: var(--radius2); padding: 14px 12px;
  text-align: center;
}
.empty-msg {
  text-align: center; color: var(--muted);
  font-size: 14px; padding: 40px 0;
}

/* ── 사용 안내 섹션 공통 ── */
.guide-section {
  margin-top: 28px;
  background: rgba(246,248,255,.6);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}
.guide-section h2 {
  font-size: 15px; font-weight: 800;
  margin: 0 0 10px; color: var(--ink);
}
.guide-section h2:not(:first-child) { margin-top: 18px }
.guide-steps, .guide-features, .guide-usecase {
  margin: 0; padding-left: 18px;
  color: var(--muted); font-size: 13px; line-height: 1.8;
}
.guide-steps li, .guide-features li, .guide-usecase li { margin-bottom: 4px }
.guide-steps strong, .guide-features strong { color: var(--ink) }
.guide-privacy {
  margin-top: 16px;
  background: #eff6ff; border: 1px solid rgba(37,99,235,.22);
  border-radius: 12px; padding: 12px 14px;
  font-size: 12px; color: #1e40af; line-height: 1.55;
}

/* ── 반응형 ── */
@media (max-width: 600px) {
  .flash-char  { font-size: 44px }
  .qchar       { font-size: 40px }
  .quiz-options { grid-template-columns: 1fr }
  .word-grid   { grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)) }
}