/* ================================================
   Stock Beginner - Master CSS Reset & Universal Design System
   ================================================ */

:root {
  --bg-dark: #0b0f19;
  --bg-card: rgba(30, 41, 59, 0.55);
  --text-main: #f8fafc;
  --text-muted: #cbd5e1;
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-green: #10b981;
}

* {
  box-sizing: border-box;
  margin: 0; padding: 0;
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  -webkit-tap-highlight-color: transparent;
}

/* GLOBAL BUTTON RESET FIX */
button {
  background: none;
  border: none;
  color: inherit;
  font: inherit;
  cursor: pointer;
  outline: none;
  -webkit-appearance: none;
  appearance: none;
}

/* CRITICAL DISPLAY ENGINE FIX */
.hidden {
  display: none !important;
}

body {
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  transition: all 0.25s ease;
}

.glass-card:hover {
  border-color: rgba(99, 102, 241, 0.4);
  transform: translateY(-3px);
}

/* Top Navbar */
.navbar {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  padding: 16px 0; background: rgba(11, 15, 25, 0.95);
  backdrop-filter: blur(16px); border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-inner { display: flex; justify-content: space-between; align-items: center; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.nav-logo { display: flex; align-items: center; gap: 8px; text-decoration: none; color: #fff; font-size: 1.3rem; font-weight: 800; }
.nav-links { display: flex; list-style: none; gap: 12px; align-items: center; }
.nav-link { text-decoration: none; color: #cbd5e1; font-weight: 600; font-size: 0.95rem; padding: 6px 14px; border-radius: 12px; white-space: nowrap; }
.nav-link:hover { color: #60a5fa; background: rgba(255, 255, 255, 0.06); }
.nav-hamburger { display: none; background: transparent; border: none; cursor: pointer; flex-direction: column; gap: 5px; padding: 5px; z-index: 1001; }
.nav-hamburger span { display: block; width: 24px; height: 2px; background-color: #fff; border-radius: 2px; }

/* Hero Section */
.hero { position: relative; min-height: 70vh; display: flex; align-items: center; justify-content: center; text-align: center; padding: 120px 20px 50px; }
.hero-bg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; z-index: 1; }
.hero-orb { position: absolute; border-radius: 50%; filter: blur(100px); opacity: 0.25; }
.orb-1 { top: 5%; left: 15%; width: 300px; height: 300px; background: #6366f1; }
.orb-2 { bottom: 10%; right: 15%; width: 350px; height: 350px; background: #3b82f6; }
.orb-3 { top: 40%; right: 30%; width: 250px; height: 250px; background: #ec4899; }

.hero-content { position: relative; z-index: 2; max-width: 850px; width: 100%; }
.hero-badge { display: inline-block; padding: 6px 18px; background: rgba(99, 102, 241, 0.15); border: 1px solid rgba(99, 102, 241, 0.3); border-radius: 30px; color: #a5b4fc; font-size: 0.88rem; font-weight: 600; margin-bottom: 20px; }
.hero-title { font-size: 3rem; font-weight: 900; line-height: 1.25; margin-bottom: 18px; letter-spacing: -1px; }
.gradient-text { background: linear-gradient(135deg, #60a5fa 0%, #a78bfa 50%, #f472b6 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero-desc { font-size: 1.1rem; color: #cbd5e1; margin-bottom: 30px; }

/* SEARCH BOX */
.hero-search-wrap { position: relative; max-width: 650px; margin: 0 auto 35px; width: 100%; }
.hero-search-box { display: flex; align-items: center; padding: 6px 8px 6px 20px; background: rgba(30, 41, 59, 0.8); border: 1px solid rgba(99, 102, 241, 0.5); border-radius: 16px; }
.search-box-icon { margin-right: 10px; font-size: 1.1rem; }
.hero-search-box input { width: 100%; background: transparent; border: none; outline: none; color: #fff; font-size: 1.05rem; padding: 10px 0; }
.hero-search-btn { background: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%) !important; border: none !important; color: #fff !important; padding: 12px 24px !important; border-radius: 12px !important; font-weight: 700 !important; cursor: pointer !important; white-space: nowrap !important; }

.hero-search-dropdown { position: absolute; top: 105%; left: 0; width: 100%; background: rgba(15, 23, 42, 0.98); backdrop-filter: blur(25px); border: 1px solid rgba(99, 102, 241, 0.4); border-radius: 16px; box-shadow: 0 20px 50px rgba(0,0,0,0.8); z-index: 100; max-height: 350px; overflow-y: auto; text-align: left; padding: 8px 0; }

.search-res-item { display: flex; justify-content: space-between; align-items: center; padding: 14px 20px; cursor: pointer; border-bottom: 1px solid rgba(255,255,255,0.05); }
.search-res-item:hover { background: rgba(99, 102, 241, 0.25); }
.search-res-title { font-weight: 700; color: #f1f5f9; font-size: 0.98rem; }
.search-res-desc { font-size: 0.83rem; color: #94a3b8; margin-top: 2px; }
.search-res-tag { background: rgba(59, 130, 246, 0.2); color: #60a5fa; padding: 4px 10px; border-radius: 10px; font-size: 0.75rem; font-weight: 600; }

.hero-keywords-recommend { display: flex; align-items: center; justify-content: center; gap: 8px; flex-wrap: wrap; margin-top: 12px; font-size: 0.85rem; color: #94a3b8; }
.tag-btn { background: rgba(255, 255, 255, 0.08) !important; border: 1px solid rgba(255, 255, 255, 0.15) !important; color: #cbd5e1 !important; padding: 6px 14px !important; border-radius: 16px !important; font-size: 0.84rem !important; cursor: pointer !important; }
.tag-btn:hover { background: rgba(99, 102, 241, 0.25) !important; color: #fff !important; }

.hero-stats { display: flex; justify-content: center; align-items: center; gap: 30px; margin-bottom: 30px; flex-wrap: wrap; }
.stat-item { text-align: center; }
.stat-num { font-size: 2.2rem; font-weight: 800; color: #60a5fa; }
.stat-label { display: block; font-size: 0.85rem; color: #cbd5e1; }
.stat-divider { width: 1px; height: 35px; background: rgba(255, 255, 255, 0.1); }

/* Sections Layout */
.section { padding: 75px 0; }
.section-dark { background: rgba(0, 0, 0, 0.25); }
.section-header { text-align: center; margin-bottom: 40px; }
.section-tag { color: #60a5fa; font-weight: 700; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 2px; margin-bottom: 8px; }
.section-title { font-size: 2.2rem; font-weight: 800; margin-bottom: 10px; }
.section-sub { color: #cbd5e1; font-size: 1.05rem; }

/* 30-DAY SINGLE CARD FLIP DESIGN */
.daily-box { padding: 35px; }
.daily-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 25px; flex-wrap: wrap; gap: 15px; }
.daily-date-badge { font-weight: 700; color: #60a5fa; font-size: 1.05rem; }
.progress-bar-bg { width: 220px; height: 10px; background: rgba(255, 255, 255, 0.1); border-radius: 5px; overflow: hidden; margin-top: 6px; }
.progress-bar-fill { height: 100%; background: linear-gradient(90deg, #60a5fa, #10b981); transition: width 0.3s ease; }

.daily-card-wrap { display: flex; align-items: center; gap: 20px; margin-bottom: 30px; }
.daily-nav-btn {
  background: rgba(255, 255, 255, 0.1) !important; border: 1px solid rgba(255, 255, 255, 0.2) !important; color: #fff !important;
  width: 50px !important; height: 50px !important; border-radius: 50% !important; cursor: pointer !important; font-size: 1.2rem !important; flex-shrink: 0 !important;
  display: flex !important; align-items: center !important; justify-content: center !important; transition: all 0.2s ease !important;
}
.daily-nav-btn:hover { background: #6366f1 !important; border-color: transparent !important; transform: scale(1.08) !important; }

.daily-concept-card {
  flex: 1; background: rgba(15, 23, 42, 0.85); border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: 24px; padding: 35px; position: relative; box-shadow: 0 15px 40px rgba(0,0,0,0.5);
}

.concept-day-tag { position: absolute; top: 25px; right: 25px; background: rgba(99, 102, 241, 0.25); color: #a5b4fc; padding: 6px 16px; border-radius: 14px; font-size: 0.9rem; font-weight: 800; }
.concept-card-icon { font-size: 3rem; margin-bottom: 15px; }
.concept-card-title { font-size: 1.8rem; font-weight: 900; color: #f1f5f9; margin-bottom: 6px; }
.concept-card-category { color: #60a5fa; font-weight: 700; font-size: 0.95rem; margin-bottom: 18px; }
.concept-card-summary { font-size: 1.1rem; color: #f1f5f9; line-height: 1.65; margin-bottom: 25px; }

.concept-card-detail { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin-bottom: 25px; }
.detail-box { background: rgba(255, 255, 255, 0.05); border-left: 4px solid #6366f1; padding: 16px; border-radius: 12px; font-size: 0.95rem; color: #f1f5f9; }
.detail-box.example { border-left-color: #f59e0b; }
.detail-box strong { display: block; color: #60a5fa; margin-bottom: 6px; }

.daily-action-btns { display: flex; gap: 15px; flex-wrap: wrap; }
.btn-check-learn {
  background: rgba(16, 185, 129, 0.2) !important; border: 1px solid #10b981 !important; color: #66bb6a !important;
  padding: 14px 28px !important; border-radius: 25px !important; font-weight: 800 !important; font-size: 1.05rem !important; cursor: pointer !important; flex: 1 !important;
}
.btn-check-learn.learned { background: #10b981 !important; color: #fff !important; border-color: transparent !important; }
.btn-random-concept { background: rgba(255, 255, 255, 0.08) !important; border: 1px solid rgba(255, 255, 255, 0.18) !important; color: #cbd5e1 !important; padding: 14px 24px !important; border-radius: 25px !important; font-weight: 700 !important; cursor: pointer !important; }

.concept-list-drawer { border-top: 1px solid rgba(255, 255, 255, 0.1); padding-top: 20px; margin-top: 10px; }
.drawer-header { margin-bottom: 15px; font-size: 1rem; color: #cbd5e1; }
.concept-chips { display: flex; gap: 10px; overflow-x: auto; padding-bottom: 10px; -webkit-overflow-scrolling: touch; }
.concept-chip { background: rgba(255, 255, 255, 0.08) !important; border: 1px solid rgba(255, 255, 255, 0.15) !important; color: #cbd5e1 !important; padding: 8px 18px !important; border-radius: 20px !important; font-size: 0.88rem !important; font-weight: 600 !important; cursor: pointer !important; white-space: nowrap !important; flex-shrink: 0 !important; }
.concept-chip.active { background: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%) !important; color: #fff !important; font-weight: 800 !important; border-color: transparent !important; }
.concept-chip.is-learned { border-color: #10b981 !important; }

/* FILTER BUTTONS STYLING (GUARANTEED NO WHITE BUTTON FALLBACK!) */
.chart-tab-btn, .slang-filter-btn, .term-filter-btn, .day-filter-btn {
  background: rgba(30, 41, 59, 0.8) !important;
  border: 1px solid rgba(255, 255, 255, 0.18) !important;
  color: #cbd5e1 !important;
  padding: 10px 22px !important;
  border-radius: 25px !important;
  font-size: 0.9rem !important;
  font-weight: 600 !important;
  cursor: pointer !important;
  white-space: nowrap !important;
  flex-shrink: 0 !important;
  transition: all 0.2s ease !important;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2) !important;
}

.chart-tab-btn:hover, .slang-filter-btn:hover, .term-filter-btn:hover, .day-filter-btn:hover {
  background: rgba(99, 102, 241, 0.25) !important;
  border-color: rgba(99, 102, 241, 0.5) !important;
  color: #ffffff !important;
}

.chart-tab-btn.active, .slang-filter-btn.active, .term-filter-btn.active, .day-filter-btn.active {
  background: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%) !important;
  border-color: transparent !important;
  color: #ffffff !important;
  font-weight: 800 !important;
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5) !important;
}

.day-filter-menu, .slang-filter-menu, .chart-tab-menu, .terms-filter-menu {
  display: flex; gap: 10px; overflow-x: auto; padding-bottom: 10px; justify-content: flex-start; -webkit-overflow-scrolling: touch; margin-bottom: 25px;
}

@media (min-width: 768px) {
  .day-filter-menu, .slang-filter-menu, .chart-tab-menu, .terms-filter-menu { justify-content: center; }
}

/* Chart Master & 20+ Slang Grid */
.chart-tab-content { display: none; }
.chart-tab-content.active { display: block; }
.guide-grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.guide-card { padding: 26px; cursor: pointer; }
.card-badge-top { display: inline-block; padding: 4px 10px; border-radius: 10px; font-size: 0.75rem; font-weight: 700; background: rgba(99, 102, 241, 0.2); color: #a5b4fc; margin-bottom: 12px; }
.guide-summary { font-size: 0.92rem; color: #cbd5e1; margin-bottom: 16px; }

.candle-visual-preview, .trend-visual-preview { display: flex; flex-direction: column; gap: 10px; margin-bottom: 16px; }
.candle-box, .trend-line-info { padding: 12px 14px; border-radius: 12px; font-size: 0.88rem; display: flex; justify-content: space-between; align-items: center; }
.candle-box.red, .trend-line-info.red { background: rgba(239, 68, 68, 0.15); border: 1px solid rgba(239, 68, 68, 0.3); color: #f87171; }
.candle-box.blue, .trend-line-info.green { background: rgba(59, 130, 246, 0.15); border: 1px solid rgba(59, 130, 246, 0.3); color: #60a5fa; }
.card-click-prompt { font-size: 0.85rem; color: #a5b4fc; font-weight: 700; }

.slang-grid, .terms-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.slang-card, .term-card { padding: 24px; cursor: pointer; border-radius: 18px; }
.slang-badge, .term-badge { display: inline-block; padding: 4px 10px; border-radius: 10px; font-size: 0.75rem; font-weight: 700; background: rgba(99, 102, 241, 0.2); color: #a5b4fc; margin-bottom: 10px; }
.slang-emoji { font-size: 2rem; margin-bottom: 6px; }
.slang-title, .term-title { font-size: 1.25rem; font-weight: 800; color: #f1f5f9; margin-bottom: 4px; }
.slang-origin, .term-eng { font-size: 0.85rem; color: #60a5fa; margin-bottom: 10px; font-weight: 600; }
.slang-desc, .term-summary { font-size: 0.9rem; color: #cbd5e1; line-height: 1.55; margin-bottom: 16px; }

.terms-search-bar { display: flex; align-items: center; padding: 10px 20px; margin-bottom: 25px; }
.terms-search-bar input { width: 100%; background: transparent; border: none; outline: none; color: #fff; font-size: 1rem; margin-left: 10px; }
.clear-search-btn { background: transparent; border: none; color: #94a3b8; font-size: 0.9rem; cursor: pointer; }

/* Live News Grid */
.news-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.news-header-bar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.news-live-indicator { display: flex; align-items: center; gap: 8px; font-weight: 600; color: #cbd5e1; }
.live-dot { width: 10px; height: 10px; background-color: #ef4444; border-radius: 50%; box-shadow: 0 0 10px #ef4444; }
.btn-refresh-news { background: rgba(255, 255, 255, 0.08) !important; border: 1px solid rgba(255, 255, 255, 0.15) !important; color: #fff !important; padding: 8px 16px !important; border-radius: 18px !important; cursor: pointer !important; font-size: 0.88rem !important; }
.news-card { padding: 22px; cursor: pointer; }
.news-card-top { display: flex; justify-content: space-between; margin-bottom: 10px; }
.news-tag { background: rgba(99, 102, 241, 0.2); color: #818cf8; padding: 4px 10px; border-radius: 10px; font-size: 0.75rem; font-weight: 700; }
.news-time { font-size: 0.78rem; color: #94a3b8; }
.news-title { font-size: 1.05rem; font-weight: 700; color: #f1f5f9; margin-bottom: 8px; line-height: 1.45; }
.news-snippet { font-size: 0.88rem; color: #cbd5e1; margin-bottom: 14px; }
.news-footer { display: flex; justify-content: space-between; font-size: 0.82rem; color: #94a3b8; }

/* Quiz Section Clean Single-State Engine */
.quiz-container { padding: 35px; text-align: center; }
.quiz-step-box { text-align: center; }
.quiz-intro-icon { font-size: 3.5rem; margin-bottom: 15px; }
.btn-start-quiz, .btn-retry-quiz { background: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%) !important; color: #fff !important; border: none !important; padding: 14px 32px !important; border-radius: 25px !important; font-size: 1.05rem !important; font-weight: 700 !important; cursor: pointer !important; }
.quiz-opt-btn { display: flex !important; align-items: center !important; gap: 12px !important; width: 100% !important; padding: 16px 20px !important; background: rgba(255, 255, 255, 0.05) !important; border: 1px solid rgba(255, 255, 255, 0.12) !important; border-radius: 14px !important; color: #f1f5f9 !important; font-size: 1rem !important; text-align: left !important; cursor: pointer !important; margin-bottom: 12px !important; }
.quiz-opt-btn.correct { background: rgba(16, 185, 129, 0.25) !important; border-color: #10b981 !important; color: #66bb6a !important; font-weight: 700 !important; }
.quiz-opt-btn.wrong { background: rgba(239, 68, 68, 0.25) !important; border-color: #ef4444 !important; color: #f87171 !important; }
.quiz-feedback-box { background: rgba(255, 255, 255, 0.05); border: 1px solid rgba(255, 255, 255, 0.12); padding: 20px; border-radius: 16px; margin-top: 20px; text-align: left; }
.btn-next-quiz { background: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%) !important; color: #fff !important; border: none !important; padding: 12px 24px !important; border-radius: 25px !important; font-size: 0.95rem !important; font-weight: 700 !important; cursor: pointer !important; margin-top: 15px !important; }

/* Universal Modal Popup */
.term-modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0, 0, 0, 0.85); backdrop-filter: blur(16px); z-index: 3000; display: flex; align-items: center; justify-content: center; padding: 15px; }
.term-modal-card { width: 100%; max-width: 650px; max-height: 90vh; overflow-y: auto; padding: 30px; position: relative; background: rgba(15, 23, 42, 0.98); border-radius: 24px; border: 1px solid rgba(99, 102, 241, 0.4); box-shadow: 0 25px 60px rgba(0,0,0,0.9); }
.modal-close-btn { position: absolute; top: 20px; right: 20px; background: transparent; border: none; color: #94a3b8; font-size: 1.6rem; cursor: pointer; }
.modal-section-box { background: rgba(255, 255, 255, 0.05); padding: 18px; border-radius: 16px; margin-bottom: 16px; border: 1px solid rgba(255, 255, 255, 0.08); }
.modal-section-box.grid-2-col { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.modal-section-box h5 { color: #60a5fa; font-size: 0.95rem; font-weight: 800; margin-bottom: 8px; }
.modal-section-box p { font-size: 0.95rem; color: #f1f5f9; line-height: 1.6; }

.footer { border-top: 1px solid rgba(255, 255, 255, 0.08); padding: 35px 0; text-align: center; color: #64748b; font-size: 0.9rem; }

/* Mobile Responsive Engine */
@media (max-width: 992px) {
  .nav-hamburger { display: flex; }
  .nav-links { position: absolute; top: 100%; left: 0; width: 100%; background: rgba(11, 15, 25, 0.98); backdrop-filter: blur(25px); flex-direction: column; padding: 20px 0; gap: 10px; display: none; }
  .nav-links.open { display: flex; }
  .nav-link { width: 90%; text-align: center; padding: 12px 0; }

  .hero-title { font-size: 2rem; }
  .hero-search-box { flex-direction: column; gap: 8px; padding: 10px; }
  .hero-search-btn { width: 100%; }

  .daily-card-wrap { flex-direction: column; }
  .daily-concept-card { padding: 22px 18px; }
  .concept-card-title { font-size: 1.4rem; }
  .concept-card-detail { grid-template-columns: 1fr; }

}

/* Beginner Starter Roadmap & Mistake Prevention Styles */
.starter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
  margin-top: 30px;
}
.starter-card {
  position: relative;
  padding: 30px 24px 24px;
  border-radius: 20px;
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.12);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.starter-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px rgba(59, 130, 246, 0.2);
  border-color: rgba(59, 130, 246, 0.4);
}
.starter-step-number {
  position: absolute;
  top: -12px;
  left: 20px;
  background: linear-gradient(135deg, #3b82f6, #6366f1);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 12px;
  border-radius: 20px;
  letter-spacing: 0.5px;
}
.starter-icon {
  font-size: 2.2rem;
  margin-bottom: 12px;
}
.starter-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: #f8fafc;
  margin-bottom: 10px;
}
.starter-card p {
  font-size: 0.92rem;
  color: #cbd5e1;
  line-height: 1.6;
  margin-bottom: 15px;
}
.starter-tip {
  background: rgba(59, 130, 246, 0.1);
  border-left: 3px solid #3b82f6;
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 0.85rem;
  color: #93c5fd;
  line-height: 1.5;
}

.mistakes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 22px;
  margin-top: 30px;
}
.mistake-card {
  padding: 26px;
  border-radius: 20px;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid rgba(239, 68, 68, 0.25);
  transition: transform 0.3s ease, border-color 0.3s ease;
}
.mistake-card:hover {
  transform: translateY(-4px);
  border-color: rgba(239, 68, 68, 0.5);
  box-shadow: 0 12px 30px rgba(239, 68, 68, 0.15);
}
.mistake-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}
.mistake-badge {
  background: rgba(239, 68, 68, 0.2);
  color: #fca5a5;
  border: 1px solid rgba(239, 68, 68, 0.4);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 12px;
  white-space: nowrap;
}
.mistake-header h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: #f8fafc;
}
.mistake-desc {
  font-size: 0.92rem;
  color: #cbd5e1;
  line-height: 1.6;
  margin-bottom: 16px;
}
.mistake-solution {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.25);
  border-radius: 12px;
  padding: 12px 14px;
  font-size: 0.88rem;
  color: #6ee7b7;
  line-height: 1.5;
}