/*
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Copyright (c) 2026 Ahngunism. All rights reserved.
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File           : style.css
Last updated:  : 20260309 015200
Version        : ver 3
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*/

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800&family=Noto+Sans+JP:wght@400;700&family=Noto+Sans+KR:wght@400;500;700&display=swap');

/* ========== DESIGN TOKENS ========== */
:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-card: rgba(17, 24, 39, 0.7);
    --bg-card-hover: rgba(30, 41, 59, 0.8);
    --glass-border: rgba(99, 102, 241, 0.15);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);

    --accent-primary: #818cf8;
    --accent-secondary: #a78bfa;
    --accent-glow: rgba(129, 140, 248, 0.3);
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --accent-gradient-hover: linear-gradient(135deg, #764ba2 0%, #667eea 100%);

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --correct-bg: rgba(52, 211, 153, 0.15);
    --correct-border: #34d399;
    --incorrect-bg: rgba(251, 113, 133, 0.15);
    --incorrect-border: #fb7185;
    --neutral-bg: rgba(148, 163, 184, 0.1);
    --neutral-border: rgba(148, 163, 184, 0.3);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;

    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========== RESET & BASE ========== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 24px 16px;
    overflow-x: hidden;
    position: relative;
}

/* ========== ANIMATED BACKGROUND ========== */
body::before {
    content: '';
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(99, 102, 241, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(167, 139, 250, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 80%, rgba(236, 72, 153, 0.04) 0%, transparent 50%);
    animation: bgShift 20s ease-in-out infinite alternate;
    z-index: -1;
}

@keyframes bgShift {
    0% { transform: translate(0, 0) rotate(0deg); }
    100% { transform: translate(-5%, -5%) rotate(3deg); }
}

/* ========== STARS ========== */
.stars {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: white;
    border-radius: 50%;
    animation: twinkle var(--duration) ease-in-out infinite alternate;
    opacity: 0;
}

@keyframes twinkle {
    0% { opacity: 0; transform: scale(0.5); }
    100% { opacity: var(--max-opacity); transform: scale(1); }
}

/* ========== HERO ========== */
.hero {
    text-align: center;
    margin-bottom: 8px;
}

.hero-moon {
    font-size: 4rem;
    margin-bottom: 8px;
    animation: moonFloat 4s ease-in-out infinite;
    filter: drop-shadow(0 0 20px rgba(251, 191, 36, 0.3));
}

@keyframes moonFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.hero h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #f1f5f9, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
    margin-bottom: 8px;
}

.hero p {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 400;
}

/* ========== GLASS CARD ========== */
.glass-card {
    width: 100%;
    max-width: 640px;
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--glass-shadow);
    transition: border-color var(--transition-smooth);
}

.glass-card:hover {
    border-color: rgba(99, 102, 241, 0.3);
}

/* ========== FORM OPTIONS ========== */
.option-section {
    margin-bottom: 28px;
}

.option-section:last-of-type {
    margin-bottom: 0;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
}

.option-label-icon {
    font-size: 1.1rem;
}

.option-group {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.option-group input[type="radio"] {
    display: none;
}

.option-group label {
    flex: 1;
    min-width: 80px;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    background: var(--neutral-bg);
    border: 1.5px solid var(--neutral-border);
    color: var(--text-secondary);
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    font-size: 0.95rem;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.option-group label:hover {
    background: rgba(99, 102, 241, 0.08);
    border-color: rgba(99, 102, 241, 0.3);
    color: var(--text-primary);
}

.option-group input[type="radio"]:checked + label {
    background: var(--accent-gradient);
    border-color: transparent;
    color: white;
    font-weight: 600;
    box-shadow: 0 4px 15px var(--accent-glow);
    transform: translateY(-1px);
}

/* ========== CTA BUTTON ========== */
.cta-button {
    width: 100%;
    padding: 16px;
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    color: white;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 20px var(--accent-glow);
    margin-top: 28px;
    position: relative;
    overflow: hidden;
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0; left: -100%;
    width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent);
    transition: left 0.5s;
}

.cta-button:hover::before {
    left: 100%;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.cta-button:active {
    transform: translateY(0) scale(0.98);
}

/* ========== CHART TOGGLE ========== */
.chart-toggle {
    width: 100%;
    max-width: 800px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 28px;
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-top: 24px;
}

.chart-toggle:hover {
    border-color: rgba(99, 102, 241, 0.3);
}

.chart-toggle h2 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
}

.chart-toggle-arrow {
    font-size: 1rem;
    color: var(--accent-primary);
    transition: transform var(--transition-smooth);
}

.chart-toggle.expanded .chart-toggle-arrow {
    transform: rotate(180deg);
}

/* ========== CHART PANEL ========== */
.chart-panel {
    width: 100%;
    max-width: 800px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease-in-out;
}

.chart-panel.expanded {
    max-height: 3000px;
}

.chart-panel-inner {
    padding-top: 16px;
}

/* ========== CHART TABS ========== */
.chart-tabs {
    display: flex;
    gap: 4px;
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    padding: 4px;
    margin-bottom: 20px;
}

.chart-tab {
    flex: 1;
    padding: 10px 16px;
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-secondary);
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.chart-tab:hover {
    color: var(--text-primary);
}

.chart-tab.active {
    background: var(--accent-gradient);
    color: white;
    font-weight: 600;
}

.chart-box { display: none; }
.chart-box.active { display: block; }

/* ========== KANA GRID ========== */
.section-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    text-align: center;
    padding-bottom: 8px;
    margin-bottom: 12px;
    border-bottom: 1px solid var(--glass-border);
}

.kana-grid {
    display: grid;
    gap: 6px;
    margin-bottom: 28px;
}

.kana-grid.cols-5 { grid-template-columns: repeat(5, 1fr); }
.kana-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }

.kana-cell {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 52px;
    border-radius: var(--radius-sm);
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--neutral-bg);
    border: 1.5px solid var(--neutral-border);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
    user-select: none;
}

.kana-cell:hover:not(.empty) {
    background: rgba(99, 102, 241, 0.15);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--accent-glow);
}

.kana-cell.empty {
    background: transparent;
    border-color: transparent;
    cursor: default;
}

.kana-cell.show-kr {
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 1.2rem;
}

.kana-cell.fade-out {
    opacity: 0;
    transition: opacity 0.25s;
}

/* ========== QUIZ ========== */
.quiz-container {
    width: 100%;
    max-width: 640px;
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--glass-shadow);
    text-align: center;
    transition: border-color var(--transition-smooth);
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: rgba(148, 163, 184, 0.15);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 8px;
}

.progress-bar-inner {
    height: 100%;
    width: 0%;
    background: var(--accent-gradient);
    border-radius: 3px;
    transition: width 0.4s ease;
}

.progress-text {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.question-display {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 8rem;
    font-weight: 700;
    color: var(--text-primary);
    height: 200px;
    display: flex;
    justify-content: center;
    align-items: center;
    text-shadow: 0 0 60px var(--accent-glow);
    opacity: 1;
    transition: opacity 0.3s ease-in-out;
    cursor: pointer;
}

.question-display.fade-out {
    opacity: 0;
}

.question-display.show-answer {
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 6rem;
    color: var(--accent-primary);
}

.answer-input {
    width: 100%;
    max-width: 320px;
    padding: 14px 20px;
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    font-size: 1.3rem;
    font-weight: 500;
    text-align: center;
    background: rgba(30, 41, 59, 0.6);
    border: 2px solid var(--neutral-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.answer-input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.answer-input::placeholder {
    color: var(--text-muted);
}

.button-container {
    display: flex;
    gap: 12px;
    margin-top: 24px;
}

.quiz-nav-button {
    flex: 1;
    padding: 12px 20px;
    border-radius: var(--radius-md);
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1.5px solid transparent;
    text-align: center;
    text-decoration: none;
}

.quiz-nav-button {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 15px var(--accent-glow);
}

.quiz-nav-button:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px var(--accent-glow);
}

.quiz-nav-button.secondary {
    background: transparent;
    border-color: var(--neutral-border);
    color: var(--text-secondary);
    box-shadow: none;
}

.quiz-nav-button.secondary:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    background: rgba(99, 102, 241, 0.05);
}

.feedback-correct {
    animation: flash-correct 0.5s;
}
.feedback-incorrect {
    animation: flash-incorrect 0.5s;
}
@keyframes flash-correct {
    50% { background-color: var(--correct-bg); border-color: var(--correct-border); }
}
@keyframes flash-incorrect {
    50% { background-color: var(--incorrect-bg); border-color: var(--incorrect-border); }
}

/* ========== RESULT ========== */
.result-container {
    width: 100%;
    max-width: 800px;
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--glass-shadow);
    text-align: center;
}

.result-container h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 4px;
    background: none;
    -webkit-text-fill-color: var(--text-primary);
}

.score {
    font-family: 'Outfit', sans-serif;
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #34d399, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 16px 0;
}

.legend {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 28px;
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 3px;
}

.chart-container {
    margin-top: 20px;
}

.chart-container h3 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    text-align: center;
    padding-bottom: 8px;
    margin-bottom: 12px;
    border-bottom: 1px solid var(--glass-border);
}

.gojuon-chart {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
    font-family: 'Noto Sans JP', sans-serif;
    margin-bottom: 28px;
}

.yoon-chart {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
    font-family: 'Noto Sans JP', sans-serif;
    margin-bottom: 28px;
}

.char-cell {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 52px;
    border-radius: var(--radius-sm);
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--neutral-bg);
    border: 1.5px solid var(--neutral-border);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
    user-select: none;
}

.char-cell:hover:not(.empty) {
    background: rgba(99, 102, 241, 0.15);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--accent-glow);
}

.char-cell.empty {
    background: transparent;
    border-color: transparent;
    cursor: default;
}

.char-cell.correct {
    background: var(--correct-bg);
    border-color: var(--correct-border);
}

.char-cell.incorrect {
    background: var(--incorrect-bg);
    border-color: var(--incorrect-border);
}

.char-cell.not-asked {
    background: var(--neutral-bg);
    border-color: var(--neutral-border);
    opacity: 0.5;
}

.char-cell.show-kr {
    font-family: 'Noto Sans KR', sans-serif;
    font-size: 1.2rem;
}

.char-cell.fade-out {
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
}

.retry-button {
    display: inline-block;
    width: 100%;
    padding: 16px;
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    color: white;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-lg);
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 20px var(--accent-glow);
    margin-top: 32px;
    position: relative;
    overflow: hidden;
}

.retry-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

/* ========== AD CONTAINERS ========== */
.ad-grid {
    display: grid;
    grid-template-columns: repeat(2, 320px);
    gap: 12px;
    justify-content: center;
    margin-top: 20px;
}

.ad-mobile-container-320-100-center {
    display: block;
    width: 320px;
    height: 100px;
}

@media (max-width: 680px) {
    .ad-grid {
        grid-template-columns: 320px;
    }
}

.ad-mobile-container-320-50-center {
    display: block;
    width: 320px;
    height: 50px;
    margin-top: 15px;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 480px) {
    .hero h1 { font-size: 1.7rem; }
    .hero-moon { font-size: 3rem; }
    .glass-card { padding: 24px 20px; }
    .quiz-container { padding: 24px 20px; }
    .result-container { padding: 24px 20px; }
    .question-display { font-size: 5rem; height: 150px; }
    .kana-cell, .char-cell { height: 44px; font-size: 1.2rem; }
    .score { font-size: 2.2rem; }
}