:root {
    --text-main: #6c3f4e; 
    --text-sub: #b18794;
    --accent-glow: rgba(255, 235, 59, 0.4);
    
    /* 背景顏色分類 */
    --bg-seion: #ffe3ec;
    --bg-bion: #fff8e1;
    --bg-dakuon: #e3f2fd;
    --bg-handakuon: #e8f5e9;
    --bg-yoon: #f3e5f5;
    
    --font-kawaii: 'Fredoka', 'Noto Sans JP', sans-serif;
    --transition: all 0.35s cubic-bezier(0.19, 1, 0.22, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    background-color: #fffafb;
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--text-main);
    overflow-x: hidden;
}

.sakura-bg {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    background: linear-gradient(135deg, #fff 0%, #ffe3ec 100%);
    z-index: -2;
}

.game-wrapper { max-width: 1200px; margin: 0 auto; padding: 40px 15px; }

.main-header { text-align: center; margin-bottom: 60px; }
.game-title { 
    font-family: var(--font-kawaii); 
    font-size: clamp(2rem, 8vw, 3.5rem); 
    letter-spacing: 2px;
}
.game-title .accent { color: #ff85a1; }

.chart-section {
    background: rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(8px);
    border: 3px solid white;
    border-radius: 30px;
    padding: 30px;
    margin-bottom: 40px;
    box-shadow: 0 10px 30px rgba(255, 133, 161, 0.1);
}

.section-header {
    display: flex; align-items: center; gap: 10px;
    margin-bottom: 25px; border-bottom: 2px dashed #ff85a1; padding-bottom: 8px;
}

/* Grid Layout */
.kana-grid {
    display: grid;
    grid-template-columns: 80px repeat(5, 1fr);
    gap: 12px;
}

.yoon-grid { grid-template-columns: 80px repeat(3, 1fr); }

.gyo-label {
    font-size: 1.2rem; font-weight: 900; color: var(--text-sub);
    display: flex; align-items: center; justify-content: center;
}

/* Card Base Style */
.kana-card {
    border: 3px solid white; border-radius: 20px;
    padding: 20px 10px; cursor: pointer;
    transition: var(--transition);
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    min-height: 140px; box-shadow: 0 4px 10px rgba(0,0,0,0.03);
}

.kana-card:hover { 
    transform: scale(1.08) translateY(-5px); 
    background-color: #fff !important;
    box-shadow: 0 15px 30px var(--accent-glow);
    z-index: 5;
}

.kana-main { display: flex; align-items: baseline; gap: 8px; margin-bottom: 8px; }

/* 顏色統一 */
.hira { font-size: 2.8rem; font-weight: 500; color: var(--text-main); }
.kata { font-size: 1.4rem; color: var(--text-main); } /* 與平假名顏色相同 */

.romaji {
    font-family: var(--font-kawaii);
    font-size: 2rem;
    /* 所有的 romaji 文字均已小寫，這裡只設定顏色 */
    color: #ffb84d; /* 金色 */
    text-transform: none; /* 取消大寫轉化 */
    background: rgba(255, 255, 255, 0.6);
    padding: 4px 14px;
    border-radius: 10px;
    margin-top: auto;
}


/* 分類背景 */
.seion-card { background-color: var(--bg-seion); }
.bion-card { background-color: var(--bg-bion); }
.dakuon-card { background-color: var(--bg-dakuon); }
.handakuon-card { background-color: var(--bg-handakuon); }
.yoon-card { background-color: var(--bg-yoon); }

.yoon-divider { grid-column: 1 / -1; height: 2px; background: #ff85a1; margin: 15px 0; opacity: 0.2; }

/* RWD */
@media (max-width: 768px) {
    .kana-grid { grid-template-columns: repeat(3, 1fr); }
    .yoon-grid { grid-template-columns: repeat(2, 1fr); }
    .gyo-label { grid-column: span 3; padding: 10px; background: rgba(255,255,255,0.5); border-radius: 10px; }
    .yoon-grid .gyo-label { grid-column: span 2; }
    .hira { font-size: 2.2rem; }
}