body {
    background: #fdf6ec;
    font-family: 'Zen Maru Gothic', sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0;
    padding: 10px;
    color: #333;
    overscroll-behavior: none;
    min-height: 100vh;
}

.back-btn {
    align-self: flex-start;
    text-decoration: none;
    color: #333;
    background: #eee;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
    margin-bottom: 5px;
}

.game-container {
    width: 100%;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

h1 {
    margin: 0;
    color: #ff6b81;
    font-size: 1.5rem;
}

p {
    margin: 0;
    color: #666;
    font-size: 0.9rem;
}

.canvas-wrapper {
    position: relative;
    width: 100%;
    height: 420px;
}

/* ひらがなが舞うエリア */
.game-canvas {
    width: 100%;
    height: 100%;
    background: #fff;
    border-radius: 20px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.06);
    overflow: hidden;
    border: 2px solid #ffede1;
    touch-action: manipulation;
    position: relative;
}

/* ★追加：スタート画面のオーバーレイ */
.overlay {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.6);
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 10;
}
.overlay.hidden {
    display: none;
}
.main-btn {
    padding: 15px 35px;
    font-size: 1.3rem;
    font-weight: bold;
    font-family: inherit;
    background: #ff6b81;
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(255, 107, 129, 0.4);
    transition: transform 0.1s;
}
.main-btn:active {
    transform: scale(0.95);
}

/* 降ってくる文字のスタイル */
.hiragana-item {
    position: absolute;
    width: 50px;
    height: 50px;
    background: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: #ff6b81;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    cursor: pointer;
    user-select: none;
    transition: transform 0.1s;
}

.hiragana-item:active {
    transform: scale(1.3);
}

.score-board {
    font-size: 1.1rem;
    font-weight: bold;
    color: #555;
    background: #fff;
    padding: 8px 20px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.04);
}
.score-board span {
    color: #ff6b81;
    font-size: 1.3rem;
}

/* SEO・AdSense用テキストボックス */
.seo-text-box {
    margin-top: 30px;
    background-color: #fff;
    padding: 20px 25px;
    border-radius: 15px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    max-width: 400px;
    width: 85%;
    color: #555;
    font-size: 0.9rem;
    line-height: 1.6;
}
.seo-text-box h2 {
    font-size: 1.1rem;
    color: #333;
    margin-top: 0;
    margin-bottom: 8px;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 6px;
}