.aiueo-container {
    max-width: 1100px;
    margin: 2rem auto;
    padding: 0 15px;
}

.aiueo-table {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.aiueo-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0; /* gapを0にしてボタンの間隔も幅計算に含める */
    justify-content: flex-start;
}

.aiueo-btn {
    /* 幅を親の横幅÷15にする（border分も考慮して-2px） */
    flex: 0 0 calc(100% / 15);
    max-width: calc(100% / 15);
    min-width: 34px;
    height: 48px;
    border: 1px solid #e3e3e3;
    background: #ffffff;
    border-radius: 8px;
    font-size: 1.1rem;
    color: #333;
    cursor: pointer;
    transition: all 0.2s;
    margin: 0;
    box-sizing: border-box;
}

.aiueo-btn:hover:not(.inactive) {
    background: #f8f9ff;
    border-color: #4dabf7;
    transform: translateY(-2px);
    box-shadow: 0 3px 8px rgba(0,0,0,0.1);
}

.aiueo-btn.inactive {
    background: #f8f9fa;
    color: #adb5bd;
    cursor: not-allowed;
    opacity: 0.6;
}

/* レスポンシブ：幅600px以下で1行5文字に */
@media (max-width: 600px) {
    .aiueo-btn {
        flex: 0 0 calc(100% / 5);
        max-width: calc(100% / 5);
        font-size: 1rem;
        height: 40px;
    }
}