.tool-container {
    background: #fff; padding: 30px; border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05); border: 1px solid #eee;
}

/* タブデザイン */
.tab-menu { display: flex; border-bottom: 2px solid #eee; margin-bottom: 25px; gap: 10px; }
.tab-btn {
    padding: 10px 20px; border: none; background: none; cursor: pointer;
    font-size: 1rem; color: #666; border-bottom: 3px solid transparent;
}
.tab-btn.active { color: #333f47; border-bottom-color: #333f47; font-weight: bold; }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* 入力・結果エリア */
.main-input {
    width: 100%; padding: 12px; border: 1px solid #ddd; border-radius: 4px;
    font-family: monospace; font-size: 1.1rem; box-sizing: border-box; margin-bottom: 10px;
}
.quick-btns button { padding: 5px 10px; font-size: 0.8rem; cursor: pointer; background: #f0f0f0; border: 1px solid #ccc; border-radius: 3px; }

.calc-box { background: #f9f9f9; padding: 15px; border-radius: 6px; margin: 20px 0; }
.calc-inputs { display: flex; align-items: center; gap: 10px; margin-top: 10px; }
.calc-inputs input { width: 60px; padding: 8px; border: 1px solid #ddd; text-align: center; }

.btn-calc { padding: 8px 15px; background: #333f47; color: #fff; border: none; border-radius: 4px; cursor: pointer; font-weight: bold; }
.btn-calc:hover { opacity: 0.9; }

.result-area { margin-top: 20px; border-top: 2px solid #eee; padding-top: 20px; }
.result-item { margin-bottom: 15px; }
.result-item .label { display: block; font-size: 0.8rem; color: #777; margin-bottom: 5px; }
.result-val { font-size: 1.5rem; font-family: monospace; font-weight: bold; color: #27ae60; }
.result-val.small { font-size: 1.2rem; }

.value-copy { display: flex; justify-content: space-between; align-items: center; background: #f0fff0; padding: 15px; border-radius: 4px; border: 1px solid #c3e6cb; }
.copy-btn { padding: 5px 12px; background: #fff; border: 1px solid #27ae60; color: #27ae60; border-radius: 3px; cursor: pointer; font-size: 0.8rem; }
.copy-btn:hover { background: #27ae60; color: #fff; }

.input-section h4 { margin: 15px 0 10px 0; color: #555; }
hr { border: none; border-top: 1px solid #eee; margin: 20px 0; }

/* 変換ボタンのグリッド */
.convert-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin: 20px 0;
}

.btn-conv {
    padding: 15px;
    border: none;
    border-radius: 6px;
    font-weight: bold;
    cursor: pointer;
    color: #fff;
    font-size: 1rem;
    transition: transform 0.1s;
}
.btn-conv:active { transform: scale(0.98); }

.btn-conv.jst { background: #2980b9; } /* 青：JST */
.btn-conv.utc { background: #8e44ad; } /* 紫：UTC */
.btn-conv-sub { background: #f0f0f0; border: 1px solid #ddd; color: #333; padding: 10px; border-radius: 6px; cursor: pointer; }

/* UnixTime用の一括結果表示 */
.unix-res-row {
    background: #f9f9f9;
    padding: 10px 15px;
    border-radius: 4px;
    margin-bottom: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* UnixTimeタブ用ボタンのカラーを明確に */
.btn-conv.unix-jst { background: #2980b9; } /* JSTへの変換は青 */
.btn-conv.unix-utc { background: #8e44ad; } /* UTCへの変換は紫 */
.btn-conv.jst-unix { background: #27ae60; } /* UnixTimeへの変換は緑 */

/* ボタン共通のホバー効果（「押せる感」を出す） */
.btn-conv:hover {
    opacity: 0.85;
    filter: brightness(1.1);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

/* モバイル対応：ボタンが詰まりすぎないよう調整 */
@media (max-width: 600px) {
    .convert-grid {
        grid-template-columns: 1fr;
    }
}