:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --secondary-color: #6b7280;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-color: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* タブ */
.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 24px;
    font-size: 1rem;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 3px solid transparent;
    transition: all 0.3s;
}

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

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    font-weight: 600;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* カード */
.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 30px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.card h2 {
    margin-bottom: 20px;
    color: var(--text-color);
}

/* フォーム */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* ボタン */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
    margin-right: 10px;
}

.btn-secondary:hover {
    opacity: 0.9;
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
    margin-top: 10px;
}

.btn-danger:hover {
    background-color: var(--danger-hover);
}

/* 一覧 */
.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 15px;
}

.filter-controls {
    display: flex;
    gap: 10px;
    align-items: center;
}

.filter-controls select {
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
}

#expense-list {
    max-height: 500px;
    overflow-y: auto;
}

.expense-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 10px;
    transition: all 0.3s;
}

.expense-item:hover {
    box-shadow: var(--shadow);
    border-color: var(--primary-color);
}

.expense-info {
    flex: 1;
}

.expense-amount {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-right: 15px;
}

.expense-category {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-right: 10px;
}

.expense-date {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.expense-memo {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 5px;
}

.expense-actions {
    display: flex;
    gap: 8px;
}

.delete-btn {
    background-color: var(--danger-color);
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
}

.delete-btn:hover {
    background-color: var(--danger-hover);
}

.total-summary {
    margin-top: 20px;
    padding: 15px;
    background-color: var(--bg-color);
    border-radius: 8px;
    text-align: right;
    font-size: 1.2rem;
}

#total-amount {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.5rem;
}

/* 統計 */
.stats-controls {
    margin-bottom: 20px;
}

.stats-controls select {
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 30px;
}

.stat-card {
    background-color: var(--bg-color);
    padding: 20px;
    border-radius: 8px;
    text-align: center;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.chart-container {
    max-width: 500px;
    margin: 0 auto;
}

/* 設定 */
.setting-group {
    margin-bottom: 30px;
}

.setting-group h3 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.setting-group p {
    color: var(--text-secondary);
    margin: 5px 0;
}

/* レスポンシブ */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .tabs {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .tab-btn {
        padding: 10px 16px;
        font-size: 0.9rem;
        white-space: nowrap;
    }

    .card {
        padding: 20px;
    }

    .list-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .expense-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .expense-amount {
        margin-bottom: 10px;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
}