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

body {
    font-family: 'Noto Sans JP', sans-serif;
    background: #fafafa;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

.header {
    text-align: center;
    margin-bottom: 40px;
    padding: 20px 0;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2c3e50;
    margin-bottom: 10px;
}

.subtitle {
    color: #7f8c8d;
    font-size: 1.1rem;
}

.add-section {
    margin-bottom: 40px;
}

.input-group {
    display: flex;
    gap: 10px;
    background: white;
    padding: 8px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: box-shadow 0.3s ease;
}

.input-group:focus-within {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

#itemInput {
    flex: 1;
    border: none;
    outline: none;
    padding: 15px 20px;
    font-size: 1rem;
    border-radius: 8px;
}

.add-btn {
    background: #3498db;
    color: white;
    border: none;
    padding: 15px 25px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
}

.add-btn:hover {
    background: #2980b9;
    transform: translateY(-1px);
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.stat-item {
    background: white;
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-2px);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: #3498db;
    margin-bottom: 5px;
}

.stat-label {
    color: #7f8c8d;
    font-size: 0.9rem;
}

.tabs {
    display: flex;
    background: white;
    border-radius: 12px;
    padding: 6px;
    margin-bottom: 30px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.tab-btn {
    flex: 1;
    padding: 12px 20px;
    border: none;
    background: transparent;
    cursor: pointer;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    color: #7f8c8d;
}

.tab-btn.active {
    background: #3498db;
    color: white;
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

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

.items-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.item {
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    position: relative;
    border-left: 4px solid #3498db;
}

.item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.item.urgent {
    border-left-color: #e74c3c;
}

.item.completed {
    opacity: 0.6;
    border-left-color: #27ae60;
}

.item-header {
    display: flex;
    justify-content: between;
    align-items: center;
    margin-bottom: 10px;
}

.item-title {
    font-weight: 500;
    font-size: 1.1rem;
    color: #2c3e50;
    flex: 1;
}

.item-actions {
    display: flex;
    gap: 10px;
}

.action-btn {
    padding: 6px 12px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.complete-btn {
    background: #27ae60;
    color: white;
}

.complete-btn:hover {
    background: #219a52;
}

.delete-btn {
    background: #e74c3c;
    color: white;
}

.delete-btn:hover {
    background: #c0392b;
}

.item-info {
    font-size: 0.9rem;
    color: #7f8c8d;
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.review-timeline {
    margin-top: 15px;
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.timeline-item {
    padding: 4px 8px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.timeline-item.completed {
    background: #d5f4e6;
    color: #27ae60;
}

.timeline-item.today {
    background: #ffeaa7;
    color: #fdcb6e;
}

.timeline-item.upcoming {
    background: #e3f2fd;
    color: #3498db;
}

.info-section {
    background: white;
    padding: 30px;
    border-radius: 12px;
    margin-top: 40px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.info-section h3 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.info-section ul {
    margin-left: 20px;
}

.info-section li {
    margin-bottom: 8px;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: #7f8c8d;
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 15px;
    opacity: 0.5;
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .stats {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    }
    
    .item-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .item-actions {
        align-self: flex-end;
    }
}