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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

header h1 {
    font-size: 28px;
    font-weight: 600;
}

.btn-management,
.btn-link {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 10px 20px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-management:hover,
.btn-link:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.header-buttons {
    display: flex;
    gap: 10px;
}

main {
    padding: 40px;
}

.billing-form {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 500;
    color: #555;
    font-size: 14px;
}

.required {
    color: #e74c3c;
}

.form-group input,
.form-group textarea {
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

.form-group textarea {
    resize: vertical;
}

.btn-submit {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 14px 28px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    margin-top: 10px;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-submit:active {
    transform: translateY(0);
}

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 6px;
    display: none;
    font-weight: 500;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
    display: block;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    display: block;
}

.filter-section {
    margin-bottom: 30px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 6px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.filter-section label {
    font-weight: 500;
    color: #555;
}

.filter-section select {
    padding: 8px 12px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 14px;
    background: white;
    cursor: pointer;
}

.filter-section select:focus {
    outline: none;
    border-color: #667eea;
}

.loading {
    text-align: center;
    padding: 40px;
    color: #666;
    font-size: 16px;
}

.data-list {
    display: grid;
    gap: 20px;
}

.data-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.data-item:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.data-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    flex-wrap: wrap;
    gap: 10px;
}

.btn-edit {
    background: #667eea;
    color: white;
    padding: 6px 12px;
    border: none;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn-edit:hover {
    background: #5568d3;
}

/* モーダル */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    overflow: auto;
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 0;
    border-radius: 12px;
    width: 90%;
    max-width: 600px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.modal-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-radius: 12px 12px 0 0;
}

.modal-header h2 {
    margin: 0;
    font-size: 24px;
}

.modal-close {
    color: white;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
    transition: opacity 0.3s ease;
}

.modal-close:hover {
    opacity: 0.7;
}

.modal-content .billing-form {
    padding: 30px;
}

.modal-content .form-group select {
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    font-family: inherit;
    background: white;
    width: 100%;
}

.modal-content .form-group select:focus {
    outline: none;
    border-color: #667eea;
}

.modal-actions {
    display: flex;
    gap: 15px;
    justify-content: flex-end;
    margin-top: 25px;
}

.btn-cancel {
    background: #e0e0e0;
    color: #333;
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn-cancel:hover {
    background: #d0d0d0;
}

.data-item-person {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
}

.data-item-person.yuki {
    background: #e3f2fd;
    color: #1976d2;
}

.data-item-person.misako {
    background: #fce4ec;
    color: #c2185b;
}

.data-item-date {
    color: #666;
    font-size: 14px;
}

.data-item-title {
    font-size: 18px;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
}

.data-item-amount {
    font-size: 24px;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 8px;
}

.data-item-comment {
    color: #666;
    font-size: 14px;
    line-height: 1.6;
    margin-top: 8px;
}

.no-data {
    text-align: center;
    padding: 60px 20px;
    color: #999;
    font-size: 16px;
}

@media (max-width: 600px) {
    header {
        flex-direction: column;
        align-items: flex-start;
    }

    main {
        padding: 20px;
    }

    .filter-section {
        flex-direction: column;
        align-items: flex-start;
    }
}