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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
    background: #f5f5f5;
    min-height: 100vh;
    padding: 40px 10px;
    line-height: 1.6;
}

.container {
    max-width: 480px;
    margin: 0 auto;
}

header {
    background: white;
    padding: 24px;
    text-align: center;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    margin-bottom: 20px;
}

header h1 {
    font-size: 1.5rem;
    margin-bottom: 6px;
    color: #1a1a1a;
    font-weight: 600;
}

.subtitle {
    font-size: 0.875rem;
    color: #666;
}

main {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

section {
    background: white;
    padding: 20px;
    border-radius: 18px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

h2 {
    font-size: 1rem;
    margin-bottom: 16px;
    color: #1a1a1a;
    font-weight: 600;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #333;
    font-size: 0.875rem;
}

.input-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

input[type="number"],
input[type="text"] {
    flex: 1;
    padding: 10px 12px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: border-color 0.2s;
    background: white;
}

input[type="number"]:focus,
input[type="text"]:focus {
    outline: none;
    border-color: #FF6B35;
}

.currency {
    font-weight: 500;
    color: #666;
    font-size: 0.95rem;
}

.add-person-form {
    display: flex;
    gap: 8px;
    margin-bottom: 8px;
}

.add-person-form input[type="text"] {
    flex: 2;
}

.add-person-form input[type="number"] {
    flex: 1;
}

.hint {
    font-size: 0.8rem;
    color: #999;
}

.btn-primary,
.btn-calculate {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: #1a1a1a;
    color: white;
}

.btn-primary:hover {
    background: #333;
}

.btn-primary:active {
    transform: scale(0.98);
}

.btn-calculate {
    width: 100%;
    background: #FF6B35;
    color: white;
    font-size: 1rem;
    padding: 12px;
}

.btn-calculate:hover {
    background: #ff5722;
}

.btn-calculate:active {
    transform: scale(0.98);
}

.btn-calculate:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.participants-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.empty-message {
    text-align: center;
    color: #999;
    padding: 24px;
    font-size: 0.9rem;
}

.participant-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px;
    background: #fafafa;
    border-radius: 8px;
    border: 1px solid #e8e8e8;
}

.participant-info {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
}

.participant-name {
    font-weight: 500;
    color: #1a1a1a;
    font-size: 0.95rem;
}

.participant-ratio {
    background: #FF6B35;
    color: white;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

.btn-remove {
    background: transparent;
    color: #ff4757;
    border: 1px solid #ff4757;
    padding: 6px 14px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.2s;
}

.btn-remove:hover {
    background: #ff4757;
    color: white;
}

.btn-remove:active {
    transform: scale(0.96);
}

.result-section {
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.result-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 16px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px;
    background: #fafafa;
    border-radius: 8px;
    border: 1px solid #e8e8e8;
}

.result-name {
    font-weight: 500;
    color: #1a1a1a;
    font-size: 0.95rem;
}

.result-amount {
    font-size: 1.1rem;
    font-weight: 600;
    color: #FF6B35;
}

.result-summary {
    border-top: 1px solid #e8e8e8;
    padding-top: 14px;
    margin-top: 14px;
}

.summary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1rem;
    font-weight: 500;
}

.summary-item .amount {
    color: #FF6B35;
    font-size: 1.2rem;
    font-weight: 600;
}

footer {
    background: white;
    padding: 20px;
    text-align: center;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    margin-top: 20px;
}

footer p {
    color: #666;
    font-size: 0.85rem;
}

.visitor-count {
    margin-bottom: 12px;
    font-weight: 500;
    color: #1a1a1a;
    font-size: 0.9rem;
}

.visitor-count span {
    color: #FF6B35;
    font-weight: 600;
}

.footer-links {
    margin: 12px 0;
    font-size: 0.85rem;
}

.footer-links a {
    color: #666;
    text-decoration: none;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: #FF6B35;
}

.footer-links .separator {
    margin: 0 8px;
    color: #ccc;
}

/* レスポンシブデザイン */
@media (max-width: 600px) {
    body {
        padding: 20px 12px;
    }

    header {
        padding: 20px;
    }

    header h1 {
        font-size: 1.3rem;
    }

    section {
        padding: 16px;
    }

    .add-person-form {
        flex-direction: column;
    }

    .add-person-form input[type="text"],
    .add-person-form input[type="number"] {
        display: block;      /* 1つずつ改行して表示 */
        margin-bottom: 8px;  /* 下に少し余白 */
    }

    .participant-item {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    .participant-info {
        flex-direction: row;
        justify-content: space-between;
    }

    .btn-remove {
        width: 100%;
    }
}