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

:root {
    --primary-color: #4F46E5;
    --primary-hover: #4338CA;
    --secondary-color: #6366F1;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --warning-color: #F59E0B;
    --background: #F9FAFB;
    --card-background: #FFFFFF;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --border-color: #E5E7EB;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji';
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.5;
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
}

/* ヘッダー */
.header {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-lg);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.app-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo {
    width: 2.5rem;
    height: 2.5rem;
    color: var(--primary-color);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.icon-btn {
    background: transparent;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.icon-btn svg {
    width: 1.25rem;
    height: 1.25rem;
}

.language-selector {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--card-background);
    cursor: pointer;
    font-size: 0.875rem;
    transition: border-color 0.2s;
}

.language-selector:hover {
    border-color: var(--primary-color);
}

/* メインコンテンツ */
.main-content {
    display: grid;
    gap: 2rem;
}

/* 為替計算カード */
.exchange-card {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.update-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.status-indicator {
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 50%;
    background: var(--success-color);
    animation: pulse 2s infinite;
}

.status-indicator.offline {
    background: var(--warning-color);
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.currency-inputs {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 1.5rem;
    align-items: end;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.currency-row {
    display: flex;
    gap: 0.5rem;
}

.amount-input {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1.125rem;
    font-weight: 600;
    transition: border-color 0.2s;
}

.amount-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.currency-select {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--card-background);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: border-color 0.2s;
}

.currency-select:hover {
    border-color: var(--primary-color);
}

.currency-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.swap-button {
    background: var(--primary-color);
    border: none;
    border-radius: 50%;
    width: 3rem;
    height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow-md);
}

.swap-button:hover {
    background: var(--primary-hover);
    transform: rotate(180deg);
}

.swap-button svg {
    width: 1.5rem;
    height: 1.5rem;
    color: white;
}

.exchange-rate-info {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.rate-display {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--primary-color);
}

.add-favorite-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: background 0.2s;
}

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

.add-favorite-btn svg {
    width: 1.25rem;
    height: 1.25rem;
}

/* チャートセクション */
.chart-section {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.chart-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

.chart-controls {
    display: flex;
    gap: 0.5rem;
}

.period-btn {
    padding: 0.5rem 1rem;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

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

.period-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.chart-container {
    position: relative;
    height: 300px;
}

/* お気に入りセクション */
.favorites-section {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.favorites-section h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.favorites-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.favorite-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--background);
    border-radius: 0.5rem;
    transition: background 0.2s;
}

.favorite-item:hover {
    background: var(--border-color);
}

.favorite-pair {
    display: flex;
    flex-direction: column;
    cursor: pointer;
}

.pair-name {
    font-weight: 600;
    color: var(--text-primary);
}

.pair-rate {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.remove-btn {
    padding: 0.25rem 0.5rem;
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    cursor: pointer;
    transition: opacity 0.2s;
}

.remove-btn:hover {
    opacity: 0.8;
}

/* クイック変換セクション */
.quick-convert-section {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.quick-convert-section h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.quick-amounts {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 0.75rem;
}

.quick-amount-btn {
    padding: 0.75rem;
    background: var(--background);
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.quick-amount-btn:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

/* フッター */
.footer {
    text-align: center;
    padding: 2rem;
    color: white;
    font-size: 0.875rem;
}

.footer p {
    margin-bottom: 0.5rem;
}

/* オフラインインジケータ */
.offline-indicator {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: var(--warning-color);
    color: white;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
}

.offline-indicator svg {
    width: 1.25rem;
    height: 1.25rem;
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
    }
    
    .currency-inputs {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .swap-button {
        transform: rotate(90deg);
    }
    
    .swap-button:hover {
        transform: rotate(270deg);
    }
    
    .exchange-rate-info {
        flex-direction: column;
        gap: 1rem;
    }
    
    .chart-header {
        flex-direction: column;
        gap: 1rem;
    }
    
    .quick-amounts {
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }
    
    .offline-indicator {
        bottom: 1rem;
        right: 1rem;
        left: 1rem;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .app-container {
        padding: 0.5rem;
    }
    
    .header {
        padding: 1rem;
    }
    
    .app-title {
        font-size: 1.5rem;
    }
    
    .logo {
        width: 2rem;
        height: 2rem;
    }
    
    .exchange-card,
    .chart-section,
    .favorites-section,
    .quick-convert-section {
        padding: 1.5rem;
    }
    
    .favorites-list {
        grid-template-columns: 1fr;
    }
}