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

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #06b6d4;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius: 0.75rem;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.container {
    width: 100%;
    max-width: 1200px;
    background: var(--bg-primary);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 2rem;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo-icon {
    width: 32px;
    height: 32px;
}

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

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

.main-content {
    padding: 2rem;
}

.card {
    background: var(--bg-primary);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.input-section h2 {
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
    font-weight: 600;
}

.unit-toggle {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.unit-btn {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    background: var(--bg-primary);
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
}

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

.unit-btn:hover:not(.active) {
    border-color: var(--primary-color);
    background: var(--bg-secondary);
}

.bmi-form {
    margin-top: 1.5rem;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.form-group {
    position: relative;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.75rem 3rem 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: all 0.2s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-group .unit {
    position: absolute;
    right: 1rem;
    top: calc(50% + 0.5rem);
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.gender-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
}

.gender-btn {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    background: var(--bg-primary);
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
}

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

.gender-btn:hover:not(.active) {
    border-color: var(--primary-color);
    background: var(--bg-secondary);
}

.calculate-btn {
    width: 100%;
    padding: 1rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.calculate-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.results-section {
    animation: fadeIn 0.5s ease;
}

.results-section.hidden {
    display: none;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.result-card {
    background: var(--bg-primary);
}

.result-card.full-width {
    grid-column: 1 / -1;
}

.result-header {
    text-align: center;
    margin-bottom: 2rem;
}

.result-header h3 {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.big-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0.5rem 0;
}

.category-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 9999px;
    font-weight: 600;
    font-size: 0.875rem;
    text-transform: uppercase;
}

.category-badge.underweight {
    background: #dbeafe;
    color: #1e40af;
}

.category-badge.normal {
    background: #d1fae5;
    color: #065f46;
}

.category-badge.overweight {
    background: #fed7aa;
    color: #9a3412;
}

.category-badge.obese {
    background: #fee2e2;
    color: #991b1b;
}

.bmi-scale {
    position: relative;
    margin: 2rem 0;
}

.scale-bar {
    display: flex;
    height: 20px;
    border-radius: 10px;
    overflow: hidden;
}

.scale-segment {
    flex: 1;
}

.scale-segment.underweight {
    background: #60a5fa;
}

.scale-segment.normal {
    background: #34d399;
}

.scale-segment.overweight {
    background: #fb923c;
}

.scale-segment.obese {
    background: #f87171;
}

.scale-indicator {
    position: absolute;
    top: -10px;
    width: 4px;
    height: 40px;
    background: var(--text-primary);
    border-radius: 2px;
    transform: translateX(-50%);
    transition: left 0.5s ease;
}

.scale-labels {
    display: flex;
    justify-content: space-between;
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.weight-range {
    display: flex;
    justify-content: space-around;
    margin: 2rem 0;
}

.range-value {
    text-align: center;
}

.range-value .label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.range-value .value {
    display: block;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.weight-difference {
    text-align: center;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
}

.diff-value {
    font-weight: 600;
    color: var(--primary-color);
    margin-left: 0.5rem;
}

.calorie-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.calorie-item {
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    text-align: center;
}

.calorie-label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.calorie-value {
    display: block;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
}

.health-tips {
    display: grid;
    gap: 1rem;
}

.tip-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
}

.tip-icon {
    width: 24px;
    height: 24px;
    color: var(--success-color);
    flex-shrink: 0;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.btn-primary,
.btn-secondary {
    flex: 1;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.history-section {
    margin-top: 2rem;
}

.history-section.hidden {
    display: none;
}

.chart-container {
    position: relative;
    height: 300px;
    margin: 2rem 0;
}

.history-table {
    overflow-x: auto;
}

.history-data-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 2rem;
}

.history-data-table th,
.history-data-table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.history-data-table th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.category-badge-small {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.category-badge-small.underweight {
    background: #dbeafe;
    color: #1e40af;
}

.category-badge-small.normal {
    background: #d1fae5;
    color: #065f46;
}

.category-badge-small.overweight {
    background: #fed7aa;
    color: #9a3412;
}

.category-badge-small.obese {
    background: #fee2e2;
    color: #991b1b;
}

.notification {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    background: var(--success-color);
    color: white;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    transform: translateX(400px);
    transition: transform 0.3s ease;
    z-index: 1000;
}

.notification.show {
    transform: translateX(0);
}

.footer {
    background: var(--bg-secondary);
    padding: 1.5rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .main-content {
        padding: 1rem;
    }
    
    .card {
        padding: 1.5rem;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .calorie-grid {
        grid-template-columns: 1fr;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }
    
    .big-number {
        font-size: 2.5rem;
    }
    
    .notification {
        right: 1rem;
        left: 1rem;
        transform: translateY(-100px);
    }
    
    .notification.show {
        transform: translateY(0);
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.25rem;
    }
    
    .logo-icon {
        width: 24px;
        height: 24px;
    }
    
    body {
        padding: 0;
    }
    
    .container {
        border-radius: 0;
        min-height: 100vh;
    }
}