/* BMI Calculator Pro - Professional Glassmorphism Design */

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;
    
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: rgba(255, 255, 255, 0.25);
    --card-border: rgba(255, 255, 255, 0.18);
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #ffffff;
    
    --shadow-light: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    --shadow-heavy: 0 12px 40px 0 rgba(31, 38, 135, 0.5);
    
    --border-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-gradient);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
.header {
    text-align: center;
    margin-bottom: 40px;
}

.header-content h1 {
    color: var(--text-light);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.header-content p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.1rem;
    font-weight: 300;
}

/* Glassmorphism Card Base */
.card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: var(--border-radius);
    border: 1px solid var(--card-border);
    box-shadow: var(--shadow-light);
    padding: 30px;
    margin-bottom: 30px;
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-heavy);
}

.calculator-card,
.results-card,
.recommendations-card,
.metrics-card,
.progress-card,
.tips-card {
    @extend .card;
}

/* Form Styles */
.bmi-form h2 {
    color: var(--text-light);
    font-size: 1.8rem;
    margin-bottom: 25px;
    text-align: center;
}

.unit-toggle {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 25px;
    padding: 5px;
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
}

.unit-btn {
    padding: 10px 20px;
    border: none;
    background: transparent;
    color: var(--text-light);
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.unit-btn.active {
    background: var(--primary-color);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}

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

.form-group label {
    color: var(--text-light);
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 0.95rem;
}

.input-with-unit {
    position: relative;
    display: flex;
    align-items: center;
}

.form-group input,
.form-group select {
    padding: 12px 15px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-light);
    font-size: 1rem;
    transition: var(--transition);
    flex: 1;
}

.input-with-unit input {
    padding-right: 50px;
}

.unit {
    position: absolute;
    right: 15px;
    color: var(--text-light);
    font-weight: 500;
    opacity: 0.7;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(240, 147, 251, 0.1);
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.calculate-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, var(--accent-color), var(--primary-color));
    color: var(--text-light);
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 20px;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(240, 147, 251, 0.4);
}

/* Results Styles */
.results-card h2 {
    color: var(--text-light);
    font-size: 1.8rem;
    margin-bottom: 25px;
    text-align: center;
}

.bmi-display {
    text-align: center;
    margin-bottom: 30px;
}

.bmi-value {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-light);
    margin-bottom: 10px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.bmi-category {
    font-size: 1.3rem;
    font-weight: 500;
    padding: 8px 20px;
    border-radius: 25px;
    display: inline-block;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* BMI Gauge */
.bmi-gauge {
    width: 200px;
    height: 100px;
    margin: 30px auto;
    position: relative;
    background: linear-gradient(to right, 
        var(--info-color) 0%, 
        var(--success-color) 25%, 
        var(--warning-color) 50%, 
        var(--danger-color) 100%);
    border-radius: 100px 100px 0 0;
    overflow: hidden;
}

.gauge-pointer {
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 4px;
    height: 80px;
    background: var(--text-light);
    transform-origin: bottom center;
    transition: var(--transition);
    border-radius: 2px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

/* BMI Scale */
.bmi-scale {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-top: 30px;
}

.scale-item {
    text-align: center;
    padding: 15px 10px;
    border-radius: 12px;
    transition: var(--transition);
}

.scale-item:hover {
    transform: scale(1.05);
}

.scale-item.underweight {
    background: rgba(59, 130, 246, 0.2);
    border: 2px solid var(--info-color);
}

.scale-item.normal {
    background: rgba(16, 185, 129, 0.2);
    border: 2px solid var(--success-color);
}

.scale-item.overweight {
    background: rgba(245, 158, 11, 0.2);
    border: 2px solid var(--warning-color);
}

.scale-item.obese {
    background: rgba(239, 68, 68, 0.2);
    border: 2px solid var(--danger-color);
}

.scale-item.active {
    transform: scale(1.1);
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.3);
}

.scale-range {
    display: block;
    font-weight: 700;
    color: var(--text-light);
    margin-bottom: 5px;
}

.scale-label {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.8);
}

/* Recommendations */
.recommendations-card h3,
.metrics-card h3,
.progress-card h3,
.tips-card h3 {
    color: var(--text-light);
    font-size: 1.5rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.recommendations-content {
    display: grid;
    gap: 15px;
}

.recommendation-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid var(--accent-color);
}

.recommendation-title {
    color: var(--text-light);
    font-weight: 600;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.recommendation-text {
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.6;
}

/* Metrics Grid */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.metric-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    transition: var(--transition);
}

.metric-item:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-3px);
}

.metric-label {
    display: block;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.metric-value {
    display: block;
    color: var(--text-light);
    font-size: 1.5rem;
    font-weight: 700;
}

/* Progress Section */
.progress-controls {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
    justify-content: center;
}

.btn-secondary {
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-light);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: var(--accent-color);
}

.chart-container {
    position: relative;
    height: 300px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 20px;
}

/* Tips Carousel */
.tips-carousel {
    display: grid;
    gap: 20px;
}

.tip-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 25px;
    border-radius: 12px;
    border-left: 4px solid var(--success-color);
    transition: var(--transition);
}

.tip-item:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateX(5px);
}

.tip-icon {
    font-size: 2rem;
    color: var(--accent-color);
    margin-bottom: 15px;
}

.tip-title {
    color: var(--text-light);
    font-weight: 600;
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.tip-text {
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.6;
}

/* Footer */
.footer {
    text-align: center;
    margin-top: 50px;
    padding: 20px;
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .header-content h1 {
        font-size: 2rem;
    }
    
    .form-row {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .bmi-value {
        font-size: 2.5rem;
    }
    
    .bmi-scale {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .metrics-grid {
        grid-template-columns: 1fr;
    }
    
    .progress-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .unit-toggle {
        width: 100%;
        margin-bottom: 20px;
    }
}

@media (max-width: 480px) {
    .card {
        padding: 20px;
    }
    
    .header-content h1 {
        font-size: 1.8rem;
    }
    
    .bmi-value {
        font-size: 2rem;
    }
    
    .bmi-scale {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.results-section {
    animation: slideIn 0.6s ease-out;
}

.card {
    animation: fadeIn 0.4s ease-out;
}

/* Loading State */
.loading {
    position: relative;
    overflow: hidden;
}

.loading::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

/* Accessibility */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus styles for better accessibility */
button:focus,
input:focus,
select:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Dark theme support */
@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #f9fafb;
        --text-secondary: #d1d5db;
    }
}