/* ============================================
   PEDIATRIC CDS CALCULATOR - MODERN HEALTHCARE UI
   Electric Tangerine + Dark Mode Theme
   WCAG 2.1 AA Compliant
   ============================================ */

:root {
    /* Electric Tangerine Brand Colors */
    --primary-orange: #ff6f00;
    --primary-orange-hover: #e66300;
    --primary-orange-light: rgba(255, 111, 0, 0.1);
    
    /* Dark Mode Palette */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: rgba(30, 41, 59, 0.5);
    --bg-input: #334155;
    
    /* Text Colors (WCAG AA Compliant) */
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    /* Safety Level Colors */
    --safe-green: #10b981;
    --safe-green-bg: rgba(16, 185, 129, 0.15);
    --safe-green-border: #10b981;
    
    --caution-yellow: #fbbf24;
    --caution-yellow-bg: rgba(251, 191, 36, 0.15);
    --caution-yellow-border: #fbbf24;
    
    --critical-red: #ef4444;
    --critical-red-bg: rgba(239, 68, 68, 0.15);
    --critical-red-border: #ef4444;
    
    /* Borders & Shadows */
    --border-color: #475569;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, #1a2332 50%, var(--bg-primary) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    padding: var(--spacing-lg);
    line-height: 1.6;
}

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

/* ============================================
   HEADER
   ============================================ */

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.header-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.header-icon {
    color: var(--primary-orange);
    display: flex;
    align-items: center;
}

.header-text h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-orange) 0%, #ff8c42 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.25rem;
}

.header-text p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Language Toggle */
.language-toggle {
    display: flex;
    gap: var(--spacing-xs);
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-secondary);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: var(--bg-input);
    color: var(--text-primary);
}

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

/* ============================================
   PURPOSE SECTION
   ============================================ */

.purpose-section {
    background: rgba(59, 130, 246, 0.1);
    border: 2px solid rgba(59, 130, 246, 0.3);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: start;
    gap: var(--spacing-md);
}

.purpose-content h3 {
    color: #60a5fa;
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.purpose-content p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.close-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    transition: color 0.3s ease;
}

.close-btn:hover {
    color: var(--text-primary);
}

/* ============================================
   CALCULATOR CARD
   ============================================ */

.calculator-card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    margin-bottom: var(--spacing-lg);
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Weight Input Group */
.weight-input-group {
    display: flex;
    gap: var(--spacing-xs);
}

.weight-input-group input {
    flex: 1;
}

input[type="number"],
select {
    width: 100%;
    padding: 0.875rem var(--spacing-md);
    background: var(--bg-input);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-orange);
    box-shadow: 0 0 0 3px rgba(255, 111, 0, 0.1);
}

input::placeholder {
    color: var(--text-muted);
}

select {
    cursor: pointer;
}

#weight-unit {
    width: auto;
    min-width: 80px;
}

/* Buttons */
.button-group {
    display: flex;
    gap: var(--spacing-md);
}

.btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.875rem var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    background: var(--primary-orange-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background: var(--bg-input);
}

/* ============================================
   RESULTS CONTAINER
   ============================================ */

.results-container {
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    transition: all 0.4s ease;
    animation: slideIn 0.5s ease;
}

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

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

/* Safety Level Variants */
.results-container.safe {
    background: var(--safe-green-bg);
    border: 2px solid var(--safe-green-border);
}

.results-container.caution {
    background: var(--caution-yellow-bg);
    border: 2px solid var(--caution-yellow-border);
}

.results-container.critical {
    background: var(--critical-red-bg);
    border: 2px solid var(--critical-red-border);
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.result-title-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.result-icon {
    font-size: 2rem;
}

.result-title h3 {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

.result-title p {
    font-size: 0.875rem;
    opacity: 0.9;
}

.result-timestamp {
    text-align: right;
    font-size: 0.875rem;
    opacity: 0.8;
}

/* Dosage Display */
.dosage-display {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.dosage-value {
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.dosage-value .dose {
    font-size: 3rem;
    font-weight: 700;
    display: block;
}

.dosage-value .medication {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-top: var(--spacing-sm);
}

.dosage-instructions {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: var(--spacing-md);
}

.dosage-instructions .label {
    font-size: 0.875rem;
    opacity: 0.7;
    margin-bottom: 0.25rem;
}

.dosage-instructions .instruction-text {
    font-size: 1.25rem;
    font-weight: 600;
}

/* Warnings Section */
.warnings-section {
    margin-bottom: var(--spacing-md);
}

.warnings-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.warning-item {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-xs);
}

/* Error Display */
.error-display {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.error-message {
    font-size: 1.125rem;
    font-weight: 600;
}

/* Metadata Grid */
.metadata-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.metadata-item {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
}

.metadata-item .label {
    font-size: 0.75rem;
    opacity: 0.7;
    margin-bottom: 0.25rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.metadata-item .value {
    font-weight: 600;
    font-size: 1rem;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    text-align: center;
    padding-top: var(--spacing-xl);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer p {
    margin-bottom: 0.25rem;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 768px) {
    .header {
        flex-direction: column;
        align-items: start;
    }
    
    .header-text h1 {
        font-size: 1.5rem;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .result-header {
        flex-direction: column;
    }
    
    .dosage-value .dose {
        font-size: 2.5rem;
    }
}

/* ============================================
   ACCESSIBILITY ENHANCEMENTS
   ============================================ */

*:focus-visible {
    outline: 3px solid var(--primary-orange);
    outline-offset: 2px;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Smooth transitions for theme changes */
* {
    transition: background-color 0.3s ease, border-color 0.3s ease;
}