/**
 * Age Calculator Styles - Modern & Flexible Design
 */

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-card: rgba(255, 255, 255, 0.8);
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    
    --border-color: #e2e8f0;
    --border-radius: 16px;
    --border-radius-sm: 12px;
    --border-radius-lg: 24px;
    
    --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);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

.age-calculator-tool {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    background: transparent;
    min-height: auto;
    position: relative;
}

.calculator-container {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    padding: var(--spacing-xl);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    z-index: 1;
}

/* Input Section */
.input-section {
    margin-bottom: var(--spacing-xl);
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.date-inputs {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.input-group {
    display: flex;
    flex-direction: column;
    position: relative;
}

.input-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-control {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    transition: all var(--transition-base);
    font-family: inherit;
    background: var(--bg-primary);
    color: var(--text-primary);
}

.form-control:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1), var(--shadow-md);
    transform: translateY(-1px);
}

/* Date Selector Styles */
.date-selector-group {
    display: flex;
    flex-direction: column;
    position: relative;
}

.date-selector-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.date-selector {
    display: flex;
    gap: var(--spacing-xs);
    align-items: stretch;
}

.date-select {
    flex: 1;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 0.9375rem;
    transition: all var(--transition-base);
    font-family: inherit;
    background: var(--bg-primary);
    color: var(--text-primary);
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%236366f1' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 12px;
    padding-right: 2.5rem;
}

.date-select:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.date-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1), var(--shadow-md);
    transform: translateY(-1px);
}

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

.date-select option {
    padding: 0.5rem;
    background: var(--bg-primary);
    color: var(--text-primary);
}

.date-select option:first-child {
    color: var(--text-tertiary);
    font-style: italic;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    padding: 0.875rem 2rem;
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 0.9375rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    min-width: 140px;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.8125rem;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.btn-primary:active {
    transform: translateY(-1px);
}

.btn-secondary {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #7c3aed 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    box-shadow: none;
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* Results Section */
.results-section {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--border-color);
    animation: fadeInUp 0.6s ease;
}

.age-display {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 50%, var(--accent-color) 100%);
    border-radius: var(--border-radius-lg);
    color: white;
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
}

.age-display::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.main-age {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
}

.main-age #years-display {
    font-size: 5rem;
    font-weight: 800;
    line-height: 1;
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    letter-spacing: -2px;
}

.main-age .age-label {
    font-size: 1.75rem;
    font-weight: 500;
    opacity: 0.95;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.detailed-age {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

.age-unit {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    min-width: 100px;
}

.age-unit span:first-child {
    font-size: 2.25rem;
    font-weight: 700;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.unit-label {
    font-size: 0.875rem;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
}

/* Age Breakdown */
.age-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.breakdown-item {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.breakdown-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.breakdown-item:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.breakdown-item:hover::before {
    transform: scaleX(1);
}

.breakdown-label {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.breakdown-value {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--primary-color);
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Section Container */
.section-container {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--border-color);
    opacity: 1;
    transition: opacity var(--transition-base), transform var(--transition-base);
}

.section-container h4 {
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.section-container h4::before {
    content: '';
    width: 4px;
    height: 24px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    border: 2px dashed var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.empty-state::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

.empty-state:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.7;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
    position: relative;
    z-index: 1;
}

.empty-message {
    color: var(--text-secondary);
    font-size: 1rem;
    margin: 0;
    font-style: italic;
    position: relative;
    z-index: 1;
}

/* Life Milestones */
.milestones-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: var(--spacing-md);
    min-height: 100px;
}

.milestone-item {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    animation: slideInUp 0.4s ease;
    animation-fill-mode: both;
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.milestone-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05), rgba(236, 72, 153, 0.05));
    opacity: 0;
    transition: opacity var(--transition-base);
}

.milestone-item:hover::after {
    opacity: 1;
}

.milestone-item:nth-child(1) { animation-delay: 0.05s; }
.milestone-item:nth-child(2) { animation-delay: 0.1s; }
.milestone-item:nth-child(3) { animation-delay: 0.15s; }
.milestone-item:nth-child(4) { animation-delay: 0.2s; }
.milestone-item:nth-child(5) { animation-delay: 0.25s; }
.milestone-item:nth-child(6) { animation-delay: 0.3s; }
.milestone-item:nth-child(n+7) { animation-delay: 0.35s; }

.milestone-item.achieved {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: var(--success-color);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.2);
}

.milestone-item.achieved:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 8px 20px rgba(16, 185, 129, 0.3);
}

.milestone-item.upcoming {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    border-color: var(--warning-color);
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.2);
}

.milestone-item.upcoming:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 8px 20px rgba(245, 158, 11, 0.3);
}

.milestone-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
    position: relative;
    z-index: 1;
}

.milestone-age {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--text-primary);
}

.milestone-icon {
    font-size: 1.5rem;
    font-weight: 700;
}

.milestone-item.achieved .milestone-icon {
    color: var(--success-color);
}

.milestone-item.upcoming .milestone-icon {
    color: var(--warning-color);
}

.milestone-title {
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    font-size: 1rem;
    position: relative;
    z-index: 1;
}

.milestone-description {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    position: relative;
    z-index: 1;
}

.milestone-status {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-secondary);
    position: relative;
    z-index: 1;
}

/* Next Birthday */
.birthday-info {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    min-height: 100px;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.birthday-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-md);
}

.birthday-item {
    text-align: center;
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.birthday-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.birthday-label {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.birthday-value {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Age Comparison */
.comparison-inputs {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-end;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-md);
}

.comparison-inputs .input-group {
    flex: 1;
    min-width: 200px;
}

.comparison-result {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    margin-top: var(--spacing-md);
    animation: fadeIn 0.5s ease;
    box-shadow: var(--shadow-sm);
}

.comparison-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-md);
}

.comparison-item {
    text-align: center;
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--border-color);
}

.comparison-label {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.comparison-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

/* Age Statistics */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-md);
}

.stat-item {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    animation: fadeIn 0.4s ease;
    animation-fill-mode: both;
    position: relative;
    overflow: hidden;
}

.stat-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.stat-item:hover::before {
    transform: scaleX(1);
}

.stat-item:nth-child(1) { animation-delay: 0.1s; }
.stat-item:nth-child(2) { animation-delay: 0.2s; }
.stat-item:nth-child(3) { animation-delay: 0.3s; }
.stat-item:nth-child(4) { animation-delay: 0.4s; }

.stat-item:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.stat-label {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--text-primary);
    transition: all var(--transition-base), transform 0.2s ease;
}

.stat-value.has-value {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-item:hover .stat-value {
    transform: scale(1.1);
}

/* Age History */
#history-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.history-item {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.history-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    transform: scaleY(0);
    transition: transform var(--transition-base);
}

.history-item:hover {
    background: var(--bg-secondary);
    border-color: var(--primary-light);
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.history-item:hover::before {
    transform: scaleY(1);
}

.history-content {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.history-age {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 1.125rem;
}

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

.history-meta {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    font-size: 0.8125rem;
    color: var(--text-tertiary);
}

/* Status Messages */
.status-message {
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
    animation: slideIn 0.3s ease;
    box-shadow: var(--shadow-md);
    border-left: 4px solid;
}

.status-success {
    background: #d1fae5;
    color: #065f46;
    border-color: var(--success-color);
}

.status-error {
    background: #fee2e2;
    color: #991b1b;
    border-color: var(--error-color);
}

.status-info {
    background: #dbeafe;
    color: #1e40af;
    border-color: var(--info-color);
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

.form-control.shake {
    animation: shake 0.5s ease;
    border-color: var(--error-color) !important;
}

.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-right: 8px;
    vertical-align: middle;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 1024px) {
    .age-calculator-tool {
        padding: var(--spacing-md);
    }
    
    .calculator-container {
        padding: var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .age-calculator-tool {
        padding: var(--spacing-sm);
        background: var(--bg-secondary);
    }
    
    .calculator-container {
        padding: var(--spacing-md);
        border-radius: var(--border-radius);
    }
    
    .date-inputs {
        grid-template-columns: 1fr;
    }
    
    .date-selector {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .date-select {
        width: 100%;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .main-age #years-display {
        font-size: 3.5rem;
    }
    
    .detailed-age {
        gap: var(--spacing-sm);
    }
    
    .age-breakdown,
    .milestones-grid,
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .comparison-inputs {
        flex-direction: column;
    }
    
    .comparison-inputs .date-selector-group {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .age-calculator-tool {
        padding: var(--spacing-xs);
    }
    
    .calculator-container {
        padding: var(--spacing-sm);
    }
    
    .main-age #years-display {
        font-size: 2.5rem;
    }
    
    .age-unit span:first-child {
        font-size: 1.5rem;
    }
    
    .section-container h4 {
        font-size: 1.25rem;
    }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #1e293b;
        --bg-secondary: #0f172a;
        --bg-tertiary: #1e293b;
        --bg-card: rgba(30, 41, 59, 0.8);
        --text-primary: #f1f5f9;
        --text-secondary: #cbd5e1;
        --text-tertiary: #94a3b8;
        --border-color: #334155;
    }
}