/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color System */
    --primary-100: #EBF5FF;
    --primary-500: #007BFF;
    --primary-700: #0056B3;
    --neutral-50: #F8F9FA;
    --neutral-100: #FFFFFF;
    --neutral-400: #6C757D;
    --neutral-700: #343A40;
    --neutral-900: #212529;
    --success: #28A745;
    --warning: #FFC107;
    --error: #DC3545;
    
    /* Spacing */
    --space-xs: 8px;
    --space-sm: 16px;
    --space-md: 24px;
    --space-lg: 32px;
    --space-xl: 48px;
    --space-xxl: 64px;
    --space-xxxl: 96px;
    
    /* Border Radius */
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-full: 999px;
    
    /* Shadows */
    --shadow-md: 0 4px 12px rgba(0, 123, 255, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 123, 255, 0.12);
}

body {
    font-family: 'Poppins', sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--neutral-700);
    background-color: var(--neutral-50);
    overflow-x: hidden;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-sm);
    width: 100%;
}

/* Mobile responsive - Simple and Fast */
@media (max-width: 768px) {
    .container {
        padding: var(--space-sm);
        margin: 0;
    }
    
    .main-content {
        padding: var(--space-sm) 0;
    }
    
    .calculator-card {
        margin: 0;
        padding: var(--space-sm);
        box-shadow: none;
        border-radius: 0;
    }
    
    .section-title {
        font-size: 20px;
        text-align: center;
    }
    
    .result-value {
        font-size: 24px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .input-field {
        font-size: 16px;
        height: 48px;
    }
}

/* Very small screens */
@media (max-width: 480px) {
    .container {
        padding: var(--space-xs);
    }
    
    .calculator-card {
        padding: var(--space-xs);
    }
    
    .section-title {
        font-size: 18px;
    }
    
    .hero-title {
        font-size: 24px;
    }
    
    .input-field {
        font-size: 16px;
        height: 44px;
    }
}

/* Header Styles */
.header {
    background: var(--neutral-100);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
    /* Add safe area for mobile status bar */
    padding-top: env(safe-area-inset-top);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-sm);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

.brand-name {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-500);
}

.nav-menu {
    display: flex;
    gap: var(--space-lg);
}

.nav-link {
    text-decoration: none;
    color: var(--neutral-700);
    font-weight: 500;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-500);
    background-color: var(--primary-100);
}

/* Ad Slots */
.ad-slot {
    background: var(--neutral-100);
    padding: var(--space-sm);
    text-align: center;
    border-bottom: 1px solid #e0e0e0;
}

.ad-slot .ads {
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.adsbygoogle {
    display: block !important;
}

/* Main Content */
.main-content {
    padding: var(--space-xl) 0;
}

.hero-section {
    text-align: center;
    margin-bottom: var(--space-xxxl);
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    color: var(--neutral-900);
    margin-bottom: var(--space-sm);
}

.hero-subtitle {
    font-size: 20px;
    color: var(--neutral-400);
    max-width: 600px;
    margin: 0 auto;
}

/* Calculator Section */
.calculator-section {
    margin-bottom: var(--space-xxl);
}

.calculator-card {
    max-width: 600px;
    margin: 0 auto;
    padding: var(--space-md);
    background: var(--neutral-100);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.section-title {
    font-size: 32px;
    font-weight: 600;
    line-height: 1.3;
    color: var(--neutral-900);
    text-align: center;
    margin-bottom: var(--space-xl);
}

.calculator-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.input-label {
    font-weight: 500;
    color: var(--neutral-700);
    font-size: 16px;
}

.input-field {
    height: 56px;
    background: var(--neutral-50);
    border: 1px solid #DEE2E6;
    border-radius: var(--radius-md);
    padding: 0 var(--space-sm);
    font-size: 16px;
    font-family: inherit;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}

.activity-selector {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
}

.activity-btn {
    height: 56px;
    padding: 0 var(--space-md);
    border: 1px solid #DEE2E6;
    border-radius: var(--radius-full);
    background: var(--neutral-50);
    color: var(--neutral-700);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.25s ease-out;
    font-family: inherit;
    font-size: 16px;
}

.activity-btn:hover {
    background: var(--primary-100);
    border-color: var(--primary-500);
}

.activity-btn.active {
    background: var(--primary-500);
    color: white;
    border-color: var(--primary-500);
    box-shadow: var(--shadow-md);
}

.calculate-btn {
    height: 64px;
    background: var(--primary-500);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
    margin-top: var(--space-sm);
}

.calculate-btn:hover {
    background: var(--primary-700);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.calculate-btn:active {
    transform: translateY(0px) scale(0.98);
}

/* Results Section */
.results-section {
    margin-top: var(--space-xl);
    /* Removed container styling - now more natural */
    animation: fadeInUp 0.3s ease-out;
}

.results-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--neutral-900);
    text-align: center;
    margin-bottom: var(--space-lg);
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.result-item {
    text-align: center;
    padding: var(--space-md);
    background: var(--neutral-100);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.result-value {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-500);
    line-height: 1.2;
}

.result-label {
    font-size: 14px;
    color: var(--neutral-400);
    margin-top: var(--space-xs);
}

/* Tracking Section */
.tracking-section {
    margin-top: var(--space-xl);
}

.tracking-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--neutral-900);
    margin-bottom: var(--space-sm);
}

.tracking-subtitle {
    color: var(--neutral-400);
    margin-bottom: var(--space-lg);
    font-size: 14px;
}

.tracking-timeline {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(45px, 1fr));
    gap: var(--space-xs);
    max-width: 100%;
    /* Ensure consistent grid layout */
    grid-auto-rows: 1fr;
    align-items: stretch;
}

.timeline-hour {
    aspect-ratio: 1;
    background: var(--neutral-50);
    border: 1px solid #DEE2E6;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 500;
    color: var(--neutral-400);
    cursor: pointer;
    transition: all 0.25s ease;
    position: relative;
    /* Ensure text is centered */
    text-align: center;
    word-wrap: break-word;
    min-height: 0;
}
}

.timeline-hour:hover {
    background: var(--primary-100);
    border-color: var(--primary-500);
}

.timeline-hour.completed {
    background: var(--success);
    color: white;
    border-color: var(--success);
}

.timeline-hour.completed::after {
    content: '✓';
    position: absolute;
    font-size: 16px;
    font-weight: bold;
}

/* Tips Section */
.tips-section {
    margin-bottom: var(--space-xl);
}

.who-subtitle {
    text-align: center;
    color: var(--neutral-400);
    font-style: italic;
    margin-bottom: var(--space-lg);
    font-size: 16px;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.tip-card {
    background: var(--neutral-100);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    transition: transform 0.25s ease-out, box-shadow 0.25s ease-out;
}

.tip-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.tip-card h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--neutral-900);
    margin-bottom: var(--space-sm);
}

.tip-card p {
    color: var(--neutral-400);
    line-height: 1.6;
}

.who-reference {
    background: var(--primary-100);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    margin-top: var(--space-xl);
    border-left: 4px solid var(--primary-500);
}

.who-reference h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--neutral-900);
    margin: var(--space-lg) 0 var(--space-sm) 0;
}

.who-reference h4:first-child {
    margin-top: 0;
}

.who-reference p {
    color: var(--neutral-700);
    line-height: 1.7;
    margin-bottom: var(--space-md);
}

.who-reference p:last-child {
    margin-bottom: 0;
}

/* Footer */
.footer {
    background: var(--neutral-900);
    color: white;
    padding: var(--space-xl) 0 var(--space-lg);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-lg);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.footer-logo {
    width: 32px;
    height: 32px;
    border-radius: 50%;
}

.footer-brand-name {
    font-size: 20px;
    font-weight: 600;
}

.footer-links {
    display: flex;
    gap: var(--space-lg);
}

.footer-link {
    color: #adb5bd;
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-link:hover {
    color: var(--primary-500);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-lg);
    border-top: 1px solid #495057;
    color: #6c757d;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Mobile Navigation Styles */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-xs);
    /* Add safe area positioning */
    margin-right: env(safe-area-inset-right);
    margin-top: env(safe-area-inset-top);
    position: relative;
    z-index: 1001;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
    align-items: center;
    justify-content: center;
    flex-direction: column;
}

.mobile-menu-toggle:hover {
    background-color: var(--primary-100);
    color: var(--primary-500);
}

.hamburger-line {
    display: block;
    width: 20px;
    height: 2px;
    background-color: currentColor;
    margin: 2px 0;
    transition: all 0.3s ease;
    border-radius: 2px;
}

.mobile-menu-toggle.active .hamburger-line:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 6px);
}

.mobile-menu-toggle.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active .hamburger-line:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -6px);
}

@media (max-width: 768px) {
    .header .container {
        padding: 0;
    }
    
    .nav-brand {
        gap: var(--space-xs);
    }
    
    .brand-name {
        font-size: 18px;
    }
    
    .logo {
        width: 32px;
        height: 32px;
    }
    
    /* Mobile Navigation */
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--neutral-100);
        flex-direction: column;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        padding: var(--space-sm);
        z-index: 200;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
        display: flex;
    }
    
    .nav-link {
        padding: var(--space-sm);
        text-align: center;
        border-bottom: 1px solid #e0e0e0;
        font-size: 16px;
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }
    
    .nav-link:hover,
    .nav-link.active {
        background-color: var(--primary-100);
    }
    
    /* Mobile menu toggle button */
    .mobile-menu-toggle {
        display: flex;
    }
    

    
    .mobile-menu-toggle.active {
        color: var(--primary-500);
    }
}

@media (max-width: 480px) {
    .brand-name {
        font-size: 16px;
    }
    
    .logo {
        width: 28px;
        height: 28px;
    }
    
    .nav-link {
        padding: var(--space-sm) var(--space-xs);
        font-size: 14px;
    }
}

/* Responsive Design for general content */
@media (max-width: 768px) {
    .hero-title {
        font-size: 32px;
        line-height: 1.2;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .result-value {
        font-size: 28px;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }
    
    .result-value {
        font-size: 36px;
    }
    
    .activity-selector {
        flex-direction: column;
    }
    
    .activity-btn {
        width: 100%;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }
    
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .tracking-timeline {
        grid-template-columns: repeat(8, 1fr);
        gap: 6px;
        max-width: 100%;
    }
    
    .tips-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .result-value {
        font-size: 28px;
    }
    
    .tracking-timeline {
        grid-template-columns: repeat(6, 1fr);
        gap: 4px;
        max-width: 100%;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print Styles */
@media print {
    .ad-slot,
    .footer {
        display: none;
    }
    
    .header {
        position: static;
        box-shadow: none;
    }
}

/* Kidney Calculator Styles */
.calculator-description {
    color: var(--neutral-400);
    margin-bottom: var(--space-lg);
    text-align: center;
}

.input-hint {
    display: block;
    font-size: 0.875rem;
    color: var(--neutral-400);
    margin-top: var(--space-xs);
}

.kidney-result-card {
    background: var(--neutral-100);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    margin-bottom: var(--space-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.kidney-result-card h4 {
    color: var(--primary-500);
    margin-bottom: var(--space-md);
    font-size: 1.125rem;
    font-weight: 600;
}

.kidney-gfr-display {
    margin-bottom: var(--space-md);
}

.gfr-value {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-500);
    line-height: 1;
}

.gfr-unit {
    font-size: 0.875rem;
    color: var(--neutral-400);
    margin-top: var(--space-xs);
}

.kidney-status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    margin-top: var(--space-md);
}

.kidney-status-green {
    background-color: rgba(40, 167, 69, 0.1);
    color: var(--success);
}

.kidney-status-yellow {
    background-color: rgba(255, 193, 7, 0.1);
    color: #CC8800;
}

.kidney-status-red {
    background-color: rgba(220, 53, 69, 0.1);
    color: var(--error);
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: currentColor;
}

.status-text {
    text-align: left;
}

.status-title {
    font-weight: 600;
    font-size: 1rem;
}

.status-description {
    font-size: 0.875rem;
    margin-top: var(--space-xs);
}

.health-info-section {
    margin-top: var(--space-xl);
}

.health-info-section h4 {
    color: var(--primary-500);
    margin-bottom: var(--space-md);
    font-size: 1.25rem;
    font-weight: 600;
}

.info-cards {
    display: grid;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.info-card {
    background: var(--neutral-100);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
}

.info-card-green {
    border-left: 4px solid var(--success);
}

.info-card-yellow {
    border-left: 4px solid #CC8800;
}

.info-card-red {
    border-left: 4px solid var(--error);
}

.info-card-low {
    border-left: 4px solid #17A2B8;
}

.info-card-high {
    border-left: 4px solid var(--warning);
}

.info-card-icon {
    font-size: 1.5rem;
    margin-top: var(--space-xs);
}

.info-card-content h4 {
    color: var(--primary-500);
    margin-bottom: var(--space-xs);
    font-size: 1rem;
    font-weight: 600;
}

.info-card-content p {
    font-size: 0.875rem;
    line-height: 1.5;
}

.medical-disclaimer {
    background: var(--primary-100);
    border: 1px solid var(--primary-500);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    margin-top: var(--space-lg);
}

.medical-disclaimer h4 {
    color: var(--primary-500);
    margin-bottom: var(--space-sm);
    font-size: 1rem;
    font-weight: 600;
}

.medical-disclaimer p {
    font-size: 0.875rem;
    line-height: 1.6;
    color: var(--neutral-700);
}

.info-section {
    margin-top: var(--space-xxl);
}

.info-grid {
    display: grid;
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.info-section .info-card {
    background: var(--neutral-100);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.info-section .info-card h3 {
    color: var(--primary-500);
    margin-bottom: var(--space-sm);
    font-size: 1.25rem;
    font-weight: 600;
}

.info-section .info-card p {
    line-height: 1.6;
}

.reference-section {
    background: var(--neutral-100);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-md);
}

.reference-section h4 {
    color: var(--primary-500);
    margin-bottom: var(--space-lg);
    font-size: 1.25rem;
    font-weight: 600;
    text-align: center;
}

.category-legend {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.category-item {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    padding: var(--space-md);
    border-radius: var(--radius-md);
}

.category-item.green {
    background-color: rgba(40, 167, 69, 0.1);
}

.category-item.yellow {
    background-color: rgba(255, 193, 7, 0.1);
}

.category-item.red {
    background-color: rgba(220, 53, 69, 0.1);
}

.category-color {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    margin-top: 2px;
    flex-shrink: 0;
}

.category-item.green .category-color {
    background-color: var(--success);
}

.category-item.yellow .category-color {
    background-color: #CC8800;
}

.category-item.red .category-color {
    background-color: var(--error);
}

.category-text {
    flex: 1;
}

.category-text strong {
    color: var(--primary-500);
    font-weight: 600;
}

.category-text p {
    margin-top: var(--space-xs);
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--neutral-700);
}

/* Responsive Design for Kidney Calculator */
@media (max-width: 768px) {
    .gfr-value {
        font-size: 2.5rem;
    }
    
    .info-cards {
        gap: var(--space-sm);
    }
    
    .info-card {
        padding: var(--space-sm);
    }
    
    .category-legend {
        gap: var(--space-sm);
    }
    
    .category-item {
        padding: var(--space-sm);
    }
    
    .category-text p {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .gfr-value {
        font-size: 2rem;
    }
    
    .kidney-status {
        flex-direction: column;
        text-align: center;
        gap: var(--space-xs);
    }
    
    .status-text {
        text-align: center;
    }
}