/* Daily Water Calculator - Optimized Styles */

/* Performance Critical Styles */
.nav-toggle {
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1001;
    background: var(--primary-blue, #1E90FF);
    border: none;
    border-radius: 0.5rem;
    padding: 0.75rem;
    cursor: pointer;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease-in-out;
    display: flex !important;
    flex-direction: column;
    gap: 0.25rem;
    min-height: 44px;
    min-width: 44px;
    contain: layout style;
}

.hamburger {
    width: 20px;
    height: 2px;
    background: white;
    transition: all 0.2s ease-in-out;
    will-change: transform;
}

/* CSS Variables */
:root {
    --primary-blue: #1E90FF;
    --primary-blue-dark: #0066CC;
    --success-green: #10B981;
    --success-green-dark: #047857;
    --neutral-50: #F9FAFB;
    --neutral-100: #F3F4F6;
    --neutral-200: #E5E7EB;
    --neutral-300: #D1D5DB;
    --neutral-400: #9CA3AF;
    --neutral-500: #6B7280;
    --neutral-600: #4B5563;
    --neutral-700: #374151;
    --neutral-800: #1F2937;
    --neutral-900: #111827;
    --white: #FFFFFF;
    
    --gradient-primary: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-dark) 100%);
    --gradient-success: linear-gradient(135deg, var(--success-green) 0%, var(--success-green-dark) 100%);
    --gradient-bg: linear-gradient(135deg, #F0F9FF 0%, #E0F2FE 50%, #F0FDF4 100%);
    
    --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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    --transition: all 0.2s ease-in-out;
    --transition-slow: all 0.3s ease-in-out;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gradient-bg);
    color: var(--neutral-800);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    margin: 0;
    transition: margin-left 0.3s ease;
    contain: layout style;
    will-change: margin-left;
}

/* Navigation Responsive Breakpoints */
@media (min-width: 769px) and (max-width: 1024px) {
    body {
        margin-left: 0;
    }

    body.nav-closed {
        margin-left: 0;
    }
    
    .side-nav {
        width: 250px;
        left: -250px;
    }
    
    .side-nav.open {
        left: 0;
    }
    
    .nav-toggle {
        display: flex !important;
    }
}

@media (min-width: 1025px) {
    body {
        margin-left: 0;
    }

    body.nav-closed {
        margin-left: 0;
    }
    
    .side-nav {
        width: 250px;
        left: -250px;
    }
    
    .side-nav.open {
        left: 0;
    }
    
    .nav-toggle {
        display: flex !important;
    }
}


/* Mobile-First Navigation Design */
@media (max-width: 768px) {
    body {
        margin-left: 0 !important;
        padding: 0.5rem;
    }
    
    .side-nav {
        position: fixed;
        top: 0;
        left: 0;
        width: 85%;
        max-width: 300px;
        height: 100vh;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        z-index: 1000;
        box-shadow: 2px 0 15px rgba(0, 0, 0, 0.15);
    }
    
    .side-nav.open {
        transform: translateX(0);
    }
    
    .nav-toggle {
        display: flex !important;
    }
    
    .footer-disclaimer {
        font-size: 0.75rem !important;
        line-height: 1.5 !important;
    }
    
    .footer a {
        padding: 0.25rem 0.5rem !important;
        display: inline-block !important;
    }
    
    .container {
        padding: 0 1rem !important;
    }
    
    .article-preview {
        grid-template-columns: 1fr !important;
        gap: 0 !important;
    }
    
    .nav-toggle {
        padding: 0.5rem !important;
        top: 0.75rem;
        left: 0.75rem;
        min-height: 40px !important;
        min-width: 40px !important;
    }
    
    /* Mobile Ad Container Optimization */
    .ad-container {
        margin: 1.5rem 0 !important;
        padding: 0.75rem !important;
        border-radius: 8px !important;
        overflow: hidden;
        min-height: 80px;
    }
    
    /* Mobile overlay for navigation */
    .nav-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
        display: none;
    }
    
    .nav-overlay.show {
        display: block;
    }
}

/* Toggle Button - Optimized */
.nav-toggle {
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    transform: translateZ(0); /* Force hardware acceleration */
}

.nav-toggle.show {
    display: flex !important;
}

.nav-toggle:hover {
    background: var(--primary-blue-dark);
    transform: scale(1.05);
}

.hamburger {
    transform: translateZ(0); /* Force hardware acceleration */
}

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

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

.nav-toggle.active .hamburger:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* Side Navigation */
.side-nav {
    position: fixed;
    left: -250px;
    top: 0;
    width: 250px;
    height: 100vh;
    background: white !important;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    display: flex !important;
    flex-direction: column;
    transition: left 0.3s ease;
    contain: layout style;
    will-change: left;
}

.side-nav.open {
    left: 0 !important;
}

.side-nav.closed {
    left: -250px;
}

.nav-header {
    padding: 1rem 1.5rem 0.75rem;
    border-bottom: 1px solid var(--neutral-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--neutral-600);
    cursor: pointer;
    transition: var(--transition);
    padding: 0.25rem;
    border-radius: var(--radius-sm);
}

.nav-close:hover {
    background: var(--neutral-100);
    color: var(--neutral-800);
}

.nav-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--neutral-800);
    margin: 0;
}

.nav-menu {
    list-style: none;
    padding: 0.5rem 0;
    margin: 0;
}

.nav-menu li {
    margin: 0;
}

.nav-link {
    display: block;
    padding: 0.75rem 1.5rem;
    color: var(--neutral-600);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.nav-link:hover {
    background: var(--neutral-50);
    color: var(--primary-blue);
}

.nav-link.active {
    background: rgba(30, 144, 255, 0.1);
    color: var(--primary-blue);
    border-left-color: var(--primary-blue);
}

/* Mobile Navigation Override */
@media (max-width: 768px) {
    .side-nav {
        position: fixed !important;
        width: 85% !important;
        max-width: 300px !important;
        height: 100vh !important;
        top: 0 !important;
        left: -85% !important;
        z-index: 1000 !important;
        transition: left 0.3s ease !important;
    }
    
    .side-nav.open {
        left: 0 !important;
    }
    
    .nav-menu {
        display: flex;
        flex-direction: column;
        padding: 1rem 0;
        overflow-y: auto;
    }
    
    .nav-menu li {
        flex-shrink: 0;
    }
    
    .nav-link {
        padding: 1rem 1.5rem;
        white-space: nowrap;
        border-left: 3px solid transparent;
        border-bottom: none;
        min-height: 48px;
        display: flex;
        align-items: center;
    }
    
    .nav-link.active {
        border-left-color: var(--primary-blue);
        border-bottom: none;
        background: rgba(30, 144, 255, 0.1);
    }
}

.container {
    max-width: 48rem;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header - Mobile Responsive */
.header {
    background: transparent;
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 3rem 0 2rem;
}

@media (max-width: 768px) {
    .header {
        padding: 1.5rem 0 1rem;
    }
    
    .header .title {
        font-size: 1.875rem;
        line-height: 1.2;
        margin-bottom: 0.75rem;
        padding: 0 0.5rem;
    }
    
    .header .subtitle {
        font-size: 1rem;
        line-height: 1.5;
        padding: 0 1rem;
        color: var(--neutral-600);
    }
}

@media (max-width: 480px) {
    .header {
        padding: 1.25rem 0 0.75rem;
    }
    
    .header .title {
        font-size: 1.625rem;
        margin-bottom: 0.5rem;
    }
    
    .header .subtitle {
        font-size: 0.95rem;
    }
}

.header-content {
    max-width: 36rem;
    margin: 0 auto;
}

.title {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.75rem;
    line-height: 1.2;
}

.subtitle {
    font-size: 1.125rem;
    color: var(--neutral-600);
    font-weight: 400;
    margin-bottom: 0;
}

/* Main Content */
.main {
    padding: 1rem 0 3rem;
}

.calculator-card {
    background: var(--white);
    border-radius: var(--radius-2xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--neutral-200);
    margin-bottom: 2rem;
}

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

.calculator-header h2 {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--neutral-900);
    margin-bottom: 0.5rem;
}

.calculator-header p {
    color: var(--neutral-600);
    font-size: 1rem;
}

/* Form Styles - Responsive */
.calculator-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

/* Form Grid for larger screens */
@media (min-width: 769px) {
    .form-row {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
    
    .form-group.full-width {
        grid-column: 1 / -1;
    }
}

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

.form-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--neutral-700);
    margin-bottom: 0.5rem;
    display: block;
}

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

.form-input {
    width: 100%;
    padding: 0.875rem 3rem 0.875rem 1rem;
    border: 2px solid var(--neutral-300);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-weight: 500;
    color: var(--neutral-900);
    background: var(--white);
    transition: var(--transition);
    appearance: none;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(30, 144, 255, 0.1);
}

.form-input:invalid {
    border-color: #EF4444;
}

.input-unit {
    position: absolute;
    right: 1rem;
    color: var(--neutral-500);
    font-weight: 600;
    font-size: 0.875rem;
    pointer-events: none;
}

.form-select {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--neutral-300);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-weight: 500;
    color: var(--neutral-900);
    background: var(--white);
    transition: var(--transition);
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.75rem center;
    background-repeat: no-repeat;
    background-size: 1rem;
    padding-right: 2.5rem;
}

.form-select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(30, 144, 255, 0.1);
}

/* Button Styles - Responsive */
.calculate-btn {
    background: var(--gradient-primary);
    color: var(--white);
    border: none;
    padding: 1rem 2rem;
    border-radius: var(--radius-xl);
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    min-height: 3.5rem;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

/* Mobile touch targets - Enhanced */
@media (max-width: 768px) {
    .calculate-btn {
        min-height: 52px;
        padding: 1rem 1.5rem;
        font-size: 1.1rem;
        width: 100%;
        font-weight: 600;
        letter-spacing: 0.025em;
        box-shadow: 0 4px 12px rgba(30, 144, 255, 0.25);
        transition: all 0.2s ease;
    }
    
    .calculate-btn:active {
        transform: translateY(1px);
        box-shadow: 0 2px 8px rgba(30, 144, 255, 0.25);
    }
    
    .action-btn {
        min-height: 48px;
        padding: 0.875rem 1.25rem;
        width: 100%;
        max-width: none;
        font-weight: 500;
    }
    
    .nav-link {
        min-height: 48px;
        padding: 1rem 1.5rem;
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
    }
    
    /* Enhanced Form Inputs for Mobile */
    .form-input, .form-select {
        min-height: 50px;
        padding: 0.875rem 1rem;
        font-size: 1rem;
        border-radius: var(--radius-lg);
        border: 2px solid var(--neutral-200);
        background: var(--white);
        transition: all 0.2s ease;
        -webkit-appearance: none;
        appearance: none;
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
    }
    
    .form-input:focus, .form-select:focus {
        border-color: var(--primary-blue);
        box-shadow: 0 0 0 3px rgba(30, 144, 255, 0.1);
        outline: none;
    }
    
    .form-label {
        font-size: 0.95rem;
        font-weight: 600;
        color: var(--neutral-700);
        margin-bottom: 0.5rem;
        display: block;
    }
    
    .form-group {
        margin-bottom: 1.25rem;
    }
}

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

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

.calculate-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-text {
    display: block;
}

/* Result Styles */
.result-section {
    animation: fadeInUp 0.6s ease-out;
}

.result-card {
    text-align: center;
    background: var(--gradient-success);
    color: var(--white);
    padding: 2.5rem 2rem;
    border-radius: var(--radius-2xl);
    margin-bottom: 2rem;
    box-shadow: var(--shadow-lg);
}

.result-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
    display: block;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
}

.result-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.result-amount {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1rem;
    font-family: 'Inter', monospace;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.result-details {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 500;
}

/* Tips Section - Enhanced Typography */
.tips-section {
    background: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius-xl);
    padding: 2rem;
    border: 1px solid rgba(226, 232, 240, 0.5);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(10px);
    transition: var(--transition);
    margin: 2.5rem 0;
}

.tips-section:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(30, 144, 255, 0.2);
}

.tips-section h4 {
    color: var(--neutral-800);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    line-height: 1.4;
}

.tips-section h4::before {
    content: "💡";
    font-size: 1.5rem;
}

.tips-section p {
    line-height: 1.6;
    color: var(--neutral-600);
    margin-bottom: 1rem;
}

.tips-section ul {
    padding-left: 1.25rem;
    margin-bottom: 1rem;
}

.tips-section li {
    line-height: 1.6;
    color: var(--neutral-600);
    margin-bottom: 0.5rem;
}

/* Responsive Tips Section - Enhanced */
@media (max-width: 480px) {
    .tips-section {
        padding: 1rem;
        border-radius: var(--radius-lg);
        margin: 1.5rem 0;
    }
    
    .tips-section h4 {
        font-size: 1.1rem;
        margin-bottom: 1rem;
        line-height: 1.3;
    }
    
    .tips-section p, .tips-section li {
        font-size: 0.95rem;
        line-height: 1.5;
    }
}

@media (min-width: 481px) and (max-width: 768px) {
    .tips-section {
        padding: 1.5rem;
        margin: 2rem 0;
    }
    
    .tips-section h4 {
        font-size: 1.15rem;
    }
}

.tips-section h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--neutral-900);
    margin-bottom: 1.5rem;
    text-align: center;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.tip-card {
    background: var(--white);
    padding: 1.25rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--neutral-200);
    transition: var(--transition);
}

.tip-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.tip-emoji {
    font-size: 2rem;
    margin-bottom: 0.75rem;
    display: block;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.tip-text {
    font-size: 0.875rem;
    color: var(--neutral-700);
    font-weight: 500;
}

/* Quick Actions */
.quick-actions {
    background: var(--white);
    border-radius: var(--radius-2xl);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--neutral-200);
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

.quick-actions h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--neutral-900);
    margin-bottom: 1.5rem;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.action-btn {
    background: var(--white);
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

/* Footer */
.footer {
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--neutral-200);
    background: var(--white);
}

.footer-content {
    max-width: 32rem;
    margin: 0 auto;
}

.footer-text {
    font-size: 1rem;
    color: var(--neutral-700);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.footer-disclaimer {
    font-size: 0.75rem;
    color: var(--neutral-500);
    font-weight: 400;
}

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

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

/* Loading State */
.loading .btn-text::after {
    content: '...';
    animation: pulse 1s infinite;
}

/* Tablet (Portrait) - 481px to 768px */
@media (min-width: 481px) and (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
        max-width: 90%;
    }
    
    .header {
        padding: 2.5rem 0 2rem;
    }
    
    .title {
        font-size: 2.25rem;
    }
    
    .subtitle {
        font-size: 1.1rem;
    }
    
    .calculator-card {
        padding: 2rem;
        margin-bottom: 1.75rem;
    }
    
    .calculator-header h2 {
        font-size: 1.6rem;
    }
    
    .calculator-form {
        gap: 1.25rem;
    }
    
    .tips-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.25rem;
    }
    
    .action-buttons {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.75rem;
    }
    
    .action-btn {
        flex: 1;
        min-width: 140px;
    }
    
    .side-nav {
        width: 280px;
    }
}

/* Mobile (Small Screens) - up to 480px */
@media (max-width: 480px) {
    .container {
        padding: 0 0.75rem;
    }
    
    .header {
        padding: 1.5rem 0 1rem;
    }
    
    .title {
        font-size: 1.75rem;
        line-height: 1.3;
        margin-bottom: 0.5rem;
    }
    
    .subtitle {
        font-size: 0.95rem;
    }
    
    .calculator-card {
        padding: 1rem;
        margin-bottom: 1.25rem;
        border-radius: var(--radius-xl);
    }
    
    .calculator-header h2 {
        font-size: 1.3rem;
        margin-bottom: 1rem;
    }
    
    .form-input, .form-select {
        padding: 0.875rem 1rem;
        font-size: 1rem;
        border-radius: var(--radius-lg);
        min-height: 48px;
        -webkit-appearance: none;
        appearance: none;
    }
    
    .calculate-btn {
        padding: 1rem 1.5rem;
        font-size: 1.1rem;
        min-height: 52px;
        border-radius: var(--radius-lg);
        width: 100%;
        margin-top: 0.5rem;
    }
    
    .result-card {
        padding: 1.25rem 1rem;
        margin-bottom: 1rem;
    }
    
    .result-amount {
        font-size: 2.25rem;
        margin-bottom: 0.5rem;
    }
    
    .result-icon {
        font-size: 2.5rem;
    }
    
    .tips-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .tip-card {
        padding: 1rem;
        border-radius: var(--radius-lg);
    }
    
    .tip-emoji {
        font-size: 1.75rem;
    }
    
    .quick-actions {
        padding: 1rem;
        margin-top: 1rem;
    }
    
    .action-buttons {
        flex-direction: column;
        align-items: center;
        gap: 0.75rem;
    }
    
    .action-btn {
        width: 100%;
        max-width: 280px;
        min-height: 48px;
        padding: 0.875rem 1.25rem;
        border-radius: var(--radius-lg);
    }
    
    /* Mobile Ad Container Optimization */
    .ad-container {
        margin: 1rem 0 !important;
        padding: 0.5rem !important;
        border-radius: 6px !important;
    }
    
    /* Mobile Touch Optimization */
    input, select, button {
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
    }
}

/* Mobile (Medium Screens) - 481px to 768px */
@media (min-width: 481px) and (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .header {
        padding: 2rem 0 1.5rem;
    }
    
    .title {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1.05rem;
    }
    
    .calculator-card {
        padding: 1.5rem;
        margin-bottom: 1.5rem;
    }
    
    .calculator-header h2 {
        font-size: 1.5rem;
    }
    
    .form-input, .form-select {
        padding: 0.875rem 1rem;
        font-size: 1rem;
        min-height: 48px;
        border-radius: var(--radius-lg);
    }
    
    .calculate-btn {
        min-height: 50px;
        padding: 1rem 1.5rem;
        font-size: 1.1rem;
        border-radius: var(--radius-lg);
        width: 100%;
    }
    
    .result-card {
        padding: 1.75rem 1.25rem;
    }
    
    .result-amount {
        font-size: 3rem;
    }
    
    .tips-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
    
    .quick-actions {
        padding: 1.25rem;
    }
    
    .action-buttons {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.75rem;
    }
    
    .action-btn {
        flex: 1;
        min-width: 140px;
        min-height: 48px;
        padding: 0.875rem 1.25rem;
        border-radius: var(--radius-lg);
    }
    
    /* Mobile Ad Container Optimization */
    .ad-container {
        margin: 1.25rem 0 !important;
        padding: 0.75rem !important;
        border-radius: 8px !important;
    }
}

/* Tablet (Landscape) - 769px to 1024px */
@media (min-width: 769px) and (max-width: 1024px) {
    body {
        margin-left: 220px;
    }
    
    .side-nav {
        width: 220px;
    }
    
    .container {
        max-width: 42rem;
        padding: 0 1.5rem;
    }
    
    .header {
        padding: 2.75rem 0 2.25rem;
    }
    
    .title {
        font-size: 2.4rem;
    }
    
    .subtitle {
        font-size: 1.15rem;
    }
    
    .calculator-card {
        padding: 2.25rem;
    }
    
    .tips-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 1.25rem;
    }
    
    .action-buttons {
        gap: 1.25rem;
    }
    
    .nav-toggle {
        display: flex !important;
    }
}

/* Large Desktop - 1025px and above */
@media (min-width: 1025px) {
    .container {
        max-width: 52rem;
        padding: 0 2rem;
    }
    
    .header {
        padding: 3.5rem 0 2.5rem;
    }
    
    .title {
        font-size: 2.75rem;
    }
    
    .subtitle {
        font-size: 1.2rem;
    }
    
    .calculator-card {
        padding: 3rem;
    }
    
    .tips-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 1.5rem;
    }
    
    .quick-actions {
        padding: 2.5rem;
    }
    
    .action-buttons {
        gap: 1.5rem;
    }
}

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

/* Focus styles for better accessibility */
.form-input:focus,
.form-select:focus,
.calculate-btn:focus,
.action-btn:focus {
    outline: 2px solid var(--primary-blue);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --neutral-300: #000000;
        --neutral-600: #000000;
        --neutral-700: #000000;
    }
}