/* Import IBM Plex Sans */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Mono:wght@400&display=swap');

/* CSS Variables */
:root {
    /* Viewport Units - Dynamic height support */
    --vh: 1vh;
    --viewport-height: 100vh;
    --dynamic-vh: 1dvh; /* Dynamic viewport height for mobile */
    
    /* Colors - WCAG 2.1 AA Compliant */
    --color-white: #FFFFFF;
    --color-black: #000000;
    --color-gray-light: #F5F5F5;
    --color-gray-medium: #E0E0E0;
    --color-gray-dark: #595959; /* Changed from #757575 to meet 4.6:1 contrast ratio */
    --color-border: #767676; /* Changed from #DDDDDD to meet 4.5:1 contrast ratio */
    --color-focus: #0056b3; /* Enhanced focus color for better contrast */
    --color-success: #0d7534; /* Changed from #00A651 to meet 4.5:1 contrast ratio */
    --color-error: #b91c1c; /* Changed from #D32F2F to meet 4.5:1 contrast ratio */
    
    /* Typography */
    --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'IBM Plex Mono', 'Monaco', monospace;
    
    /* Font Sizes - Ultra Compact */
    --text-xl: clamp(20px, 2.5vw, 24px);
    --text-lg: clamp(16px, 2vw, 18px);
    --text-md: clamp(14px, 1.8vw, 16px);
    --text-base: 13px;
    --text-sm: 11px;
    --text-xs: 10px;
    
    /* Font Weights */
    --weight-regular: 400;
    --weight-medium: 500;
    --weight-semibold: 600;
    
    /* Line Heights */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.6;
    
    /* Spacing - Ultra Compact */
    --space-xs: 2px;
    --space-sm: 4px;
    --space-md: 8px;
    --space-lg: 12px;
    --space-xl: 16px;
    --space-2xl: 20px;
    --space-3xl: 24px;
    --space-4xl: 32px;
    
    /* Container */
    --container-max-width: 1200px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
}

/* Reset */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Base */
html {
    font-size: 16px;
    min-height: var(--viewport-height);
    min-height: var(--dynamic-vh, var(--viewport-height)); /* Fallback for browsers without dvh */
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: var(--weight-regular);
    line-height: var(--line-height-normal);
    color: var(--color-black);
    background: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: var(--viewport-height);
    min-height: var(--dynamic-vh, var(--viewport-height)); /* Fallback for browsers without dvh */
    display: flex;
    flex-direction: column;
    margin: 0;
    padding: 0;
}

/* Container */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 100%;
}

/* Main container - base styles with proper flex inheritance */
.tab-content[data-tab="optimize"] {
    display: grid;
    flex: 1 1 auto;
    min-height: 0; /* Allow grid to shrink properly */
    /* Grid layout defined in media queries below */
}

/* =================================================================
   MOBILE-FIRST RESPONSIVE GRID LAYOUT
   ================================================================= */

/* Base Mobile (0px+) - Default single column */
.tab-content[data-tab="optimize"] {
    grid-template-areas: 
        "input-area"
        "results-area";
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
    gap: var(--space-sm);
}


/* Large Phone (480px+) - Better spacing */
@media (min-width: 480px) {
    .tab-content[data-tab="optimize"] {
        gap: var(--space-md);
    }
    
}

/* Tablet (768px+) - Side by side layout */
@media (min-width: 768px) {
    .tab-content[data-tab="optimize"] {
        grid-template-areas: "input-area results-area";
        grid-template-columns: 1fr 1fr;
        grid-template-rows: 1fr;
        gap: var(--space-lg);
    }
    
}

/* Desktop (1024px+) - Optimized proportions */
@media (min-width: 1024px) {
    .tab-content[data-tab="optimize"] {
        grid-template-columns: 45% 55%;
        gap: var(--space-xl);
        max-width: 1400px;
        margin: 0 auto;
    }
    
}

/* Large Desktop (1440px+) - Ultra-wide optimization */
@media (min-width: 1440px) {
    .tab-content[data-tab="optimize"] {
        grid-template-columns: 40% 60%;
        gap: var(--space-2xl);
        max-width: 1800px;
    }
    
}

/* Skip link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--color-black);
    color: var(--color-white);
    padding: 8px;
    text-decoration: none;
    font-weight: var(--weight-medium);
    border-radius: 4px;
    z-index: 1000;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 6px;
}

/* Enhanced Focus styles */
:focus-visible {
    outline: 3px solid var(--color-focus);
    outline-offset: 2px;
    border-radius: 2px;
}

/* Ensure focus is visible on all interactive elements */
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
a:focus-visible {
    outline: 3px solid var(--color-focus);
    outline-offset: 2px;
}

/* Header */
.header {
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-xs) 0;
    background: var(--color-white);
    flex-shrink: 0;
    height: 32px;
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: var(--text-base);
    font-weight: var(--weight-semibold);
    color: var(--color-black);
    cursor: pointer;
    padding: var(--space-xs);
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.7;
}

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

.nav-link {
    color: var(--color-black);
    text-decoration: none;
    font-size: var(--text-base);
    font-weight: var(--weight-regular);
    transition: opacity var(--transition-fast);
}

.nav-link:hover {
    opacity: 0.6;
}

.nav-link.active {
    background: var(--color-black);
    color: var(--color-white);
}

/* Tab System */
.tab-content {
    display: none;
}

.tab-content[data-tab="optimize"] {
    display: block;
}

.tab-content.active {
    display: block;
}

/* Advanced Feature Styles */
.analytics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.analytics-card {
    background: var(--color-gray-light);
    padding: var(--space-md);
    border: 1px solid var(--color-border);
}

.analytics-card h3 {
    margin-bottom: var(--space-sm);
    font-size: var(--text-base);
    font-weight: var(--weight-medium);
}

.battle-setup {
    margin-bottom: var(--space-lg);
}

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

.pattern-categories {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.pattern-category {
    padding: var(--space-sm) var(--space-md);
    background: var(--color-gray-light);
    border: 1px solid var(--color-border);
    font-family: var(--font-sans);
    font-size: var(--text-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pattern-category.active {
    background: var(--color-black);
    color: var(--color-white);
}

.pattern-category:hover {
    background: var(--color-gray-medium);
}

/* Main */
.main {
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    min-height: 0; /* Allow flex child to shrink */
    padding: var(--space-lg) 0;
}

/* Hero - now inline with logo */
.hero-inline {
    font-size: var(--text-xs);
    color: var(--color-gray-dark);
    font-style: italic;
    margin-left: var(--space-sm);
}

.hero {
    display: none;
}

.hero h1 {
    display: none;
}

.hero p {
    font-size: var(--text-md);
    font-weight: var(--weight-regular);
    color: var(--color-gray-dark);
    line-height: var(--line-height-relaxed);
}

/* Input Panel - Left Side */
.input-panel {
    grid-area: input-area;
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    min-height: 0;
}

.input-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    flex: 1;
}

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

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

.clear-btn {
    background: var(--color-gray-light);
    border: 1px solid var(--color-border);
    width: 20px;
    height: 20px;
    font-size: var(--text-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-sans);
    color: var(--color-gray-dark);
    transition: all var(--transition-fast);
}

.clear-btn:hover {
    background: var(--color-gray-medium);
    color: var(--color-black);
}

/* Results Panel - Right Side */
.results-panel {
    grid-area: results-area;
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    min-height: 0;
}

.panel-title {
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
    color: var(--color-black);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Compact Provider Grid */
.provider-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-sm);
}

/* Inline Metrics Bar */
.metrics-bar {
    display: flex;
    gap: var(--space-lg);
    padding: var(--space-sm) 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.metrics-bar .metric {
    flex: 1;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--text-xs);
}

.metrics-bar .metric-label {
    color: var(--color-gray-dark);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.metrics-bar .metric-value {
    font-weight: var(--weight-semibold);
    color: var(--color-black);
}

/* Quality Results Bar */
.quality-results-bar {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--color-gray-light);
    border: 1px solid var(--color-border);
    border-radius: 4px;
}

.quality-result-item {
    text-align: center;
}

.quality-result-label {
    font-size: var(--text-xs);
    color: var(--color-gray-dark);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    margin-bottom: var(--space-xs);
}

.quality-result-score {
    font-size: var(--text-lg);
    font-weight: var(--weight-semibold);
    color: var(--color-black);
    display: block;
}

.quality-result-delta {
    font-size: var(--text-xs);
    color: var(--color-success);
    font-weight: var(--weight-medium);
    margin-top: var(--space-xs);
}

/* Results Content Area */
.result-content {
    flex: 1;
    padding: var(--space-lg);
    background: var(--color-gray-light);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-size: var(--text-sm);
    line-height: var(--line-height-normal);
    overflow-y: auto;
}

.results-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    color: var(--color-gray-dark);
    min-height: 150px;
}

.result-actions {
    display: flex;
    gap: var(--space-md);
    margin-top: var(--space-md);
}

.result-actions .btn {
    flex: 1;
    padding: var(--space-sm);
    background: var(--color-gray-light);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-size: var(--text-xs);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.result-actions .btn:hover {
    background: var(--color-gray-medium);
}

.label {
    display: block;
    margin-bottom: var(--space-sm);
    font-size: var(--text-base);
    font-weight: var(--weight-medium);
    color: var(--color-black);
}

.textarea {
    width: 100%;
    flex: 1;
    min-height: 200px;
    padding: var(--space-md);
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: var(--weight-regular);
    line-height: var(--line-height-relaxed);
    color: var(--color-black);
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: 0;
    resize: none; /* Disable resize for grid layout */
    transition: border-color var(--transition-fast);
    overflow-y: auto;
}

.textarea:focus {
    outline: none;
    border-color: var(--color-black);
}

.textarea::placeholder {
    color: var(--color-gray-dark);
    font-style: normal;
}

.input-footer {
    display: flex;
    justify-content: flex-end;
    margin-top: var(--space-sm);
}

.counter {
    font-size: var(--text-sm);
    font-weight: var(--weight-regular);
    color: var(--color-gray-dark);
}

/* Providers */
.providers {
    grid-area: controls;
}

.provider-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: var(--space-sm);
}

.provider-btn {
    padding: var(--space-sm) var(--space-md);
    background: var(--color-white);
    color: var(--color-black);
    border: 1px solid var(--color-border);
    font-family: var(--font-sans);
    font-size: var(--text-sm);
    font-weight: var(--weight-regular);
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: 0;
}

.provider-btn:hover {
    background: var(--color-gray-light);
    border-color: var(--color-black);
}

.provider-btn.active {
    background: var(--color-black);
    color: var(--color-white);
    border-color: var(--color-black);
}

/* Metrics */
.metrics {
    grid-area: metrics;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-sm);
}

.metric {
    padding: var(--space-sm);
    background: var(--color-gray-light);
    text-align: center;
    border-radius: 0;
}

.metric-label {
    display: block;
    font-size: var(--text-sm);
    font-weight: var(--weight-regular);
    color: var(--color-gray-dark);
    margin-bottom: var(--space-sm);
}

.metric-value {
    display: block;
    font-size: var(--text-lg);
    font-weight: var(--weight-semibold);
    font-family: var(--font-mono);
    color: var(--color-black);
    line-height: var(--line-height-tight);
}

/* Optimize Button */
.optimize-btn {
    grid-area: optimize;
    width: 100%;
    padding: var(--space-md);
    background: var(--color-black);
    color: var(--color-white);
    border: none;
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: var(--weight-medium);
    cursor: pointer;
    transition: background-color var(--transition-fast);
    border-radius: 0;
}

.optimize-btn:hover {
    background: #1a1a1a;
}

.optimize-btn:disabled {
    background: var(--color-gray-dark);
    cursor: not-allowed;
}

/* Results */
.results {
    grid-area: results-area;
    border: 1px solid var(--color-border);
    padding: var(--space-md);
    background: var(--color-gray-light);
    overflow-y: auto;
    min-height: 0; /* Allow grid item to shrink */
}

.results h2 {
    font-size: var(--text-md);
    font-weight: var(--weight-semibold);
    color: var(--color-black);
    margin-bottom: var(--space-lg);
}

.results h3 {
    font-size: var(--text-base);
    font-weight: var(--weight-medium);
    color: var(--color-black);
    margin: var(--space-lg) 0 var(--space-sm) 0;
}

/* Quality Metrics */
.quality-metrics {
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: var(--color-gray-light);
}

.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: var(--space-sm);
    margin-top: var(--space-sm);
}

.metric-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--space-sm);
    border: 1px solid var(--color-border);
    background: var(--color-white);
}

.metric-item.overall {
    grid-column: span 2;
    font-weight: var(--weight-semibold);
}

.metric-name {
    font-size: var(--text-xs);
    text-transform: lowercase;
    color: var(--color-gray-dark);
    margin-bottom: var(--space-xs);
}

.metric-score {
    font-family: var(--font-mono);
    font-size: var(--text-base);
    font-weight: var(--weight-semibold);
}

/* Score Classes */
.metric-score.excellent {
    color: #22c55e;
}

.metric-score.very-good {
    color: #84cc16;
}

.metric-score.good {
    color: #eab308;
}

.metric-score.adequate {
    color: #f59e0b;
}

.metric-score.needs-improvement {
    color: #f97316;
}

.metric-score.poor {
    color: #ef4444;
}

/* Safety Status */
.safety-status {
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: var(--color-gray-light);
}

.safety-indicator {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-top: var(--space-sm);
}

.safety-badge {
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-border);
    background: var(--color-white);
    font-size: var(--text-xs);
    text-transform: lowercase;
    font-weight: var(--weight-medium);
}

.safety-badge.safe {
    color: #22c55e;
    border-color: #22c55e;
}

.safety-badge.needs-review {
    color: #f59e0b;
    border-color: #f59e0b;
}

.safety-badge.unsafe {
    color: #ef4444;
    border-color: #ef4444;
}

.safety-score {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
}

/* Improvement Summary */
.improvement-summary {
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: var(--color-gray-light);
}

.improvement-list {
    list-style: none;
    margin-top: var(--space-sm);
}

.improvement-item {
    padding: var(--space-xs) 0;
    font-size: var(--text-sm);
    border-bottom: 1px solid var(--color-border);
}

.improvement-item:last-child {
    border-bottom: none;
}

.improvement-item:before {
    content: "• ";
    color: var(--color-gray-dark);
    font-weight: var(--weight-medium);
}

.result-content {
    padding: var(--space-lg);
    background: var(--color-gray-light);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    line-height: var(--line-height-relaxed);
    color: var(--color-black);
    margin-bottom: var(--space-md);
    white-space: pre-wrap;
    word-wrap: break-word;
}

.result-actions {
    display: flex;
    gap: var(--space-sm);
}

/* Buttons */
.btn {
    padding: var(--space-sm) var(--space-lg);
    background: var(--color-white);
    color: var(--color-black);
    border: 1px solid var(--color-border);
    font-family: var(--font-sans);
    font-size: var(--text-sm);
    font-weight: var(--weight-regular);
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: 0;
}

.btn:hover {
    background: var(--color-gray-light);
    border-color: var(--color-black);
}

.btn-small {
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--text-xs);
}

/* Footer */
.footer {
    border-top: 1px solid var(--color-border);
    padding: var(--space-xs) 0;
    background: var(--color-white);
    flex-shrink: 0;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xs);
    color: var(--color-gray-dark);
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.footer-links a {
    color: var(--color-black);
    text-decoration: none;
    font-size: var(--text-sm);
    font-weight: var(--weight-regular);
    transition: opacity var(--transition-fast);
}

.footer-links a:hover {
    opacity: 0.6;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal.open {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--color-white);
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    border: 1px solid var(--color-border);
    transform: translateY(20px);
    transition: transform var(--transition-normal);
}

.modal.open .modal-content {
    transform: translateY(0);
}

.modal-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--color-white);
}

.modal-header h2 {
    font-size: var(--text-md);
    font-weight: var(--weight-semibold);
    color: var(--color-black);
}

.close-btn {
    width: 32px;
    height: 32px;
    background: var(--color-white);
    color: var(--color-black);
    border: 1px solid var(--color-border);
    cursor: pointer;
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: var(--weight-regular);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    background: var(--color-gray-light);
}

.modal-body {
    padding: var(--space-lg);
}

.setting-group {
    margin-bottom: var(--space-lg);
}

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-group label {
    display: block;
    margin-bottom: var(--space-sm);
    font-size: var(--text-base);
    font-weight: var(--weight-medium);
    color: var(--color-black);
}

.input-group {
    display: flex;
    gap: var(--space-sm);
}

.input {
    flex: 1;
    padding: var(--space-sm);
    border: 1px solid var(--color-border);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--color-black);
    background: var(--color-white);
    transition: border-color var(--transition-fast);
}

.input:focus {
    outline: none;
    border-color: var(--color-black);
}

.modal-footer {
    padding: var(--space-lg);
    border-top: 1px solid var(--color-border);
    display: flex;
    justify-content: flex-end;
    background: var(--color-white);
}

/* Toast */
.toast-container {
    position: fixed;
    top: var(--space-lg);
    right: var(--space-lg);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    pointer-events: none;
}

.toast {
    padding: var(--space-sm) var(--space-md);
    background: var(--color-white);
    border: 1px solid var(--color-border);
    font-size: var(--text-sm);
    color: var(--color-black);
    min-width: 200px;
    pointer-events: auto;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
}

.toast.show {
    transform: translateX(0);
}

.toast.success {
    border-left: 3px solid var(--color-success);
}

.toast.error {
    border-left: 3px solid var(--color-error);
}

/* Responsive Design - Mobile First Approach */

/* Navigation Toggle for Mobile */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: var(--text-lg);
    cursor: pointer;
    padding: var(--space-xs);
}

/* OLD BREAKPOINT REMOVED - Using new adaptive breakpoints above */
    
    .optimize-btn {
        position: fixed;
        bottom: var(--space-lg);
        right: var(--space-lg);
        width: auto;
        min-width: 200px;
        z-index: 1000;
        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    }
}

/* OLD TABLET BREAKPOINT REMOVED - Using new adaptive breakpoints above */

    .provider-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--space-xs);
    }
    
    .provider-btn {
        padding: var(--space-xs);
        font-size: var(--text-xs);
    }

    .nav {
        gap: var(--space-sm);
    }
    
    .nav-link {
        padding: var(--space-xs) var(--space-sm);
        font-size: var(--text-xs);
    }
}

/* OLD MOBILE BREAKPOINT - Preserving other mobile styles but removing grid conflicts */
@media (max-width: 767px) {
    .container {
        padding: 0 var(--space-sm);
    }

    .header {
        height: 50px;
        position: sticky;
        top: 0;
        z-index: 100;
    }
    
    .header .container {
        position: relative;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-white);
        border: 1px solid var(--color-border);
        border-top: none;
        display: none;
        flex-direction: column;
        z-index: 99;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }
    
    .nav.active {
        display: flex;
    }
    
    .nav-link {
        width: 100%;
        text-align: left;
        padding: var(--space-md);
        border-bottom: 1px solid var(--color-border);
        border-radius: 0;
        background: var(--color-white);
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }

    /* OLD GRID REMOVED - Using new adaptive breakpoints above */

    .hero h1 {
        font-size: var(--text-lg);
        line-height: var(--line-height-tight);
    }

    .input-section {
        position: relative;
    }
    
    .providers {
        margin-bottom: var(--space-sm);
    }
    
    .provider-fieldset {
        border: none;
        padding: 0;
    }
    
    .provider-legend {
        font-size: var(--text-sm);
        font-weight: var(--weight-medium);
        margin-bottom: var(--space-sm);
    }

    .provider-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-xs);
    }
    
    .provider-btn {
        padding: var(--space-sm);
        font-size: var(--text-xs);
        text-align: center;
        min-height: 44px;
    }

    .metrics {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: var(--space-xs);
        margin-bottom: var(--space-sm);
    }

    .metric {
        flex-direction: column;
        text-align: center;
        padding: var(--space-sm);
        background: var(--color-gray-light);
        border: 1px solid var(--color-border);
        border-radius: 4px;
    }
    
    .metric-label {
        font-size: var(--text-xs);
        margin-bottom: var(--space-xs);
    }
    
    .metric-value {
        font-size: var(--text-md);
        font-weight: var(--weight-semibold);
    }

    .optimize-btn {
        position: fixed;
        bottom: var(--space-md);
        left: var(--space-md);
        right: var(--space-md);
        width: auto;
        z-index: 1000;
        box-shadow: 0 4px 12px rgba(0,0,0,0.2);
        font-size: var(--text-base);
        padding: var(--space-md);
    }

    .results {
        margin-bottom: var(--space-3xl);
    }

    .footer {
        padding: var(--space-md) 0;
        margin-top: var(--space-lg);
    }
    
    .footer .container {
        flex-direction: column;
        gap: var(--space-sm);
        text-align: center;
    }
    
    .footer-links {
        display: none; /* Hide footer links on mobile to save space */
    }

    /* Touch-friendly interactions */
    .provider-btn,
    .nav-link,
    .clear-btn,
    .btn {
        min-height: 44px; /* Apple's recommended touch target */
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    .clear-btn {
        width: 44px;
        height: 44px;
        font-size: var(--text-lg);
    }
    
    /* Input improvements for mobile */
    .textarea {
        font-size: 16px; /* Prevent zoom on iOS */
        min-height: 120px;
    }

    .modal-content {
        width: 95%;
        margin: var(--space-md);
    }
    
    .toast-container {
        left: var(--space-md);
        right: var(--space-md);
        bottom: 100px; /* Above fixed button */
}

/* Ultra-wide screens (>1400px) */
@media (min-width: 1400px) {
    .main .container {
        grid-template-columns: 40% 60%;
        gap: var(--space-2xl);
        max-width: 1600px;
    }
}

/* Utility classes for responsive behavior */
.mobile-single-column .provider-grid {
    grid-template-columns: 1fr !important;
}

.mobile-fixed {
    position: fixed !important;
    bottom: var(--space-md) !important;
    left: var(--space-md) !important;
    right: var(--space-md) !important;
    z-index: 1000 !important;
}

/* Print styles */
@media print {
    .nav-toggle,
    .nav,
    .optimize-btn,
    .footer-links {
        display: none !important;
    }
    
    /* OLD GRID REMOVED - Using new adaptive breakpoints above */
}

@media (max-width: 480px) {
    .main {
        padding: var(--space-2xl) 0;
    }
    
    .hero {
        margin-bottom: var(--space-2xl);
    }
    
    .optimize-btn {
        padding: var(--space-md);
    }
}

/* Print styles moved to responsive section above */

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --color-border: #999999;
        --color-gray-dark: #333333;
    }
}

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

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    /* Keep light theme for now as per requirements */
}

/* Input error styles */
.input-error {
    display: block;
    color: var(--color-error);
    font-size: var(--text-sm);
    margin-top: var(--space-xs);
    font-weight: var(--weight-medium);
}

.input-error:empty {
    display: none;
}

/* Provider fieldset styles */
.provider-fieldset {
    border: 1px solid var(--color-border);
    margin: 0;
    padding: var(--space-md);
    border-radius: 4px;
}

.provider-legend {
    font-weight: var(--weight-semibold);
    padding: 0 var(--space-sm);
    color: var(--color-black);
}

/* Navigation button styles */
.nav-link[data-action] {
    background: none;
    border: none;
    color: var(--color-black);
    text-decoration: none;
    font-size: var(--text-base);
    font-weight: var(--weight-regular);
    cursor: pointer;
    transition: opacity var(--transition-fast);
}

.nav-link[data-action]:hover {
    opacity: 0.6;
}

/* Utility classes */
.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;
}

.hidden {
    display: none !important;
}

.loading {
    opacity: 0.5;
    pointer-events: none;
}