/* Euler Buckling Visualizer Styles */

/* CSS Custom Properties for Theming */
:root {
    /* Light theme colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --border-color: #dee2e6;
    --accent-color: #0066cc;
    --accent-hover: #0052a3;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 8px rgba(0, 0, 0, 0.15);
}

/* Dark theme colors */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #1a1a1a;
        --bg-secondary: #2d2d2d;
        --bg-tertiary: #404040;
        --text-primary: #ffffff;
        --text-secondary: #b0b0b0;
        --border-color: #555555;
        --accent-color: #4da6ff;
        --accent-hover: #66b3ff;
        --success-color: #40c057;
        --warning-color: #fab005;
        --danger-color: #f03e3e;
        --shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
        --shadow-hover: 0 4px 8px rgba(0, 0, 0, 0.4);
    }
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    font-size: 16px;
}

/* App Container */
.app-container {
    min-height: 100vh;
    display: grid;
    grid-template-rows: auto 1fr auto;
    grid-template-areas: 
        "header"
        "main"
        "footer";
}

/* Header */
.app-header {
    grid-area: header;
    background-color: var(--bg-secondary);
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
    text-align: center;
}

.app-header h1 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

.app-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.tooltip-trigger {
    cursor: help;
    margin-left: 0.5rem;
    color: var(--accent-color);
}

.tooltip {
    display: none;
    position: absolute;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.5rem;
    font-size: 0.9rem;
    max-width: 300px;
    z-index: 1000;
    box-shadow: var(--shadow);
}

/* Main Layout */
.app-main {
    grid-area: main;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
    padding: 2rem;
    min-height: 0;
}

/* Parameter Panel */
.parameter-panel {
    background-color: var(--bg-secondary);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    height: fit-content;
    position: sticky;
    top: 2rem;
}

.parameter-panel h2 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--accent-color);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

.parameter-panel section {
    margin-bottom: 2rem;
}

.parameter-panel h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
}

/* Shape Selector */
.shape-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

.shape-checkbox {
    display: flex;
    align-items: center;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.shape-checkbox:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--accent-color);
}

.shape-checkbox input[type="checkbox"] {
    margin-right: 0.5rem;
}

/* Mode Selector */
.radio-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.radio-label {
    display: flex;
    align-items: center;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 4px;
    transition: background-color 0.2s ease;
}

.radio-label:hover {
    background-color: var(--bg-tertiary);
}

.radio-label input[type="radio"] {
    margin-right: 0.5rem;
}

/* Input Groups */
.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(0, 102, 204, 0.2);
}

.input-with-slider {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 0.5rem;
    align-items: center;
}

/* Reset Button */
.reset-button {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--warning-color);
    color: var(--text-primary);
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.reset-button:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-hover);
}

.reset-button:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(0, 102, 204, 0.5);
}

/* Loading Indicator */
.loading-indicator {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-hover);
    z-index: 1000;
    display: none;
    align-items: center;
    gap: 1rem;
    font-weight: 500;
    color: var(--text-primary);
}

.loading-spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-top: 2px solid var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Loading state for containers */
.loading {
    position: relative;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: inherit;
    pointer-events: none;
    z-index: 1;
}

@media (prefers-color-scheme: dark) {
    .loading::after {
        background-color: rgba(0, 0, 0, 0.2);
    }
}

/* Main Content */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    min-height: 0;
}

.main-content section {
    background-color: var(--bg-secondary);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.main-content h2 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--accent-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

/* Chart Section */
.chart-container {
    position: relative;
    height: 400px;
    width: 100%;
}

/* Preview Section */
.preview-controls {
    margin-bottom: 1rem;
}

.animation-button {
    padding: 0.5rem 1rem;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.animation-button:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

.preview-container {
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--bg-primary);
}

#cross-section-svg {
    width: 100%;
    height: auto;
    display: block;
    background-color: var(--bg-primary);
}

/* SVG Shape Styles */
.shape-group {
    cursor: pointer;
}

.shape-group:hover .shape-path {
    stroke: var(--accent-color);
    stroke-width: 3;
    opacity: 1;
    filter: drop-shadow(0 2px 4px rgba(0, 102, 204, 0.3));
}

.shape-group:focus {
    outline: none;
}

.shape-group:focus .shape-path {
    stroke: var(--accent-color);
    stroke-width: 3;
    opacity: 1;
    filter: drop-shadow(0 2px 4px rgba(0, 102, 204, 0.5));
}

.shape-path {
    transition: all 0.2s ease;
}

/* Animation states for compression animation */
.shape-group.compressed .shape-path {
    stroke: var(--warning-color);
    stroke-width: 3;
}

.shape-group.weakest .shape-path {
    stroke: var(--danger-color);
    stroke-width: 4;
    filter: drop-shadow(0 2px 8px rgba(220, 53, 69, 0.5));
}

.shape-group.compressed.weakest .shape-path {
    stroke: var(--danger-color);
    stroke-width: 4;
    filter: drop-shadow(0 2px 8px rgba(220, 53, 69, 0.7));
}

/* Shape Tooltip Styles */
.shape-tooltip {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 12px;
    font-size: 14px;
    box-shadow: var(--shadow-hover);
    z-index: 1000;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease;
    max-width: 280px;
    min-width: 200px;
    color: var(--text-primary);
    line-height: 1.4;
}

.tooltip-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.tooltip-header strong {
    color: var(--accent-color);
    font-size: 16px;
    font-weight: 600;
}

.tooltip-type {
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: normal;
}

.tooltip-mode {
    color: var(--text-secondary);
    font-size: 12px;
    margin-bottom: 0.75rem;
    font-style: italic;
}

.tooltip-content {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.tooltip-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.2rem 0;
}

.tooltip-label {
    color: var(--text-secondary);
    font-weight: 500;
    min-width: 100px;
}

.tooltip-value {
    color: var(--text-primary);
    font-weight: 600;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    text-align: right;
}

.critical-load-row {
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border-color);
}

.critical-load-row .tooltip-value {
    color: var(--success-color);
    font-size: 15px;
    font-weight: 700;
}

/* Dark theme adjustments for tooltip */
@media (prefers-color-scheme: dark) {
    .shape-tooltip {
        background-color: var(--bg-secondary);
        border-color: var(--border-color);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    }
}

/* Compression Animation Styles */
.compression-arrows {
    pointer-events: none;
}

.compression-arrow {
    animation: compressionPulse 1s ease-in-out infinite;
    transform-origin: center;
}

@keyframes compressionPulse {
    0% {
        opacity: 0.4;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.1);
    }
    100% {
        opacity: 0.4;
        transform: scale(1);
    }
}

/* Shape deformation animations - using SVG native animations */
.shape-group.compressed {
    /* Animation will be handled by JavaScript using SVG transforms */
    transition: transform 0.5s ease-in-out;
}

.shape-group.weakest {
    animation: weakestHighlight 1s ease-in-out infinite alternate;
}

.shape-group.compressed.weakest {
    animation: weakestHighlight 1s ease-in-out infinite alternate;
}

@keyframes weakestHighlight {
    0% {
        filter: drop-shadow(0 2px 8px rgba(220, 53, 69, 0.3));
    }
    100% {
        filter: drop-shadow(0 2px 12px rgba(220, 53, 69, 0.8));
    }
}

/* Animation button states */
.animation-button[aria-pressed="true"] {
    background-color: var(--warning-color);
    color: var(--text-primary);
}

.animation-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    .compression-arrow,
    .shape-group.compressed,
    .shape-group.weakest {
        animation: none !important;
    }
    
    .shape-group.compressed .shape-path {
        transition: none;
    }
    
    .shape-group.weakest .shape-path {
        filter: drop-shadow(0 2px 8px rgba(220, 53, 69, 0.8));
        transition: none;
    }
}

/* Results Table */
.table-container {
    overflow-x: auto;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-primary);
}

.results-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
    min-width: 600px; /* Ensure minimum width for readability */
}

.results-table th,
.results-table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    vertical-align: middle;
}

.results-table th {
    background-color: var(--bg-tertiary);
    font-weight: 600;
    color: var(--text-primary);
    position: sticky;
    top: 0;
    z-index: 10;
    white-space: nowrap;
}

.results-table th.sortable {
    cursor: pointer;
    user-select: none;
    transition: all 0.2s ease;
    position: relative;
}

.results-table th.sortable:hover {
    background-color: var(--accent-color);
    color: white;
    transform: translateY(-1px);
}

.results-table th.sortable:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: -2px;
}

.results-table th.sortable::after {
    content: ' ↕';
    opacity: 0.5;
    font-size: 0.8em;
    margin-left: 0.25rem;
}

.results-table th.sort-asc::after {
    content: ' ↑';
    opacity: 1;
    color: var(--success-color);
}

.results-table th.sort-desc::after {
    content: ' ↓';
    opacity: 1;
    color: var(--success-color);
}

/* Table body styles */
.results-table tbody tr {
    transition: background-color 0.2s ease;
}

.results-table tbody tr:hover {
    background-color: var(--bg-tertiary);
}

.results-table tbody tr:nth-child(even) {
    background-color: rgba(0, 0, 0, 0.02);
}

@media (prefers-color-scheme: dark) {
    .results-table tbody tr:nth-child(even) {
        background-color: rgba(255, 255, 255, 0.02);
    }
}

/* Table cell content styling */
.shape-name {
    font-weight: 500;
    min-width: 120px;
}

.shape-type-indicator {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    margin-right: 0.5rem;
    vertical-align: middle;
}

.shape-type-indicator.circle {
    background-color: var(--accent-color);
}

.shape-type-indicator.polygon {
    background-color: var(--success-color);
    border-radius: 2px;
}

.sides-count {
    color: var(--text-secondary);
    font-size: 0.8em;
    margin-left: 0.25rem;
}

.numerical-value {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    text-align: right;
    min-width: 80px;
}

.valid-value {
    color: var(--text-primary);
}

.error-value {
    color: var(--danger-color);
    font-weight: 500;
}

.invalid-value {
    color: var(--warning-color);
    font-style: italic;
}

.highest-load {
    color: var(--success-color);
    font-weight: 600;
}

.critical-load {
    font-weight: 500;
}

.empty-results {
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
    padding: 2rem;
}

/* Responsive table design */
@media (max-width: 768px) {
    .table-container {
        border: none;
        border-radius: 0;
    }
    
    .results-table {
        min-width: unset;
        font-size: 0.8rem;
    }
    
    .results-table,
    .results-table thead,
    .results-table tbody,
    .results-table th,
    .results-table td,
    .results-table tr {
        display: block;
    }
    
    .results-table thead tr {
        position: absolute;
        top: -9999px;
        left: -9999px;
    }
    
    .results-table tr {
        border: 1px solid var(--border-color);
        border-radius: 8px;
        margin-bottom: 1rem;
        padding: 0.5rem;
        background-color: var(--bg-secondary);
    }
    
    .results-table td {
        border: none;
        border-bottom: 1px solid var(--border-color);
        position: relative;
        padding: 0.5rem 0.5rem 0.5rem 40%;
        text-align: right;
    }
    
    .results-table td:last-child {
        border-bottom: none;
    }
    
    .results-table td::before {
        content: attr(data-label) ": ";
        position: absolute;
        left: 0.5rem;
        width: 35%;
        padding-right: 0.5rem;
        white-space: nowrap;
        text-align: left;
        font-weight: 600;
        color: var(--text-primary);
    }
    
    .shape-name {
        min-width: unset;
    }
    
    .numerical-value {
        min-width: unset;
        font-family: inherit;
    }
    
    .shape-type-indicator {
        display: none;
    }
}

@media (max-width: 480px) {
    .results-table {
        font-size: 0.75rem;
    }
    
    .results-table td {
        padding: 0.4rem 0.4rem 0.4rem 35%;
    }
    
    .results-table td::before {
        width: 30%;
        left: 0.4rem;
        font-size: 0.7rem;
    }
}

/* Footer */
.app-footer {
    grid-area: footer;
    background-color: var(--bg-secondary);
    padding: 1rem 2rem;
    border-top: 1px solid var(--border-color);
}

.export-controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.export-button {
    padding: 0.5rem 1rem;
    background-color: var(--success-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.export-button:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-hover);
}

.export-button:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(40, 167, 69, 0.5);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .app-main {
        grid-template-columns: 1fr;
        gap: 1rem;
        padding: 1rem;
    }
    
    .parameter-panel {
        position: static;
    }
}

@media (max-width: 768px) {
    .app-header {
        padding: 1rem;
    }
    
    .app-header h1 {
        font-size: 1.5rem;
    }
    
    .app-description {
        font-size: 1rem;
    }
    
    .shape-grid {
        grid-template-columns: 1fr;
    }
    
    .input-with-slider {
        grid-template-columns: 1fr;
    }
    
    .export-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .chart-container {
        height: 300px;
    }
}

@media (max-width: 480px) {
    .app-main {
        padding: 0.5rem;
    }
    
    .parameter-panel,
    .main-content section {
        padding: 1rem;
    }
    
    .results-table {
        font-size: 0.8rem;
    }
    
    .results-table th,
    .results-table td {
        padding: 0.5rem;
    }
}

/* Screen Reader Only Content */
.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;
}

/* Skip Navigation Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--accent-color);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
    font-weight: 600;
}

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

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

/* Enhanced focus indicators for keyboard navigation */
button:focus,
input:focus,
select:focus,
.shape-checkbox:focus-within,
.radio-label:focus-within,
.sortable:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
    box-shadow: 0 0 0 4px rgba(0, 102, 204, 0.2);
}

/* Enhanced focus for keyboard users */
.keyboard-focused {
    outline: 3px solid var(--accent-color) !important;
    outline-offset: 3px !important;
    box-shadow: 0 0 0 6px rgba(0, 102, 204, 0.3) !important;
}

/* Focus management for interactive elements */
.shape-group:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

.shape-group:focus .shape-path {
    stroke: var(--accent-color);
    stroke-width: 3;
    filter: drop-shadow(0 2px 4px rgba(0, 102, 204, 0.5));
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
        --accent-color: #0000ff;
        --success-color: #008000;
        --warning-color: #ff8c00;
        --danger-color: #ff0000;
    }
    
    .results-table th,
    .results-table td {
        border: 2px solid var(--border-color);
    }
    
    .shape-path {
        stroke-width: 3;
    }
    
    button,
    input,
    select {
        border: 2px solid var(--border-color);
    }
    
    .export-button,
    .reset-button,
    .animation-button {
        border: 2px solid var(--text-primary);
    }
}

/* Enhanced high contrast class for programmatic control */
.high-contrast {
    --border-color: #000000 !important;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.8) !important;
}

.high-contrast .results-table th,
.high-contrast .results-table td {
    border: 2px solid var(--border-color) !important;
}

.high-contrast .shape-path {
    stroke-width: 4 !important;
}

/* Mobile device optimizations */
.mobile-device .parameter-panel {
    position: static;
    margin-bottom: 1rem;
}

.mobile-device .input-with-slider {
    grid-template-columns: 1fr;
    gap: 0.75rem;
}

.mobile-device .shape-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.mobile-device .export-controls {
    flex-direction: column;
    gap: 0.75rem;
}

.mobile-device .chart-container {
    height: 250px;
}

/* Touch device optimizations */
.mobile-device button,
.mobile-device input[type="checkbox"],
.mobile-device input[type="radio"] {
    min-height: 44px;
    min-width: 44px;
}

.mobile-device .shape-checkbox {
    padding: 0.75rem;
    min-height: 44px;
}

.mobile-device .radio-label {
    padding: 0.75rem;
    min-height: 44px;
}

.mobile-device .sortable {
    min-height: 44px;
    padding: 0.75rem;
}

/* Touch hover states */
.touch-hover .shape-path {
    stroke: var(--accent-color);
    stroke-width: 3;
    opacity: 1;
    filter: drop-shadow(0 2px 4px rgba(0, 102, 204, 0.3));
}

/* Touching state optimizations */
.touching {
    -webkit-overflow-scrolling: touch;
}

.touching * {
    pointer-events: none;
}

.touching button,
.touching input,
.touching select,
.touching [role="button"] {
    pointer-events: auto;
}