/* ==========================================================================
   CSS Custom Properties (CSS Variables)
   ========================================================================== */
:root {
    /* Color palette */
    --color-primary: #4169E1;
    --color-primary-dark: #27408B;
    --color-primary-light: #6495ED;
    
    --color-success: #10B981;
    --color-warning: #F59E0B;
    --color-error: #EF4444;
    --color-info: #3B82F6;
    
    /* Light theme */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-family-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-family-mono: 'Fira Code', 'JetBrains Mono', Consolas, 'Courier New', monospace;
    
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 var(--shadow-color);
    --shadow-md: 0 4px 6px -1px var(--shadow-color);
    --shadow-lg: 0 10px 15px -3px var(--shadow-color);
    --shadow-xl: 0 20px 25px -5px var(--shadow-color);
}

/* Dark theme */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border-color: #475569;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

/* ==========================================================================
   Reset and Base Styles
   ========================================================================== */
*,
*::before,
*::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

html {
    line-height: 1.5;
    -webkit-text-size-adjust: 100%;
    -moz-tab-size: 4;
    tab-size: 4;
    font-family: var(--font-family-main);
    font-feature-settings: normal;
    font-variation-settings: normal;
    scroll-behavior: smooth;
}

/* Global styles for the page */
body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-family-main);
    font-size: var(--font-size-base);
    line-height: 1.6;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: var(--font-weight-semibold);
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-xl);
}

h2 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-lg);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

/* General link styles */
a {
    color: var(--color-primary);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-dark);
}

a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

/* ==========================================================================
   Theme Toggle
   ========================================================================== */
.theme-toggle {
    position: absolute;
    top: var(--spacing-xl);
    right: var(--spacing-xl);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    font-size: var(--font-size-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.theme-toggle:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ==========================================================================
   Loading States
   ========================================================================== */
.loading-container {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
    margin: var(--spacing-xl) 0;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    min-width: 300px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-md);
}

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

.loading-text {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-medium);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background-color: var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-sm);
    transition: width var(--transition-normal);
    width: 0%;
}

.loading-details {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    text-align: center;
    max-width: 250px;
    line-height: 1.4;
}

/* ==========================================================================
   Error States
   ========================================================================== */
.error-container {
    display: none;
    align-items: center;
    padding: var(--spacing-xl);
    margin: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    border: 1px solid #fca5a5;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    max-width: 600px;
}

[data-theme="dark"] .error-container {
    background: linear-gradient(135deg, #451a1a 0%, #3a1515 100%);
    border-color: #7f1d1d;
}

.error-icon {
    font-size: var(--font-size-2xl);
    margin-right: var(--spacing-lg);
    flex-shrink: 0;
}

.error-content {
    flex: 1;
}

.error-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-error);
    margin-bottom: var(--spacing-sm);
}

.error-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.5;
    white-space: pre-line; /* Preserve line breaks for better error formatting */
    max-height: 200px;
    overflow-y: auto;
}

.retry-button {
    background: var(--color-primary);
    color: white;
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.retry-button:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.retry-button:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ==========================================================================
   Table Styles
   ========================================================================== */
#materials-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    margin: var(--spacing-xl) 0;
}

/* Category badge styles */
.category-badge {
    display: inline-block;
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-medium);
    padding: 0.15rem 0.5rem;
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-xs);
    margin-right: var(--spacing-xs);
    text-transform: capitalize;
    color: white;
}

.category-ceramic {
    background-color: #3B82F6;
}

.category-adhesive {
    background-color: #10B981;
}

.category-foam {
    background-color: #F59E0B;
}

.category-soil {
    background-color: #8B5A2B;
}

.category-composite {
    background-color: #8B5CF6;
}

#materials-table thead tr {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
}

#materials-table th {
    padding: var(--spacing-lg);
    text-align: left;
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
    position: relative;
}

#materials-table th:hover {
    background: var(--bg-tertiary);
}

#materials-table td {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    vertical-align: top;
    transition: background-color var(--transition-fast);
}

#materials-table tbody tr {
    transition: all var(--transition-fast);
    cursor: pointer;
}

#materials-table tbody tr:hover {
    background: var(--bg-secondary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

#materials-table tbody tr:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: -2px;
}

#materials-table tbody tr.shown {
    background: var(--bg-secondary);
}

#materials-table td:last-child {
    width: 10ch;
    white-space: nowrap;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Styles for blocks */
.reference-block {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin: 0 auto var(--spacing-lg) auto;
    border-left: 4px solid var(--color-primary);
    word-wrap: break-word;
    overflow-wrap: break-word;
    text-overflow: ellipsis;
    max-width: 1200px;
    text-align: left;
    overflow: hidden;
}

.reference-block strong {
    color: var(--text-primary);
    font-weight: var(--font-weight-semibold);
}

/* ==========================================================================
   About Page Styles
   ========================================================================== */
.about-section {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    line-height: 1.7;
}

.about-section p {
    text-align: justify;
    margin-bottom: var(--spacing-lg);
}

.back-link {
    text-align: center;
    margin-top: var(--spacing-2xl);
}

.back-link a {
    display: inline-block;
    background: var(--color-primary);
    color: white;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-md);
}

.back-link a:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ==========================================================================
   Code Blocks
   ========================================================================== */
.code-container {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin: var(--spacing-lg) auto;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    width: 90ch;
    max-width: 100%;
    box-sizing: border-box;
    text-align: left;
    position: relative;
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--border-color) 100%);
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.code-title {
    font-family: var(--font-family-mono);
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
    font-size: var(--font-size-sm);
}

.copy-button {
    background: var(--bg-primary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.copy-button:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.copy-button:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.copy-button.copied {
    background: var(--color-success);
    color: white;
    border-color: var(--color-success);
}

.code-container pre {
    margin: 0;
    padding: var(--spacing-lg);
    overflow-x: auto;
    background: var(--bg-primary);
    font-family: var(--font-family-mono);
    font-size: var(--font-size-sm);
    line-height: 1.6;
    color: var(--text-primary);
    white-space: pre;
}

/* Loading indicator styling */
.loading-indicator {
    display: none;
    text-align: center;
    padding: var(--spacing-xl);
    font-weight: var(--font-weight-medium);
    color: var(--color-primary);
}

/* Error message styling */
#error-message {
    display: none;
    color: var(--color-error);
    background-color: #ffebee;
    border: 1px solid #ffcdd2;
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    margin: var(--spacing-md) 0;
    font-weight: var(--font-weight-medium);
}

[data-theme="dark"] #error-message {
    background-color: #451a1a;
    border-color: #7f1d1d;
}

#error-message.visible-error {
    display: block;
}

/* Notification for copy to clipboard */
.copy-notification {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    transition: opacity 0.5s ease-out;
}

.copy-notification.fade-out {
    opacity: 0;
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }
    
    h1 {
        font-size: var(--font-size-2xl);
    }
    
    #materials-table th,
    #materials-table td {
        padding: var(--spacing-md);
    }
    
    .code-container {
        margin: var(--spacing-md) 0;
        width: 100%;
    }
    
    .code-header {
        padding: var(--spacing-sm) var(--spacing-md);
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: flex-start;
    }
    
    .code-container pre {
        padding: var(--spacing-md);
        font-size: var(--font-size-xs);
    }
    
    .error-container {
        flex-direction: column;
        text-align: center;
    }
    
    .error-icon {
        margin-right: 0;
        margin-bottom: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .container {
        padding: var(--spacing-sm);
    }
    
    .loading-container {
        min-width: auto;
        width: 100%;
    }
}

/* ==========================================================================
   Button Styles
   ========================================================================== */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: center;
    line-height: 1.4;
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-xs);
}

.btn-edit {
    background: var(--color-primary);
    color: white;
    border: 1px solid var(--color-primary);
}

.btn-edit:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.btn-edit:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

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

/* ==========================================================================
   Network Notifications
   ========================================================================== */
.network-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 12px 20px;
    border-radius: 8px;
    color: white;
    font-weight: 500;
    z-index: 10000;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    font-size: var(--font-size-sm);
    max-width: 300px;
    word-wrap: break-word;
}

.network-notification.success {
    background-color: var(--color-success);
}

.network-notification.warning {
    background-color: var(--color-warning);
}

.network-notification.error {
    background-color: var(--color-error);
}

.network-notification.info {
    background-color: var(--color-info);
}

/* Responsive network notifications */
@media (max-width: 768px) {
    .network-notification {
        top: 10px;
        right: 10px;
        left: 10px;
        max-width: none;
        text-align: center;
    }
}
    
    #materials-table th,
    #materials-table td {
        padding: var(--spacing-sm);
        font-size: var(--font-size-sm);
    }
    
    .copy-notification {
        bottom: var(--spacing-md);
        right: var(--spacing-md);
        left: var(--spacing-md);
        max-width: none;
    }
}