:root {
    /* Light Theme Colors */
    --primary-color: #4f46e5;
    --primary-light: #6366f1;
    --primary-dark: #4338ca;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-tertiary: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --success-color: #10b981;
    --info-color: #3b82f6;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;

    /* Border Radius */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 1rem;
    --border-radius-full: 9999px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Theme Colors */
[data-theme="dark"] {
    --primary-color: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --text-primary: #f9fafb;
    --text-secondary: #e5e7eb;
    --text-tertiary: #9ca3af;
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --border-color: #374151;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

button {
    cursor: pointer;
    font-family: inherit;
}

ul {
    list-style: none;
}

/* Layout */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    background-color: var(--bg-primary);
    box-shadow: 0 2px 10px var(--shadow-color);
    padding: var(--spacing-md) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.main-content {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    width: 100%;
}

.footer {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-md);
    margin-top: var(--spacing-xxl);
}

/* Logo */
.logo-container {
    display: flex;
    flex-direction: column;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.lambda {
    color: var(--primary-color);
    font-weight: 700;
}

.tagline {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    margin-left: 2rem;
}

/* Navigation */
.main-nav ul {
    display: flex;
    gap: var(--spacing-xl);
}

.main-nav a {
    color: var(--text-secondary);
    font-weight: 500;
    padding: var(--spacing-sm) 0;
    position: relative;
}

.main-nav a:hover {
    color: var(--primary-color);
}

.main-nav a.active {
    color: var(--primary-color);
}

.main-nav a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
    border-radius: var(--border-radius-full);
}

/* Theme Toggle */
.theme-toggle button {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.25rem;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-full);
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.theme-toggle button:hover {
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
}

/* Hero Section */
.hero-section {
    display: flex;
    align-items: center;
    gap: var(--spacing-xxl);
    margin-bottom: var(--spacing-xxl);
    padding: var(--spacing-xxl) 0;
}

.hero-content {
    flex: 1;
}

.hero-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.hero-content p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    max-height: 400px;
}

/* Analysis Section */
.analysis-section {
    background-color: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 4px 20px var(--shadow-color);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xxl);
}

/* Tabs */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--spacing-xl);
}

.tab-btn {
    background: none;
    border: none;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    transition: color var(--transition-fast);
}

.tab-btn:hover {
    color: var(--primary-color);
}

.tab-btn.active {
    color: var(--primary-color);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

.tab-pane {
    display: none;
}

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

/* File Upload */
.upload-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xxl);
    text-align: center;
    transition: border-color var(--transition-fast), background-color var(--transition-fast);
    cursor: pointer;
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary-color);
    background-color: rgba(79, 70, 229, 0.05);
}

.upload-area i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.upload-area p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.upload-area p.small {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.file-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--bg-tertiary);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
}

.file-preview {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.file-preview i {
    font-size: 1.5rem;
    color: var(--text-secondary);
}

/* URL Input */
.url-container {
    display: flex;
    gap: var(--spacing-md);
}

.input-group {
    flex: 1;
    display: flex;
    align-items: center;
    background-color: var(--bg-tertiary);
    border-radius: var(--border-radius-md);
    padding: 0 var(--spacing-md);
    transition: box-shadow var(--transition-fast);
}

.input-group:focus-within {
    box-shadow: 0 0 0 2px var(--primary-light);
}

.input-group i {
    color: var(--text-tertiary);
    font-size: 1.25rem;
}

.input-group input {
    flex: 1;
    border: none;
    background: none;
    padding: var(--spacing-md);
    font-size: 1rem;
    color: var(--text-primary);
    outline: none;
    width: 100%;
}

.input-group input::placeholder {
    color: var(--text-tertiary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--border-radius-md);
    font-weight: 500;
    transition: all var(--transition-fast);
    border: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
}

.btn-primary:disabled {
    background-color: var(--text-tertiary);
    cursor: not-allowed;
}

/* Results Section */
.results-section {
    margin-bottom: var(--spacing-xxl);
}

.results-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.results-container {
    background-color: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 4px 20px var(--shadow-color);
    overflow: hidden;
}

.results-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xxl);
    color: var(--text-tertiary);
    text-align: center;
}

.results-placeholder i {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.results-content {
    padding: var(--spacing-xl);
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.results-type {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
}

.results-type i {
    color: var(--primary-color);
}

.results-timestamp {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.results-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.summary-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
}

.summary-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius-full);
    background-color: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--info-color);
}

.summary-icon.safe {
    color: var(--success-color);
}

.summary-icon.warning {
    color: var(--warning-color);
}

.summary-icon.danger {
    color: var(--danger-color);
}

.summary-text h4 {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    margin-bottom: var(--spacing-xs);
}

.summary-text p {
    font-weight: 500;
    color: var(--text-primary);
}

/* Accordion */
.accordion {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    overflow: hidden;
}

.accordion-item {
    border-bottom: 1px solid var(--border-color);
}

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

.accordion-header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--bg-secondary);
    border: none;
    text-align: left;
    font-weight: 500;
    color: var(--text-primary);
    transition: background-color var(--transition-fast);
}

.accordion-header:hover {
    background-color: var(--bg-tertiary);
}

.accordion-header i {
    transition: transform var(--transition-fast);
}

.accordion-header.active i {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.accordion-content.active {
    max-height: 500px;
    overflow-y: auto;
}

.accordion-content pre {
    padding: var(--spacing-lg);
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    font-family: monospace;
    overflow-x: auto;
    white-space: pre-wrap;
}

/* Features Section */
.features-section {
    margin-bottom: var(--spacing-xxl);
}

.features-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xl);
    text-align: center;
    color: var(--text-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    background-color: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: 0 4px 20px var(--shadow-color);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-color);
}

.feature-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--border-radius-full);
    background-color: rgba(79, 70, 229, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.feature-card h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Footer */
.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--spacing-lg);
}

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

.footer-logo h2 {
    font-size: 1.25rem;
    font-weight: 700;
}

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

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.875rem;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.loading-overlay.active {
    opacity: 1;
    visibility: visible;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-md);
}

.loading-overlay p {
    color: white;
    font-size: 1.125rem;
}

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

/* Responsive Styles */
@media (max-width: 992px) {
    .hero-section {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-content p {
        margin: 0 auto;
    }
    
    .url-container {
        flex-direction: column;
    }
}

@media (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .main-nav ul {
        gap: var(--spacing-lg);
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .results-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-md);
    }
}

@media (max-width: 576px) {
    .main-nav ul {
        gap: var(--spacing-md);
    }
    
    .footer-links ul {
        flex-wrap: wrap;
        justify-content: center;
    }
}