/* CSS Variables */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --accent-primary: #6366f1;
    --accent-secondary: #818cf8;
    --accent-light: #e0e7ff;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --shadow-sm: 0 1px 2px 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);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border-color: #334155;
    --accent-light: #312e81;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography */
h1 { font-size: 2.5rem; font-weight: 700; }
h2 { font-size: 1.75rem; font-weight: 600; }
h3 { font-size: 1.25rem; font-weight: 600; }
h4 { font-size: 1rem; font-weight: 600; }

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(12px);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    width: 28px;
    height: 28px;
    color: var(--accent-primary);
}

.nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--accent-primary);
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    transition: background 0.2s, color 0.2s;
}

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

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

.sun-icon { display: none; }
.moon-icon { display: block; }

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }

/* Hero Section */
.hero {
    padding: 48px 0 32px;
    text-align: center;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero h1 {
    margin-bottom: 12px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 32px;
}

/* Tool Navigation */
.tool-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    max-width: 900px;
    margin: 0 auto;
}

.tool-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.tool-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.tool-btn.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
}

/* Tools Section */
.tools-section {
    padding: 48px 0;
}

.tool-panel {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tool-panel.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.tool-header {
    margin-bottom: 24px;
}

.tool-header h2 {
    margin-bottom: 8px;
}

.tool-header p {
    color: var(--text-secondary);
}

/* Tool Content Layout */
.tool-content {
    margin-bottom: 24px;
}

.tool-content.dual-panel {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.tool-content.single-input .input-group {
    margin-bottom: 24px;
}

/* Input Groups */
.input-group,
.output-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.input-group label,
.output-group label {
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.text-input {
    width: 100%;
    padding: 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 1rem;
    resize: vertical;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.text-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-light);
}

.text-input.output {
    background: var(--bg-secondary);
}

.text-input.mono {
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

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

/* Output Header */
.output-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.copy-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.copy-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

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

.copy-btn svg {
    width: 14px;
    height: 14px;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 16px;
}

.stat-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Action Buttons */
.action-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
    margin-top: 16px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--accent-secondary);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-accent {
    background: linear-gradient(135deg, #10b981, #059669);
    color: white;
    text-decoration: none;
    display: inline-block;
}

.btn-accent:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Options */
.option-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.option-group.inline {
    flex-direction: row;
    align-items: center;
    gap: 12px;
}

.option-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.option-group input[type="text"],
.option-group input[type="password"],
.option-group input[type="number"],
.option-group select {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.9rem;
    min-width: 120px;
}

.option-group input:focus,
.option-group select:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.875rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--accent-primary);
}

.option-row {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.option-row .option-group {
    flex: 1;
    min-width: 200px;
}

.option-row.checkboxes {
    gap: 24px;
}

.hint {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-style: italic;
}

/* Lorem Ipsum Options */
.lorem-options {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: flex-end;
    margin-bottom: 24px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

/* Find Replace Options */
.find-replace-options {
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    margin: 16px 0;
}

/* Diff Output */
.diff-output {
    margin-top: 24px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.8;
    white-space: pre-wrap;
    word-break: break-word;
    display: none;
}

.diff-output.show {
    display: block;
}

.diff-add {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.diff-remove {
    background: rgba(239, 68, 68, 0.2);
    color: var(--error);
    text-decoration: line-through;
}

/* Preview Box */
.preview-box {
    margin-top: 24px;
    padding: 24px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    display: none;
}

.preview-box.show {
    display: block;
}

.preview-box h1, .preview-box h2, .preview-box h3 {
    margin: 1em 0 0.5em;
}

.preview-box p {
    margin: 0.5em 0;
}

.preview-box ul, .preview-box ol {
    margin: 0.5em 0;
    padding-left: 2em;
}

.preview-box code {
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
}

.preview-box pre {
    background: var(--bg-tertiary);
    padding: 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
}

/* Ad Banner */
.ad-banner {
    margin-top: 48px;
    padding: 24px;
    background: var(--bg-secondary);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    text-align: center;
}

.ad-placeholder {
    color: var(--text-muted);
}

.ad-placeholder span {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.ad-placeholder p {
    margin-top: 8px;
    font-size: 0.9rem;
}

/* API Section */
.api-section {
    padding: 64px 0;
    background: var(--bg-secondary);
}

.api-section h2 {
    text-align: center;
    margin-bottom: 12px;
}

.api-section > .container > p {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.api-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.api-card {
    position: relative;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.api-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.api-card.featured {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 1px var(--accent-primary);
}

.api-card .badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent-primary);
    color: white;
    padding: 4px 16px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.api-card h3 {
    margin-bottom: 20px;
}

.api-card ul {
    list-style: none;
    text-align: left;
    margin-bottom: 24px;
}

.api-card li {
    padding: 8px 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.api-card li:last-child {
    border-bottom: none;
}

.api-card li::before {
    content: "✓ ";
    color: var(--success);
}

.api-card .price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
}

/* Affiliate Section */
.affiliate-section {
    padding: 48px 0;
}

.affiliate-card {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-lg);
    padding: 40px;
    color: white;
    text-align: center;
}

.affiliate-card h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
}

.affiliate-card p {
    opacity: 0.9;
    margin-bottom: 24px;
}

.affiliate-card .btn {
    background: white;
    color: var(--accent-primary);
    padding: 12px 28px;
    font-size: 1rem;
}

.affiliate-card .btn:hover {
    box-shadow: var(--shadow-lg);
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 48px 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 32px;
}

.footer-brand .logo {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links h4 {
    margin-bottom: 16px;
}

.footer-links a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 6px 0;
    transition: color 0.2s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    
    .tool-content.dual-panel {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .api-features {
        grid-template-columns: 1fr;
    }
    
    .option-row .option-group {
        min-width: 100%;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero {
        padding: 32px 0 24px;
    }
    
    .tool-nav {
        gap: 6px;
    }
    
    .tool-btn {
        padding: 6px 12px;
        font-size: 0.8rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .action-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .btn {
        width: 100%;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.loading {
    animation: pulse 1.5s infinite;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    padding: 12px 24px;
    background: var(--text-primary);
    color: var(--bg-primary);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}