* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --secondary-color: #06b6d4;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --card-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-light);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: var(--bg-color);
    box-shadow: var(--card-shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

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

nav {
    display: flex;
    gap: 2rem;
}

nav a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.95;
}

/* Tools Section */
.tools-section {
    padding: 4rem 0;
}

.tools-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.tool-card {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    transition: all 0.3s;
    text-decoration: none;
    color: var(--text-color);
    display: block;
}

.tool-card:hover {
    box-shadow: var(--card-shadow-hover);
    transform: translateY(-5px);
}

.tool-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.tool-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.tool-card p {
    color: var(--text-light);
}

/* Features Section */
.features-section {
    background: var(--bg-color);
    padding: 4rem 0;
}

.features-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature {
    text-align: center;
    padding: 2rem;
}

.feature h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

/* Tool Page Styles */
.tool-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 20px;
}

.tool-header {
    text-align: center;
    margin-bottom: 2rem;
}

.tool-header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.tool-header p {
    color: var(--text-light);
    font-size: 1.1rem;
}

.ad-placeholder {
    background: var(--bg-light);
    border: 2px dashed var(--border-color);
    padding: 2rem;
    text-align: center;
    margin: 2rem 0;
    border-radius: 8px;
    color: var(--text-light);
    font-size: 0.875rem;
}

.tool-content {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s;
}

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

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.btn {
    padding: 0.75rem 2rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
    text-decoration: none;
    display: inline-block;
}

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

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

.btn-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.result-box {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 1.5rem;
    border: 2px solid var(--border-color);
}

.result-box h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.stat-item {
    background: var(--bg-color);
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

/* SEO Content */
.seo-content {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    margin: 2rem 0;
}

.seo-content h2 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.seo-content h3 {
    color: var(--primary-color);
    margin: 1.5rem 0 1rem;
}

.seo-content p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-light);
}

.seo-content ul {
    margin: 1rem 0 1rem 2rem;
}

.seo-content li {
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

/* FAQ Section */
.faq-section {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    margin-top: 2rem;
}

.faq-section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.faq-item {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

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

.faq-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
}

.faq-item p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Image Preview */
.image-preview {
    margin-top: 1rem;
    text-align: center;
}

.image-preview img {
    max-width: 100%;
    max-height: 400px;
    border-radius: 8px;
    box-shadow: var(--card-shadow);
}

#qrcode {
    display: flex;
    justify-content: center;
    margin-top: 1rem;
}

#qrcode canvas {
    border-radius: 8px;
    box-shadow: var(--card-shadow);
}

/* Footer */
footer {
    background: var(--text-color);
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* Content Pages */
.content-page {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 20px;
}

.content-page h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.content-page h2 {
    font-size: 1.75rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.content-page p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-light);
}

.content-page ul {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.content-page li {
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .tools-grid {
        grid-template-columns: 1fr;
    }

    nav {
        gap: 1rem;
    }

    .header-content {
        flex-direction: column;
        gap: 1rem;
    }

    .btn-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

/* Utility Classes */
.hidden {
    display: none;
}

.text-center {
    text-align: center;
}

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }