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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #0ea5e9;
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-card-hover: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border: #334155;
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --gradient-hero: linear-gradient(180deg, #0f172a 0%, #1e1b4b 100%);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

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

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

.hero {
    padding: 160px 0 100px;
    background: var(--gradient-hero);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    pointer-events: none;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero h1 span {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
}

.search-box {
    max-width: 560px;
    margin: 0 auto;
    position: relative;
}

.search-box input {
    width: 100%;
    padding: 18px 24px 18px 56px;
    font-size: 1rem;
    border: 2px solid var(--border);
    border-radius: 16px;
    background: var(--bg-card);
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

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

.search-box input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
}

.search-icon {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.categories {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

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

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

.category-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px;
    transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.category-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.category-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.category-icon.code { background: linear-gradient(135deg, #3b82f6 0%, #6366f1 100%); }
.category-icon.image { background: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%); }
.category-icon.text { background: linear-gradient(135deg, #10b981 0%, #059669 100%); }
.category-icon.convert { background: linear-gradient(135deg, #f59e0b 0%, #eab308 100%); }
.category-icon.encrypt { background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%); }
.category-icon.dev { background: linear-gradient(135deg, #06b6d4 0%, #0ea5e9 100%); }

.category-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.category-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.tools {
    padding: 80px 0;
    background: rgba(30, 41, 59, 0.3);
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
}

.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    display: flex;
    align-items: flex-start;
    gap: 16px;
    transition: border-color 0.2s, background 0.2s;
    cursor: pointer;
}

.tool-card:hover {
    border-color: var(--primary);
    background: var(--bg-card-hover);
}

.tool-icon {
    width: 48px;
    height: 48px;
    border-radius: 10px;
    background: var(--bg-card-hover);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.tool-info h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.4;
    max-height: 2.8em;
}

.tool-info p {
    color: var(--text-secondary);
    font-size: 0.85rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.5;
    max-height: 4.5em;
}

.features {
    padding: 80px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.feature-card {
    text-align: center;
    padding: 32px;
}

.feature-icon {
    width: 72px;
    height: 72px;
    border-radius: 20px;
    background: rgba(99, 102, 241, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    color: var(--primary-light);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-secondary);
}

footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 48px 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand p {
    color: var(--text-secondary);
    margin-top: 16px;
    font-size: 0.9rem;
}

.footer-links h4 {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 20px;
}

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

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.85rem;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: block;
    }

    .hero {
        padding: 120px 0 60px;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

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

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}