:root {
    --primary: #0066cc;
    --primary-dark: #004499;
    --secondary: #00d4aa;
    --accent: #ff6b35;
    --dark: #0f172a;
    --darker: #020617;
    --light: #f8fafc;
    --gray: #94a3b8;
    --gray-dark: #475569;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --card-bg: rgba(255,255,255,0.03);
    --border: rgba(255,255,255,0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, var(--darker) 0%, var(--dark) 100%);
    color: var(--light);
    line-height: 1.6;
    min-height: 100vh;
}

/* Header */
.main-header {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
}

/* LOGO STİLLERİ */

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
}

/* VSlogo.png için stil */
.logo-img {
    /* Boyut ayarı - istediğin gibi değiştir */
    height: 70px;        /* Yükseklik */
    width: auto;         /* Genişlik otomatik */
    
    /* Yuvarlak köşe (istersen) */
    border-radius: 10px;
    
    /* Gölge efekti */
    filter: drop-shadow(0 4px 6px rgba(0,0,0,0.3));
    
    /* Üzerine gelince büyüme efekti */
    transition: transform 0.3s ease;
}

.logo:hover .logo-img {
    transform: scale(1.05);
}

/* 
↓↓↓ EĞER LOGO YUVARLAK OLSUN İSTERSEN ↓↓↓
border-radius: 50%; yap
*/
.logo-yuvarlak {
    height: 50px;
    width: 50px;        /* Genişlik sabit olmalı yuvarlak için */
    border-radius: 50%;
    object-fit: cover;  /* Resmi ortala ve kırp */
    border: 3px solid var(--secondary);
    box-shadow: 0 0 20px rgba(0, 212, 170, 0.4);
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.main-nav a {
    color: var(--gray);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s;
    position: relative;
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--secondary);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary);
    transition: width 0.3s;
}

.main-nav a:hover::after,
.main-nav a.active::after {
    width: 100%;
}

/* Social Icons - PNG Version */
.social-icon img {
    width: 24px;
    height: 24px;
    vertical-align: middle;
    transition: transform 0.3s ease, filter 0.3s ease;
    filter: brightness(0.9);
}

.social-icon:hover img {
    transform: translateY(-3px) scale(1.1);
    filter: brightness(1.2) drop-shadow(0 0 8px rgba(0, 212, 170, 0.5));
}

/* Alternatif: Daha büyük boyut istersen */
.social-icon.large img {
    width: 32px;
    height: 32px;
}

/* Sosyal Medya */
.social-links {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

.social-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    text-decoration: none;
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--border);
    color: var(--gray);
    transition: all 0.3s ease;
}

.social-icon:hover {
    transform: translateY(-3px);
    color: white;
}

.social-icon.linkedin:hover {
    background: #0077b5;
    border-color: #0077b5;
    box-shadow: 0 10px 20px rgba(0,119,181,0.3);
}

.social-icon.instagram:hover {
    background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
    border-color: transparent;
    box-shadow: 0 10px 20px rgba(220,39,67,0.3);
}

.social-icon.youtube:hover {
    background: #ff0000;
    border-color: #ff0000;
    box-shadow: 0 10px 20px rgba(255,0,0,0.3);
}

/* Hero */
.hero {
    padding: 4rem 0;
    text-align: center;
    background: radial-gradient(ellipse at center, rgba(0,102,204,0.1) 0%, transparent 70%);
}

.hero h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #fff 0%, var(--gray) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.2rem;
    color: var(--gray);
    max-width: 600px;
    margin: 0 auto 2rem;
}

/* Container */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Categories */
.categories {
    padding: 2rem 0 4rem;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.category-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 2rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    transform: scaleX(0);
    transition: transform 0.3s;
}

.category-card:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 212, 170, 0.3);
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}

.category-card:hover::before {
    transform: scaleX(1);
}

.category-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.category-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #fff;
}

.category-card p {
    color: var(--gray);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.solution-count {
    display: inline-block;
    background: rgba(0,212,170,0.1);
    color: var(--secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* Solutions List */
.solutions-list {
    padding: 2rem 0;
}

.solution-item {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s;
}

.solution-item:hover {
    border-color: var(--primary);
    transform: translateX(10px);
}

.solution-item .icon {
    font-size: 2rem;
    width: 60px;
    height: 60px;
    background: rgba(0,102,204,0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.solution-item h4 {
    color: #fff;
    margin-bottom: 0.25rem;
}

.solution-item p {
    color: var(--gray);
    font-size: 0.9rem;
}

.difficulty {
    margin-left: auto;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
}

.difficulty.easy { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.difficulty.medium { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.difficulty.hard { background: rgba(239, 68, 68, 0.1); color: var(--danger); }

/* Footer */
.main-footer {
    background: rgba(0,0,0,0.3);
    border-top: 1px solid var(--border);
    padding: 3rem 0;
    margin-top: 4rem;
    text-align: center;
    color: var(--gray);
}

.footer-logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: #fff;
    margin-bottom: 0.5rem;
}

.footer-social {
    margin: 1.5rem 0;
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.footer-social .social-icon {
    background: rgba(255,255,255,0.05);
    width: 45px;
    height: 45px;
    font-size: 1.3rem;
}

/* Responsive */
@media (max-width: 968px) {
    .header-container {
        flex-wrap: wrap;
    }
    
    .social-links {
        order: 3;
        width: 100%;
        justify-content: center;
        margin-top: 1rem;
        padding-top: 1rem;
        border-top: 1px solid var(--border);
    }
}

@media (max-width: 768px) {
    .main-nav { display: none; }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .solution-item {
        flex-direction: column;
        text-align: center;
    }
    
    .difficulty {
        margin-left: 0;
        margin-top: 1rem;
    }
}