:root {
    --space-xs: 0.25rem; --space-sm: 0.5rem; --space-md: 1rem;
    --space-lg: 1.5rem; --space-xl: 2rem; --space-2xl: 3rem;
    --border-radius: 12px; --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1); --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 25px rgba(0,0,0,0.2);
    --glass-bg: rgba(255,255,255,0.05); --glass-border: rgba(255,255,255,0.1);
    --modal-bg: rgba(255,255,255,0.1); --modal-border: rgba(255,255,255,0.15);
    --text-primary: #ffffff; --text-secondary: rgba(255,255,255,0.8);
    --text-muted: rgba(255,255,255,0.6); --notification-badge: #ff4757;
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif; 
    line-height: 1.6; 
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.header {
    position: fixed; 
    top: 0; 
    left: 0; 
    right: 0; 
    z-index: 1000;
    background: rgba(0, 0, 0, 0); 
    border-bottom: 1px solid var(--glass-border);
    transition: all 0.3s ease; 
    will-change: transform, background, backdrop-filter;
    height: 70px;
    padding: 0 1rem;
}

.header.scrolled {
    background: var(--modal-bg); 
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--modal-border);
    padding: 0 1rem;
}

.header-inner {
    max-width: 1440px; 
    margin: 0 auto;
    height: 100%;
    display: flex; 
    align-items: center;
    justify-content: space-between; 
    gap: var(--space-sm);
}

.logo {
    display: flex; 
    align-items: center; 
    gap: var(--space-xs);
    text-decoration: none; 
    font-family: 'Space Grotesk', sans-serif;
    transition: var(--transition); 
    flex-shrink: 0;
    color: inherit;
}

.logo:hover { transform: scale(1.02); }
.logo-icon {
    width: 40px; 
    height: 40px; 
    background: var(--secondary-gradient);
    border-radius: var(--border-radius); 
    display: flex; 
    align-items: center;
    justify-content: center; 
    box-shadow: var(--shadow-md); 
    transition: var(--transition);
    position: relative; 
    overflow: hidden; 
    flex-shrink: 0;
    background-image: url('/upload/web-photo/f.jpeg');
    background-size: cover; 
    background-position: center; 
    background-repeat: no-repeat;
    flex: 0 0 auto;
}

.logo-icon::before {
    content: ''; 
    position: absolute; 
    inset: 0;
    background: linear-gradient(45deg, transparent, rgba(255,255,255,0.3), transparent);
    transform: translateX(-100%); 
    transition: transform 0.6s;
    pointer-events: none;
}

.logo:hover .logo-icon::before { transform: translateX(100%); }
.logo-icon i { 
    font-size: 1.2rem; 
    color: white;
    z-index: 1;
    display: none;
}
.logo-text {
    font-size: 1.1rem; 
    font-weight: 700;
    background: var(--secondary-gradient); 
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent; 
    background-clip: text;
    white-space: nowrap;
    flex: 0 0 auto;
}

.nav-list {
    display: flex; 
    list-style: none; 
    gap: 2rem; 
    align-items: center;
    margin: 0;
    flex: 1;
    justify-content: center;
}

.nav-link {
    color: var(--text-secondary); 
    text-decoration: none; 
    font-weight: 500;
    padding: 0.5rem 0.75rem; 
    border-radius: var(--border-radius);
    transition: var(--transition); 
    font-size: 0.95rem; 
    letter-spacing: 0.025em;
    white-space: nowrap; 
    display: flex; 
    align-items: center; 
    gap: var(--space-xs);
    position: relative;
    flex-shrink: 0;
    min-width: 100px; /* Kaymayı önlemek için min-width eklendi (en uzun metne göre ayarlayın) */
    justify-content: center; /* İçerikleri ortala */
}

.nav-link i { 
    font-size: 1rem; 
    color: var(--text-muted); 
    transition: color 0.3s; 
    width: 16px;
    text-align: center;
}

.nav-link::after {
    content: ''; 
    position: absolute; 
    bottom: 0; 
    left: 50%;
    width: 0; 
    height: 2px; 
    background: var(--accent-gradient);
    transition: width 0.3s ease, left 0.3s ease;
    transform: translateX(-50%);
}

.nav-link:hover, 
.nav-link.active {
    color: var(--text-primary);
}

.nav-link:hover i, 
.nav-link.active i { 
    color: #4facfe; 
}

.nav-link:hover::after, 
.nav-link.active::after {
    width: 100%; 
    left: 50%;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    flex-shrink: 0;
}

.lang-switcher { 
    display: flex; 
    gap: var(--space-xs); 
    position: relative;
}
        
.lang-btn {
    padding: 0.4rem 0.75rem; 
    background: transparent; 
    border: 1px solid var(--glass-border);
    color: var(--text-secondary); 
    border-radius: var(--border-radius); 
    cursor: pointer;
    transition: var(--transition); 
    font-size: 0.8rem;
    font-weight: 500;
    min-width: 36px;
    text-align: center;
    position: relative;
    z-index: 10;
}

.lang-btn:focus {
    outline: 2px solid #4facfe;
    outline-offset: 2px;
}

.lang-btn.active, 
.lang-btn:hover {
    background: var(--accent-gradient); 
    color: white;
    border-color: transparent;
    z-index: 11;
}

.lang-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    background: var(--modal-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--modal-border);
    border-radius: var(--border-radius);
    padding: var(--space-sm);
    margin-top: var(--space-xs);
    min-width: 120px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    z-index: 1001;
    box-shadow: var(--shadow-lg);
}

.lang-switcher:hover .lang-dropdown,
.lang-btn:focus + .lang-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-dropdown button {
    display: block;
    width: 100%;
    text-align: left;
    padding: var(--space-xs) var(--space-sm);
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 8px;
    transition: var(--transition);
}

.lang-dropdown button:hover {
    background: rgba(102, 126, 234, 0.1);
    color: var(--text-primary);
}

.notification-toggle {
    width: 44px; 
    height: 44px; 
    background: var(--glass-bg);
    border: 1px solid var(--glass-border); 
    border-radius: var(--border-radius);
    display: flex; 
    align-items: center; 
    justify-content: center;
    cursor: pointer; 
    transition: var(--transition); 
    color: var(--text-secondary);
    flex-shrink: 0;
    position: relative;
}

.notification-toggle:hover {
    background: var(--accent-gradient); 
    color: white;
    transform: scale(1.05); 
    box-shadow: var(--shadow-md);
}

.notification-badge {
    position: absolute; 
    top: -4px; 
    right: -4px; 
    min-width: 20px; 
    height: 20px;
    background: var(--notification-badge); 
    color: white; 
    font-size: 0.7rem;
    font-weight: 600; 
    border-radius: 50%; 
    display: flex; 
    align-items: center;
    justify-content: center; 
    padding: 0 4px; 
    box-shadow: var(--shadow-sm);
    animation: pulse 2s infinite; 
    z-index: 1;
    line-height: 1;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.2); opacity: 0.8; }
}

.cta-header {
    padding: 0.75rem 1.5rem; 
    background: var(--secondary-gradient);
    color: white; 
    border: none; 
    border-radius: var(--border-radius);
    font-weight: 600; 
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md); 
    font-size: 0.9rem;
    letter-spacing: 0.025em; 
    flex-shrink: 0; 
    white-space: nowrap;
    text-decoration: none; 
    display: inline-flex; 
    align-items: center;
    gap: var(--space-xs);
    position: relative;
    overflow: hidden;
    min-width: 120px; /* CTA için de min-width ekleyerek kaymayı önle */
    justify-content: center;
}

.cta-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.cta-header:hover::before {
    left: 100%;
}

.cta-header:hover { 
    transform: translateY(-2px); 
    box-shadow: var(--shadow-lg);
}

/* Desktop specific styles */
@media (max-width: 1200px) {
    .nav-list { gap: 1.5rem; }
    .nav-link { 
        font-size: 0.9rem; 
        padding: 0.5rem 0.5rem;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --glass-border: rgba(255,255,255,0.3);
        --modal-border: rgba(255,255,255,0.3);
    }
    .nav-link::after {
        height: 3px;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Hide mobile elements on desktop */
.menu-toggle,
.nav-drawer,
.drawer-overlay {
    display: none !important;
}