/* Header Styles */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    height: 60px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-primary);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.hamburger-menu {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.2rem;
    padding: 0.5rem;
    border-radius: 0.375rem;
    cursor: pointer;
    transition: all 0.3s ease;
    outline: none;
    -webkit-tap-highlight-color: transparent;
}

.hamburger-menu:hover {
    color: var(--accent-primary);
    background: rgba(49, 130, 206, 0.1);
}

.header-brand {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

/* 타이핑 효과 */
.header-brand span {
    display: inline-block;
    transition: all 0.3s ease;
}

.header-brand:hover span {
    animation: typewriter 0.8s ease-in-out;
}

@keyframes typewriter {
    0% { opacity: 0; transform: translateX(-10px); }
    100% { opacity: 1; transform: translateX(0); }
}

.header-brand:hover {
    color: var(--accent-primary);
    transform: scale(1.05);
}

.header-brand i {
    font-size: 1.75rem;
    color: var(--accent-primary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.1rem;
    padding: 0.5rem;
    border-radius: 0.375rem;
    cursor: pointer;
    transition: all 0.3s ease;
    outline: none;
    -webkit-tap-highlight-color: transparent;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    opacity: 0.7;
}

.theme-toggle:hover {
    color: var(--accent-primary);
    background: rgba(49, 130, 206, 0.1);
    opacity: 1;
    transform: scale(1.05);
}

.theme-toggle:focus {
    outline: none;
}

.theme-toggle:active {
    outline: none;
    -webkit-tap-highlight-color: transparent;
    transform: scale(0.95);
}

.theme-toggle:focus,
.theme-toggle:focus-visible {
    outline: none !important;
    border: none !important;
    box-shadow: none !important;
}

/* Sidebar overlay for mobile */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Mobile responsive */
@media (max-width: 768px) {
    .header {
        padding: 0 1rem;
    }
    
    .hamburger-menu {
        display: block;
    }
    
    .header-brand {
        font-size: 1.25rem;
    }
    
    .header-nav {
        display: none;
    }
}