.header-placeholder {
    display: none;
}

.header-placeholder.active {
    display: block;
}

.header {
    border-bottom: 1px solid var(--color-border);
    margin-bottom: var(--spacing-xl);
    position: sticky;
    top: 0;
    background: var(--color-bg);
    backdrop-filter: blur(10px);
    z-index: 100;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
}

.header.collapsed {
    position: fixed;
    height: 3rem;
    margin-bottom: 0;
    width: 100%;
}

.header.collapsed .nav {
    padding: 0 0;
    transform: translateY(-100%);
}

.header.collapsed .collapse-indicator {
    display: block;
    opacity: 1;
    transform: translate(-50%, -25%);
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.collapse-indicator {
    display: none;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, calc(-50% + 100%));
    opacity: 0;
    color: var(--color-accent);
    cursor: pointer;
    background: var(--color-bg);
    z-index: 10;
}

.collapse-indicator:hover {
    background: var(--color-border);
    transform: translate(-50%, calc(-50% + 100%)) scale(1.1);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.3rem;
    font-weight: bold;
    color: var(--color-accent);
    text-decoration: none;
    transition: transform 0.2s ease;
}

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

.logo-icon {
    font-size: 1.5rem;
    animation: rotate 12s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    color: var(--color-text);
    font-weight: 500;
    text-decoration: none;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 6px;
    transition: all 0.2s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--color-accent);
    background: var(--color-border);
}

.nav-link.active {
    color: var(--color-accent);
    background: var(--color-border);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background: var(--color-accent);
    border-radius: 1px;
}

header a, header a:visited {
    color: var(--color-text);
}

.dark-theme header a, .dark-theme header a:visited {
    color: var(--color-text);
}

.name-text {
    font-family: 'Segoe Print', 'Bradley Hand', Chilanka, TSCu_Comic, casual, cursive;
    font-weight: normal;
    font-size: 1.0em;
    color: var(--color-text);
}

@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: var(--spacing-sm);
        padding: var(--spacing-sm) 0;
    }

    .nav-links {
        gap: var(--spacing-sm);
        flex-wrap: wrap;
        justify-content: center;
    }

    .logo-icon {
        display: none;
    }

    .theme-toggle {
        position: absolute;
        top: var(--spacing-sm);
        right: 0;
    }
}

@media (max-width: 480px) {
    .nav-links {
        width: 100%;
        justify-content: space-around;
    }

    .nav-link {
        flex: 1;
        text-align: center;
    }
}