/* ============================================================
   HEADER BASE
   ============================================================ */
header {
    background: var(--nav-bg);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
    height: 64px;
    display: flex;
    align-items: center;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 16px;
    box-sizing: border-box;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.logo-box {
    background: var(--primary);
    color: #fff;
    width: 34px;
    height: 34px;
    border-radius: 8px;
    display: grid;
    place-items: center;
    font-weight: 800;
}

.brand span {
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--text-main);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

/* ============================================================
   HEADER NAVIGATION LINKS & ANIMATION
   ============================================================ */
.header-nav {
    display: flex;
    gap: 24px;
}

.header-nav a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    display: inline-block; /* Required for the transform lift effect */
    transition: color 0.3s ease, transform 0.3s ease;
}

.header-nav a:hover {
    color: var(--primary);
    transform: translateY(-2px); /* Smooth micro-bounce lift up */
}

.header-nav a.active {
    color: var(--primary);
    transform: none; /* Keeps the active page link steady */
}

/* ============================================================
   THEME SWITCH BUTTONS
   ============================================================ */
.theme-btn {
    background: none;
    border: 1px solid var(--border);
    width: 32px;
    height: 32px;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-main);
    transition: border-color 0.25s ease;
}

.theme-btn:hover {
    border-color: var(--primary);
}

.theme-btn svg {
    width: 20px;
    height: 20px;
    display: none;
    pointer-events: none !important;
}

[data-theme="light"] .theme-btn .moon-icon { display: block !important; }
[data-theme="dark"] .theme-btn .sun-icon { display: block !important; }

/* ============================================================
   RESPONSIVE MOBILE OVERRIDES
   ============================================================ */
@media (max-width: 768px) {
    /* Completely hides text navigation links on mobile devices */
    .header-nav {
        display: none !important;
    }
}