/* header.css — modern glass header with subtle hover/active states */
:root {
    --bg: #0b1220;
    --bg-2: #0e1a2f;
    --text: #0f172a;
    --ink: #0b1220;
    --brand: #12d6a7;
    --brand-2: #8be9d2;
    --link: #0f3d8a;
    --link-hover: #12d6a7;
    --ring: rgba(18, 214, 167, 0.35);
    --panel: rgba(255, 255, 255, 0.6);
    --blur: 12px;
    --shadow: 0 10px 30px rgba(2, 6, 23, 0.12);
}

/* Header Container */
.custom-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: saturate(160%) blur(var(--blur));
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(255, 255, 255, 0.66));
    border-bottom: 1px solid rgba(2, 6, 23, 0.06);
    box-shadow: var(--shadow);
    padding: 0.6rem 1rem;
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* Branding */
.brand {
    display: flex;
    align-items: center;
    text-decoration: none;
    gap: 0.75rem;
}

.logo {
    width: 44px;
    height: auto;
    filter: drop-shadow(0 2px 8px rgba(18, 214, 167, 0.35));
    transition: transform .25s ease, filter .25s ease;
}

.brand:hover .logo {
    transform: translateY(-1px) scale(1.03);
}

.brand-name {
    font-family: 'Plus Jakarta Sans', 'Inter', system-ui, sans-serif;
    font-size: 1.6rem;
    font-weight: 800;
    letter-spacing: .2px;
    color: #0b1220;
    background: linear-gradient(90deg, #0b1220, #0f3d8a 60%, var(--brand));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* Navigation */
.nav-links {
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

.nav-link {
    position: relative;
    font-family: 'Inter', system-ui, sans-serif;
    text-decoration: none;
    font-weight: 600;
    font-size: .98rem;
    color: #1f2a44;
    padding: .5rem .25rem;
    transition: color .2s ease;
}

.nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 6px;
    width: 0%;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--brand), var(--brand-2));
    transition: width .25s ease;
}

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

.nav-link:hover::after {
    width: 100%;
}

.nav-link.active {
    color: var(--link-hover);
    text-shadow: 0 0 0 transparent;
}

.nav-link.active::after {
    width: 100%;
}

/* Login/Logout Button */
.login-btn {
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    background: linear-gradient(180deg, var(--brand), #0dbf98);
    color: #04131a !important;
    padding: .55rem 1rem;
    border-radius: 999px;
    font-weight: 800;
    box-shadow: 0 8px 20px var(--ring);
    transition: transform .2s ease, box-shadow .2s ease, filter .2s ease;
    border: 1px solid rgba(4, 19, 26, 0.08);
}

.login-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 12px 28px var(--ring);
    filter: brightness(1.03);
}

/* Mobile Menu Toggle (hamburger) */
.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
    padding: .35rem;
    border-radius: 10px;
    transition: background .2s ease;
}

.menu-toggle:hover {
    background: rgba(2, 6, 23, 0.06);
}

.menu-toggle span {
    width: 26px;
    height: 2.5px;
    background-color: #1f2a44;
    border-radius: 2px;
    transition: transform .25s ease, opacity .25s ease;
}

/* Responsive Navigation */
@media (max-width: 900px) {
    .nav-links {
        position: absolute;
        left: 0;
        right: 0;
        top: 100%;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        background: rgba(255, 255, 255, 0.92);
        backdrop-filter: blur(var(--blur));
        border-bottom: 1px solid rgba(2, 6, 23, 0.06);
        box-shadow: 0 16px 30px rgba(2, 6, 23, 0.08);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-link {
        padding: 0.9rem 1.25rem;
        border-top: 1px solid rgba(2, 6, 23, 0.05);
    }

    .menu-toggle {
        display: flex;
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {

    .logo,
    .nav-link::after,
    .login-btn {
        transition: none;
    }
}

/* Remove underline effect for login button in all states */
.login-btn::after,
.login-btn:hover::after,
.login-btn.active::after {
    display: none !important;
}