/* header */
.site-header {
    position: sticky;
    top: 32px;
    z-index: 60;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    min-height: 58px;
    padding: 8px 12px;
    border: 1px solid rgba(56, 189, 248, 0.16);
    border-radius: 999px;
    background: rgba(17, 23, 34, 0.82);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow:
        0 12px 30px rgba(0, 0, 0, 0.35),
        0 4px 12px rgba(56, 189, 248, 0.06);
}

.brand {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-left: 8px;
}

.brand img {
    display: block;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
    cursor: pointer;
}

.brand-title {
    display: none;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 30px;
    padding: 0 18px;
    font-weight: 500;
}

.site-nav a {
    color: var(--text-dim);
    font-size: 1.05rem;
    transition: color 0.25s ease;
}

.site-nav a:hover {
    color: var(--tile-accent);
    cursor: pointer;
}

/* hamburger */
.menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    padding: 0;
    border: 1px solid var(--tile-border);
    border-radius: 50%;
    background: transparent;
    color: var(--text);
    font-size: 1.25rem;
    line-height: 1;
    cursor: pointer;
    transition:
        color 0.25s ease,
        border-color 0.25s ease,
        background 0.25s ease;
}

.menu-toggle i {
    cursor: pointer;
}

.menu-toggle:hover {
    color: var(--tile-accent);
    border-color: var(--tile-accent);
    background: rgba(56, 189, 248, 0.04);
}

/* menu backdrop */
.menu-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(5, 8, 15, 0.45);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    z-index: 40;
    transition:
        opacity 0.3s ease,
        visibility 0.3s ease;
}

.menu-backdrop.open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

/* responsive */
@media (max-width: 1100px) {
    .site-header {
        top: 20px;
        margin-bottom: 45px;
    }
}

@media (min-width: 801px) {
    .menu-backdrop {
        display: none;
    }
}

@media (max-width: 800px) {

    .container {
        padding-top: 20px;
    }

    .site-header {
        top: 20px;
        margin-bottom: 45px;
        min-height: 45px;
        padding: 6px 8px;
    }

    .brand img {
        width: 26px;
        height: 26px;
    }

    .menu-toggle {
        display: inline-flex;
        width: 36px;
        height: 36px;
        font-size: 1.1rem;
    }

    .site-nav {
        position: absolute;
        top: -1px;
        left: -1px;
        right: -1px;
        display: flex;
        flex-direction: column;
        align-items: flex-start;
        gap: 0;
        padding: 12px 20px;
        background: rgba(17, 23, 34, 0.92);
        border: 1px solid rgba(56, 189, 248, 0.14);
        border-radius: 24px;
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        box-shadow:
            0 18px 40px rgba(0, 0, 0, 0.45),
            0 6px 18px rgba(56, 189, 248, 0.08);

        transform: translateY(-12px);
        opacity: 0;
        visibility: hidden;
        pointer-events: none;
        z-index: 70;
        transition:
            transform 0.35s var(--ease-out),
            opacity 0.25s ease,
            visibility 0.35s ease;
    }

    .site-nav.open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
    }

    .site-nav a {
        display: flex;
        align-items: center;
        justify-content: flex-start;
        width: 100%;
        min-height: 50px;
        padding: 8px 0;
        border-bottom: 1px solid rgba(32, 41, 54, 0.7);
        color: var(--text-dim);
        font-size: 1.15rem;
        text-align: left;
        transition: color 0.2s ease;
    }

    .site-nav a:last-child {
        border-bottom: none;
    }

    .site-nav a:hover {
        color: var(--tile-accent);
    }
}