:root {
    --lab-shell-chip-bg: rgba(255, 255, 255, 0.92);
    --lab-shell-chip-border: rgba(0, 0, 0, 0.06);
    --lab-shell-chip-shadow: 0 4px 10px rgba(0, 0, 0, 0.10);
    --lab-shell-chip-text: #2c3e50;
    --lab-shell-safe-top: 64px;
}

.lab-shell-safe {
    padding-top: calc(var(--lab-shell-safe-top) + env(safe-area-inset-top));
    box-sizing: border-box;
}

.lab-shell {
    position: fixed;
    top: 14px;
    left: 14px;
    right: 14px;
    z-index: 120;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    pointer-events: none;
}

.lab-shell__left {
    display: flex;
    gap: 10px;
    align-items: center;
    pointer-events: auto;
}

.lab-shell__chip {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    border-radius: 999px;
    background: var(--lab-shell-chip-bg);
    border: 1px solid var(--lab-shell-chip-border);
    box-shadow: var(--lab-shell-chip-shadow);
    color: var(--lab-shell-chip-text);
    font-weight: 700;
    font-size: 14px;
    line-height: 1;
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

button.lab-shell__chip {
    cursor: pointer;
}

.lab-shell__chip:hover {
    background: rgba(255, 255, 255, 0.98);
}

.lab-shell__chip:focus-visible {
    outline: 3px solid rgba(74, 144, 226, 0.35);
    outline-offset: 2px;
}

.lab-shell__brand {
    pointer-events: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.76);
    border: 1px solid rgba(0, 0, 0, 0.05);
    color: rgba(44, 62, 80, 0.78);
    font-weight: 700;
    font-size: 13px;
    white-space: nowrap;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
}

.lab-shell__spark {
    opacity: 0.95;
}

@media (max-width: 520px) {
    .lab-shell {
        right: auto;
    }

    .lab-shell__brand {
        display: none;
    }
}