:root {
    --panel-gap: 20px;
    --panel-width: min(24rem, calc(100vw - (2 * var(--panel-gap))));
}

@media (max-width: 768px) {
    :root {
        --panel-width: min(20rem, calc(100vw - (2 * var(--panel-gap))));
    }
}

body {
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #000;
    font-family: sans-serif;
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.4);
}

.glass-panel {
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

#countryPanel {
    width: var(--panel-width);
    max-width: calc(100vw - (2 * var(--panel-gap)));
}

.back-link {
    position: absolute;
    top: 20px;
    right: 20px;
    color: white;
    text-decoration: none;
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 8px 16px;
    border-radius: 20px;
    transition: all 0.3s ease;
    z-index: 100;
    background: rgba(0, 0, 0, 0.5);
}

.back-link:hover {
    background: white;
    color: black;
}

body.panel-open .back-link {
    right: calc(var(--panel-gap) + var(--panel-width));
}

@media (max-width: 768px) {
    body.panel-open .back-link {
        right: var(--panel-gap);
        top: calc(20px + 70px);
    }
}