/* ==========================================
   后端管理 · 暗色渐变背景
   安全区适配 + 低性能渐变
   ========================================== */

:root {
    --bg-dark: #0a0a1a;
    --g1: rgba(100, 150, 255, 0.55);
    --g2: rgba(180, 120, 255, 0.5);
}

.gradient-bg {
    position: fixed;
    inset: 0;
    z-index: -2;
    padding:
        env(safe-area-inset-top, 0px)
        env(safe-area-inset-right, 0px)
        env(safe-area-inset-bottom, 0px)
        env(safe-area-inset-left, 0px);
    background:
        radial-gradient(circle at 20% 30%, var(--g1), transparent 55%),
        radial-gradient(circle at 80% 70%, var(--g2), transparent 55%),
        linear-gradient(to bottom, var(--bg-dark), #0f0f2a);
    background-size: 140% 140%, 140% 140%, 100% 100%;
}

html, body {
    margin: 0; padding: 0;
    width: 100%; height: 100%;
    overflow: hidden;
    background: var(--bg-dark);
}