.flash-stack{position:fixed;z-index:1000;top:20px;right:20px;display:grid;gap:10px;width:min(420px,calc(100vw - 32px));pointer-events:none}
.flash{margin:0;padding:14px 16px;border:1px solid var(--line);border-radius:12px;box-shadow:0 14px 34px rgba(0,0,0,.28);transition:opacity .2s ease,transform .2s ease}
.flash.is-hiding{opacity:0;transform:translateY(-8px)}
.flash.error{background:#4a1f2a;color:#ffd9df;border-color:#7b3043}
.flash.success{background:#183d2b;color:#d1ffe6;border-color:#276646}