.app-shell {
    width: min(960px, calc(100% - 32px));
    margin: 0 auto;
    padding: max(24px, env(safe-area-inset-top)) 0 max(24px, env(safe-area-inset-bottom));
}

.app-header, .panel-heading {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.app-header { margin-bottom: 24px; }
.app-header h1, .panel h2 { margin: 0; }

.panel {
    border: 1px solid rgba(255,255,255,.1);
    border-radius: 18px;
    padding: 24px;
    background: rgba(18, 23, 40, .88);
    box-shadow: 0 20px 60px rgba(0,0,0,.25);
    backdrop-filter: blur(12px);
}

.stack { display: grid; gap: 16px; }
.stack label { display: grid; gap: 7px; }

.state-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    margin-top: 24px;
}

@media (max-width: 720px) {
    .app-shell { width: min(100% - 20px, 960px); }
    .app-header, .panel-heading { align-items: flex-start; }
    .state-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 460px) {
    .app-header { display: grid; }
    .panel { padding: 18px; border-radius: 14px; }
    .state-grid { grid-template-columns: 1fr; }
}