:root {
    --bg: #0f172a; --card: #0b1220; --muted: #94a3b8; --text: #e2e8f0;
    --primary: #7c3aed; --primary-2: #06b6d4; --danger: #ef4444;
    --shadow: 0 10px 30px rgba(124, 58, 237, .25), 0 6px 12px rgba(0, 0, 0, .25);
    --radius: 18px;
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
    margin: 0; font-family: Inter, system-ui, sans-serif; color: var(--text);
    background: linear-gradient(180deg, #0b1020 0%, #0f172a 100%);
    display: flex; align-items: center; justify-content: center; padding: 2rem;
}
.shell { width: 100%; max-width: 480px; }
.card {
    background: linear-gradient(180deg, rgba(255, 255, 255, .04), rgba(255, 255, 255, .02));
    border: 1px solid rgba(148, 163, 184, .18); border-radius: var(--radius);
    box-shadow: var(--shadow); overflow: hidden;
}
header.hero {
    padding: 2rem 2rem 1rem; text-align: center;
    background: linear-gradient(180deg, rgba(124, 58, 237, .08), transparent);
}
.brand { font-size: 1rem; letter-spacing: .12em; color: var(--muted); text-transform: uppercase; }
.title { margin: .25rem 0 0; font-weight: 800; font-size: 1.75rem; }
.pad { padding: 1.5rem; }
.login { display: grid; gap: 1.25rem; }
.input {
    background: #0a0f1d; border: 1px solid rgba(148, 163, 184, .25); color: var(--text);
    border-radius: 12px; padding: .85rem 1rem; font-size: 1rem; width: 100%;
}
.btn {
    appearance: none; border: none; border-radius: 12px; padding: .9rem 1.2rem;
    font-weight: 700; cursor: pointer; color: white; font-size: 1.1rem;
    background-image: linear-gradient(135deg, var(--primary), var(--primary-2));
    box-shadow: 0 10px 18px rgba(124, 58, 237, .35);
}
.error { color: var(--danger); min-height: 1.25rem; text-align: center; }