body {
    min-height: 100vh;
    font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    background:
        radial-gradient(circle at top left, rgba(13, 110, 253, 0.16), transparent 36%),
        radial-gradient(circle at bottom right, rgba(25, 135, 84, 0.16), transparent 30%),
        linear-gradient(180deg, #f8fbff 0%, #eef2f8 100%);
    color: #14213d;
}

.hero-shell {
    min-height: 100vh;
}

.hero-card,
.assignment-card {
    border: 1px solid rgba(20, 33, 61, 0.08);
    border-radius: 1.5rem;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(10px);
}

.hero-intro,
.hero-form,
.assignment-card {
    padding: 2rem;
}

.hero-intro {
    background: linear-gradient(145deg, rgba(13, 110, 253, 0.06), rgba(13, 202, 240, 0.08));
    border-bottom-left-radius: 1.5rem;
    border-top-left-radius: 1.5rem;
}

.eyebrow {
    margin-bottom: 0.75rem;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: #0d6efd;
}

.info-panel {
    padding: 1.5rem;
    border-radius: 1.25rem;
    background: #f8fbff;
    border: 1px solid rgba(20, 33, 61, 0.08);
}

.pin-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 7rem;
    padding: 0.85rem 1.25rem;
    border-radius: 999px;
    background: linear-gradient(135deg, #0d6efd, #0dcaf0);
    color: #fff;
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.alert {
    border-radius: 1rem;
}

.link-action-group {
    display: flex;
    align-items: stretch;
    gap: 0.5rem;
}

.link-action-group .btn-lg {
    flex: 1 1 auto;
}

.copy-only-button {
    min-width: 2.8rem;
    font-size: 1rem;
    font-weight: 700;
    line-height: 1;
}

@media (max-width: 991.98px) {
    .hero-intro {
        border-top-right-radius: 1.5rem;
        border-bottom-left-radius: 0;
    }
}

@media (max-width: 575.98px) {
    .hero-intro,
    .hero-form,
    .assignment-card {
        padding: 1.5rem;
    }

    .pin-badge {
        min-width: 100%;
    }
}