.authentication-shell {
    display: grid;
    place-items: center;
    min-height: 32rem;
    padding: clamp(2rem, 6vw, 5rem) 1rem;
}

.authentication-card {
    width: min(100%, 30rem);
    padding: clamp(1.5rem, 4vw, 2.5rem);
    border: 1px solid var(--border-colour);
    border-radius: 0.75rem;
    background: var(--surface-background);
    box-shadow: 0 1rem 3rem rgb(0 0 0 / 12%);
}

.authentication-eyebrow {
    margin: 0 0 0.5rem;
    color: var(--accent-success);
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.authentication-card h1 {
    margin: 0;
    color: var(--text-primary);
    font-size: clamp(1.75rem, 5vw, 2.35rem);
    line-height: 1.15;
}

.authentication-introduction {
    margin: 1rem 0 1.5rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.authentication-alert {
    margin-bottom: 1.25rem;
    padding: 0.85rem 1rem;
    border: 1px solid var(--accent-warning);
    border-radius: 0.4rem;
    background: var(--surface-muted);
    color: var(--text-primary);
    line-height: 1.5;
}

.authentication-form {
    display: grid;
    gap: 1.25rem;
}

.authentication-field {
    display: grid;
    gap: 0.5rem;
}

    .authentication-field label {
        color: var(--text-primary);
        font-weight: 700;
    }

    .authentication-field input {
        box-sizing: border-box;
        width: 100%;
        min-height: 2.9rem;
        padding: 0.7rem 0.8rem;
        border: 1px solid var(--border-colour);
        border-radius: 0.4rem;
        background: var(--page-background);
        color: var(--text-primary);
        font: inherit;
    }

        .authentication-field input:focus-visible {
            outline: 0.2rem solid var(--focus-ring);
            outline-offset: 0.15rem;
        }

.authentication-submit,
.authentication-link-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.9rem;
    padding: 0.7rem 1rem;
    border: 1px solid transparent;
    border-radius: 0.4rem;
    background: var(--accent-primary);
    color: #ffffff;
    font: inherit;
    font-weight: 700;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
}

    .authentication-submit:hover,
    .authentication-link-button:hover {
        border-color: var(--accent-warning);
        background: var(--accent-warning);
        color: #ffffff;
    }

    .authentication-submit:focus-visible,
    .authentication-link-button:focus-visible {
        outline: 0.2rem solid var(--focus-ring);
        outline-offset: 0.2rem;
    }

.authentication-help,
.authentication-secondary-actions {
    margin: 1.25rem 0 0;
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
}

    .authentication-secondary-actions a {
        color: var(--accent-primary);
    }

        .authentication-secondary-actions a:hover {
            color: var(--accent-warning);
        }

.authentication-guidance {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.5;
}