body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    background: radial-gradient(circle at top, var(--bi-blue-light) 0%, #ffffff 55%);
}

.auth-card {
    width: min(420px, 100%);
    background: #ffffff;
    border: 1.5px solid var(--bi-blue);
    border-radius: var(--bi-radius-lg);
    padding: 40px 36px;
    box-shadow:
        0 24px 48px -12px rgba(47, 111, 237, 0.2),
        0 8px 20px rgba(0, 0, 0, 0.06);
    opacity: 0;
    transform: translateY(24px);
    animation: bi-card-enter 0.6s ease-out forwards;
}

.auth-logo {
    text-align: center;
    font-size: 30px;
    font-weight: 700;
    color: var(--bi-blue);
    letter-spacing: 0.5px;
    margin: 0 0 4px;
    text-shadow:
        0 0 14px rgba(255, 255, 255, 0.9),
        0 0 26px rgba(120, 180, 255, 0.55);
}

.auth-subtitle {
    text-align: center;
    font-size: 14px;
    color: var(--bi-muted);
    margin: 0 0 28px;
}

.auth-error {
    background: var(--bi-error-bg);
    color: var(--bi-error-text);
    border: 1px solid var(--bi-error-border);
    border-radius: var(--bi-radius-md);
    padding: 12px 16px;
    margin: 0 0 20px;
    font-size: 14px;
    text-align: center;
    opacity: 0;
    transform: translateY(-10px);
    animation: bi-error-enter 0.4s ease-out 0.15s forwards;
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.auth-field label {
    display: block;
    margin-bottom: 6px;
    font-size: 13px;
    font-weight: 600;
    color: var(--bi-muted);
}

.auth-field input {
    width: 100%;
    padding: 12px 14px;
    font-size: 15px;
    font-family: inherit;
    color: var(--bi-text);
    background: #fbfdff;
    border: 1.5px solid var(--bi-blue-border);
    border-radius: var(--bi-radius-md);
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.auth-field input:focus {
    border-color: var(--bi-blue);
    background: #ffffff;
    box-shadow: 0 0 0 4px rgba(47, 111, 237, 0.15);
}

.auth-submit {
    margin-top: 6px;
    padding: 13px;
    border: none;
    border-radius: var(--bi-radius-md);
    color: #ffffff;
    font-size: 16px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    background: linear-gradient(135deg, #4c8dff, var(--bi-blue));
    box-shadow: 0 10px 24px -8px rgba(47, 111, 237, 0.55);
    transition: filter 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.auth-submit:hover {
    filter: brightness(1.08);
    transform: translateY(-2px);
    box-shadow: 0 14px 30px -8px rgba(47, 111, 237, 0.6);
}

.auth-submit:active {
    transform: translateY(0);
    filter: brightness(0.97);
}

@keyframes bi-error-enter {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 480px) {
    body {
        padding: 24px 32px;
    }

    .auth-card {
        padding: 32px 22px;
        border-radius: 16px;
    }

    .auth-logo {
        font-size: 26px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .auth-card,
    .auth-error {
        animation: none;
        opacity: 1;
        transform: none;
    }
}

.auth-link-button {
    display: block;
    text-align: center;
    text-decoration: none;
}