:root {
    --page-bg: #f5f7fb;
    --card-border: #e5e7eb;
    --text: #111827;
    --muted: #6b7280;
    --brand: #2563eb;
    --brand-dark: #1d4ed8;
    --google: #ea4335;
    --microsoft: #0f6cbd;
    --yahoo: #6001d2;
}

html, body {
    min-height: 100%;
}

body {
    margin: 0;
    color: var(--text);
    background: var(--page-bg);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.auth-shell {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 2rem 1rem;
}

.auth-card {
    border: 1px solid var(--card-border);
    border-radius: 1.25rem;
    background: #fff;
}

.brand-chip {
    width: 2.75rem;
    height: 2.75rem;
    border-radius: 0.9rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--brand), var(--brand-dark));
    color: #fff;
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.08em;
}

.eyebrow {
    color: var(--brand);
    text-transform: uppercase;
    letter-spacing: 0.14em;
    font-size: 0.68rem;
    font-weight: 800;
}

.brand-name {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.page-headline,
.page-subtitle {
    color: var(--muted);
}

.page-headline {
    font-size: 0.95rem;
    font-weight: 600;
}

.page-subtitle {
    font-size: 0.9rem;
}

.form-floating > .form-control {
    height: calc(3.5rem + 2px);
    min-height: calc(3.5rem + 2px);
    padding-top: 1.625rem;
    padding-bottom: 0.625rem;
}

.form-floating > label {
    color: var(--muted);
}

.or-divider {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--muted);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.or-divider::before,
.or-divider::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--card-border);
}

.flat-tab {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.45rem 0.75rem;
    border-radius: 999px;
    border: 1px solid var(--card-border);
    color: var(--muted);
    background: #fff;
    text-decoration: none;
    font-size: 0.84rem;
    font-weight: 600;
}

.flat-tab.active {
    color: #fff;
    border-color: var(--text);
    background: var(--text);
}

.flat-input {
    border-radius: 0.85rem;
    border-color: #d1d5db;
    box-shadow: none;
}

.flat-input:focus {
    border-color: var(--brand);
    box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.08);
}

.helper-link {
    color: var(--brand);
    text-decoration: none;
    font-weight: 600;
}

.helper-link:hover {
    text-decoration: underline;
}

.social-actions {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.social-button {
    width: 2.9rem;
    height: 2.9rem;
    border-radius: 999px;
    border: 1px solid var(--card-border);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    background: #fff;
    color: var(--text);
    text-decoration: none;
    font-size: 0.92rem;
    font-weight: 700;
}

.social-button:hover {
    background: #f8fafc;
}

.social-badge {
    width: 1.75rem;
    height: 1.75rem;
    border-radius: 999px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 0.75rem;
    font-weight: 800;
}

.social-button.social-google,
.social-button.social-microsoft,
.social-button.social-yahoo {
    transition: transform 0.12s ease, background-color 0.12s ease;
}

.social-button.social-google:hover,
.social-button.social-microsoft:hover,
.social-button.social-yahoo:hover {
    transform: translateY(-1px);
}

.social-badge-google {
    background: var(--google);
}

.social-badge-microsoft {
    background: var(--microsoft);
}

.social-badge-yahoo {
    background: var(--yahoo);
}

.social-google {
    color: var(--google);
}

.social-microsoft {
    color: var(--microsoft);
}

.social-yahoo {
    color: var(--yahoo);
}

.small-note {
    color: var(--muted);
    font-size: 0.82rem;
    line-height: 1.45;
}

@media (max-width: 575px) {
    .auth-shell {
        padding: 1rem 0.5rem;
    }

    .auth-card {
        border-radius: 1rem;
    }
}