:root {
    --brand: #906cdc;
    --brand-d: #7a57cb;
    --muted: #6b7280;
    --danger: #ef4444;
    --bg: #ffffff;
    --ring: 0 0 0 4px rgba(144, 108, 220, .18);
}

html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
    /* prevent horizontal scroll only */
}


body {
    margin: 0;
    font-family: system-ui, sans-serif;
    background: var(--bg);
    color: #111;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 1rem;
}

.signin-container {
    width: 100%;
    max-width: 600px;
    background: #fff;
    border-radius: 1rem;
    box-shadow: 0 4px 24px rgba(0, 0, 0, .08);
    padding: 2rem 1.5rem;
    box-sizing: border-box;
}

.signin-container h1 {
    font-size: 1.5rem;
    text-align: center;
    color: var(--brand-d);
    margin-top: 0;
    margin-bottom: 1.5rem;
}

form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

input {
    padding: 0.85rem 1rem;
    border: 1px solid #e5e7eb;
    border-radius: 0.75rem;
    font-size: 1rem;
    transition: border 0.2s, box-shadow 0.2s;
}

input:focus {
    outline: none;
    border-color: var(--brand);
    box-shadow: var(--ring);
}

button {
    background: var(--brand);
    border: none;
    color: white;
    font-weight: 600;
    font-size: 1rem;
    padding: 0.9rem;
    border-radius: 0.75rem;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background: var(--brand-d);
}

.error {
    margin-top: 0.5rem;
    font-size: 0.9rem;
    color: var(--danger);
    text-align: center;
}