* { box-sizing: border-box; }

body {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: linear-gradient(135deg, #0f172a 0%, #1a56db 100%);
    min-height: 100vh;
}

.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.login-card {
    width: 100%;
    max-width: 420px;
    background: #fff;
    border-radius: 16px;
    padding: 40px 36px;
    box-shadow: 0 24px 64px rgba(15, 23, 42, 0.25);
}

.login-brand h1 {
    margin: 0 0 8px;
    text-align: center;
    font-size: 28px;
    color: #0f172a;
}

.login-subtitle {
    text-align: center;
    color: #64748b;
    font-size: 14px;
    margin: 0 0 28px;
}

.login-error {
    background: #fef2f2;
    color: #b91c1c;
    border: 1px solid #fecaca;
    border-radius: 8px;
    padding: 12px 14px;
    font-size: 14px;
    margin-bottom: 20px;
}

form .txt_field {
    position: relative;
    border-bottom: 2px solid #e2e8f0;
    margin: 28px 0;
}

.txt_field input {
    width: 100%;
    padding: 8px 4px;
    height: 42px;
    font-size: 16px;
    border: none;
    background: none;
    outline: none;
}

.txt_field label {
    position: absolute;
    top: 50%;
    left: 4px;
    color: #94a3b8;
    transform: translateY(-50%);
    font-size: 15px;
    pointer-events: none;
    transition: 0.2s;
}

.txt_field input:focus ~ label,
.txt_field input:valid ~ label {
    top: -6px;
    font-size: 12px;
    color: #1a56db;
}

input[type="submit"] {
    width: 100%;
    height: 48px;
    border: none;
    background: #1a56db;
    border-radius: 10px;
    font-size: 16px;
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    margin-top: 8px;
    transition: background 0.2s;
}

input[type="submit"]:hover {
    background: #1241a8;
}

.login-back {
    display: block;
    text-align: center;
    margin-top: 24px;
    color: #64748b;
    font-size: 14px;
    text-decoration: none;
}

.login-back:hover {
    color: #1a56db;
}

.center {
    position: static;
    transform: none;
    width: auto;
    height: auto;
    background: transparent;
    border-radius: 0;
}