body {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f5f7fa;
    font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

.container {
    text-align: center;
    background: #fff;
    padding: 50px;
    border-radius: 15px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    max-width: 520px;
    width: 100%;
}

.form-group.vertical { margin-top: 30px; text-align: left; }

.field { display: block; margin-bottom: 16px; }
.label { display: inline-block; margin-bottom: 8px; font-weight: 600; color: #333; }

input[type="email"],
input[type="password"] {
    width: 100%;
    box-sizing: border-box;
    padding: 14px;
    font-size: 1.1rem;
    border: 1px solid #ccc;
    border-radius: 8px;
    outline: none;
    transition: border-color 0.2s;
}

input[type="email"]:focus,
input[type="password"]:focus {
    border-color: #0077cc;
}

button {
    padding: 14px 24px;
    margin-top: 8px;
    border: none;
    border-radius: 8px;
    background-color: #0077cc;
    color: #fff;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

button:hover { background-color: #005fa3; transform: scale(1.03); }

.hint { margin-top: 10px; color: #6b7280; font-size: 0.95rem; }
.error { margin-top: 10px; color: #d32f2f; font-weight: 600; }

.message.success {
    margin-top: 20px;
    color: #2e7d32;
    font-size: 1.05rem;
    font-weight: 600;
}