* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: #f4f7fa;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 420px;
    padding: 2rem;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

h2 {
    margin-bottom: 1.5rem;
    color: #1e293b;
    text-align: center;
}

.subtitle {
    margin-bottom: 1.2rem;
    color: #64748b;
    text-align: center;
    font-size: 0.9rem;
}

.form-group {
    margin-bottom: 1.2rem;
}

label {
    display: block;
    margin-bottom: 0.3rem;
    color: #334155;
    font-weight: 600;
}

input[type="email"],
input[type="password"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-size: 1rem;
}

input:focus {
    border-color: #2563eb;
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

button {
    width: 100%;
    margin-top: 0.5rem;
    padding: 0.8rem;
    border: none;
    border-radius: 8px;
    background: #2563eb;
    color: #ffffff;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
}

button:hover {
    background: #1d4ed8;
}

.message {
    display: none;
    margin-bottom: 1rem;
    padding: 0.7rem;
    border-radius: 8px;
    text-align: center;
}

.message.error {
    display: block;
    border: 1px solid #fecaca;
    background: #fee2e2;
    color: #991b1b;
}

.message.success {
    display: block;
    border: 1px solid #bbf7d0;
    background: #dcfce7;
    color: #166534;
}

.strength-warning {
    display: none;
    margin-top: 0.4rem;
    font-size: 0.85rem;
    font-weight: 600;
}

.strength-warning.visible {
    display: block;
}

.strength-warning.weak {
    color: #991b1b;
}

.strength-warning.medium {
    color: #92400e;
}

.strength-warning.strong {
    color: #166534;
}

.hidden {
    display: none;
}