* { box-sizing: border-box; font-family: 'Segoe UI', sans-serif; }

body {
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
}

.container {
    background: #ffffff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 450px;
}

h2 { text-align: center; color: #333; margin-bottom: 25px; }

.form-group { margin-bottom: 15px; position: relative; }

label { display: block; margin-bottom: 5px; font-weight: 600; color: #444; }

input, textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

input:focus, textarea:focus { outline: none; border-color: #007bff; }

/* Состояния валидации */
input.valid, textarea.valid { border-color: #28a745; }
input.invalid, textarea.invalid { border-color: #dc3545; }

.error-msg {
    color: #dc3545;
    font-size: 12px;
    margin-top: 4px;
    display: block;
    min-height: 15px;
}

.submit-btn {
    width: 100%;
    padding: 14px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

.submit-btn:disabled { background-color: #ccc; cursor: not-allowed; }

.response-msg {
    margin-top: 15px;
    text-align: center;
    font-weight: bold;
}

@media (max-width: 480px) {
    .container { padding: 20px; }
}