* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Segoe UI", "Microsoft YaHei", -apple-system, sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    color: #555;
    margin-bottom: 6px;
}

.form-group input {
    width: 100%;
    padding: 12px 14px;
    font-size: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.submit-btn {
    width: 100%;
    padding: 12px;
    font-size: 16px;
    color: #fff;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.1s;
}

.submit-btn:hover {
    opacity: 0.9;
}

.submit-btn:active {
    transform: scale(0.98);
}

.error-msg {
    display: none;
    background: #fdecea;
    color: #c0392b;
    font-size: 13px;
    padding: 10px 12px;
    border-radius: 8px;
    margin-bottom: 18px;
}