body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f9;
    color: #333;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 600px;
}

h1, h2 {
    text-align: center;
    color: #2c3e50;
}

.card {
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    padding: 25px;
    margin-bottom: 20px;
}

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

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

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #dcdfe6;
    border-radius: 4px;
    box-sizing: border-box;
}

button {
    width: 100%;
    padding: 12px;
    background-color: #409eff;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #66b1ff;
}

button:disabled {
    background-color: #a0cfff;
    cursor: not-allowed;
}

.loader {
    border: 6px solid #f3f3f3;
    border-top: 6px solid #409eff;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

#packagesList .package {
    border: 1px solid #e4e7ed;
    border-radius: 5px;
    padding: 15px;
    margin-bottom: 10px;
}

#packagesList .package h3 {
    margin-top: 0;
    color: #303133;
}

#packagesList .package p {
    margin: 5px 0;
    font-size: 14px;
    color: #606266;
}

#packagesList .package .price {
    font-weight: bold;
    color: #e6a23c;
}

#packagesList .package .discount {
    color: #67c23a;
}

#resultMessage {
    background-color: #f9fafb;
    padding: 15px;
    border-radius: 4px;
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: "Courier New", Courier, monospace;
}