* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(45deg, #a0c4ff, #c6e2ff);
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    text-align: center;
}
.container {
    max-width: 600px;
    width: 100%;
    padding: 30px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
}
header {
    margin-bottom: 30px;
    background: linear-gradient(45deg, #FF7E5F, #FEB47B);
    padding: 20px;
    border-radius: 10px;
}
header h1 {
    font-size: 2.5em;
    color: white;
    letter-spacing: 1px;
    margin-bottom: 10px;
}
header p {
    color: #fff;
    font-size: 1.1em;
}
.content {
    padding: 20px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0px 0px 20px rgba(0, 0, 0, 0.1);
}
h2, h3 {
    color: #333;
    margin-top: 20px;
    font-size: 1.5em;
    font-weight: 600;
}
.input-field {
    display: block;
    width: 100%;
    padding: 12px;
    margin: 10px 0;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1.1em;
    transition: border-color 0.3s ease;
}
.input-field:focus {
    border-color: #3498db;
    outline: none;
}
.input-container {
    display: flex;
    justify-content: space-between;
    gap: 10px;
}
.btn {
    background: linear-gradient(45deg, #6A82FB, #FC5C7D);
    color: white;
    border: none;
    padding: 12px;
    width: 100%;
    margin-bottom: 10px;
    border-radius: 8px;
    font-size: 1.2em;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
.btn:hover {
    background: linear-gradient(45deg, #FC5C7D, #6A82FB);
}
#mensaje {
    margin-top: 20px;
    color: green;
    font-size: 1.2em;
    font-weight: bold;
}
#listaVentas {
    list-style: none;
    padding: 0;
    margin-top: 10px;
}
#listaVentas li {
    background: #ecf0f1;
    margin: 5px 0;
    padding: 12px;
    border-radius: 8px;
    font-size: 1.1em;
    color: #333;
    transition: background-color 0.3s ease;
}
#listaVentas li:hover {
    background: #dfe6e9;
}