/* Layout and Structural Styles */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    height: 100%;
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    flex-direction: column;
    min-width: 740px;
}

/* Wrapper to hold everything */
.wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
header {
    background-color: #666;
    padding: 10px;
    text-align: center;
    font-size: 15px;
    color: white;
    position: relative;
    z-index: 1;
}

/* Section layout */
section {
    flex: 1;
    display: flex;
    flex-direction: row;
    align-items: stretch;
    justify-content: space-between;
    padding: 0 20px;
    min-height: 0;
    overflow: hidden;
}

/* Sidebar navigation */
nav {
    width: 200px;
    background: #ccc;
    padding: 20px;
    flex-shrink: 1;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    min-height: 0;
    overflow-y: auto;
}

nav ul {
    list-style-type: none;
    padding: 0;
    width: 100%;
}

/* Payment section */
payment {
    width: 240px;
    background-color: #8c8b8b;
    padding: 20px;
    flex-shrink: 1;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    min-height: 0;
    overflow-y: auto;
}

/* Footer */
footer {
    background-color: #777;
    padding: 10px;
    text-align: center;
    color: white;
    width: 100%;
    margin-top: auto;
}

/* Main container */
.main-container {
    width: 100%;
    min-height: 100vh;
    overflow-x: hidden;
}