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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #2c3e50;
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

header {
    background: #1a252f;
    padding: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px; 
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    z-index: 10;
}

select {
    padding: 10px;
    border-radius: 5px;
    border: none;
    font-size: 16px;
    min-width: 250px;
}

#toggle-toolbar-btn {
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    width: 40px;
    height: 40px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.container {
    flex-grow: 1;
    width: 100%;
    height: 85vh; 
    min-height: 400px; 
}

#flipbook {
    height: 100%;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hide-toolbar .df-ui-controls {
    display: none !important;
}

/* FIXED: The "Nuclear Option" to forcefully erase the download and outline buttons */
.df-ui-download,
.df-ui-outline,
.df-ui-bookmark,
[title="Download PDF"],
[title="Outline"] {
    display: none !important;
}