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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    min-height: 100vh;
    background-color: white;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.maximize-btn {
    background-color: transparent;
    border: 2px solid white;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.maximize-btn:hover {
    background-color: rgba(255, 255, 255, 0.2);
    transform: scale(1.1);
}

/* Fullscreen styles */
.container.fullscreen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    max-width: none;
    z-index: 9999;
    margin: 0;
}

.main-content {
    display: flex;
    min-height: calc(100vh - 120px);
}

.sidebar {
    width: 300px;
    background-color: #2c3e50;
    color: white;
    padding: 1rem;
    display: flex;
    flex-direction: column;
}

.controls {
    margin-bottom: 1rem;
}

.controls button {
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    border: none;
    background-color: #34495e;
    color: white;
    cursor: pointer;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.controls button:hover,
.controls button.active {
    background-color: #3498db;
}

.search-section {
    margin-bottom: 1rem;
}

.search-box {
    display: flex;
    gap: 0.5rem;
}

#searchInput {
    flex: 1;
    padding: 0.5rem;
    border: none;
    border-radius: 4px;
    background-color: #34495e;
    color: white;
}

#searchInput::placeholder {
    color: #bbb;
}

#searchBtn {
    padding: 0.5rem;
    border: none;
    background-color: #3498db;
    color: white;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#searchBtn:hover {
    background-color: #2980b9;
}

.input-section {
    background-color: #34495e;
    padding: 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.input-section h3 {
    margin-bottom: 0.75rem;
    color: #ecf0f1;
}

.input-section input,
.input-section select {
    width: 100%;
    padding: 0.5rem;
    margin-bottom: 0.5rem;
    border: none;
    border-radius: 4px;
}

.input-section button {
    width: 100%;
    padding: 0.75rem;
    background-color: #27ae60;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.input-section button:hover {
    background-color: #2ecc71;
}

.list-section {
    flex: 1;
    overflow-y: auto;
}

.list-section h3 {
    margin-bottom: 0.75rem;
    color: #ecf0f1;
}

#itemList {
    list-style: none;
}

#itemList li {
    padding: 0.75rem;
    background-color: #34495e;
    margin-bottom: 0.5rem;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#itemList li:hover {
    background-color: #3da0db;
}

.viewer {
    flex: 1;
    position: relative;
}

.pdf-container,
.web-container {
    width: 100%;
    height: 100%;
    border: none;
}

#welcomeMessage {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    color: #7f8c8d;
}

#welcomeMessage h2 {
    margin-bottom: 1rem;
    color: #2c3e50;
}

@media (max-width: 768px) {
    .main-content {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        max-height: 40vh;
    }
}