/* Reset and Base Styles */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body, html {
    width: 100%;
    height: 100%;
    overflow-x: hidden;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #000; /* Default background */
    color: #fff;
}

/* Presentation Container */
#presentation-container {
    width: 100%;
    display: flex;
    flex-direction: column;
}

.slide {
    width: 100vw;
    height: auto;
    display: block;
    object-fit: contain; /* Ensures the whole image is visible */
}

/* Loading Screen */
#loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #111;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.loader {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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

/* Admin Styles */
.admin-body {
    background-color: #f4f4f9;
    color: #333;
    padding: 20px;
}

#auth-container {
    max-width: 400px;
    margin: 100px auto;
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    text-align: center;
}

#auth-container input {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    border: 1px solid #ddd;
    border-radius: 4px;
}

#auth-container button {
    width: 100%;
    padding: 10px;
    background: #3498db;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

#admin-panel {
    max-width: 800px;
    margin: 0 auto;
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

section {
    margin-bottom: 40px;
}

h3 {
    margin-bottom: 15px;
    border-bottom: 1px solid #eee;
    padding-bottom: 5px;
}

#upload-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 15px 0;
}

.preview-img {
    width: 100px;
    height: 100px;
    object-fit: cover;
    border-radius: 4px;
}

#slides-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 20px;
}

.slide-item {
    background: #eee;
    padding: 10px;
    border-radius: 4px;
    text-align: center;
}

.slide-item img {
    width: 100%;
    height: 100px;
    object-fit: cover;
    margin-bottom: 10px;
}

.slide-item button {
    background: #e74c3c;
    color: #fff;
    border: none;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
}

#upload-btn {
    padding: 10px 20px;
    background: #2ecc71;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

#logout-btn {
    padding: 5px 15px;
    background: #7f8c8d;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}