:root {
    --dark: #1f1f1f;
    --accent: #8b5e3c;
    --light: #faf7f2;
}

body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background-color: var(--light);
    color: #333;
}

/* Header */
header {
    background: linear-gradient(to right, #1f1f1f, #3a2f2a);
    color: white;
    padding: 50px 20px;
    text-align: center;
}

header h1 {
    letter-spacing: 4px;
    margin-bottom: 10px;
}

/* Navigation */
nav {
    background-color: white;
    padding: 15px;
    text-align: center;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

nav a {
    color: var(--dark);
    text-decoration: none;
    margin: 0 20px;
    font-weight: 600;
}

nav a:hover {
    color: var(--accent);
}

/* Search box */
.search-box {
    text-align: center;
    margin: 30px 0;
}

.search-box input {
    width: 60%;
    max-width: 500px;
    padding: 14px;
    font-size: 16px;
    border-radius: 30px;
    border: 1px solid #ccc;
    outline: none;
}

/* Main container */
.container {
    max-width: 1100px;
    margin: auto;
    padding: 30px;
    text-align: center;
}

.container h2 {
    margin-bottom: 10px;
}

/* Videos */
.videos {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.videos video {
    width: 180px;
    height: 100px;
    border: 4px solid black;
}
.site-footer {
  text-align: center;
  padding: 24px 0;
  margin-top: 60px;
  font-size: 13px;
  color: #666;
  border-top: 1px solid #e5e5e5;
}
.site-footer {
    margin-top: 80px;      /* space from content above */
    padding: 30px 0;
    text-align: center;
    font-size: 8px;
    color: #666;
    background-color: #f4f4f4;
    border-top: 1px solid #e0e0e0;
}
/* Modal background */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6);
}

/* Modal box */
.modal-content {
    background: #fff;
    max-width: 600px;
    margin: 10% auto;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    position: relative;
}

/* Close button */
.close {
    position: absolute;
    top: 12px;
    right: 18px;
    font-size: 22px;
    cursor: pointer;
    color: #333;
}

.close:hover {
    color: #000;
}
.sidebar {
    position: absolute;
    top: 40px;
    right: 20px;
    width: 220px;
    border: 2px solid black;
    padding: 15px;
    background: #f9f9f9;
}

.sidebar h3 {
    margin-top: 0;
    font-size: 16px;
}

.sidebar input {
    width: 100%;
    padding: 5px;
    margin-bottom: 10px;
    border: 1px solid black;
}

.sidebar ul {
    list-style: none;
    padding-left: 0;
}

.sidebar li {
    margin-bottom: 5px;
}
.sidebar ul {
    display: none;
}

.sidebar.active ul {
    display: block;
}
.sidebar {
    border: 2px solid black;
    padding: 15px;
    background: #f9f9f9;
}

.sidebar h3,
.sidebar ul {
    display: none;
}

.sidebar.active h3,
.sidebar.active ul {
    display: block;
}
.image-container {
    border: 3px solid white;
}

footer {
    padding: 20px;
}

.video {
    border-radius: 10px;
}

table {
    background-color: #111;
}
/* External CSS */

/* Background Color */
body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background-color: black;
    color: white;
}

/* Image Row Layout */
.image-grid {
    display: flex;
    justify-content: center;     /* center horizontally */
    align-items: center;
    gap: 30px;                   /* spacing between boxes */
    flex-wrap: wrap;             /* responsive on small screens */
    margin: 40px 0;
}

/* Grey Box Container */
.book-container {
    background-color: #2c2c2c;   /* Grey background */
    width: 180px;                /* Smaller size */
    height: 250px;
    padding: 12px;
    border-radius: 10px;
    box-shadow: 0 6px 18px rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    transition: 0.3s ease;
}

/* Hover effect */
.book-container:hover {
    transform: translateY(-6px);
}

/* Image inside box */
.book-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 6px;
}
.external-paragraph {
    color: purple;
    text-decoration: underline;
}

.highlight3 {
    color: darkblue;
}

.building3 {
    color: darkred;
}