:root {
    --primary: #5E3023;       /* Rich brown - representing earth/roots */
    --secondary: #E5B151;     /* Gold - representing heritage/legacy */
    --accent: #39877B;        /* Teal - representing growth/connection */
    --dark: #2F2F2F;          /* Near black */
    --light: #F6F4EB;         /* Off-white */
    --gray: #D9D9D9;          /* Light gray */
    --gradient-start: #5E3023;
    --gradient-end: #89452E;
    --section-spacing: 4rem;
}

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

body {
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background-color: var(--light);
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23e5b151' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: all 0.3s ease;
}

a:hover {
    color: var(--secondary);
    text-decoration: underline;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.navbar {
    background: linear-gradient(to right, var(--gradient-start), var(--gradient-end));
    color: white;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
}

.logo a {
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 2px;
}

.logo a:hover {
    text-decoration: none;
}

.nav-menu {
    display: flex;
}

.nav-menu li {
    margin-left: 1.5rem;
}

.nav-menu a {
    color: white;
    font-weight: 500;
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 0.5rem;
    border-bottom: 2px solid transparent;
}

.nav-menu a:hover {
    text-decoration: none;
    border-bottom: 2px solid var(--secondary);
}

.nav-toggle {
    display: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1609637384060-1ca18a5a464b?q=80&w=1974&auto=format&fit=crop');
    background-size: cover;
    background-position: center;
    color: white;
    text-align: center;
    padding: 6rem 1rem;
    margin-bottom: var(--section-spacing);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

/* MODIFIED: Hero Section Adjustments */
.hero h1 {
    font-size: 3.5rem; /* Make course title larger */
    margin-bottom: 0.5rem; /* Reduce space below main title */
    color: white;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.6);
}

/* ADDED: Hero Subtitle Style */
.hero .hero-subtitle {
    font-size: 1.8rem; /* Style for the lab name subtitle */
    font-family: 'Montserrat', sans-serif;
    font-weight: 600;
    color: var(--secondary); /* Use gold color for emphasis */
    margin-bottom: 1.5rem;
    opacity: 0.95;
}

/* ADDED: Hero Description Style */
.hero .hero-description {
    font-size: 1.3rem; /* Slightly larger description */
    margin-bottom: 2rem;
    opacity: 0.9;
    max-width: 750px; /* Keep description width reasonable */
    margin-left: auto;
    margin-right: auto;
}

/* MODIFIED: Hero Attribution Style */
.hero-attribution {
    /* Optional: Slightly smaller/more subtle if needed */
    font-size: 1.1rem;
    opacity: 0.8;
    margin-top: 1.5rem;
}

.hero-attribution span {
    margin: 0.2rem 0;
}

.hero-attribution {
    /* Remove flex-direction: column if you previously added it */
    /* Ensure text-align: center is inherited or applied here */
    margin-top: 1.5rem; /* Adjust as needed */
}

.hero-attribution span {
    display: inline; /* Display spans on the same line */
    margin: 0 0.25rem; /* Optional: Add small space around text */
    line-height: 1.5; /* Adjust if wrapping looks odd */
}

/* Add the dot separator using ::after pseudo-element */
.hero-attribution span:not(:last-child)::after {
    content: "•";      /* The dot character */
    margin-left: 0.5rem; /* Space after the text, before the dot */
    margin-right: 0.25rem;/* Space after the dot */
    color: var(--secondary); /* Style the dot - using gold */
    opacity: 0.8;     /* Match text opacity */
    /* Prevent the dot from being selected */
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

/* Sections */
.section {
    margin-bottom: var(--section-spacing);
}

.section-header {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
}

.section-icon {
    font-size: 2rem;
    color: var(--secondary);
    margin-right: 1rem;
}

.section h2 {
    font-size: 2rem;
    border-bottom: 3px solid var(--secondary);
    padding-bottom: 0.5rem;
}

.content-card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    padding: 2rem;
    margin-bottom: 2rem;
}

.content-card p {
    margin-bottom: 1rem;
}

/* Course Info */
.course-header {
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--gray);
    padding-bottom: 1rem;
}

.course-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 0.5rem;
}

.course-meta span {
    display: inline-flex;
    align-items: center;
    background-color: var(--secondary);
    color: var(--dark);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.course-meta i {
    margin-right: 0.5rem;
}

.course-details {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 2rem;
}

.course-logistics h4, .course-description h4 {
    margin-bottom: 1rem;
    color: var(--accent);
}

.course-logistics ul li {
    margin-bottom: 0.7rem;
    display: flex;
    align-items: center;
}

.course-logistics ul li i {
    color: var(--secondary);
    margin-right: 0.8rem;
    width: 20px;
    text-align: center;
}

/* ADDED: Course Description Readability */
.course-description p {
    margin-bottom: 1.5rem; /* Add more space between paragraphs */
}
.course-description p:last-child {
    margin-bottom: 0; /* No margin after the last paragraph */
}


/* Structure Grid */
.structure-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.structure-item {
    background-color: var(--light);
    border: 2px solid rgba(229, 177, 81, 0.3);
    border-radius: 8px;
    padding: 1.5rem;
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.05);
}

.structure-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.08);
    border-color: rgba(229, 177, 81, 0.6);
}

.structure-number {
    position: absolute;
    top: -15px;
    left: -15px;
    background-color: var(--secondary);
    color: var(--dark);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    font-size: 1.1rem;
}

.structure-item h4 {
    color: var(--primary);
    margin-bottom: 0.5rem;
    /* No underline decoration or color change that would suggest a link */
    text-decoration: none;
    font-weight: 600;
}

.structure-item p {
    font-size: 0.95rem;
    margin-bottom: 0;
    color: var(--dark);
}

.structure-note {
    text-align: center;
    margin: 1.5rem 0 0.5rem;
    font-size: 0.9rem;
    color: #666;
    background-color: rgba(229, 177, 81, 0.08);
    padding: 0.6rem;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.structure-note i {
    margin-right: 0.5rem;
    color: var(--secondary);
}

.textbook-link {
    text-align: center;
    margin-top: 1.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    background-color: var(--accent);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 4px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn:hover {
    background-color: var(--primary);
    color: white;
    text-decoration: none;
    transform: translateY(-2px);
}

.btn i {
    margin-right: 0.5rem;
}

/* Lab Series */
.tabs {
    display: flex;
    flex-wrap: wrap;
    border-bottom: 2px solid var(--gray);
    margin-bottom: 1.5rem;
}

.tab-btn {
    background: none;
    border: none;
    padding: 0.8rem 1.5rem;
    cursor: pointer;
    font-family: 'Montserrat', sans-serif;
    font-weight: 600;
    color: var(--dark);
    opacity: 0.7;
    transition: all 0.3s ease;
    position: relative;
}

.tab-btn:after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 3px;
    background-color: var(--secondary);
    transition: width 0.3s ease;
}

.tab-btn.active {
    opacity: 1;
}

.tab-btn.active:after {
    width: 100%;
}

.tab-btn:hover {
    opacity: 1;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.lab-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
}

.lab-list li a {
    display: flex;
    align-items: center;
    background-color: rgba(57, 135, 123, 0.05);
    padding: 1rem;
    border-radius: 6px;
    transition: all 0.3s ease;
    border: 1px solid rgba(57, 135, 123, 0.2);
    color: var(--accent);
    text-decoration: none;
    position: relative;
}

.lab-list li a:after {
    content: '→';
    position: absolute;
    right: 1rem;
    opacity: 0;
    transform: translateX(-5px);
    transition: all 0.3s ease;
}

.lab-list li a:hover {
    background-color: rgba(57, 135, 123, 0.1);
    transform: translateY(-2px);
    text-decoration: none;
    border-color: var(--accent);
    padding-right: 2rem;
}

.lab-list li a:hover:after {
    opacity: 1;
    transform: translateX(0);
}

.lab-number {
    background-color: var(--secondary);
    color: var(--dark);
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    font-size: 0.9rem;
    margin-right: 0.8rem;
    flex-shrink: 0;
}

/* Footer */
footer {
    background-color: var(--dark);
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 3rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-info h3 {
    color: var(--secondary);
    margin-bottom: 1rem;
}

.footer-links h4, .footer-contact h4 {
    color: var(--secondary);
    margin-bottom: 1rem;
}

.footer-links ul li {
    margin-bottom: 0.5rem;
}

.footer-links ul li a {
    color: white;
    opacity: 0.8;
}

.footer-links ul li a:hover {
    opacity: 1;
}

.footer-contact p {
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
}

.footer-contact i {
    margin-right: 0.8rem;
    color: var(--secondary);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1.5rem;
    text-align: center;
    font-size: 0.9rem;
    opacity: 0.8;
}

/* --- Add to styles.css --- */

/* ==========================
   Textbook Page Styles
   ========================== */

   body.textbook-page {
    /* Styles specific to textbook pages like contents.html */
    background-color: var(--light); /* Ensure consistent background */
}

.textbook-header {
    background-color: var(--light);
    padding: 2.5rem 1rem 1.5rem; /* More padding top */
    text-align: center;
    border-bottom: 4px solid var(--primary); /* Thicker border */
}

.textbook-header h1 {
    color: var(--primary);
    font-size: 2.8rem; /* Prominent Title */
    margin-bottom: 0.5rem;
}

.textbook-header p {
    color: var(--dark);
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 0;
}

.textbook-nav {
    background-color: var(--primary); /* Darker nav bar */
    padding: 0.75rem 0;
    text-align: center;
    margin-bottom: var(--section-spacing);
    box-shadow: 0 3px 6px rgba(0,0,0,0.1);
}

.textbook-nav a {
    color: white;
    margin: 0 1.5rem;
    padding: 0.5rem 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    display: inline-flex; /* Align icon and text */
    align-items: center;
}

.textbook-nav a i {
    margin-right: 0.5rem; /* Space between icon and text */
}

.textbook-nav a:hover,
.textbook-nav a.active {
    border-bottom-color: var(--secondary);
    text-decoration: none;
    color: var(--secondary); /* Highlight active/hover link */
}

/* Main title for modules/resources */
.textbook-main-title {
    font-size: 2.2rem;
    color: var(--primary);
    text-align: center;
    margin-bottom: 2rem;
    border-bottom: 3px solid var(--secondary); /* Gold line */
    padding-bottom: 0.75rem;
    display: inline-block; /* Center the line under the text */
    position: relative;
    left: 50%;
    transform: translateX(-50%);
}


/* Module Sections Styling */
.module-section {
    margin-bottom: 3rem;
    padding-bottom: 1.5rem;
    /* Optional: Add border between sections */
    /* border-bottom: 1px solid var(--gray); */
}

.module-section:last-child {
    border-bottom: none;
}

.module-section h3 { /* e.g., "Getting Started" */
    color: var(--primary);
    font-size: 1.7rem;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--secondary);
    display: inline-block; /* Limit border width */
}

/* Module List Container */
.module-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}


.module-item {
    margin-bottom: 0; /* Remove bottom margin since we're using gap in .module-list */
    padding-left: 1rem; /* Indent the whole item slightly */
    border-left: 3px solid transparent; /* Placeholder for hover effect */
    transition: border-left-color 0.3s ease;
}

.module-item:hover {
    border-left-color: var(--secondary); /* Highlight on hover */
}


.module-item a {
     text-decoration: none;
}

.module-item h4 { /* Lab titles - e.g., "Lab 0: Environment Setup" */
    color: var(--primary);
    margin-bottom: 0.4rem;
    font-size: 1.25rem; /* Slightly larger */
    font-weight: 600;
    transition: color 0.3s ease;
}

 .module-item a:hover h4 {
     color: var(--accent); /* Teal on hover */
     /* text-decoration: underline; */ /* Optional underline */
 }


.module-item p { /* Lab descriptions */
    color: var(--dark);
    font-size: 1rem; /* Slightly larger description */
    margin-left: 0em; /* Remove previous indent, rely on padding-left of parent */
    opacity: 0.85;
    line-height: 1.5;
    margin-bottom: 0;
}

/* Resources List Styling */
.resources-list {
    list-style: none; /* Remove default bullets */
    padding-left: 1rem;
}

.resources-list li {
    margin-bottom: 0.8rem;
}

.resources-list li a {
    color: var(--accent);
    font-size: 1.1rem;
    display: inline-flex; /* Align icon and text */
    align-items: center;
    transition: color 0.3s ease;
}

.resources-list li a:hover {
    color: var(--secondary);
    text-decoration: underline;
}

.resources-list li a i {
    margin-right: 0.6rem;
    color: var(--secondary); /* Icon color */
    width: 20px; /* Consistent icon width */
    text-align: center;
}


/* Footer for textbook pages */
 .textbook-footer {
     background-color: var(--light);
     color: var(--dark);
     text-align: center;
     padding: 2rem 0;
     margin-top: var(--section-spacing);
     border-top: 1px solid var(--gray);
     font-size: 0.9rem;
     opacity: 0.8;
 }

 /* Responsive adjustments for textbook pages if needed */
 @media (max-width: 768px) {
    .textbook-header h1 {
        font-size: 2.2rem;
    }
    .textbook-main-title {
        font-size: 1.8rem;
    }
    .module-section h3 {
        font-size: 1.5rem;
    }
    .module-item h4 {
        font-size: 1.15rem;
    }
    .module-item p {
        font-size: 0.9rem;
    }
    .textbook-nav a {
        margin: 0 0.5rem;
        font-size: 0.8rem;
    }
 }

/* Additional Lab Content Styling */
.lab-content {
    max-width: 900px;
    margin: 0 auto;
    line-height: 1.7;
    font-size: 1.05rem;
}

.lab-content h2 {
    font-size: 2.3rem;
    color: var(--primary);
    margin: 1.5rem 0 2rem;
    text-align: center;
    position: relative;
}

.lab-content h2:after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background-color: var(--secondary);
}

.lab-content h3 {
    font-size: 1.8rem;
    color: var(--primary);
    margin: 2.5rem 0 1.2rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--secondary);
}

.lab-content h4 {
    font-size: 1.4rem;
    color: var(--accent);
    margin: 1.8rem 0 1rem;
    position: relative;
    padding-left: 1rem;
}

.lab-content h4:before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.3rem;
    height: 70%;
    width: 4px;
    background-color: var(--secondary);
    border-radius: 4px;
}

.lab-content p {
    margin-bottom: 1.2rem;
    color: var(--dark);
}

.lab-content ul, .lab-content ol {
    margin: 1.2rem 0 1.5rem 1.8rem;
}

.lab-content ul li, .lab-content ol li {
    margin-bottom: 0.7rem;
    position: relative;
}

.lab-content ul {
    list-style-type: none;
}

.lab-content ul li:before {
    content: "•";
    color: var(--secondary);
    font-weight: bold;
    font-size: 1.2rem;
    position: absolute;
    left: -1.2rem;
    top: -0.1rem;
}

.lab-content ol {
    counter-reset: item;
    list-style-type: none;
}

.lab-content ol li {
    counter-increment: item;
    position: relative;
}

.lab-content ol li:before {
    content: counter(item) ".";
    font-weight: 600;
    color: var(--accent);
    position: absolute;
    left: -1.5rem;
}

.concept-section {
    background-color: rgba(248, 249, 250, 0.7);
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    border-left: 4px solid var(--accent);
}

.concept-section h4 {
    margin-top: 0;
    color: var(--primary);
    padding-left: 0;
}

.concept-section h4:before {
    display: none;
}

.alert {
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 8px;
    position: relative;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
}

.alert p {
    margin-bottom: 0;
}

.alert strong {
    color: inherit;
}

.alert-info {
    background-color: rgba(57, 135, 123, 0.1);
    border-left: 5px solid var(--accent);
}

.alert-warning {
    background-color: rgba(229, 177, 81, 0.15);
    border-left: 5px solid var(--secondary);
}

.alert-success {
    background-color: rgba(76, 175, 80, 0.1);
    border-left: 5px solid #4CAF50;
}

/* Learning Pathway */
.learning-pathway {
    margin: 3rem 0;
    position: relative;
    padding: 2rem;
    background-color: rgba(248, 249, 250, 0.7);
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.learning-pathway:before {
    content: "Learning Pathway";
    position: absolute;
    top: -12px;
    left: 20px;
    background-color: var(--accent);
    color: white;
    padding: 0.3rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.pathway-steps {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
    position: relative;
}

.pathway-step {
    flex: 1;
    min-width: 170px;
    text-align: center;
    padding: 1rem;
    background-color: white;
    border-radius: 8px;
    position: relative;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    border-bottom: 3px solid var(--secondary);
}

.pathway-step h5 {
    margin: 0 0 0.5rem 0;
    color: var(--primary);
}

.pathway-step p {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

.pathway-step.active {
    border-color: var(--accent);
    background-color: rgba(57, 135, 123, 0.05);
}

.pathway-step.active h5 {
    color: var(--accent);
}

/* Exercise Section */
.exercises-section {
    background-color: rgba(229, 177, 81, 0.05);
    border-radius: 10px;
    padding: 1.5rem 2rem;
    margin: 2rem 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    border-top: 3px solid var(--secondary);
}

.exercises-section h3 {
    color: var(--primary);
    margin-top: 0;
    border-bottom: none;
    padding-bottom: 0;
}

.exercises-section ol {
    margin-left: 1rem;
}

.exercises-section ol li {
    margin-bottom: 1rem;
}

/* Key Takeaways Box */
.key-takeaway {
    background-color: rgba(94, 48, 35, 0.05);
    border-radius: 10px;
    padding: 1.5rem;
    margin: 2rem 0;
    position: relative;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(94, 48, 35, 0.1);
}

.key-takeaway:before {
    content: "Key Takeaway";
    position: absolute;
    top: -12px;
    left: 20px;
    background-color: var(--primary);
    color: white;
    padding: 0.3rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.key-takeaway p {
    margin-bottom: 0;
    font-weight: 500;
}

/* Definition Lists in Glossary */
dl {
    margin: 1.5rem 0;
}

dt {
    font-weight: 600;
    color: var(--primary);
    margin-top: 1.2rem;
    font-size: 1.1rem;
}

dd {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
    position: relative;
    line-height: 1.6;
}

dd:before {
    content: "→";
    position: absolute;
    left: -1.2rem;
    color: var(--secondary);
    font-weight: bold;
}

/* Code Blocks */
pre {
    background-color: #f6f8fa;
    padding: 1.2rem 1.5rem;
    border-radius: 8px;
    overflow-x: auto;
    border-left: 4px solid var(--secondary);
    margin: 1.5rem 0;
    font-size: 0.9rem;
    box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.05);
}

code {
    font-family: 'Courier New', Courier, monospace;
    background-color: rgba(248, 249, 250, 0.8);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-size: 0.9em;
    color: var(--accent);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

pre code {
    padding: 0;
    background-color: transparent;
    border: none;
    color: inherit;
}

/* Lab Navigation Improvements */
.lab-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 4rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray);
}

.prev-lab, .next-lab {
    padding: 0.8rem 1.2rem;
    border-radius: 6px;
    background-color: white;
    color: var(--accent);
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--gray);
    display: inline-flex;
    align-items: center;
}

.prev-lab:before {
    content: '←';
    margin-right: 0.5rem;
    font-size: 1.1rem;
}

.next-lab:after {
    content: '→';
    margin-left: 0.5rem;
    font-size: 1.1rem;
}

.prev-lab:hover, .next-lab:hover {
    background-color: var(--accent);
    color: white;
    transform: translateY(-2px);
    text-decoration: none;
    box-shadow: 0 4px 8px rgba(57, 135, 123, 0.2);
    border-color: var(--accent);
}

/* --- End of Textbook Styles --- */

/* Responsive Styles */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--primary);
        padding: 1rem 0;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    }

    .nav-menu.show {
        display: flex;
    }

    .nav-menu li {
        margin: 0;
    }

    .nav-menu a {
        display: block;
        padding: 0.8rem 1.5rem;
        border-bottom: none;
    }

    .nav-toggle {
        display: block;
    }

    /* ADDED: Responsive Adjustments for Hero Title */
    .hero h1 {
        font-size: 2.8rem;
    }
    .hero .hero-subtitle {
        font-size: 1.5rem;
    }
    .hero .hero-description {
        font-size: 1.1rem;
    }

    /* MODIFIED: Removed old generic hero p rule as specific ones handle text size */
    /* .hero p { ... } removed */


    .section-header {
        flex-direction: column;
        text-align: center;
    }

    .section-icon {
        margin-right: 0;
        margin-bottom: 0.5rem;
    }

    .course-details {
        grid-template-columns: 1fr;
    }

    .course-logistics {
        order: 2;
    }

    .course-description {
        order: 1;
        margin-bottom: 2rem;
    }

    .tabs {
        justify-content: center;
    }

    .tab-btn {
        padding: 0.8rem 1rem;
        font-size: 0.9rem;
    }

    .lab-list {
        grid-template-columns: 1fr;
    }

    .structure-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 4rem 1rem;
    }

    /* ADDED: Responsive Adjustments for Hero Title */
    .hero h1 {
        font-size: 2.2rem;
    }
    .hero .hero-subtitle {
        font-size: 1.3rem;
    }

    .section h2 {
        font-size: 1.7rem;
    }

    .content-card {
        padding: 1.5rem;
    }

    .course-meta {
        flex-direction: column;
        gap: 0.5rem;
        align-items: flex-start; /* Align items left on smallest screens */
    }

     .course-meta span {
        /* Ensure badges don't stretch full width */
        display: inline-flex;
     }


    .tab-btn {
        padding: 0.6rem 0.8rem;
        font-size: 0.8rem;
    }
}

/* Additional Utility Classes */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* Code Styles (maintaining from your original CSS) */
pre {
    background-color: #f5f7fa;
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    border-left: 4px solid var(--secondary);
    margin: 1.5rem 0;
}

code {
    font-family: 'Courier New', Courier, monospace;
    background-color: #f5f7fa;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
}

pre code {
    padding: 0;
    background-color: transparent;
}

/* Alert Styles (maintaining from your original CSS) */
.alert {
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 4px;
    border-left: 4px solid;
}
.alert-info { background-color: rgba(33, 150, 243, 0.1); border-left-color: #2196F3; }
.alert-warning { background-color: rgba(255, 193, 7, 0.1); border-left-color: #FFC107; }
.alert-success { background-color: rgba(76, 175, 80, 0.1); border-left-color: #4CAF50; }

/* Table Styles (maintaining from your original CSS) */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
}
th, td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid #ddd;
}
th {
    background-color: #f5f5f5;
    font-weight: bold;
    color: var(--primary);
}
tr:nth-child(even) {
    background-color: #f9f9f9;
}

/* Lab Navigation (maintaining from your original CSS) */
.lab-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    padding-top: 1rem;
    border-top: 1px solid #ddd;
}
.prev-lab, .next-lab {
    padding: 0.5rem 1rem;
    border-radius: 4px;
    text-decoration: none;
    background-color: #f5f5f5;
    color: var(--primary);
    transition: background-color 0.3s ease;
}
.prev-lab:hover, .next-lab:hover {
    background-color: var(--secondary);
    color: white;
}
.prev-lab:before { content: '← '; }
.next-lab:after { content: ' →'; }