:root {
    --primary: #4a6fa5;
    --secondary: #6b8cbc;
    --accent: #50c878;
    --light: #f8f9fa;
    --dark: #343a40;
    --text: #495057;
    --border: #dee2e6;
}

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

body {
    font-family: 'Open Sans', sans-serif;
    line-height: 1.4;
    color: var(--text);
    background-color: #f5f7fa;
    font-size: 13px;
}

h1, h2, h3, h4, h5 {
    font-family: 'Poppins', sans-serif;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 0.6rem;
}

h1 {
    font-size: 1.6rem;
}

h2 {
    font-size: 1.3rem;
    border-bottom: 1px solid var(--secondary);
    padding-bottom: 0.3rem;
    margin-top: 1.2rem;
}

h3 {
    font-size: 1.1rem;
    /* color: var(--primary); */
    margin-top: 0.9rem;
}

h4 {
    font-size: 1rem;
}

p {
    margin-bottom: 0.7rem;
    font-size: 0.85rem;
}

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

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

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 12px;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 0.8rem 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo i {
    font-size: 1.3rem;
}

.logo h1 {
    color: white;
    margin: 0;
    font-size: 1.2rem;
}

/* Enhanced Navigation - Always Visible */
.nav-container {
    background-color: var(--light);
    padding: 0.6rem 0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 99;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none; /* Firefox */
}

.nav-container::-webkit-scrollbar {
    display: none; /* Chrome, Safari, Edge */
}

.nav-wrapper {
    display: flex;
    min-width: max-content;
    padding: 0 10px;
}

.nav-menu {
    display: flex;
    gap: 6px;
    list-style: none;
    margin: 0 auto;
}

.nav-item {
    flex-shrink: 0;
}

.nav-link {
    background-color: white;
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 0.8rem;
    color: var(--dark);
    white-space: nowrap;
}

.nav-link:hover, .nav-link.active {
    background-color: var(--primary);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 3px 6px rgba(0,0,0,0.1);
}

/* Sub Navigation Styles */
.sub-nav {
    background-color: #e9ecef;
    border-top: 1px solid var(--border);
}

.sub-nav .nav-link {
    background-color: #f8f9fa;
    font-size: 0.75rem;
}

.sub-nav .nav-link:hover, 
.sub-nav .nav-link.active {
    background-color: var(--secondary);
    color: white;
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(74, 111, 165, 0.9), rgba(74, 111, 165, 0.8)), url('https://images.unsplash.com/photo-1551288049-bebda4e38f71?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80');
    background-size: cover;
    background-position: center;
    color: white;
    padding: 2.5rem 0;
    text-align: center;
}

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

.hero h1 {
    color: white;
    font-size: 1.8rem;
    margin-bottom: 0.8rem;
}

.hero p {
    font-size: 0.9rem;
    margin-bottom: 1.2rem;
}

.btn {
    display: inline-block;
    background-color: var(--accent);
    color: white;
    padding: 0.6rem 1.3rem;
    border-radius: 25px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 0.8rem;
}

.btn:hover {
    background-color: #3da865;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}

/* Main Content */
main {
    padding: 2rem 0;
    margin: 15px 0;
}

section {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.2rem 0;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    display: none;
}

section.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

.section-icon {
    font-size: 1.3rem;
    color: var(--primary);
    margin-bottom: 0.6rem;
}

/* Course Sections */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.2rem;
    margin-top: 1.2rem;
}

.course-card {
    background-color: white;
    border-radius: 6px;
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s;
    cursor: pointer;
}

.course-card:hover {
    transform: translateY(-5px);
}

.card-header {
    background-color: var(--primary);
    color: white;
    padding: 1rem;
    text-align: center;
}

.course-card .card-header h3 {
    color: white;
}

.card-body {
    padding: 1rem;
}

.card-body ul {
    list-style-type: none;
    padding-left: 0;
}

.card-body li {
    margin-bottom: 0.5rem;
    padding-left: 1rem;
    position: relative;
    font-size: 0.8rem;
}

.card-body li:before {
    content: '✓';
    color: var(--accent);
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* Code Examples */
.code-example {
    background-color: #2d3748;
    color: #e2e8f0;
    border-radius: 6px;
    padding: 1rem;
    margin: 1rem 0;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.8rem;
}

.code-comment {
    color: #a0aec0;
}

.code-keyword {
    color: #fc8181;
}

.code-string {
    color: #68d391;
}

.code-function {
    color: #63b3ed;
}

/* Tables */
.methods-table, .selector-table, .comparison-table, .http-table, .tools-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    font-size: 0.8rem;
    overflow-x: auto;
    display: block;
}

.methods-table th, .methods-table td, 
.selector-table th, .selector-table td,
.comparison-table th, .comparison-table td,
.http-table th, .http-table td,
.tools-table th, .tools-table td {
    border: 1px solid var(--border);
    padding: 0.5rem;
    text-align: left;
}

.methods-table th, .selector-table th, 
.comparison-table th, .http-table th,
.tools-table th {
    background-color: var(--primary);
    color: white;
}

.methods-table tr:nth-child(even), 
.selector-table tr:nth-child(even),
.comparison-table tr:nth-child(even),
.http-table tr:nth-child(even),
.tools-table tr:nth-child(even) {
    background-color: var(--light);
}

/* HTTP Diagrams */
.http-diagram {
    background-color: var(--light);
    border-radius: 6px;
    padding: 1rem;
    margin: 1rem 0;
    border-left: 3px solid var(--primary);
    font-size: 0.8rem;
}

.http-title {
    font-weight: bold;
    margin-bottom: 0.3rem;
    color: var(--primary);
}

.http-line {
    font-family: 'Courier New', monospace;
    margin-bottom: 0.15rem;
}

/* Step by Step Guide */
.step-guide {
    counter-reset: step-counter;
    margin: 1.2rem 0;
}

.step {
    display: flex;
    margin-bottom: 1.2rem;
    align-items: flex-start;
}

.step-number {
    background-color: var(--primary);
    color: white;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    margin-right: 0.7rem;
    flex-shrink: 0;
    font-size: 0.8rem;
}

.step-content {
    flex: 1;
}

.step-image {
    width: 100%;
    max-width: 400px;
    border-radius: 6px;
    margin-top: 0.5rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

/* Developer Section */
.developer {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    margin-top: 1.2rem;
}

.developer-img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--secondary);
}

.developer-info h3 {
    margin-top: 0;
}

.social-links {
    display: flex;
    gap: 0.6rem;
    margin-top: 0.6rem;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background-color: var(--primary);
    color: white;
    border-radius: 50%;
    transition: all 0.3s;
}

.social-links a:hover {
    background-color: var(--accent);
    transform: translateY(-2px);
}

/* Sub-section styling */
.sub-section {
    margin: 1.5rem 0;
    padding: 1rem;
    background-color: var(--light);
    border-radius: 6px;
    border-left: 4px solid var(--accent);
}

.sub-section h3 {
    margin-top: 0;
    color: var(--primary);
}

/* External link styling */
.external-link {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    color: var(--accent);
    font-weight: 500;
}

.external-link:hover {
    text-decoration: underline;
}

/* Tool comparison */
.tool-comparison {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.tool-card {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    border: 1px solid var(--border);
}

.tool-card h3 {
    color: var(--primary);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tool-card ul {
    list-style: none;
    padding: 0;
}

.tool-card li {
    padding: 0.3rem 0;
    border-bottom: 1px solid var(--border);
}

.tool-card li:last-child {
    border-bottom: none;
}

/* Footer */
footer {
    background-color: var(--dark);
    color: white;
    padding: 2rem 0 1rem;
    font-size: 0.8rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.2rem;
    margin-bottom: 1.2rem;
}

.footer-column h3 {
    color: white;
    font-size: 1rem;
    margin-bottom: 0.8rem;
    position: relative;
}

.footer-column h3:after {
    content: '';
    position: absolute;
    width: 35px;
    height: 2px;
    background-color: var(--accent);
    bottom: -4px;
    left: 0;
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    color: #adb5bd;
    transition: color 0.3s;
    cursor: pointer;
    font-size: 0.8rem;
}

.footer-links a:hover {
    color: white;
    padding-left: 3px;
}

.copyright {
    text-align: center;
    padding-top: 1rem;
    border-top: 1px solid #495057;
    color: #adb5bd;
    font-size: 0.75rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .logo {
        margin-bottom: 0.6rem;
    }
    
    .hero h1 {
        font-size: 1.4rem;
    }
    
    .developer {
        flex-direction: column;
        text-align: center;
    }
    
    section {
        padding: 1rem;
    }
    
    .methods-table, .selector-table, .comparison-table, .http-table, .tools-table {
        font-size: 0.75rem;
    }
    
    .nav-wrapper {
        padding: 0 5px;
    }
    
    .nav-link {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
    }
    
    .tool-comparison {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .hero {
        padding: 1.8rem 0;
    }
    
    .hero h1 {
        font-size: 1.3rem;
    }
    
    .course-grid {
        grid-template-columns: 1fr;
    }
    
    h1 {
        font-size: 1.4rem;
    }
    
    h2 {
        font-size: 1.1rem;
    }
    
    h3 {
        font-size: 1rem;
    }
    
    .container {
        width: 95%;
        padding: 0 10px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .nav-link {
        padding: 0.4rem 0.7rem;
        font-size: 0.7rem;
    }
}

@media (max-width: 400px) {
    .nav-link {
        padding: 0.35rem 0.6rem;
        font-size: 0.65rem;
    }
    
    .nav-link i {
        font-size: 0.7rem;
    }
}

/* Visitor Counter Styles */
#visitor-counter .footer-links li {
    border-left: 3px solid transparent;
    transition: all 0.3s ease;
    padding: 5px 0;
}

#visitor-counter .footer-links li:hover {
    border-left-color: #50c878;
    background: rgba(255, 255, 255, 0.05);
    padding-left: 10px;
}

#visitor-counter .footer-links strong {
    color: #50c878;
    float: right;
}

#visitor-counter .footer-links i {
    width: 20px;
    text-align: center;
    margin-right: 8px;
}

/* Ensure footer content layout works with additional column */
.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

/* Hide counter on expiration page */
body:has(> div > div > .fa-clock) #visitor-counter {
    display: none;
}