:root {
    --primary-color: #5624d0;
    --secondary-color: #f5f5f5;
    --dark-color: #1c1d1f;
    --light-color: #fff;
    --border-color: #d1d7dc;
    --text-color: #2d2f31;
    --hover-color: #401b9c;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    color: var(--text-color);
    background-color: var(--light-color);
}

/* Login/Signup Buttons */
.login-btn {
    color: var(--primary-color) !important;
    font-weight: 600 !important;
}

.signup-btn {
    background-color: var(--primary-color);
    color: white !important;
    padding: 8px 12px;
    border-radius: 4px;
    font-weight: 600 !important;
}

/* Mobile view buttons */
.mobile-nav-links .login-btn {
    color: var(--primary-color) !important;
    display: block;
    padding: 10px 0;
}

.mobile-nav-links .signup-btn {
    background-color: var(--primary-color);
    color: white !important;
    display: inline-block;
    padding: 10px 15px;
    border-radius: 4px;
    margin-top: 5px;
}

/* Header Styles */
header {
    background-color: var(--light-color);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: all 0.3s ease;
}

header.scrolled {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* Navigation Styles */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1440px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

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

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 0;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

.nav-actions {
    display: flex;
    align-items: center;
}

.search-bar {
    position: relative;
    margin-right: 1rem;
}

.search-bar input {
    padding: 0.5rem 1rem 0.5rem 2.5rem;
    border: 1px solid var(--border-color);
    border-radius: 50px;
    width: 200px;
    outline: none;
}

.search-bar i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-color);
}

.user-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-left: 1rem;
    cursor: pointer;
    font-weight: bold;
}

/* Mobile Navigation */
.mobile-nav-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-color);
}

.mobile-nav {
    position: fixed;
    top: 0;
    left: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background-color: var(--light-color);
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: left 0.3s ease;
    padding: 1rem;
    overflow-y: auto;
}

.mobile-nav.active {
    left: 0;
}

.mobile-nav-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.mobile-nav-links {
    list-style: none;
}

.mobile-nav-links li {
    margin-bottom: 1rem;
}

.mobile-nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    display: block;
    padding: 0.5rem 0;
}

.mobile-nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.mobile-nav-overlay.active {
    opacity: 1;
    pointer-events: all;
}

/* Main Content */
.container {
    max-width: 1440px;
    margin: 2rem auto;
    padding: 0 2rem;
}

/* Course Tabs */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.tab {
    padding: 0.75rem 1.5rem;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-color);
    border-bottom: 3px solid transparent;
    transition: all 0.3s;
}

.tab.active {
    color: var(--primary-color);
    border-bottom: 3px solid var(--primary-color);
}

.tab-content {
    display: none;
}

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

/* Course Grid */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
}

.course-card {
    border: 1px solid var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.course-img {
    height: 160px;
    width: 100%;
    object-fit: cover;
}

.course-info {
    padding: 1rem;
}

.course-title {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.course-instructor {
    color: #6a6f73;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.course-price {
    font-weight: 700;
    margin-bottom: 1rem;
}

/* Responsive Styles */
@media (max-width: 992px) {
    .nav-links {
        display: none;
    }

    .mobile-nav-btn {
        display: block;
    }

    .search-bar input {
        width: 150px;
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }

    .search-bar {
        display: none;
    }

    .course-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
}

@media (max-width: 576px) {
    /* Previously cart-modal width, now removed */
}