:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #38bdf8;
    --accent: #f472b6;
    --dark: #1e293b;
    --light: #f8fafc;
    --success: #22c55e;
    --warning: #eab308;
    --danger: #ef4444;
    --text: #334155;
    --text-light: #64748b;
    --bg: #ffffff;
    --bg-alt: #f1f5f9;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --border-radius: 0.375rem;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

body {
    color: var(--text);
    background-color: var(--bg);
    line-height: 1.6;
    font-size: 16px;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header Styles */
header {
    background-color: var(--primary);
    color: white;
    padding: 1rem 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    margin-right: 0.5rem;
    font-size: 1.8rem;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.nav-link:hover {
    color: white;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero p {
    font-size: 1.25rem;
    max-width: 800px;
    margin: 0 auto 2rem;
    opacity: 0.9;
}

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

.card {
    background-color: var(--bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.card:hover {
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--bg-alt);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--dark);
}

/* Tabs */
.tabs {
    display: flex;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--bg-alt);
}

.tab {
    padding: 0.75rem 1.5rem;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-light);
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.tab.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
}

.tab:hover:not(.active) {
    color: var(--dark);
    border-bottom: 2px solid var(--bg-alt);
}

.tab-content {
    display: none;
}

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

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input, select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.btn:hover {
    background-color: var(--primary-dark);
}

.btn-secondary {
    background-color: var(--secondary);
}

.btn-secondary:hover {
    background-color: #0ea5e9;
}

.btn-outline {
    background-color: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

.btn-outline:hover {
    background-color: var(--primary);
    color: white;
}

.btn-danger {
    background-color: var(--danger);
}

.btn-danger:hover {
    background-color: #dc2626;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-icon {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Table Styles */
table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5rem;
}

th, td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--bg-alt);
}

th {
    font-weight: 600;
    color: var(--dark);
    background-color: var(--bg-alt);
}

tr:hover {
    background-color: rgba(241, 245, 249, 0.5);
}

/* Course Entry */
.course-entry {
    background-color: var(--bg-alt);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    position: relative;
}

.course-entry-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.remove-course {
    background: none;
    border: none;
    color: var(--danger);
    cursor: pointer;
    font-size: 1.25rem;
    opacity: 0.7;
    transition: var(--transition);
}

.remove-course:hover {
    opacity: 1;
}

.course-inputs {
    display: grid;
    grid-template-columns: 1fr 120px 120px;
    gap: 1rem;
}

/* Results Section */
.results {
    text-align: center;
    padding: 1.5rem;
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
    margin: 2rem 0;
}

.gpa-result {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.result-label {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.result-details {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.detail-item {
    text-align: center;
}

.detail-value {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--dark);
}

.detail-label {
    font-size: 0.875rem;
    color: var(--text-light);
}

/* Visualization Section */
.visualization {
    margin: 2rem 0;
}

.chart-container {
    height: 300px;
    margin: 1.5rem 0;
}

/* Grade Distribution */
.grade-distribution {
    display: flex;
    gap: 0.5rem;
    margin: 1.5rem 0;
    height: 200px;
    align-items: flex-end;
}

.grade-bar {
    flex: 1;
    background-color: var(--primary);
    transition: var(--transition);
    min-height: 5px;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    position: relative;
}

.grade-bar-label {
    position: absolute;
    bottom: -25px;
    left: 0;
    right: 0;
    text-align: center;
    font-size: 0.875rem;
}

.grade-bar-value {
    position: absolute;
    top: -25px;
    left: 0;
    right: 0;
    text-align: center;
    font-size: 0.875rem;
    font-weight: 600;
}

/* Planning Tools */
.planning-form {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

/* Planning Navigation */
.planning-nav {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.planning-nav-btn {
    flex: 1;
    min-width: 180px;
    text-align: center;
    padding: 1rem;
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
    border: none;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
    transition: var(--transition);
}

.planning-nav-btn:hover {
    background-color: var(--primary);
    color: white;
}

.planning-tool {
    display: none;
}

.planning-tool.active {
    display: block;
}

/* Settings Section */
.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.setting-item {
    padding: 1rem;
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
}

.setting-header {
    font-weight: 600;
    margin-bottom: 0.5rem;
}

/* Info Sections */
.info-section {
    margin: 3rem 0;
}

.info-header {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--dark);
    position: relative;
    padding-bottom: 0.75rem;
}

.info-header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background-color: var(--primary);
    border-radius: 4px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.feature-item {
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    background-color: var(--bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--dark);
}

/* Example Section */
.example-box {
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
    padding: 1.25rem;
    margin: 1.5rem 0;
    border-left: 4px solid var(--primary);
}

.example-title {
    color: var(--primary);
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.example-scenario {
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px dashed #ddd;
}

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

.input-item {
    display: flex;
    justify-content: space-between;
    background-color: white;
    padding: 0.5rem 0.75rem;
    border-radius: var(--border-radius);
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.input-label {
    font-weight: 500;
}

.input-value {
    font-family: monospace;
    color: var(--primary);
}

.example-result {
    font-weight: 600;
    color: var(--dark);
    padding: 0.75rem;
    background-color: white;
    border-radius: var(--border-radius);
    margin-top: 1rem;
    text-align: center;
}

/* FAQ Section */
.faq-item {
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--bg-alt);
    padding-bottom: 1rem;
}

.faq-question {
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
}

.faq-answer {
    padding: 0.75rem 0;
    display: none;
}

.faq-answer.active {
    display: block;
}

/* How to Use Section */
.how-to-card {
    border-left: 4px solid var(--primary);
    padding-left: 1.5rem;
    margin-bottom: 2rem;
}

.step-number {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    width: 2rem;
    height: 2rem;
    background-color: var(--primary);
    color: white;
    border-radius: 50%;
    font-weight: bold;
    margin-right: 0.75rem;
}

.step-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
}

.step-content {
    padding-left: 2.75rem;
    margin-bottom: 1.5rem;
}

.tip-box {
    background-color: var(--light);
    border-left: 4px solid var(--secondary);
    padding: 1.25rem 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.tip-box h4 {
    color: var(--secondary);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Assignment Section */
.assignment-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
    margin-bottom: 0.75rem;
}

.assignment-details {
    flex: 1;
}

.assignment-name {
    font-weight: 500;
}

.assignment-grade {
    color: var(--text-light);
    font-size: 0.875rem;
}

.assignment-weight {
    background-color: var(--primary);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    margin-left: 1rem;
}

/* Final Grade Calculator */
.grade-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.grade-category {
    background-color: var(--bg-alt);
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary);
}

.category-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.category-name {
    font-weight: 600;
}

.category-weight {
    color: var(--text-light);
    font-size: 0.875rem;
}

.category-average {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary);
}

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

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

.footer-section h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    position: relative;
    padding-bottom: 0.5rem;
}

.footer-section h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 2px;
    background-color: var(--secondary);
}

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

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

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive Styles */
@media (max-width: 768px) {
    .course-inputs {
grid-template-columns: 1fr;
    }

    .nav-links {
display: none;
position: absolute;
top: 100%;
left: 0;
right: 0;
background-color: var(--primary);
flex-direction: column;
padding: 1rem;
box-shadow: var(--shadow);
    }

    .nav-links.active {
display: flex;
    }

    .menu-toggle {
display: block;
    }

    .hero h1 {
font-size: 2rem;
    }

    .hero p {
font-size: 1rem;
    }

    .tabs {
flex-wrap: wrap;
    }

    .tab {
padding: 0.5rem 1rem;
    }
}

/* Custom Alerts */
.alerts-container {
    position: fixed;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    width: 100%;
    max-width: 600px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    pointer-events: none;
}

.custom-alert {
    padding: 1rem 1.5rem;
    border-radius: var(--border-radius);
    background-color: white;
    color: white;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    opacity: 0;
    transform: translateY(-20px);
    transition: var(--transition);
    pointer-events: auto;
}

.custom-alert.show {
    opacity: 1;
    transform: translateY(0);
}

.custom-alert .alert-content {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.custom-alert .alert-icon {
    font-size: 1.25rem;
}

.custom-alert .alert-message {
    font-weight: 500;
}

.custom-alert .alert-close {
    background: none;
    border: none;
    color: inherit;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0.8;
    transition: var(--transition);
    padding: 0;
}

.custom-alert .alert-close:hover {
    opacity: 1;
}

.alert-success {
    background-color: var(--success);
}

.alert-error {
    background-color: var(--danger);
}

.alert-warning {
    background-color: var(--warning);
}

.alert-info {
    background-color: var(--primary);
}

/* Utils */
.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 2rem;
}

.mb-2 {
    margin-bottom: 2rem;
}

.flex {
    display: flex;
}

.justify-between {
    justify-content: space-between;
}

.gap-1 {
    gap: 1rem;
}

/* Ad Containers */
.banner-300x250-container {
    width: 300px;
    height: 250px;
    margin: 2rem auto;
    text-align: center;
    overflow: hidden;
}

.native-ad-container {
    margin: 2rem 0;
    padding: 1rem;
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
    max-width: 100%;
}

.top-banner-container {
    width: 100%;
    max-width: 728px;
    margin: 1rem auto;
    text-align: center;
    overflow: hidden;
}

.footer-banner-container {
    width: 100%;
    max-width: 728px;
    margin: 2rem auto;
    text-align: center;
    overflow: hidden;
}

.sidebar-banner-container {
    width: 300px;
    margin: 1rem auto;
    text-align: center;
}

@media (max-width: 768px) {
    .sidebar-banner-container {
        width: 100%;
        max-width: 300px;
    }
}

.social-bar-container {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    z-index: 99;
    text-align: center;
    background: transparent;
}

/* Charts */
#gpaChart, #gradeDistributionChart, #semesterComparisonChart {
    width: 100%;
    height: 100%;
}

/* Calculator Navigation */
.calculator-nav {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.calc-nav-btn {
    flex: 1;
    min-width: 180px;
    text-align: center;
    padding: 1rem;
    background-color: var(--bg-alt);
    border-radius: var(--border-radius);
    border: 2px solid transparent;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
    transition: var(--transition);
}

.calc-nav-btn:hover {
    background-color: var(--light);
    border-color: var(--primary);
    color: var(--primary);
}

.calc-nav-btn.active {
    background-color: var(--primary);
    color: white;
    border-color: var(--primary);
}

.grade-calc-section {
    display: none;
}

.grade-calc-section.active {
    display: block;
}