/* ============= General Styles ============= */
:root {
    --primary-color: #1e3a8a;
    --secondary-color: #4f74c9;
    --accent-color: #f59e0b;
    --text-color: #333;
    --text-light: #666;
    --text-white: #fff;
    --bg-light: #f9fafb;
    --bg-dark: #1f2937;
    --heading-color: #1e293b;
    --border-color: #e5e7eb;
    --transition: all 0.3s ease;
    --box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --container-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-light);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    color: var(--heading-color);
    line-height: 1.2;
    margin-bottom: 15px;
}

h1 {
    font-size: 44px;
}

h2 {
    font-size: 36px;
}

h3 {
    font-size: 28px;
}

h4 {
    font-size: 22px;
}

h5 {
    font-size: 18px;
}

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

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

ul, ol {
    list-style: none;
    padding: 0;
    margin: 0;
}

img {
    max-width: 100%;
    height: auto;
}

section {
    padding: 100px 0;
}

.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--text-white);
    padding: 12px 30px;
    border-radius: 5px;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 1px;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

.btn:hover {
    background-color: var(--secondary-color);
    color: var(--text-white);
    transform: translateY(-3px);
}

.btn-sm {
    padding: 8px 20px;
    font-size: 14px;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    position: relative;
    display: inline-block;
    margin-bottom: 15px;
    text-transform: uppercase;
}

.section-title .underline {
    display: block;
    width: 80px;
    height: 4px;
    background-color: var(--accent-color);
    margin: 0 auto;
}

/* ============= Header Styles ============= */
#header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    padding: 20px 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

#header.scrolled {
    padding: 15px 0;
    background-color: #fff;
}

#header .container {
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo {
    max-width: 160px;
}

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

.nav-menu ul li {
    margin: 0 15px;
}

.nav-menu ul li a {
    color: var(--text-color);
    font-weight: 500;
    position: relative;
    padding: 5px 0;
}

.nav-menu ul li a:hover,
.nav-menu ul li a.active {
    color: var(--primary-color);
}

.nav-menu ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-menu ul li a:hover::after,
.nav-menu ul li a.active::after {
    width: 100%;
}

.lang-switch a {
    display: inline-flex;
    align-items: center;
    background-color: var(--primary-color);
    color: white !important;
    padding: 5px 15px;
    border-radius: 50px;
    font-size: 14px;
    padding: 5px 15px !important;
}

.lang-switch a:hover {
    background-color: var(--secondary-color);
}

.text-justify {
    text-align: justify !important;
}

.mobile-menu-toggle {
    display: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--primary-color);
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
}

.mobile-menu {
    position: fixed;
    top: 0;
    left: -300px;
    width: 300px;
    height: 100vh;
    background-color: var(--bg-light);
    z-index: 2000;
    padding: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

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

.mobile-menu ul li {
    margin: 20px 0;
}

.mobile-menu ul li a {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-color);
    display: block;
    transition: var(--transition);
}

.mobile-menu ul li a:hover {
    color: var(--primary-color);
    padding-left: 10px;
}

/* ============= Hero Section ============= */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    background: url('../images/bg.jpg') no-repeat center center/cover;
    display: flex;
    align-items: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, rgba(0, 0, 0, 0.8) 0%, rgba(0, 0, 0, 0.6) 50%, rgba(0, 0, 0, 0.4) 100%);
    z-index: 1;
}

.hero .container {
    position: relative;
    z-index: 2;
}

.hero-content {
    max-width: 800px;
    text-align: center;
    margin: 0 auto;
    color: var(--text-white);
}

.hero-content h1 {
    font-size: 48px;
    color: var(--text-white);
    margin-bottom: 15px;
    text-shadow: 2px 2px 5px rgba(0, 0, 0, 0.3);
    animation: fadeInDown 1s;
}

.hero-content h2 {
    font-size: 28px;
    color: var(--accent-color);
    margin-bottom: 20px;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s;
}

.hero-content p {
    font-size: 20px;
    margin-bottom: 30px;
    animation: fadeIn 1.5s;
}

.university-logo {
    max-width: 180px;
    margin: 0 auto 30px;
    animation: fadeIn 2s;
}

.university-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 auto 30px;
    max-width: 380px;
    animation: fadeIn 2s;
}

.arts-logo, .yu-logo {
    max-width: 160px;
    margin: 0 10px;
}

.hero-content .btn {
    animation: fadeInUp 1.5s;
}

/* ============= About Section ============= */
.about-section {
    background-color: var(--bg-light);
}

.about-content {
    display: grid;
    grid-gap: 40px;
}

.introduction, .objectives, .themes {
    margin-bottom: 40px;
}

.content {
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
}

.introduction h3, .objectives h3, .themes h3 {
    position: relative;
    padding-bottom: 15px;
    margin-bottom: 20px;
}

.introduction h3::after, .objectives h3::after, .themes h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    width: 50px;
    background-color: var(--accent-color);
}

.introduction p {
    margin-bottom: 15px;
}

.objectives ol {
    padding-left: 20px;
    list-style-type: decimal;
}

.objectives ol li {
    margin-bottom: 10px;
}

.theme {
    margin-bottom: 30px;
}

.theme h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.theme h5 {
    color: var(--secondary-color);
    margin: 20px 0 10px;
}

.theme ul {
    padding-left: 20px;
    list-style-type: disc;
}

.theme ul li {
    margin-bottom: 8px;
}

/* ============= Committees Section ============= */
.committees-section {
    background-color: #fff;
}

.tabs {
    background-color: #fff;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    overflow: hidden;
}

.tab-header {
    display: flex;
    flex-wrap: wrap;
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    padding: 15px 25px;
    background-color: #f1f5f9;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    flex: 1;
    text-align: center;
}

.tab-btn:hover {
    background-color: #e2e8f0;
}

.tab-btn.active {
    background-color: var(--primary-color);
    color: var(--text-white);
}

.tab-content {
    padding: 30px;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.5s;
}

.table-responsive {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

table th, table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

table th {
    background-color: #f8fafc;
    font-weight: 600;
}

table tr:last-child td {
    border-bottom: none;
}

.view-more {
    text-align: center;
    margin-top: 20px;
}

/* ============= Participation Section ============= */
.participation-section {
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('../images/register-bg.jpg') no-repeat center center/cover;
    color: var(--text-white);
}

.participation-section .section-title h2 {
    color: var(--text-white);
}

.participation-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-gap: 40px;
}

.instructions, .fees {
    background-color: rgba(255, 255, 255, 0.1);
    padding: 30px;
    border-radius: 10px;
    backdrop-filter: blur(10px);
}

.instructions h3, .fees h3 {
    color: var(--text-white);
    margin-bottom: 20px;
}

.instructions ol {
    padding-left: 20px;
    list-style-type: decimal;
}

.instructions ol li, .fees ul li {
    margin-bottom: 10px;
}

.fees ul {
    padding-left: 20px;
    list-style-type: disc;
}

.register-btn {
    grid-column: 1 / -1;
    text-align: center;
    margin-top: 20px;
}

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

.register-btn .btn:hover {
    background-color: #e67e22;
}

/* ============= Contact Section ============= */
.contact-section {
    background-color: var(--bg-light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-gap: 40px;
}

.contact-info, .contact-form {
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
}

.contact-info h3, .contact-form h3 {
    margin-bottom: 20px;
}

.info-item {
    display: flex;
    margin-bottom: 15px;
}

.info-item i {
    color: var(--primary-color);
    font-size: 20px;
    margin-right: 15px;
    min-width: 20px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: 'Poppins', sans-serif;
    transition: var(--transition);
}

.form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    height: 150px;
}

/* ============= Footer ============= */
footer {
    background-color: var(--bg-dark);
    color: var(--text-white);
    padding: 30px 0;
}

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

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text-white);
    border-radius: 50%;
    margin-left: 10px;
    transition: var(--transition);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

/* ============= Back to Top ============= */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 44px;
    height: 44px;
    background-color: var(--primary-color);
    color: var(--text-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 99;
}

.back-to-top.active {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--secondary-color);
    color: var(--text-white);
}

/* ============= Animations ============= */
@keyframes fadeIn {
    0% { opacity: 0; }
    100% { opacity: 1; }
}

@keyframes fadeInUp {
    0% {
        opacity: 0;
        transform: translateY(20px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    0% {
        opacity: 0;
        transform: translateY(-20px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============= Responsive Styles ============= */
@media screen and (max-width: 1024px) {
    section {
        padding: 80px 0;
    }
    
    h1 {
        font-size: 40px;
    }
    
    h2 {
        font-size: 32px;
    }
    
    .hero {
        height: auto;
        min-height: 500px;
    }
    
    .hero-content h1 {
        font-size: 40px;
    }
    
    .hero-content h2 {
        font-size: 24px;
    }
    
    .participation-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
}

@media screen and (max-width: 768px) {
    section {
        padding: 60px 0;
    }
    
    .nav-menu {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero-content h1 {
        font-size: 36px;
    }
    
    .hero-content h2 {
        font-size: 22px;
    }
    
    .tab-header {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .social-links {
        margin-top: 20px;
    }
    
    .social-links a {
        margin: 0 5px;
    }
}

@media screen and (max-width: 576px) {
    h1 {
        font-size: 32px;
    }
    
    h2 {
        font-size: 28px;
    }
    
    .hero-content h1 {
        font-size: 30px;
    }
    
    .hero-content h2 {
        font-size: 20px;
    }
    
    .tab-content {
        padding: 20px;
    }
    
    .arts-logo, .yu-logo {
        max-width: 120px;
        margin: 0 8px;
    }
}

@media screen and (max-width: 480px) {
    section {
        padding: 50px 0;
    }
    
    .hero-content h1 {
        font-size: 26px;
    }
    
    .hero-content h2 {
        font-size: 18px;
    }
    
    .content {
        padding: 20px;
    }
    
    .arts-logo, .yu-logo {
        max-width: 100px;
        margin: 0 5px;
    }
}

@media screen and (max-width: 400px) {
    .hero-content h1 {
        font-size: 24px;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .arts-logo, .yu-logo {
        max-width: 100px;
        margin: 0 5px;
    }
}