/* css/style.css - Master Stylesheet for ICAT 2026 */

/* CSS Variables for Easy Theming */
:root {
    --primary-color: #002856;
    --secondary-color: #003f6f;
    --accent-color: #f7b731;
    --accent-hover: #e5a523;
    --text-dark: #333;
    --text-light: #666;
    --text-white: #fff;
    --bg-light: #f4f7fc;
    --bg-dark: #002244;
    --gradient-primary: linear-gradient(135deg, #002856, #003f6f);
    --gradient-accent: linear-gradient(135deg, #f7b731, #e5a523);
    --box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    --box-shadow-hover: 0 15px 40px rgba(0,0,0,0.15);
    --transition: all 0.3s ease;
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Preloader */
.preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gradient-primary);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.preloader.fade-out {
    opacity: 0;
    visibility: hidden;
}

.loader {
    width: 50px;
    height: 50px;
    border: 5px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: var(--accent-color);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Progress Bar */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 4px;
    background: var(--accent-color);
    z-index: 1001;
    transition: width 0.3s ease;
}

/* Header Styles */
.header {
    background: var(--gradient-primary);
    color: var(--text-white);
    padding: 20px 0;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 30px;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
}

.logo {
    width: 80px;
    height: auto;
    background: white;
    padding: 10px;
    border-radius: 15px;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.05);
    box-shadow: var(--box-shadow-hover);
}

.college-info h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 5px;
}

.tagline {
    font-size: 0.9rem;
    opacity: 0.9;
}

.conference-dates-header {
    background: rgba(255,255,255,0.1);
    padding: 12px 25px;
    border-radius: 50px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.conference-dates-header i {
    color: var(--accent-color);
    margin-right: 10px;
}

.conference-banner {
    text-align: center;
    padding: 40px 20px;
    background: rgba(255,255,255,0.05);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.1);
}

.conference-banner h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 15px;
}

.conference-banner h2 span {
    color: var(--accent-color);
    display: block;
    font-size: 1.8rem;
    margin-top: 10px;
}

.venue {
    font-size: 1.2rem;
}

.venue i {
    color: var(--accent-color);
    margin-right: 10px;
}

/* Navigation Bar */
.navbar {
    background: var(--bg-dark);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.nav-toggle {
    display: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 15px;
    text-align: center;
}

.nav-menu {
    display: flex;
    list-style: none;
    justify-content: center;
    flex-wrap: wrap;
}

.nav-menu li a {
    display: block;
    color: white;
    text-decoration: none;
    padding: 15px 20px;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-menu li a i {
    margin-right: 8px;
    color: var(--accent-color);
}

.nav-menu li a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: var(--accent-color);
    transition: var(--transition);
}

.nav-menu li a:hover::before,
.nav-menu li a.active::before {
    width: 80%;
}

.nav-menu li a:hover,
.nav-menu li a.active {
    color: var(--accent-color);
    background: rgba(255,255,255,0.1);
}

/* Main Content */
.main-content {
    min-height: 500px;
    padding: 40px 0;
}

/* Page Header */
.page-header {
    background: var(--gradient-primary);
    color: white;
    padding: 60px 0;
    text-align: center;
    margin-bottom: 40px;
    position: relative;
    overflow: hidden;
}

.page-header h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 15px;
    animation: fadeInUp 1s ease;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 800px;
    margin: 0 auto;
    animation: fadeInUp 1s ease 0.2s both;
}

.breadcrumb {
    margin-top: 20px;
    animation: fadeInUp 1s ease 0.4s both;
}

.breadcrumb a {
    color: white;
    text-decoration: none;
}

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

.breadcrumb i {
    margin: 0 10px;
    font-size: 0.8rem;
    opacity: 0.7;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Cards and Sections */
.section-title {
    font-size: 2.2rem;
    color: var(--primary-color);
    margin-bottom: 30px;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: var(--accent-color);
    border-radius: 2px;
}

.section-title.center {
    text-align: center;
}

.section-title.center::after {
    left: 50%;
    transform: translateX(-50%);
}

.card {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    height: 100%;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: var(--box-shadow-hover);
}

/* Grid Systems */
.grid-2, .grid-3, .grid-4 {
    display: grid;
    gap: 30px;
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255,255,255,0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 5px 15px rgba(0,40,86,0.3);
}

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

.btn-outline {
    background: transparent;
    border: 2px solid var(--accent-color);
    color: var(--primary-color);
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

.btn:active {
    transform: translateY(-1px);
}

/* Footer */
.footer {
    background: var(--bg-dark);
    color: var(--text-white);
    padding: 60px 0 20px;
    position: relative;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.footer-col h3 {
    color: var(--accent-color);
    font-size: 1.2rem;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

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

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-links a {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

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

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

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: #ddd;
    text-decoration: none;
    transition: var(--transition);
    display: inline-block;
}

.footer-links a i {
    font-size: 0.8rem;
    margin-right: 10px;
    color: var(--accent-color);
}

.footer-links a:hover {
    color: var(--accent-color);
    transform: translateX(5px);
}

.contact-info {
    list-style: none;
}

.contact-info li {
    margin-bottom: 15px;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.contact-info i {
    color: var(--accent-color);
    font-size: 1.2rem;
    margin-top: 3px;
}

.contact-info a {
    color: #ddd;
    text-decoration: none;
    transition: var(--transition);
}

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

.newsletter-form {
    display: flex;
    margin-top: 15px;
}

.newsletter-form input {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 50px 0 0 50px;
    outline: none;
}

.newsletter-form button {
    width: 50px;
    background: var(--accent-color);
    border: none;
    border-radius: 0 50px 50px 0;
    color: var(--primary-color);
    cursor: pointer;
    transition: var(--transition);
}

.newsletter-form button:hover {
    background: var(--accent-hover);
}

.cmt-acknowledgment {
    background: rgba(255,255,255,0.05);
    padding: 20px;
    border-radius: 10px;
    margin: 40px 0;
    font-size: 0.9rem;
    border-left: 5px solid var(--accent-color);
}

.cmt-acknowledgment i {
    color: var(--accent-color);
    margin-right: 10px;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 0.9rem;
}

.footer-bottom p {
    margin: 5px 0;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--accent-color);
    color: var(--primary-color);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    justify-content: center;
    align-items: center;
    font-size: 1.2rem;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    z-index: 999;
}

.back-to-top:hover {
    background: var(--accent-hover);
    transform: translateY(-5px);
}

.back-to-top.show {
    display: flex;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-top {
        flex-direction: column;
        text-align: center;
    }
    
    .logo-wrapper {
        justify-content: center;
    }
    
    .conference-banner h2 {
        font-size: 1.8rem;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .nav-menu {
        display: none;
        flex-direction: column;
        width: 100%;
    }
    
    .nav-menu.show {
        display: flex;
    }
    
    .nav-menu li {
        width: 100%;
        text-align: center;
    }
    
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .conference-dates-header {
        width: 100%;
        text-align: center;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 1s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.slide-in-left {
    animation: slideInLeft 1s ease;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-right {
    animation: slideInRight 1s ease;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-light);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}