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

:root {
    --primary: #00629B;
    --secondary: #003B5C;
    --accent: #FF6B00;
    --light: #F2F2F2;
    --dark: #333333;
    --gray: #6D6E70;
}

body {
    color: var(--dark);
    line-height: 1.6;
    background-color: #fff;
}

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

/* Header Styles */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-top {
    background-color: var(--primary);
    color: white;
    padding: 8px 0;
    font-size: 0.9rem;
}

.header-top .container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.header-main {
    padding: 15px 0;
}

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

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

.logo-text h1 {
    font-size: 1.8rem;
    color: var(--primary);
    line-height: 1.2;
}

.logo-text span {
    font-size: 1rem;
    color: var(--gray);
}

.ieee-logo {
    height: 55px;
    width: auto;
}

/* Navigation */
nav ul {
    display: flex;
    list-style: none;
    gap: 20px;
    flex-wrap: wrap;
}

nav ul li a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    transition: color 0.3s;
    padding: 5px 0;
    font-size: 1rem;
}

nav ul li a:hover {
    color: var(--primary);
}

nav ul li a.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--primary);
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(0, 98, 155, 0.85), rgba(0, 59, 92, 0.9)), url('https://images.unsplash.com/photo-1535223289827-42f1e9919769?ixlib=rb-4.0.3&auto=format&fit=crop&w=1200&q=80');
    background-size: cover;
    background-position: center;
    color: white;
    padding: 100px 0;
    text-align: center;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto 30px;
}

.date-venue {
    background-color: rgba(255, 255, 255, 0.2);
    display: inline-block;
    padding: 15px 30px;
    border-radius: 5px;
    margin-bottom: 30px;
}

.btn {
    display: inline-block;
    background-color: var(--accent);
    color: white;
    padding: 12px 30px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #e05a00;
}

/* Section Styles */
section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
    color: var(--primary);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background-color: var(--accent);
}

/* About Section */
.about-card p {
    text-align: justify;
    margin-bottom: 15px;
}

.about-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.about-card {
    background-color: white;
    padding: 30px;
    border-radius: 5px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}

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

.about-card h3 {
    color: var(--primary);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.about-card h3 i {
    color: var(--accent);
}

.theme-box, .highlight {
    background: var(--light);
    padding: 15px;
    border-radius: 5px;
    margin: 15px 0;
}

.accreditation-badge {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    margin: 5px 5px 0 0;
}

/* Important Dates */
.dates-container {
    background-color: var(--light);
    padding: 40px;
    border-radius: 5px;
}

.dates-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.date-item {
    background-color: white;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.05);
    border-left: 4px solid var(--primary);
}

.date-item h4 {
    color: var(--primary);
    margin-bottom: 10px;
}

/* Committee Section */
.committee-tabs {
    margin-bottom: 30px;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
}

.tab-btn {
    padding: 10px 20px;
    background-color: var(--light);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 500;
}

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

.tab-content {
    display: none;
}

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

.committee-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.committee-member {
    background-color: white;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.05);
    text-align: center;
}

.member-role {
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 5px;
}

.member-name {
    font-weight: 500;
    margin-bottom: 5px;
}

.member-affiliation {
    color: var(--gray);
    font-size: 0.9rem;
}

.committee-group {
    margin-bottom: 40px;
}

.group-title {
    font-size: 1.4rem;
    color: var(--secondary);
    margin-bottom: 20px;
    padding-left: 15px;
    border-left: 4px solid var(--accent);
}

/* Call for Papers */
.cfp-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.cfp-card {
    background: #fff;
    padding: 30px;
    border-radius: 5px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}

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

.cfp-card h4 {
    color: var(--primary);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.cfp-card ul {
    padding-left: 20px;
}

.cfp-card li {
    margin-bottom: 8px;
}

.cfp-note {
    margin-top: 40px;
    background: #fff;
    border-left: 4px solid var(--accent);
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.05);
}

/* Registration Section */
.reg-container {
    max-width: 1100px;
    margin: 0 auto;
}

.fee-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    margin-bottom: 35px;
    overflow: hidden;
    border: 1px solid #eef2f6;
}

.fee-header {
    background: var(--primary);
    color: white;
    padding: 18px 25px;
    font-size: 1.3rem;
    font-weight: 600;
}

.fee-header i {
    margin-right: 12px;
}

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

.fee-table th,
.fee-table td {
    padding: 14px 20px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.fee-table th {
    background-color: #f8fafc;
    font-weight: 600;
    color: var(--secondary);
}

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

.note-box {
    background: #fef9e6;
    border-left: 5px solid var(--accent);
    padding: 18px 25px;
    border-radius: 12px;
    margin: 25px 0;
}

.ieee-benefit {
    background: #e6f3ff;
    padding: 20px;
    border-radius: 12px;
    margin: 20px 0;
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.ieee-benefit i {
    font-size: 2rem;
    color: var(--primary);
}

.reg-subnote {
    font-size: 0.9rem;
    color: #5a6e7c;
    margin-top: 20px;
    padding: 15px;
    background: var(--light);
    border-radius: 8px;
}

/* Contact Section */
.contact-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.contact-info {
    background-color: var(--light);
    padding: 30px;
    border-radius: 5px;
}

.contact-item {
    margin-bottom: 20px;
    display: flex;
    align-items: flex-start;
    gap: 15px;
}

.contact-item i {
    color: var(--primary);
    margin-top: 5px;
}

.map-container {
    height: 100%;
    min-height: 300px;
    border-radius: 5px;
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

/* Footer */
footer {
    background-color: var(--secondary);
    color: white;
    padding: 50px 0 20px;
    margin-top: 40px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.footer-column h3 {
    color: white;
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.footer-column ul {
    list-style: none;
}

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

.footer-column ul li a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-column ul li a:hover {
    color: white;
}

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

.copyright a {
    color: var(--accent);
    text-decoration: none;
}

.copyright a:hover {
    color: white;
    text-decoration: underline;
}

/* Responsive Styles */
@media (max-width: 992px) {
    .header-main .container {
        flex-direction: column;
        text-align: center;
        gap: 15px;
    }

    .logo-container {
        justify-content: center;
    }

    nav ul {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: block;
        position: absolute;
        top: 20px;
        right: 20px;
    }

    nav {
        display: none;
        width: 100%;
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
        align-items: center;
        gap: 15px;
        padding: 20px 0;
    }

    .hero h2 {
        font-size: 1.8rem;
    }

    section {
        padding: 50px 0;
    }

    .fee-table th,
    .fee-table td {
        padding: 10px 12px;
        font-size: 0.85rem;
    }
}