:root {
    /* Professional Brand Colors */
    --primary-sapphire: #1e3a5f;     /* Main brand color - trust, professionalism */
    --primary-green: #006a4e;        /* Bangladesh heritage green */
    --primary-gold: #d4af37;          /* Excellence, premium quality */

    /* Neutral Colors */
    --white: #ffffff;
    --charcoal: #2d3748;              /* Professional text */
    --slate-blue: #4a5568;            /* Secondary text */
    --warm-gray: #f7fafc;             /* Clean backgrounds */
    --light-sage: #e8f5e8;            /* Subtle accent backgrounds */
    --light-gray: #e2e8f0;            /* Borders, dividers */

    /* Accent Colors */
    --accent-coral: #e53e3e;           /* Important CTAs, energy */
    --accent-teal: #38b2ac;           /* Secondary actions */
    --accent-gold: #d4af37;            /* Highlights, premium features */

    /* Shadows */
    --shadow: rgba(30, 58, 95, 0.08);    /* Soft professional shadow */
    --shadow-hover: rgba(30, 58, 95, 0.16); /* Hover shadow */
    --primary-shadow: rgba(30, 58, 95, 0.15); /* Brand shadow */

    /* Legacy Color Mapping (for gradual transition) */
    --crimson: var(--primary-sapphire);
    --bd-red: var(--primary-sapphire);
    --bd-green: var(--primary-green);
    --bd-yellow: var(--primary-gold);
    --bd-pink: var(--accent-coral);
    --black: var(--charcoal);
    --gray: var(--slate-blue);
    --off-white: var(--warm-gray);
    --dark-gray: var(--charcoal);
    --crimson-shadow: var(--primary-shadow);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--dark-gray);
    line-height: 1.6;
    background-color: var(--white);
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Merriweather', serif;
    color: var(--black);
    line-height: 1.3;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background: var(--white);
    box-shadow: 0 2px 10px var(--shadow);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-img {
    height: 50px;
    width: auto;
}

.logo-text {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--crimson);
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--dark-gray);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu a:hover {
    color: var(--crimson);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--crimson);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--crimson);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-sapphire), var(--primary-green));
    color: var(--white);
    padding: 120px 0 80px;
    margin-top: 70px;
    position: relative;
    overflow: hidden;
    transform: none !important; /* Prevent parallax issues */
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: -50%;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.05" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,112C672,96,768,96,864,112C960,128,1056,160,1152,160C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: cover;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--white);
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--primary-gold);
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-description {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    opacity: 0.9;
    animation: fadeInUp 1.2s ease;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
    animation: fadeInUp 1.4s ease;
}

.btn {
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--primary-gold);
    color: var(--charcoal);
}

.btn-primary:hover {
    background: var(--accent-coral);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px var(--primary-shadow);
}

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

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

/* Stats Container */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
    animation: fadeInUp 1.6s ease;
}

.stat-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.15);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-gold);
}

.stat-label {
    font-size: 1rem;
    margin-top: 0.5rem;
    opacity: 0.9;
}

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

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    color: var(--crimson);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--bd-green);
}

/* About Section */
.about {
    background: var(--off-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text h3 {
    color: var(--crimson);
    margin-bottom: 1rem;
}

.vision-mission {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.vision, .mission {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px var(--shadow);
}

.vision h4, .mission h4 {
    color: var(--bd-green);
    margin-bottom: 0.5rem;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 10px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--bd-pink);
}

.timeline-item {
    position: relative;
    padding-bottom: 2rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -34px;
    top: 5px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--bd-pink);
    border: 3px solid var(--white);
}

.timeline-date {
    color: var(--crimson);
    font-weight: 600;
}

.timeline-content {
    margin-top: 0.5rem;
    color: var(--gray);
}

/* Partners Section */
.partners {
    background: var(--white);
}

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

.partner-card {
    background: var(--off-white);
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 3px 10px var(--shadow);
    transition: all 0.3s ease;
    border-left: 4px solid var(--bd-yellow);
}

.partner-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px var(--shadow-hover);
}

.partner-card h3 {
    color: var(--crimson);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.partner-card p {
    color: var(--gray);
    font-size: 0.9rem;
}

/* Mission Section */
.objectives-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.objective-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px var(--shadow);
    transition: all 0.3s ease;
    border-top: 4px solid var(--bd-green);
}

.objective-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px var(--shadow-hover);
}

.objective-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.objective-card h3 {
    color: var(--crimson);
    margin-bottom: 1rem;
}

/* Research Section */
.research {
    background: var(--off-white);
}

.research-filter {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.filter-btn {
    padding: 8px 20px;
    border: 2px solid var(--crimson);
    background: transparent;
    color: var(--crimson);
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--crimson);
    color: var(--white);
}

.publications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.publication-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px var(--shadow);
    transition: all 0.3s ease;
}

.publication-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-hover);
}

.pub-category {
    display: inline-block;
    background: var(--bd-yellow);
    color: var(--black);
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.pub-date {
    color: var(--gray);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.pub-link {
    color: var(--bd-green);
    text-decoration: none;
    font-weight: 600;
    display: inline-block;
    margin-top: 1rem;
    transition: color 0.3s ease;
}

.pub-link:hover {
    color: var(--crimson);
}

/* Programs Section */
.programs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.program-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px var(--shadow);
    transition: all 0.3s ease;
}

.program-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-hover);
}

.program-card h3 {
    color: var(--crimson);
    margin-bottom: 1rem;
}

.program-card ul {
    list-style-position: inside;
    margin: 1rem 0;
    color: var(--gray);
}

.program-card ul li {
    margin-bottom: 0.5rem;
}

/* Team Section */
.team {
    background: var(--off-white);
}

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

.team-member {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px var(--shadow);
    transition: all 0.3s ease;
}

.team-member:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-hover);
}

.member-photo {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--bd-pink), var(--crimson));
    margin: 0 auto 1rem;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.member-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.member-role {
    color: var(--bd-green);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

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

/* Events Section */
.events-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.event-card {
    background: var(--white);
    border-radius: 15px;
    box-shadow: 0 5px 15px var(--shadow);
    overflow: hidden;
    display: flex;
    transition: all 0.3s ease;
}

.event-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px var(--shadow-hover);
}

.event-card.upcoming {
    border-left: 4px solid var(--bd-yellow);
}

.event-date {
    background: var(--crimson);
    color: var(--white);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 80px;
}

.event-date .day {
    font-size: 2rem;
    font-weight: 700;
}

.event-date .month {
    font-size: 0.875rem;
}

.event-content {
    padding: 1.5rem;
    flex: 1;
}

.event-tag {
    display: inline-block;
    background: var(--bd-pink);
    color: var(--white);
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.event-content h3 {
    margin-bottom: 0.5rem;
}

.event-link {
    color: var(--bd-green);
    text-decoration: none;
    font-weight: 600;
    display: inline-block;
    margin-top: 0.5rem;
    transition: color 0.3s ease;
}

.event-link:hover {
    color: var(--crimson);
}

/* Get Involved Section */
.get-involved {
    background: linear-gradient(135deg, var(--primary-green), var(--primary-sapphire));
    color: var(--white);
}

.get-involved .section-title {
    color: var(--white);
}

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

.involved-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.involved-card:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-5px);
}

.involved-card h3 {
    color: var(--white);
    margin-bottom: 1rem;
}

/* Contact Section */
.contact {
    background: var(--off-white);
}

.contact-content {
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.contact-info-centered {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 800px;
    width: 100%;
}

.contact-form {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px var(--shadow);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--light-gray);
    border-radius: 8px;
    font-family: 'Inter', sans-serif;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--bd-green);
    box-shadow: 0 0 0 3px rgba(0, 103, 71, 0.1);
}

.contact-info {
    padding: 2rem;
}

.info-item {
    margin-bottom: 2rem;
}

.info-item h3 {
    color: var(--crimson);
    margin-bottom: 0.5rem;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-link {
    color: var(--bd-green);
    text-decoration: none;
    padding: 8px 16px;
    border: 2px solid var(--bd-green);
    border-radius: 20px;
    transition: all 0.3s ease;
}

.social-link:hover {
    background: var(--bd-green);
    color: var(--white);
}

/* Newsletter Section */
.newsletter {
    background: var(--black);
    color: var(--white);
    padding: 40px 0;
}

.newsletter-content {
    text-align: center;
}

.newsletter-content h3 {
    color: var(--white);
    margin-bottom: 0.5rem;
}

.newsletter-form {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.newsletter-form input {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 30px;
    font-family: 'Inter', sans-serif;
}

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

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    color: var(--white);
    margin-bottom: 1rem;
}

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

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

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--bd-yellow);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px var(--shadow);
        padding: 2rem 0;
    }

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

    .nav-toggle {
        display: flex;
    }

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

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }

    .vision-mission {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .newsletter-form {
        flex-direction: column;
    }

    .stats-container {
        grid-template-columns: 1fr;
    }

    /* Contact Form Mobile Responsiveness */
    .contact-form {
        padding: 1.5rem;
    }

    .contact-info {
        padding: 1rem;
    }

    .social-links {
        flex-wrap: wrap;
        justify-content: center;
    }

    /* Make research filters wrap on mobile */
    .research-filter {
        flex-wrap: wrap;
    }

    /* Ensure event cards stack properly on mobile */
    .event-card {
        flex-direction: column;
    }

    .event-date {
        min-width: 100%;
        flex-direction: row;
        justify-content: flex-start;
        gap: 1rem;
        padding: 1rem;
    }

    /* Adjust section padding for mobile */
    section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 2rem;
    }

    /* Adjust logo size for mobile */
    .logo-text {
        font-size: 1.4rem;
    }

    /* Timeline adjustments */
    .timeline {
        padding-left: 30px;
    }
}

/* Smaller mobile devices */
@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

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

    .section-title {
        font-size: 1.75rem;
    }

    .btn {
        padding: 10px 24px;
        font-size: 0.9rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .objectives-grid,
    .publications-grid,
    .programs-grid,
    .team-grid,
    .events-grid {
        grid-template-columns: 1fr;
    }

    .research-filter {
        gap: 0.5rem;
    }

    .filter-btn {
        padding: 6px 16px;
        font-size: 0.875rem;
    }

    .contact-form {
        padding: 1rem;
    }

    .form-group input,
    .form-group select,
    .form-group textarea {
        padding: 10px;
        font-size: 0.9rem;
    }
}