/* ============================================
   1. GLOBAL RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    /* Scaled slightly down so the layout looks perfect at 100% zoom without needing to zoom out to 90% */
    font-size: 15.5px; 
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: #f8fafc;
    color: #334155;
    line-height: 1.6;
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}



/* Global Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 28px; /* বাটনকে একটু চওড়া ও সুন্দর দেখানোর জন্য প্যাডিং বাড়ানো হয়েছে */
    border-radius: 40px; /* মডার্ন পিল-শেপ */
    font-weight: 500;
    font-size: 1rem;
    text-decoration: none;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}

/* Primary Button (Download CV) */
.btn-primary {
    background: #2563eb;
    color: white;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3); /* সুন্দর নীল শ্যাডো */
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-3px); /* হোভার করলে বাটন একটু উপরে উঠবে */
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

/* Outline Button (Contact Me) */
.btn-outline {
    border: 2px solid #2563eb;
    color: #2563eb;
    background: transparent;
}

.btn-outline:hover {
    background: #2563eb;
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.2);
}

/* ============================================
   2. HEADER & NAVIGATION
   ============================================ */
.header {
    position: sticky;
    top: 0;
    background: #ffffff;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    z-index: 999;
    padding: 15px 0;
}

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

.logo {
    font-size: 1.6rem;
    font-weight: 700;
    color: #2563eb;
}

.nav-menu {
    display: flex;
    gap: 30px;
}

.nav-menu a {
    color: #475569;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #2563eb;
}

.menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #0f172a;
}

/* ============================================
   2. HEADER & NAVIGATION (GLASSMORPHISM STYLE)
   ============================================ */
.header {
    position: sticky;
    top: 0;
    /* Glassmorphism Effect */
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.04);
    z-index: 999;
    padding: 12px 0;
    transition: all 0.3s ease;
}

/* Logo with gradient text */
.logo {
    font-size: 1.6rem;
    font-weight: 700;
    background: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

/* Active nav link with underline indicator */
.nav-menu a {
    position: relative;
    color: #475569;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
    padding: 5px 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 50%;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #2563eb, #7c3aed);
    transition: all 0.3s ease;
    transform: translateX(-50%);
    border-radius: 2px;
}

.nav-menu a:hover {
    color: #2563eb;
}

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

.nav-menu a.active {
    color: #2563eb;
    font-weight: 600;
}

.nav-menu a.active::after {
    width: 100%;
}
/* ============================================
   3. HERO SECTION
   Main container with gradient background
   ============================================ */

.hero {
    min-height: calc(100vh - 80px);
    display: flex;
    align-items: flex-start; /* ✅ center থেকে flex-start করা হয়েছে */
    background: linear-gradient(135deg, #f8fbff, #eef5ff);
    padding: 20px 0;
}

.hero {
    min-height: auto; /* ✅ পুরো স্ক্রিন জোর করে নেওয়া বন্ধ */
    display: flex;
    align-items: flex-start;
    background: linear-gradient(135deg, #f8fbff, #eef5ff);
    padding: 40px 0 40px 0; /* ✅ উপরে 50px, নিচে 40px */
}


/* Two-column grid: Left (text) + Right (image + stats) */
.hero-content {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 30px;
    align-items: center; /* ✅ দুই কলাম নিজেদের মধ্যে সমান উচ্চতায় থাকবে */
    padding-top: -30px; /* ✅ হেডারের নিচে একটু ফাঁকা জায়গা রাখতে */
}


/* ============================================
   LEFT COLUMN - Text Content
   ============================================ */
.hero-text {
    padding-top: 0;
}

/* Small greeting badge */
.hero-tag {
    display: inline-block;
    background: #dbeafe;
    color: #2563eb;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 400;
    margin-bottom: 15px;
}

/* Main name heading */
.hero-text h1 {
    font-size: 2.5rem;
    line-height: 1.1;
    color: #0f172a;
    margin-bottom: 10px;
}

/* Subtitle / Role */
.hero-text h2 {
    font-size: 1.3rem;
    color: #2563eb;
    margin-bottom: 20px;
    font-weight: 550;
}

/* Bio paragraph */
.hero-text p {
    font-size: 1.05rem;
    color: #475569;
    line-height: 1.8;
    max-width: 500px;
    margin-bottom: 20px;
}

/* Action buttons (About Me, Contact Me) */
.hero-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

/* ============================================
   RIGHT COLUMN - Image, Stats, Social Icons
   ============================================ */
.hero-right {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    margin-top: 0px;
}

/* Profile image container */
.hero-image {
    margin-bottom: 10px;
}

/* Circular profile image with shadow */
.hero-image img {
    width: 210px;
    height: 210px;
    object-fit: cover;
    border-radius: 50%;
    border: 5px solid white;
    box-shadow: 0 15px 35px rgba(37, 99, 235, 0.15);
    transition: transform 0.4s ease;
}

/* Subtle zoom on hover */
.hero-image img:hover {
    transform: scale(1.03);
}

/* ============================================
   STATS - Publications, Projects, Research
   ============================================ */
.hero-stats {
    display: flex;
    gap: 15px;
    margin-bottom: 10px;
    justify-content: center;
}

/* Stat number */
.hero-stat h3 {
    color: #2563eb;
    font-size: 1.8rem;
    margin-bottom: 5px;
}

/* Stat label */
.hero-stat p {
    color: #64748b;
    font-size: 0.9rem;
    font-weight: 400;
}

/* ============================================
   SOCIAL ICONS - GitHub, LinkedIn, etc.
   ============================================ */
.social-icons {
    display: flex;
    gap: 10px;
    justify-content: center;
}

/* Individual social icon button */
.social-icons a {
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: white;
    color: #2563eb;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    font-size: 1.1rem;
}

/* Hover effect: fill with blue + lift up */
.social-icons a:hover {
    background: #2563eb;
    color: white;
    transform: translateY(-3px);
}

/* ============================================
   RESPONSIVE - Tablet & Mobile
   ============================================ */
@media (max-width: 992px) {
    /* Stack columns vertically on tablet/mobile */
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    /* Reset text padding */
    .hero-text {
        padding-top: 0;
    }

    /* Center text and buttons */
    .hero-text p,
    .hero-buttons {
        margin-left: auto;
        margin-right: auto;
        justify-content: center;
    }

    /* Move image to top on mobile */
    .hero-right {
        margin-top: 20px;
        order: -1;
    }

    /* Slightly larger image for mobile */
    .hero-image img {
        width: 250px;
        height: 250px;
    }
}

/* ============================================
   4. GLOBAL SECTION TITLES
   ============================================ */

/* Base padding for all sections */
section {
    padding: 30px 0;
}

/* Centered title container */
.section-title {
    text-align: center;
    margin-bottom: 50px;
}

/* Main heading */
.section-title h2 {
    font-size: 2rem;
    font-weight: 700;
    color: #0f172a;
    margin-bottom: 10px;
}

/* Subtitle paragraph */
.section-title p {
    color: #64748b;
    font-size: 1.05rem;
    max-width: 650px;
    margin: 0 auto;
}
/* ============================================
   5. ABOUT SECTION
   ============================================ */
.about-section {
    background-color: #ffffff;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 50px;
    align-items: start;
}

.about-image-wrapper {
    position: sticky;
    top: 100px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}


.about-image img {
    width: 250px;      /* আপনার পছন্দমতো সাইজ দিন (যেমন: 250px, 300px, 350px) */
    height: 300px;     /* width-এর সমান রাখলে ছবি স্কয়ার হবে */
    object-fit: cover; /* ছবি ক্রপ করে ফিট করবে, ডিস্টর্শন হবে না */
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border: 4px solid #ffffff;
    display: block;
    margin: 0 auto ;    /* ছবিকে মাঝখানে সেন্টার করবে */
}

.about-quick-info {
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: #f8fafc;
    padding: 8px;
    border-radius: 10px;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
    color: #475569;
}

.info-item i {
    color: #2563eb;
    width: 20px;
    text-align: center;
}

.about-content .section-subtitle {
    color: #2563eb;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.85rem;
}

.about-content .section-title {
    text-align: left;
    margin-bottom: 20px;
}

.about-content .section-title h2 {
    font-size: 2rem;
}

.about-text {
    font-size: 1rem;
    line-height: 1.8;
    color: #475569;
    margin-bottom: 20px;
    text-align: justify;
}

.subsection-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #0f172a;
    margin: 30px 0 20px 0;
    display: flex;
    align-items: center;
    gap: 10px;
}

.subsection-title i {
    color: #2563eb;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 25px;
    border-left: 2px solid #e2e8f0;
}

.timeline-item {
    position: relative;
    margin-bottom: 25px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -31px;
    top: 5px;
    width: 12px;
    height: 12px;
    background-color: #2563eb;
    border-radius: 50%;
    border: 3px solid #ffffff;
    box-shadow: 0 0 0 2px #2563eb;
}

.timeline-year {
    font-size: 0.8rem;
    font-weight: 600;
    color: #2563eb;
    background-color: #eff6ff;
    padding: 3px 10px;
    border-radius: 4px;
    display: inline-block;
    margin-bottom: 6px;
}

.timeline-content h4 {
    font-size: 1.05rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 4px;
}

.timeline-content .institution {
    font-size: 0.9rem;
    color: #475569;
    font-weight: 500;
    margin-bottom: 4px;
}

.timeline-content .details {
    font-size: 0.85rem;
    color: #64748b;
}

/* Awards */
.award-item {
    display: flex;
    gap: 15px;
    background-color: #f8fafc;
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid #f59e0b;
}

.award-item i {
    font-size: 1.3rem;
    color: #f59e0b;
    margin-top: 3px;
}

.award-item h4 {
    font-size: 1rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 5px;
}

.award-item p {
    font-size: 0.85rem;
    color: #64748b;
    line-height: 1.5;
}

/* ============================================
   6. PROJECTS SECTION
   ============================================ */
.featured-projects, .projects-section {
    background-color: #f8fafc;
}

.project-category {
    font-size: 1.4rem;
    font-weight: 700;
    color: #0f172a;
    margin: 40px 0 25px;
    border-left: 5px solid #2563eb;
    padding-left: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.project-category i {
    color: #2563eb;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.project-card {
    background: #ffffff;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
    border: 1px solid #e2e8f0;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
}

.project-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.project-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.project-card:hover img {
    transform: scale(1.05);
}

.project-content {
    padding: 24px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-content h3 {
    font-size: 1.15rem;
    margin-bottom: 12px;
    color: #0f172a;
    font-weight: 600;
}

.project-content p {
    color: #64748b;
    line-height: 1.7;
    font-size: 0.95rem;
    margin-bottom: 15px;
    flex-grow: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.project-tech span {
    background-color: #eff6ff;
    color: #2563eb;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 20px;
}

.project-buttons {
    display: flex;
    gap: 12px;
    margin-top: auto;
}

.btn-project {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 16px;
    font-size: 0.85rem;
    font-weight: 600;
    color: #475569;
    background-color: #f1f5f9;
    border-radius: 8px;
    transition: all 0.3s ease;
    flex: 1;
    text-align: center;
}

.btn-project:hover {
    background-color: #e2e8f0;
    color: #0f172a;
}

.btn-project.primary {
    background-color: #2563eb;
    color: #ffffff;
}

.btn-project.primary:hover {
    background-color: #1d4ed8;
}

.view-projects, .view-all-wrapper {
    text-align: center;
    margin-top: 50px;
}

/* ============================================
   7. SKILLS SECTION
   ============================================ */
.skills-section {
    background-color: #ffffff;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.skill-card {
    background-color: #f8fafc;
    border-radius: 12px;
    padding: 25px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid #e2e8f0;
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.05);
    border-color: #bfdbfe;
}

.skill-category-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e2e8f0;
    display: flex;
    align-items: center;
    gap: 10px;
}

.skill-category-title i {
    color: #2563eb;
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.skill-item {
    display: flex;
    align-items: center;
    gap: 8px;
    background-color: #ffffff;
    padding: 8px 14px;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    transition: all 0.2s ease;
}

.skill-item:hover {
    background-color: #eff6ff;
    border-color: #bfdbfe;
}

.skill-item i {
    font-size: 1.3rem;
}

.skill-item span {
    font-size: 0.85rem;
    font-weight: 500;
    color: #334155;
}

.skill-item span small {
    font-size: 0.7rem;
    color: #64748b;
    font-weight: 400;
    display: block;
    margin-top: 2px;
}

/* ============================================
   8. CERTIFICATIONS SECTION
   ============================================ */
.certifications-preview,
.certifications-page-section {
    background-color: #f8fafc;
}

.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.cert-card {
    background-color: #ffffff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.04);
    border: 1px solid #e2e8f0;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.cert-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.08);
    border-color: #bfdbfe;
}

.cert-image-placeholder {
    width: 100%;
    height: 180px;
    background-color: #f1f5f9;
    overflow: hidden;
}

.cert-image-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.cert-card:hover .cert-image-placeholder img {
    transform: scale(1.05);
}

.cert-content {
    padding: 20px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.cert-content h3 {
    font-size: 1.05rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 8px;
    line-height: 1.4;
}

.cert-issuer {
    font-size: 0.85rem;
    color: #2563eb;
    font-weight: 600;
    margin-bottom: 10px;
}

.cert-date {
    font-size: 0.8rem;
    color: #64748b;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.cert-btn {
    margin-top: auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 16px;
    background-color: #eff6ff;
    color: #2563eb;
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.cert-btn:hover {
    background-color: #2563eb;
    color: #ffffff;
}

.cert-btn.disabled {
    background-color: #f1f5f9;
    color: #94a3b8;
    cursor: not-allowed;
    pointer-events: none;
}

/* ============================================
   9. RESEARCH & PUBLICATIONS SECTION
   ============================================ */
.publications-section {
    background-color: #ffffff;
}

.publication-category {
    font-size: 1.4rem;
    font-weight: 700;
    color: #0f172a;
    margin: 40px 0 25px;
    border-left: 5px solid #2563eb;
    padding-left: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.publication-category i {
    color: #2563eb;
}

.publication-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.publication-card {
    background-color: #f8fafc;
    border-radius: 12px;
    padding: 25px;
    border-left: 4px solid #2563eb;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.03);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.publication-card:hover {
    transform: translateX(5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.06);
}

.pub-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 8px;
    line-height: 1.4;
}

.authors {
    font-size: 0.9rem;
    color: #475569;
    margin-bottom: 6px;
}

.authors strong {
    color: #2563eb;
    font-weight: 600;
}

.journal {
    font-size: 0.85rem;
    color: #2563eb;
    font-weight: 600;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.pub-desc {
    font-size: 0.9rem;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 15px;
}

.publication-links {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.link-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background-color: #eff6ff;
    color: #2563eb;
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.link-btn:hover {
    background-color: #2563eb;
    color: #ffffff;
}

/* ============================================
   10. BLOG SECTION
   ============================================ */
.blogs-section {
    background-color: #f8fafc;
}

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

.blog-card {
    background-color: #ffffff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.04);
    border: 1px solid #e2e8f0;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.08);
}

.blog-image {
    width: 100%;
    height: 180px;
    overflow: hidden;
}

.blog-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.blog-card:hover .blog-image img {
    transform: scale(1.05);
}

.blog-content {
    padding: 24px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.blog-category {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    color: #ffffff;
    background-color: #2563eb;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 12px;
    width: fit-content;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.blog-content h3 {
    font-size: 1.15rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 10px;
    line-height: 1.4;
}

.blog-content p {
    font-size: 0.9rem;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 15px;
    flex-grow: 1;
}

.blog-meta {
    display: flex;
    gap: 15px;
    font-size: 0.8rem;
    color: #94a3b8;
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid #f1f5f9;
}

.blog-meta i {
    margin-right: 5px;
}

.blog-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: #2563eb;
    transition: gap 0.3s ease, color 0.3s ease;
}

.blog-link:hover {
    color: #1d4ed8;
    gap: 12px;
}

/* ============================================
   11. CONTACT SECTION
   ============================================ */
.contact {
    background-color: #ffffff;
}

.contact-container {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 40px;
    align-items: start;
    background: #f8fafc;
    border-radius: 16px;
    padding: 40px;
    border: 1px solid #e2e8f0;
}

.contact-info h3 {
    font-size: 1.5rem;
    color: #0f172a;
    margin-bottom: 15px;
}

.contact-info > p {
    color: #64748b;
    line-height: 1.7;
    margin-bottom: 25px;
    font-size: 0.95rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 15px;
    color: #334155;
    font-size: 0.95rem;
}

.contact-item i {
    color: #2563eb;
    font-size: 1.1rem;
    width: 20px;
}

.social-links {
    display: flex;
    gap: 12px;
    margin-top: 25px;
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: #ffffff;
    color: #2563eb;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: #2563eb;
    color: white;
    border-color: #2563eb;
}

.contact-form form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-family: 'Poppins', sans-serif;
    font-size: 0.95rem;
    outline: none;
    background: #ffffff;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.contact-form input:focus,
.contact-form textarea:focus {
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.contact-form button {
    padding: 14px 20px;
    border: none;
    border-radius: 8px;
    background: #2563eb;
    color: white;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s ease;
}

.contact-form button:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
}

/* ============================================
   12. FOOTER
   ============================================ */
footer {
    padding: 30px 0;
    text-align: center;
    background: #0f172a;
    color: #94a3b8;
    font-size: 0.9rem;
}

/* ============================================
   13. RESPONSIVE MEDIA QUERIES
   ============================================ */
@media (max-width: 992px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-text p, .hero-buttons, .hero-stats, .social-icons {
        justify-content: center;
        margin-left: auto;
        margin-right: auto;
    }

    .hero-image {
        order: -1; /* Move image to top on tablet/mobile */
    }

    .hero-image img {
        width: 250px;
        height: 250px;
    }

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

    .about-image-wrapper {
        position: relative;
        top: 0;
        max-width: 350px;
        margin: 0 auto 30px auto;
    }

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

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

@media (max-width: 768px) {
    html {
        font-size: 14.5px; /* Scale down slightly for mobile screens */
    }

    .nav-menu {
        display: none; /* Requires JS to toggle '.active' class */
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    }

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

    .menu-btn {
        display: block;
    }

    .section-title h2 {
        font-size: 1.8rem;
    }

    .hero-text h1 {
        font-size: 2.5rem;
    }

    .hero-text h2 {
        font-size: 1.2rem;
    }

    .project-grid, .skills-grid, .cert-grid, .blog-grid {
        grid-template-columns: 1fr;
    }
}


/* ============================================
   EXPERIENCE SECTION STYLES
   ============================================ */
.experience-section {
    padding: 80px 0;
    background-color: #ffffff;
}

.experience-timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding-left: 30px;
    border-left: 3px solid #e2e8f0;
}

.experience-item {
    position: relative;
    margin-bottom: 45px;
    padding-left: 30px;
}

/* Timeline Dot */
.experience-item::before {
    content: '';
    position: absolute;
    left: -39px;
    top: 8px;
    width: 16px;
    height: 16px;
    background-color: #2563eb;
    border-radius: 50%;
    border: 4px solid #ffffff;
    box-shadow: 0 0 0 2px #2563eb;
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 8px;
}

.experience-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #0f172a;
    margin: 0;
}

.company-name {
    font-size: 1rem;
    font-weight: 600;
    color: #2563eb;
    display: block;
    margin-top: 4px;
}

.location-tag {
    font-size: 0.85rem;
    color: #64748b;
    font-weight: 500;
    background: #f1f5f9;
    padding: 4px 10px;
    border-radius: 6px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.experience-duration {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: #2563eb;
    font-weight: 600;
    margin-bottom: 15px;
    background: #eff6ff;
    padding: 4px 12px;
    border-radius: 20px;
}

.experience-details {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.experience-details li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 10px;
    font-size: 0.95rem;
    color: #475569;
    line-height: 1.6;
}

/* Custom bullet points for experience */
.experience-details li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: #2563eb;
    font-weight: bold;
    font-size: 1.1rem;
}

/* ============================================
   LEADERSHIP SECTION STYLES
   ============================================ */
.leadership-section {
    padding: 80px 0;
    background-color: #f8fafc;
}

.leadership-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    max-width: 1000px;
    margin: 0 auto;
}

.leadership-card {
    background: #ffffff;
    padding: 30px;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

.leadership-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.06);
    border-color: #bfdbfe;
}

.leadership-icon {
    font-size: 2rem;
    color: #2563eb;
    margin-bottom: 15px;
}

.leadership-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 8px;
}

.leadership-card .org {
    font-size: 0.95rem;
    color: #2563eb;
    font-weight: 500;
    margin-bottom: 12px;
}

.leadership-card .duration {
    font-size: 0.85rem;
    color: #64748b;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: #f1f5f9;
    padding: 4px 12px;
    border-radius: 20px;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .experience-header {
        flex-direction: column;
    }
    
    .experience-timeline {
        padding-left: 20px;
    }
    
    .experience-item {
        padding-left: 20px;
    }
    
    .experience-item::before {
        left: -29px;
    }
}


/* ============================================
   EXPERIENCE PAGE TIMELINE STYLES
   ============================================ */
.experience-page-section {
    padding: 60px 0 80px 0;
    background-color: #f8fafc;
}

.experience-category {
    margin-bottom: 60px;
}

.category-header {
    font-size: 1.5rem;
    font-weight: 700;
    color: #0f172a;
    margin-bottom: 30px;
    padding-bottom: 12px;
    border-bottom: 3px solid #e2e8f0;
    display: flex;
    align-items: center;
    gap: 12px;
}

.category-header i {
    color: #2563eb;
    font-size: 1.3rem;
}

/* Timeline Container */
.timeline {
    position: relative;
    padding-left: 30px;
    margin-left: 10px;
}

/* Vertical Line */
.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    bottom: 0;
    width: 3px;
    background: linear-gradient(to bottom, #2563eb, #93c5fd);
    border-radius: 3px;
}

/* Timeline Item */
.timeline-item {
    position: relative;
    margin-bottom: 35px;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

/* Timeline Dot */
.timeline-dot {
    position: absolute;
    left: -36px;
    top: 8px;
    width: 16px;
    height: 16px;
    background-color: #ffffff;
    border: 4px solid #2563eb;
    border-radius: 50%;
    z-index: 2;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

/* Timeline Content Card */
.timeline-content {
    background: #ffffff;
    padding: 25px 30px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.04);
    border: 1px solid #e2e8f0;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.timeline-content:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(37, 99, 235, 0.08);
    border-color: #bfdbfe;
}

/* Header inside Timeline Card */
.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 8px;
}

.timeline-header h4 {
    font-size: 1.15rem;
    font-weight: 600;
    color: #0f172a;
    margin: 0;
}

.timeline-date {
    font-size: 0.85rem;
    font-weight: 600;
    color: #2563eb;
    background-color: #eff6ff;
    padding: 4px 12px;
    border-radius: 20px;
    white-space: nowrap;
}

/* Company & Location */
.timeline-company {
    font-size: 0.95rem;
    color: #475569;
    font-weight: 500;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.location-badge {
    font-size: 0.8rem;
    color: #64748b;
    font-weight: 400;
    background-color: #f1f5f9;
    padding: 2px 8px;
    border-radius: 4px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

/* Bullet Points */
.timeline-details {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.timeline-details li {
    position: relative;
    padding-left: 22px;
    margin-bottom: 8px;
    font-size: 0.95rem;
    color: #475569;
    line-height: 1.6;
}

.timeline-details li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: #2563eb;
    font-weight: bold;
    font-size: 1.1rem;
    line-height: 1.4;
}

/* Responsive Adjustments for Timeline */
@media (max-width: 768px) {
    .timeline-header {
        flex-direction: column;
        gap: 8px;
    }
    
    .timeline-content {
        padding: 20px;
    }
    
    .timeline {
        padding-left: 20px;
    }
    
    .timeline-dot {
        left: -26px;
        width: 14px;
        height: 14px;
        border-width: 3px;
    }
}



/* ============================================
   VERTICAL SKILL ITEMS (One below another)
   ============================================ */
.skill-items-vertical {
    display: flex;
    flex-direction: column; /* একটার নিচে একটা সাজানোর জন্য */
    gap: 12px; /* প্রতিটি আইটেমের মাঝখানের ফাঁকা জায়গা */
}

.skill-items-vertical .skill-item {
    width: 100%; /* পুরো কার্ডের প্রস্থ জুড়ে থাকবে */
    justify-content: flex-start; /* বাম পাশে অ্যালাইন থাকবে */
    background-color: #f8fafc;
    padding: 12px 16px;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.skill-items-vertical .skill-item:hover {
    background-color: #eff6ff;
    border-color: #bfdbfe;
    transform: translateX(5px); /* হোভার করলে সামান্য ডানে সরে যাবে */
}

.skill-items-vertical .skill-item i {
    font-size: 1.4rem;
    flex-shrink: 0;
}

.skill-items-vertical .skill-item span {
    font-size: 0.95rem;
    font-weight: 600;
    color: #334155;
    display: flex;
    flex-direction: column;
    line-height: 1.3;
}

.skill-items-vertical .skill-item span small {
    font-size: 0.75rem;
    color: #64748b;
    font-weight: 400;
    margin-top: 2px;
}


/* ============================================
   FEATURED RESEARCH SECTION (Unique Horizontal Style)
   ============================================ */
.featured-research {
    padding: 80px 0;
    background-color: #ffffff;
}

.research-list {
    display: flex;
    flex-direction: column;
    gap: 25px;
    max-width: 900px;
    margin: 0 auto 40px auto;
}

.research-item {
    display: flex;
    gap: 25px;
    background: #f8fafc;
    padding: 30px;
    border-radius: 12px;
    border-left: 4px solid #2563eb;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
}

.research-item:hover {
    transform: translateX(8px);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.08);
    background: #ffffff;
}

.research-icon {
    flex-shrink: 0;
    width: 55px;
    height: 55px;
    background: #eff6ff;
    color: #2563eb;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.research-details h3 {
    font-size: 1.15rem;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 8px;
    line-height: 1.4;
}

.research-authors {
    font-size: 0.9rem;
    color: #475569;
    margin-bottom: 6px;
}

.research-authors strong {
    color: #2563eb;
    font-weight: 600;
}

.research-journal {
    font-size: 0.85rem;
    color: #2563eb;
    font-weight: 600;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.research-desc {
    font-size: 0.95rem;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 15px;
}

.research-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: #2563eb;
    text-decoration: none;
    transition: gap 0.3s ease;
}

.research-link:hover {
    gap: 12px;
}

/* Responsive for Research List */
@media (max-width: 768px) {
    .research-item {
        flex-direction: column;
        gap: 15px;
    }
}

/* ============================================
   COMPACT & ELEGANT SECTIONS (Projects & Certs)
   ============================================ */


/* Compact Grid Layout */
.compact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px; /* আগের 30px থেকে কমিয়ে 20px করা হয়েছে */
}

/* Compact Card Style */
.compact-card {
    background: #ffffff;
    border: 1px solid #e2e8f0; /* হালকা বর্ডার, ভারী শ্যাডো বাদ */
    border-radius: 8px; /* কম রাউন্ডেড, বেশি প্রফেশনাল */
    padding: 20px; /* আগের 25-30px থেকে কমিয়ে 20px করা হয়েছে */
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
}

.compact-card:hover {
    border-color: #cbd5e1;
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04); /* খুব হালকা শ্যাডো */
}

/* Tag for Projects */
.compact-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    color: #2563eb;
    background: #eff6ff;
    padding: 3px 10px;
    border-radius: 4px;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Card Headings (Smaller) */
.compact-content h3 {
    font-size: 1.05rem; /* আগের 1.15-1.2rem থেকে কম */
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 8px;
    line-height: 1.4;
}

/* Card Text (Smaller & Clean) */
.compact-content p {
    font-size: 0.9rem; /* ছোট ফন্ট */
    color: #475569;
    line-height: 1.6;
    margin-bottom: 15px;
    flex-grow: 1;
}

/* Certification Specific Header */
.cert-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.cert-provider {
    font-size: 0.8rem;
    font-weight: 600;
    color: #64748b;
}

.cert-date {
    font-size: 0.8rem;
    color: #94a3b8;
    margin-bottom: 12px;
}

/* Clean Text Links instead of bulky buttons */
.compact-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    color: #2563eb;
    text-decoration: none;
    transition: gap 0.2s ease;
}

.compact-link:hover {
    gap: 10px;
    color: #1d4ed8;
}

/* View All Wrapper (Text based, not bulky button) */
.view-all-wrapper {
    text-align: center;
    margin-top: 35px;
}

.btn-text {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    color: #2563eb;
    text-decoration: none;
    padding-bottom: 2px;
    border-bottom: 1px solid transparent;
    transition: all 0.2s ease;
}

.btn-text:hover {
    border-bottom-color: #2563eb;
}

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

/* ============================================
   RESEARCH SPECIFIC STYLES FOR COMPACT CARDS
   ============================================ */

/* Green tag for Research to distinguish from Projects */
.research-tag {
    background-color: #f0fdf4 !important;
    color: #16a34a !important;
}

.compact-authors {
    font-size: 0.85rem;
    color: #475569;
    margin-bottom: 4px;
    line-height: 1.4;
}

.compact-authors strong {
    color: #2563eb;
    font-weight: 600;
}

.compact-journal {
    font-size: 0.8rem;
    color: #16a34a; /* Green color for journal name */
    font-weight: 600;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
}

/* Fade Up Animation for Hero Elements */
.animate-fade-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease-out forwards;
}

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


/* =========================
   SCROLL DOWN ANIMATION
========================= */
.scroll-down {
    text-align: center;
    margin-top: 70px;
    font-size: 30px;
    color: #2563eb;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

/* ============================================
   SECTION TITLES (PILL SHAPE)
   ============================================ */
.section-title {
    text-align: center;
    margin-bottom: 45px;
}

.section-title h2 {
    font-size: 1.2rem;
    font-weight: 600;
    color: #0f172a;
    display: inline-block;
    padding: 10px 30px;
    background: #f1f5f9;
    border-radius: 50px;
    border: 1px solid #ce1212;
    letter-spacing: -0.3px;
}

.section-title p {
    color: #64748b;
    font-size: 0.95rem;
    max-width: 600px;
    margin: 18px auto 0 auto;
    line-height: 1.6;
}

/* ============================================
   MOBILE NAVIGATION (MUST HAVE)
   ============================================ */
@media (max-width: 768px) {
    .nav-menu {
        display: none; /* Default hidden on mobile */
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        gap: 15px;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        border-top: 1px solid #e2e8f0;
        z-index: 998;
    }

    /* THIS IS THE KEY CLASS - Without this, menu won't show */
    .nav-menu.active {
        display: flex !important;
    }

    .nav-menu a {
        font-size: 1rem;
        padding: 10px 20px;
        width: 100%;
        text-align: center;
    }

    .menu-btn {
        display: block !important;
    }
}