html {
    scroll-behavior: smooth;
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: #121212;
    color: #ffffff;
    line-height: 1.6;
}

a {
    color: #ffca28;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* ✅ Container Padding */
section {
    padding: 60px 30px;
}

/* ✅ Section Title */
section h2 {
    font-size: 28px;
    margin-bottom: 20px;
    color: #ffca28;
    text-align: center;
}

/* ✅ Hero Section */
.hero-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    padding: 60px 30px;
    background-color: #1e1e1e;
}

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-size: 42px;
    font-weight: 700;
    color: #ffca28;
}

.hero-text h3 {
    font-size: 22px;
    margin: 10px 0;
    color: #ffffff;
}

.hero-text p {
    font-size: 16px;
    color: #dddddd;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    margin-top: 20px;
    flex-wrap: wrap;
}

/* ✅ Typing Effect Styling */
.typewriter-text {
    font-size: 22px;
    font-weight: 500;
    color: #ffca28;
    border-right: 2px solid #ffca28;
    white-space: nowrap;
    overflow: hidden;
    display: inline-block;
    animation: blinkCursor 0.8s infinite;
}

@keyframes blinkCursor {
    0% {
        border-right-color: #ffca28;
    }

    50% {
        border-right-color: transparent;
    }

    100% {
        border-right-color: #ffca28;
    }
}

/* ✅ Hero Image */
.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

.hero-image img {
    max-width: 280px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

/* ✅ CV Button */
.cv-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background-color: #ffca28;
    color: #121212;
    padding: 10px 16px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: background 0.3s ease;
}

.cv-btn:hover {
    background-color: #ffd860;
}

.cv-btn img {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    object-fit: cover;
}

/* ✅ Button Styling */
.btn {
    display: inline-block;
    background-color: #ffca28;
    color: #121212;
    padding: 10px 20px;
    border-radius: 6px;
    transition: background 0.3s;
}

.btn:hover {
    background-color: #ffd860;
}

.btn-outline {
    border: 2px solid #ffca28;
    color: #ffca28;
    padding: 8px 18px;
    border-radius: 6px;
    background-color: transparent;
}

.contact-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 10px 0;
}

.contact-label {
    flex: 1;
    font-weight: bold;
}

.contact-info {
    flex: 2;
    padding-left: 20px;
}

.btn-outline:hover {
    background-color: #ffca28;
    color: #121212;
}

/* ✅ About Section */
.profile-pic {
    width: 160px;
    border-radius: 50%;
    display: block;
    margin: 0 auto 20px auto;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

/* ✅ Skills Section */
.skill {
    margin-bottom: 20px;
}

.skill-bar {
    background: #2c2c2c;
    border-radius: 6px;
    overflow: hidden;
    height: 18px;
}

.skill-progress {
    height: 18px;
    width: 0%;
    background: #ffca28;
    border-radius: 6px;
    opacity: 0;
    transition: width 1s ease-out;
}

/* ✅ Projects */
.projects-container {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.project-card {
    flex: 1 1 300px;
    background: #1e1e1e;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.project-card h3 {
    margin-bottom: 10px;
    color: #ffca28;
}

.project-links {
    margin-top: 15px;
    display: flex;
    gap: 12px;
}

/* ✅ Contact */
#contact p {
    margin: 10px 0;
}

.contact-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 10px 0;
}

.contact-label {
    flex: 1;
    font-weight: bold;
}

.contact-info {
    flex: 2;
    text-align: right;
    word-break: break-word;
}

/* ✅ Footer */
footer {
    text-align: center;
    padding: 20px;
    background-color: #1e1e1e;
    font-size: 14px;
}

/* ✅ Scroll Button */
#scrollTopBtn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    font-size: 22px;
    background-color: #ffca28;
    color: #121212;
    border: none;
    border-radius: 50%;
    padding: 10px 14px;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    display: none;
    z-index: 99;
}

#scrollTopBtn:hover {
    background-color: #ffd860;
}

/* ✅ Dark Mode Toggle */
.dark-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 100;
    font-size: 16px;
    background: #1e1e1e;
    padding: 8px 12px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    color: #ffca28;
}

/* ✅ Dark Mode Classes */
.dark-mode {
    background-color: #ffffff;
    color: #121212;
}

.dark-mode a {
    color: #0d6efd;
}

.dark-mode .btn {
    background-color: #0d6efd;
    color: #ffffff;
}

.dark-mode .hero-container,
.dark-mode footer {
    background-color: #f5f5f5;
}

/* ✅ Responsive Mobile View */
@media screen and (max-width: 768px) {
    .hero-container {
        flex-direction: column;
        text-align: center;
    }

    @media (max-width: 600px) {
        .contact-item {
            flex-direction: column;
            align-items: flex-start;
        }

        .contact-info {
            text-align: left;
            margin-top: 5px;
        }
    }

    .hero-text h1 {
        font-size: 32px;
    }

    .hero-text h3 {
        font-size: 18px;
    }

    .hero-image img {
        max-width: 200px;
    }

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

    .projects-container {
        flex-direction: column;
    }
}

@media (max-width: 600px) {
    .contact-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .contact-info {
        padding-left: 0;
        margin-top: 5px;
        text-align: left;
    }
}

.contact-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 20px;
}

.contact-link {
    color: #ffca28;
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: color 0.3s ease;
}

.contact-link:hover {
    color: #ffd860;
    text-decoration: underline;
    cursor: pointer;
}

.contact-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 20px;
}

.contact-link {
    position: relative;
    color: #ffca28;
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: color 0.3s ease;
    padding-bottom: 2px;
}

.contact-link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0%;
    height: 2px;
    background-color: #ffca28;
    transition: width 0.3s ease;
}

.contact-link:hover {
    color: #ffd860;
    cursor: pointer;
}

.contact-link:hover::after {
    width: 100%;
}

.about-container {
    display: flex;
    gap: 30px;
    align-items: center;
    flex-wrap: wrap;
}

.about-image img {
    max-width: 220px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.about-text p {
    font-size: 16px;
    color: #dddddd;
    margin-bottom: 12px;
    line-height: 1.8;
}

@media screen and (max-width: 768px) {
    .about-container {
        flex-direction: column;
        text-align: center;
    }

    .about-text p {
        text-align: justify;
    }
}

.about-container {
    display: flex;
    gap: 30px;
    align-items: center;
    flex-wrap: wrap;
}

.about-image img {
    max-width: 220px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.about-text p {
    font-size: 16px;
    color: #dddddd;
    margin-bottom: 12px;
    line-height: 1.8;
}

.about-text .highlight {
    color: #ffca28;
    font-weight: 500;
}

@media screen and (max-width: 768px) {
    .about-container {
        flex-direction: column;
        text-align: center;
    }

    .about-text p {
        text-align: justify;
    }
}

.skill-bar {
    background: #2c2c2c;
    border-radius: 6px;
    overflow: hidden;
    height: 18px;
    position: relative;
}

.skill-progress {
    height: 18px;
    width: 0%;
    border-radius: 6px;
    opacity: 0;
    transition: width 1s ease-out;
    background: linear-gradient(90deg, #ffca28, #ffd860);
}

.skill-label {
    position: absolute;
    right: 10px;
    top: 0;
    font-size: 12px;
    color: #ffca28;
    font-weight: 500;
}

nav {
    background: rgba(28, 28, 28, 0.85);
    backdrop-filter: blur(5px);
    transition: background 0.3s ease;
}

nav.scrolled {
    background: rgba(20, 20, 20, 0.95);
    box-shadow: 0 6px 18px rgba(255, 202, 40, 0.4);
}

footer p {
    margin: 5px 0;
    font-size: 16px;
    font-family: 'Poppins', sans-serif;
}

#currentTime {
    font-weight: bold;
    color: #00bcd4;
}

footer p {
    margin: 5px 0;
    font-size: 16px;
    font-family: 'Poppins', sans-serif;
    color: #cccccc;
    /* Footer text color */
}

/* 🔷 Aminul Islam highlight */
footer p span#currentYear {
    font-weight: bold;
    color: #00ffc6;
    /* একটুখানি ব্রাইট সায়ান-গ্রিন রঙ */
    font-family: 'Poppins', sans-serif;
}

/* 🔶 Current Time style */
#currentTime {
    font-weight: bold;
    color: #ffcc00;
    /* হালকা গোল্ডেন টাইম কালার */
    font-family: 'Courier New', monospace;
    /* টাইমের জন্য ক্লাসিক মনো ফন্ট */
    letter-spacing: 1px;
}

.custom-section {
    background-color: #f1f1f1;
    color: #333;
    padding: 30px 20px;
    text-align: center;
    font-family: 'Poppins', sans-serif;
    margin-top: 50px;
    border-top: 2px solid #00bcd4;
}

.custom-section h2 {
    color: #00bcd4;
    margin-bottom: 10px;
    font-size: 22px;
}

.custom-section p {
    font-size: 16px;
    margin-bottom: 15px;
}

.custom-section a.btn {
    display: inline-block;
    background-color: #00bcd4;
    color: white;
    padding: 10px 20px;
    text-decoration: none;
    font-weight: bold;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.custom-section a.btn:hover {
    background-color: #0097a7;
}

/* Scroll Reveal Animation */
.reveal-section {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s ease-in-out;
}

.reveal-section.visible {
    opacity: 1;
    transform: translateY(0);
}

.main-nav {
    background-color: #2b7a78;
    padding: 12px 20px;
    text-align: center;
}

.main-nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.main-nav a {
    color: #fff;
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s;
}

.main-nav a:hover {
    color: #ffd400;
}

.paper-viewer {
    text-align: center;
    margin: 30px auto;
}

.paper-viewer iframe {
    width: 90%;
    height: 500px;
    border-radius: 6px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.download-btn {
    display: inline-block;
    margin-top: 15px;
    background-color: #2b7a78;
    color: white;
    padding: 10px 16px;
    border-radius: 6px;
    text-decoration: none;
}

.paper-gallery {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 30px;
    flex-wrap: wrap;
}

.thumbnail {
    max-width: 180px;
    border: 2px solid #2b7a78;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.3s;
}

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

/* 🔲 Lightbox modal */
.lightbox {
    display: none;
    position: fixed;
    z-index: 999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
}

.lightbox-img {
    max-width: 90%;
    max-height: 80%;
    border-radius: 6px;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 30px;
    color: white;
    cursor: pointer;
}

.research-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: center;
    margin-top: 30px;
}

.paper-card {
    width: 300px;
    background-color: #fff;
    border: 2px solid #2b7a78;
    border-radius: 10px;
    padding: 15px;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.08);
    text-align: center;
}

.paper-card h4 {
    margin-bottom: 10px;
    color: #2b7a78;
}

.paper-card iframe {
    width: 100%;
    height: 250px;
    border-radius: 6px;
    margin-bottom: 10px;
}

.download-btn {
    background-color: #2b7a78;
    color: white;
    padding: 8px 16px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: bold;
}

.download-btn:hover {
    background-color: #205b57;
}

.paper-viewer {
    text-align: center;
    margin-top: 30px;
}

.paper-viewer iframe {
    width: 90%;
    height: 400px;
    border-radius: 6px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.download-btn {
    margin-top: 12px;
    display: inline-block;
    background-color: #2b7a78;
    color: white;
    padding: 10px 16px;
    border-radius: 6px;
    text-decoration: none;
}

.download-btn:hover {
    background-color: #205b57;
}

.paper-gallery {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 20px;
    flex-wrap: wrap;
}

.thumbnail {
    max-width: 180px;
    border: 2px solid #2b7a78;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.3s;
}

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

.lightbox {
    display: none;
    position: fixed;
    z-index: 999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
}

.lightbox-img {
    max-width: 90%;
    max-height: 80%;
    border-radius: 6px;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 30px;
    color: white;
    cursor: pointer;
}

.paper-viewer {
    text-align: center;
    margin-top: 30px;
}

.paper-viewer iframe {
    width: 90%;
    height: 400px;
    border-radius: 6px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.download-btn {
    margin-top: 12px;
    display: inline-block;
    background-color: #2b7a78;
    color: white;
    padding: 10px 16px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: bold;
}

.download-btn:hover {
    background-color: #205b57;
}

.paper-gallery {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 20px;
    flex-wrap: wrap;
}

.thumbnail {
    max-width: 180px;
    border: 2px solid #2b7a78;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.3s;
}

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

.lightbox {
    display: none;
    position: fixed;
    z-index: 999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
}

.lightbox-img {
    max-width: 90%;
    max-height: 80%;
    border-radius: 6px;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 30px;
    color: white;
    cursor: pointer;
}

body {
    user-select: none;
    -webkit-user-select: none;
}

.toast-warning {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: #f44336;
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    font-family: 'Segoe UI', sans-serif;
    font-size: 14px;
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
    z-index: 9999;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.toast-warning.show {
    opacity: 1;
}

.about-section {
    padding: 60px 20px;
    background-color: var(--bg-light);
    color: var(--text-color);
}

.section-title {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 30px;
}

.about-content {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
    justify-content: center;
}

.bio-left,
.bio-right {
    flex: 1 1 400px;
    max-width: 600px;
}

.bio-left p {
    margin: 15px 0;
    font-size: 1rem;
    line-height: 1.6;
}

.highlight-list {
    list-style-type: "✅ ";
    padding-left: 20px;
    margin: 20px 0;
}

.cta-links {
    display: flex;
    gap: 20px;
    margin-top: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.cta-btn {
    background: #1a1a1a;
    color: #fff;
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 8px;
    transition: background 0.3s ease;
}

.cta-btn:hover {
    background: #333;
}

.research-section {
    padding: 60px 20px;
    background-color: var(--bg-light);
    color: var(--text-color);
}

.research-section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 30px;
}

.research-block {
    background: #ffffff;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 30px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.08);
}

.research-block h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.research-block p {
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 15px;
}

.download-btn {
    display: inline-block;
    padding: 8px 16px;
    background-color: #1a1a1a;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    transition: background 0.3s ease;
}

.download-btn:hover {
    background-color: #333;
}

.pdf-preview iframe {
    width: 100%;
    height: 700px;
    /* চাইলে 100vh বা auto ব্যবহার করতে পারো */
    border: none;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
    border-radius: 6px;
}

.pdf-preview {
    max-width: 1000px;
    margin: 0 auto;
}

.download-btn {
    background-color: #1a1a1a;
    color: #fff;
    padding: 10px 20px;
    text-decoration: none;
    border-radius: 8px;
    display: inline-block;
    transition: background 0.3s ease;
}

.download-btn:hover {
    background-color: #333;
}