:root {
    /* Dark theme variables */
    --bg: #0a192f;
    --card: #112240;
    --muted: #8892b0;
    --accent: #64ffda;
    --glass: rgba(100, 255, 218, 0.05);
    --max-width: 1200px;
    --text-primary: #e6eef6;
    --text-secondary: #ccd6f6;
    --border-color: rgba(100, 255, 218, 0.1);
    --card-shadow: 0 10px 30px rgba(2, 6, 23, 0.7);
    --hover-shadow: 0 15px 40px rgba(2, 6, 23, 0.8);
    
    font-family: "Inter", ui-sans-serif, system-ui, -apple-system,
      "Segoe UI", Roboto, "Helvetica Neue", Arial;
}

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

body {
    background: linear-gradient(180deg, #020c1b 0%, var(--bg) 100%);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Animations */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

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

/* Base styles */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--accent);
    color: var(--bg);
    padding: 8px;
    z-index: 100;
    transition: top 0.3s;
}
.skip-link:focus {
    top: 0;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 25, 47, 0.9);
    backdrop-filter: blur(10px);
    z-index: 100;
    padding: 16px 0;
    border-bottom: 1px solid var(--border-color);
}

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

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
    transition: transform 0.3s ease;
}
.logo:hover {
    transform: scale(1.05);
}

.nav-links {
    display: flex;
    gap: 24px;
    list-style: none;
}

.nav-links a {
    color: var(--muted);
    text-decoration: none;
    transition: color 0.3s;
    font-weight: 500;
    position: relative;
}

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

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

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

/* Header */
header {
    padding-top: 120px;
    padding-bottom: 60px;
    text-align: center;
    position: relative;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    animation: fadeInUp 0.8s ease;
}

.avatar {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--accent);
    margin-bottom: 24px;
    box-shadow: 0 10px 30px rgba(100, 255, 218, 0.2);
    transition: transform 0.5s ease, box-shadow 0.5s ease;
}

.avatar:hover {
    transform: scale(1.05);
    box-shadow: 0 15px 40px rgba(100, 255, 218, 0.4);
}

h1 {
    font-size: 3rem;
    margin-bottom: 16px;
    background: linear-gradient(90deg, #ffffff, var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: fadeIn 1s ease 0.3s both;
}

.sub {
    font-size: 1.3rem;
    color: var(--muted);
    margin-bottom: 32px;
    animation: fadeIn 1s ease 0.5s both;
}

header p {
    animation: fadeIn 1s ease 0.7s both;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeIn 1s ease 0.9s both;
}

/* Sections */
section {
    padding: 80px 0;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

.section-title {
    font-size: 2.5rem;
    margin-bottom: 48px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: "";
    position: absolute;
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
}

/* Card component */
.card {
    background: var(--card);
    padding: 28px;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

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

/* About Section */
.about-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
    gap: 40px;
}

.about-text {
    text-align: left;
    max-width: 600px;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.about-image {
    width: 100%;
    max-width: 500px;
    position: relative;
    overflow: hidden;
    border-radius: 12px;
}

.about-image img {
    width: 100%;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: transform 0.5s ease;
}

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

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    max-width: 1200px;
    margin: 0 auto;
}

.skill-category {
    background: var(--glass);
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.skill-category h3 {
    color: var(--accent);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.skill-tag {
    background: rgba(100, 255, 218, 0.1);
    color: var(--accent);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.9rem;
    border: 1px solid rgba(100, 255, 218, 0.2);
    transition: all 0.3s ease;
}

.skill-tag:hover {
    background: rgba(100, 255, 218, 0.2);
    transform: scale(1.05);
}

/* Certificates */
.certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    max-width: 1200px;
    margin: 0 auto;
}

.certificate-card {
    text-align: center;
    transition: all 0.3s ease;
    background: var(--card);
    padding: 20px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
}

.certificate-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.certificate-image {
    width: 100%;
    height: 215px;
    object-fit: contain;
    border-radius: 8px;
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
    padding: 10px;
    background: var(--card);
    cursor: pointer;
    transition: all 0.3s ease;
}

.certificate-image:hover {
    transform: scale(1.03);
    border-color: var(--accent);
}

.certificate-name {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--accent);
}

.certificate-issuer {
    color: var(--muted);
    font-size: 0.9rem;
}

/* Common styles for projects and writeups */
.project-card, .writeup-card {
    position: relative;
    overflow: hidden;
    border-radius: 12px;
    height: 100%;
    background: var(--card);
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.project-card:hover, .writeup-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.project-image, .writeup-image {
    width: 100%;
    max-height: 300px;
    height: auto;
    object-fit: cover;
    border-radius: 12px 12px 0 0;
    transition: transform 0.5s ease;
}

.project-card:hover .project-image,
.writeup-card:hover .writeup-image {
    transform: scale(1.02);
}

.project-content, .writeup-content {
    padding: 24px;
    color: var(--text-primary);
}

.project-title, .writeup-title {
    font-size: 1.5rem;
    margin-bottom: 12px;
    color: var(--accent);
}

.project-description, .writeup-description {
    font-size: 1rem;
    margin-bottom: 16px;
    color: var(--text-secondary);
}

.project-tags, .writeup-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.project-tag, .writeup-tag {
    background: rgba(100, 255, 218, 0.1);
    color: var(--accent);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.8rem;
}

.project-links, .writeup-links {
    display: flex;
    gap: 12px;
    margin-top: 16px;
}

.project-link, .writeup-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--glass);
    color: var(--accent);
    border-radius: 6px;
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.project-link:hover, .writeup-link:hover {
    background: rgba(100, 255, 218, 0.2);
    transform: translateY(-2px);
}

.project-link.github-link, .writeup-link.github-link {
    background: rgba(24, 23, 23, 0.3);
}

.project-link.github-link:hover, .writeup-link.github-link:hover {
    background: rgba(24, 23, 23, 0.5);
}

/* Grid layouts */
.projects-preview, .writeups-preview {
    display: flex;
    flex-direction: column;
    gap: 30px;
    margin-bottom: 40px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.projects-grid, .writeups-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

/* Filters */
.projects-filter, .writeups-filter {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 8px 16px;
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--muted);
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover, .filter-btn.active {
    background: var(--glass);
    color: var(--accent);
    border-color: var(--accent);
}

.section-cta {
    text-align: center;
    margin-top: 40px;
}

/* Contact */
.contact-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
    max-width: 700px;
    margin: 0 auto;
    background: var(--card);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
    padding: 40px 30px;
}

.contact-info h3 {
    color: var(--accent);
    margin-bottom: 20px;
    font-size: 1.8rem;
    text-align: center;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
    transition: all 0.3s ease;
}

.contact-item:hover {
    transform: translateX(10px);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--glass);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    font-size: 1.5rem;
}

.contact-form {
    background: var(--card);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--accent);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    background: var(--glass);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(100, 255, 218, 0.1);
}

textarea.form-control {
    min-height: 150px;
    resize: vertical;
}

.form-error {
    color: #ff6b6b;
    font-size: 0.85rem;
    margin-top: 5px;
    display: none;
}

.form-group.error .form-control {
    border-color: #ff6b6b;
}

.form-group.error .form-error {
    display: block;
}

/* Footer */
footer {
    padding: 40px 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
    color: var(--muted);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.social-links a {
    color: var(--muted);
    font-size: 1.5rem;
    transition: all 0.3s ease;
    position: relative;
}

.social-links a::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

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

.social-links a:hover::after {
    width: 100%;
}

/* Modal */
.modal {
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    background: rgba(2, 6, 23, 0.85);
    z-index: 1000;
    padding: 20px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal.open {
    display: flex;
    opacity: 1;
}

.modal img {
    max-width: 95%;
    max-height: 95%;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: var(--hover-shadow);
}

.modal-close {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--accent);
    color: #0a192f;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.modal-close:hover {
    transform: rotate(90deg);
}

/* Back to top button */
.back-to-top {
    position: fixed;
    bottom: 80px;
    right: 20px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--card);
    border: 1px solid var(--border-color);
    color: var(--accent);
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99;
    box-shadow: var(--card-shadow);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

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

/* Notification toast */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--card);
    color: var(--text-primary);
    padding: 16px 24px;
    border-radius: 8px;
    box-shadow: var(--hover-shadow);
    border: 1px solid var(--border-color);
    z-index: 1001;
    opacity: 0;
    transition: all 0.3s ease;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success {
    border-left: 4px solid #4caf50;
}

.toast.error {
    border-left: 4px solid #ff6b6b;
}

/* Responsive styles */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--bg);
        flex-direction: column;
        padding: 20px;
        gap: 16px;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        box-shadow: var(--hover-shadow);
        z-index: 99;
    }
    
    .nav-links.open {
        transform: translateX(0);
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    h1 {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .about-content {
        flex-direction: column;
        gap: 30px;
    }
    
    .about-text {
        max-width: 100%;
    }
    
    .about-image {
        max-width: 100%;
    }
    
    .projects-grid, .writeups-grid {
        grid-template-columns: 1fr;
    }
    
    .certificates-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
}

@media (max-width: 576px) {
    .container {
        padding: 0 15px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .about-text p, .project-description, .writeup-description {
        font-size: 1rem;
    }
    
    .project-title, .writeup-title {
        font-size: 1.3rem;
    }
    
    .certificates-grid {
        grid-template-columns: 1fr;
    }
    
    .writeups-preview {
        grid-template-columns: 1fr;
    }
    
    .contact-container {
        padding: 30px 20px;
    }
}

@media (min-width: 769px) and (max-width: 992px) {
    .about-content {
        flex-direction: row;
        gap: 40px;
    }
    
    .about-text {
        max-width: 450px;
    }
    
    .about-image {
        max-width: 350px;
    }
    
    .certificates-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .projects-grid, .writeups-grid {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    }
    
    .writeups-preview {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 993px) {
    .about-content {
        flex-direction: row;
        gap: 60px;
    }
    
    .about-text {
        max-width: 550px;
    }
    
    .about-image {
        max-width: 450px;
    }
    
    .certificates-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .writeups-preview {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Horizontal layout for projects and writeups on desktop */
@media (min-width: 768px) {
    .project-card, .writeup-card {
        display: flex;
        flex-direction: row;
        align-items: center;
        gap: 32px;
        background: none;
        border: none;
        box-shadow: none;
        border-radius: 0;
        padding: 0;
        height: auto;
        min-height: 220px;
        overflow: visible;
    }
    
    .project-image, .writeup-image {
        width: 320px;
        height: 220px;
        flex-shrink: 0;
        border-radius: 12px;
        object-fit: cover;
        margin: 0;
        transition: transform 0.5s ease;
        transform-origin: center center;
    }
    
    .project-content, .writeup-content {
        padding: 0;
        flex: 1;
    }
    
    .projects-grid, .writeups-preview {
        grid-template-columns: 1fr;
    }
    
    .project-card:hover .project-image,
    .writeup-card:hover .writeup-image {
        transform: scale(1.03);
    }
    
    .project-card:hover, .writeup-card:hover {
        transform: none;
        box-shadow: none;
        background: none;
    }
}

/* Mobile layout for projects and writeups */
@media (max-width: 767px) {
    .projects-grid, .writeups-preview {
        grid-template-columns: 1fr;
    }
}