:root {
    --primary-color: #1a1a2e;
    --secondary-color: #fff;
    --background-color: #f8f9fa;
    --text-color: #333;
    --hover-color: #16213e;
    --accent-color: #4361ee;
    --accent-hover: #3a56d4;
    --card-shadow: rgba(0, 0, 0, 0.1) 0px 10px 15px -3px, rgba(0, 0, 0, 0.05) 0px 4px 6px -2px;
    --transition-speed: 0.4s;
}

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

body {
    font-family: 'Lato', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    line-height: 1.6;
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Header Styles with Animation */
header {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    padding: 0.8rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: all var(--transition-speed) ease;
}

header:hover {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

header .logo {
    margin-left: 1rem;
    transition: transform var(--transition-speed) ease;
}

header .logo:hover {
    transform: translateY(-2px);
}

header .logo span {
    font-size: 1.6rem;
    font-weight: bold;
    background: linear-gradient(90deg, var(--accent-color), #4895ef);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    transition: all var(--transition-speed) ease;
}

nav {
    margin-right: 1rem;
}

nav ul {
    list-style: none;
    padding: 0;
    display: flex;
    gap: 1.5rem;
    margin: 0;
}

nav ul li {
    margin: 0;
    position: relative;
}

nav ul li a {
    color: var(--secondary-color);
    text-decoration: none;
    padding: 0.7rem 1.2rem;
    font-size: 1.05rem;
    font-weight: 500;
    transition: all var(--transition-speed) ease;
    position: relative;
    display: inline-block;
}

nav ul li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--accent-color);
    transition: width var(--transition-speed) ease;
}

nav ul li a:hover::after {
    width: 100%;
}

nav ul li a:hover {
    color: var(--accent-color);
    transform: translateY(-2px);
}

/* Active nav link */
nav ul li a.active,
nav ul li a[aria-current="page"] {
    color: var(--accent-color);
}
nav ul li a.active::after,
nav ul li a[aria-current="page"]::after {
    width: 100%;
}

/* Section Styles */
section {
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
}

section h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 2.5rem;
    position: relative;
    display: inline-block;
}

section h2::after {
    content: '';
    position: absolute;
    width: 50%;
    height: 3px;
    bottom: -10px;
    left: 25%;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
}

/* Category Filter Bar */
.projects-filter {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    align-items: center;
    margin: 1rem auto 2rem;
}

.filter-btn {
    border: 1px solid #d9def2;
    background: #fff;
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 999px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
}

.filter-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.08);
}

.filter-btn.active {
    background: var(--accent-color);
    color: #fff;
    border-color: var(--accent-color);
}

/* Subsections */
.projects-section {
    max-width: 1200px;
    margin: 0 auto 2.5rem;
    text-align: left;
}

.projects-section .section-subtitle {
    font-size: 1.6rem;
    color: var(--primary-color);
    margin: 0 0 1.2rem 0.25rem;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto 4rem;
}

.project-preview {
    background-color: var(--secondary-color);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-speed) ease;
    opacity: 0;
    transform: translateY(20px);
}

.project-preview.visible {
    opacity: 1;
    transform: translateY(0);
}

.project-preview:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.preview-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    position: relative;
}

.project-tag {
    position: absolute;
    top: 10px;
    left: 10px;
    background: rgba(26,26,46,0.85);
    color: #fff;
    font-size: 0.75rem;
    letter-spacing: 0.02em;
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
    z-index: 1;
}

.preview-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.project-preview:hover .preview-image img {
    transform: scale(1.1);
}

.preview-content {
    padding: 1.5rem;
    text-align: left;
}

.preview-content h3 {
    font-size: 1.4rem;
    margin-bottom: 0.8rem;
    color: var(--primary-color);
}

.preview-content p {
    font-size: 0.95rem;
    color: #666;
    margin-bottom: 1.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    height: 4.5rem;
}

.preview-content .learn-more {
    display: inline-block;
    padding: 0.6rem 1.2rem;
    background-color: var(--accent-color);
    color: white;
    text-decoration: none;
    border-radius: 30px;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all var(--transition-speed) ease;
    box-shadow: 0 4px 10px rgba(67, 97, 238, 0.2);
}

.preview-content .learn-more:hover {
    background-color: var(--accent-hover);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(67, 97, 238, 0.3);
}

/* Project Detail Section */
.project-details {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0;
    display: none;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.5s ease;
}

.project-details.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.details-container {
    background-color: var(--secondary-color);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    margin-bottom: 3rem;
}

.details-header {
    padding: 2rem;
    background-color: var(--primary-color);
    color: var(--secondary-color);
    position: relative;
}

.details-header h3 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.close-details {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    font-size: 1.5rem;
    color: var(--secondary-color);
    background: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.close-details:hover {
    transform: rotate(90deg);
    color: #ff6b6b;
}

.details-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    padding: 2rem;
}

.photos-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.main-photo {
    width: 100%;
    height: 300px;
    border-radius: 10px;
    overflow: hidden;
}

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

.main-photo:hover img {
    transform: scale(1.05);
}

/* Video container styles */
.main-photo video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    background-color: #000;
    border-radius: 10px;
}

/* Thumbnail styles */
.photo-gallery {
    display: flex;
    gap: 0.8rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.photo-gallery .thumbnail {
    width: 80px;
    height: 80px;
    position: relative;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 8px;
    overflow: hidden;
    border: 2px solid transparent;
}

.photo-gallery .thumbnail.active {
    border-color: var(--accent-color);
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

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

.photo-gallery .video-thumbnail::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.3);
}

.photo-gallery .video-thumbnail i {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 24px;
    z-index: 2;
}

.details-text {
    text-align: left;
}

.details-text p {
    margin-bottom: 1rem;
    font-size: 1.05rem;
    line-height: 1.7;
}

.view-full-photo {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.6rem 1.2rem;
    background-color: var(--accent-color);
    color: white;
    text-decoration: none;
    border-radius: 30px;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all var(--transition-speed) ease;
    box-shadow: 0 4px 10px rgba(67, 97, 238, 0.2);
}

.view-full-photo:hover {
    background-color: var(--accent-hover);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(67, 97, 238, 0.3);
}

/* Modal Enhancements */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity var(--transition-speed) ease;
}

.modal.show {
    opacity: 1;
}

.modal-content {
    max-width: 90%;
    max-height: 90%;
    border-radius: 8px;
    box-shadow: 0 5px 30px rgba(0, 0, 0, 0.3);
    transform: scale(0.9);
    transition: all var(--transition-speed) ease;
}

.modal.show .modal-content {
    transform: scale(1);
}

.modal-content video {
    max-width: 100%;
    max-height: 90vh;
    background-color: #000;
    border-radius: 8px;
}

.close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #fff;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
    opacity: 0.8;
    transition: all var(--transition-speed) ease;
}

.close:hover,
.close:focus {
    color: var(--accent-color);
    opacity: 1;
    transform: rotate(90deg);
}

/* Enhanced Footer */
footer {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    text-align: center;
    padding: 2rem 0;
    margin-top: auto;
}

footer ul {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

footer ul li {
    margin: 0 15px;
    transition: all var(--transition-speed) ease;
}

footer ul li:hover {
    transform: translateY(-3px);
}

footer ul li a {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 1.1rem;
    position: relative;
    padding: 5px 0;
    transition: all var(--transition-speed) ease;
}

footer ul li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--accent-color);
    transition: width var(--transition-speed) ease;
}

footer ul li a:hover {
    color: var(--accent-color);
}

footer ul li a:hover::after {
    width: 100%;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: var(--accent-color);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    text-decoration: none;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
}

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

.back-to-top:hover {
    background-color: var(--accent-hover);
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3);
}

/* Responsive styles */
@media (max-width: 992px) {
    .details-content {
        grid-template-columns: 1fr;
    }
    
    .main-photo {
        height: 250px;
    }
}

@media (max-width: 768px) {
    .projects-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
    .projects-section .section-subtitle {
        margin-left: 0;
        text-align: center;
    }
    
    section {
        padding: 3rem 1.5rem;
    }
    
    header {
        padding: 0.5rem 1rem;
    }
    
    nav ul {
        gap: 0.7rem;
    }
    
    nav ul li a {
        padding: 0.5rem 0.8rem;
        font-size: 0.95rem;
    }
}

@media (max-width: 576px) {
    header {
        flex-direction: column;
        height: auto;
        padding: 1rem;
    }
    
    header .logo {
        margin-bottom: 1rem;
        margin-left: 0;
    }
    
    nav {
        margin-right: 0;
    }
    
    section h2 {
        font-size: 2rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .details-header h3 {
        font-size: 1.5rem;
    }
}