/* ===== CSS Variables ===== */
:root {
    --primary-blue: #4A90E2;
    --dark-blue: #357ABD;
    --light-gray: #F5F7FA;
    --medium-gray: #E8ECEF;
    --text-dark: #2C3E50;
    --text-medium: #5A6C7D;
    --text-light: #7F8C8D;
    --white: #FFFFFF;
    --border-color: #DFE6E9;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--white);
}

/* ===== Navigation ===== */
.navbar {
    position: sticky;
    top: 0;
    background-color: var(--white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    text-decoration: none;
    letter-spacing: -0.5px;
}

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

.nav-link {
    color: var(--text-medium);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-blue);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--primary-blue);
}

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

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===== Hero Section ===== */
.hero {
    padding: 6rem 0;
    background: linear-gradient(135deg, var(--light-gray) 0%, var(--white) 100%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: 1.5rem;
    font-weight: 400;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-medium);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
}

.profile-photo {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: var(--shadow-lg);
    border: 4px solid var(--white);
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background-color: var(--primary-blue);
    color: var(--white);
}

.btn-primary:hover {
    background-color: var(--dark-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background-color: var(--primary-blue);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-small {
    padding: 0.5rem 1.25rem;
    font-size: 0.9rem;
}

/* ===== Sections ===== */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    text-align: center;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-medium);
    text-align: center;
    margin-bottom: 3rem;
}

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

.about-content {
    display: grid;
    gap: 3rem;
}

.about-text {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    margin-bottom: 1.25rem;
    color: var(--text-medium);
    font-size: 1.05rem;
}

.lead {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 2rem;
}

.highlight-card {
    background-color: var(--light-gray);
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
    transition: var(--transition);
}

.highlight-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.highlight-card h3 {
    font-size: 2rem;
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
}

.highlight-card p {
    color: var(--text-medium);
    font-size: 0.95rem;
}

/* ===== Projects Section ===== */
.projects {
    background-color: var(--light-gray);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.project-card {
    background-color: var(--white);
    border-radius: 10px;
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    gap: 1rem;
}

.project-header h3 {
    font-size: 1.4rem;
    color: var(--text-dark);
    font-weight: 600;
}

.project-tag {
    background-color: var(--light-gray);
    color: var(--primary-blue);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    white-space: nowrap;
}

.project-description {
    color: var(--text-medium);
    margin-bottom: 1.5rem;
    flex-grow: 1;
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tech-badge {
    background-color: var(--medium-gray);
    color: var(--text-medium);
    padding: 0.375rem 0.75rem;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: 1rem;
}

/* ===== Skills Section ===== */
.skills {
    background-color: var(--white);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.skill-category h3 {
    color: var(--text-dark);
    font-size: 1.25rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background-color: var(--light-gray);
    color: var(--text-medium);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.skill-tag:hover {
    background-color: var(--primary-blue);
    color: var(--white);
    border-color: var(--primary-blue);
}

/* ===== Contact Section ===== */
.contact {
    background-color: var(--light-gray);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.contact-card {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.contact-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.contact-icon {
    width: 60px;
    height: 60px;
    background-color: var(--light-gray);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: var(--primary-blue);
}

.contact-card h3 {
    font-size: 1.125rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.contact-card a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.contact-card a:hover {
    color: var(--dark-blue);
    text-decoration: underline;
}

/* ===== Footer ===== */
.footer {
    background-color: var(--text-dark);
    color: var(--white);
    text-align: center;
    padding: 2rem;
}

.footer p {
    color: var(--light-gray);
    font-size: 0.95rem;
}

/* ===== Project Detail Pages ===== */
.project-detail-hero {
    background: linear-gradient(135deg, var(--light-gray) 0%, var(--white) 100%);
    padding: 4rem 0 3rem;
}

.project-detail-title {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
    font-weight: 700;
}

.project-detail-description {
    font-size: 1.125rem;
    color: var(--text-medium);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.project-detail-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.project-detail-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.project-content {
    padding: 4rem 0;
}

.content-section {
    margin-bottom: 3rem;
}

.content-section h2 {
    font-size: 2rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.content-section h3 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
}

.content-section p,
.content-section li {
    color: var(--text-medium);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.content-section ul {
    margin-left: 1.5rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.feature-item {
    background-color: var(--light-gray);
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid var(--primary-blue);
}

.feature-item h4 {
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    font-size: 1.125rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 500;
    margin-bottom: 2rem;
    transition: var(--transition);
}

.back-link:hover {
    color: var(--dark-blue);
    gap: 0.75rem;
}

/* ===== All Projects Page ===== */
.page-header {
    background: linear-gradient(135deg, var(--light-gray) 0%, var(--white) 100%);
    padding: 4rem 0 3rem;
    text-align: center;
}

.page-title {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
    font-weight: 700;
}

.page-subtitle {
    font-size: 1.125rem;
    color: var(--text-medium);
    line-height: 1.6;
    max-width: 800px;
    margin: 0 auto;
}

.all-projects-section {
    padding: 4rem 0;
    background-color: var(--white);
}

.project-item {
    background-color: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 2.5rem;
    margin-bottom: 2.5rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.project-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-blue);
}

.project-item-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.5rem;
    gap: 1rem;
    border-bottom: 2px solid var(--light-gray);
    padding-bottom: 1rem;
}

.project-item-header h2 {
    font-size: 1.75rem;
    color: var(--text-dark);
    font-weight: 600;
    margin: 0;
}

.project-item-content h3 {
    font-size: 1.25rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
    font-weight: 600;
}

.project-item-content p {
    color: var(--text-medium);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.project-item-content p strong {
    color: var(--text-dark);
    font-weight: 600;
}

.project-item-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.nav-link.active {
    color: var(--primary-blue);
}

.nav-link.active::after {
    width: 100%;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
    }

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

    .hero-title {
        font-size: 2.25rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .hero-buttons {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .profile-placeholder {
        width: 200px;
        height: 200px;
    }

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

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

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

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

    .project-detail-title {
        font-size: 2rem;
    }

    .project-detail-tech {
        gap: 0.5rem;
    }

    .project-detail-buttons {
        gap: 0.75rem;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 1rem;
    }

    .nav-menu {
        gap: 0.75rem;
        font-size: 0.9rem;
    }

    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 3rem 0;
    }

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

    section {
        padding: 3rem 0;
    }

    .btn:not(.btn-small) {
        padding: 0.75rem 1.5rem;
    }

    .project-detail-title {
        font-size: 1.75rem;
    }

    .project-detail-description {
        font-size: 1rem;
    }

    .project-detail-buttons {
        flex-direction: column;
    }

    .project-detail-buttons .btn {
        width: 100%;
        text-align: center;
    }
}