:root {
    /* Leather Black & Orange Theme */
    --bg-main: #121212;
    --bg-card: #1A1A1A;
    --text-primary: #F3F4F6;
    --text-secondary: #9CA3AF;
    --accent: #F9A826; /* Photo Golden Orange */
    --accent-hover: #E69213;
    --border-color: #2D2D2D;
    
    /* Layout */
    --nav-height: 80px;
    --container-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-main);
    line-height: 1.6;
}

body {
    overflow-x: hidden;
    animation: fadeInPage 0.4s ease-out forwards;
}

@keyframes fadeInPage {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

body.no-scroll {
    overflow: hidden;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 {
    font-size: 3.5rem;
    letter-spacing: -1px;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

/* Layout Utilities */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 6rem 0;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--nav-height);
    background: rgba(18, 18, 18, 0.95); /* Matches --bg-main */
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

nav.scrolled {
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.nav-content {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: 1px;
}

.logo span {
    color: var(--accent);
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    transition: color 0.3s;
}

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

.nav-links a.active-link {
    position: relative;
}

.nav-links a.active-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--accent);
    border-radius: 2px;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: calc(var(--nav-height) + 2rem);
    background-color: var(--bg-card);
}

.hero .hero-content {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    gap: 4rem;
}

.hero-content > div:first-child {
    flex: 1;
}

.hero h1 {
    margin-bottom: 1rem;
    font-size: 3rem;
    font-weight: 800;
}

.hero h2 {
    font-size: 1.5rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.hero p {
    font-size: 1.1rem;
    max-width: 600px;
    margin-bottom: 2rem;
}

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

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 4px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    border: 2px solid transparent;
}

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

.primary-btn:hover {
    background-color: var(--accent-hover);
}

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

.secondary-btn:hover {
    background-color: var(--text-primary);
    color: white;
}

/* Profile Image */
.hero-image {
    flex-shrink: 0;
}

.profile-placeholder {
    width: 320px;
    height: 320px;
    border-radius: 50%;
    background-color: var(--bg-main);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 8px solid var(--bg-card);
    box-shadow: 0 10px 30px rgba(0,0,0,0.5); /* Stronger shadow for dark mode */
    overflow: hidden;
}

.placeholder-text {
    font-size: 4rem;
    font-weight: 800;
    color: #cbd5e1;
}

.profile-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: none;
}

.profile-placeholder.has-image .placeholder-text {
    display: none;
}

.profile-placeholder.has-image img {
    display: block;
}

/* Section Titles */
.section-title {
    text-align: center;
    margin-bottom: 4rem;
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background-color: var(--accent);
    border-radius: 2px;
}

/* About Grid */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.education-timeline {
    border-left: 2px solid var(--border-color);
    padding-left: 2rem;
}

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.6rem;
    top: 0;
    width: 1rem;
    height: 1rem;
    background-color: var(--bg-card);
    border: 3px solid var(--accent);
    border-radius: 50%;
}

.timeline-item h3 {
    font-size: 1.2rem;
    margin-bottom: 0.3rem;
}

.timeline-item .institution {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.2rem;
}

.timeline-item .date {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Skills Grid */
.skills {
    background-color: var(--bg-card);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-card {
    background: var(--bg-main);
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

.skill-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.skill-card h3 {
    font-size: 1.1rem;
}

/* Projects Timeline */
.project-timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding-left: 3rem;
    border-left: 3px solid var(--border-color);
    margin-bottom: 4rem;
}

.project-timeline .project-card {
    position: relative;
    background: var(--bg-card);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    padding: 2.5rem;
    margin-bottom: 3rem;
    transition: all 0.3s ease;
}

.project-timeline .project-card::before {
    content: '';
    position: absolute;
    left: -3.65rem;
    top: 2.5rem;
    width: 1.2rem;
    height: 1.2rem;
    background-color: var(--bg-main);
    border: 4px solid var(--accent);
    border-radius: 50%;
    z-index: 1;
}

.project-timeline .project-card:hover {
    box-shadow: 0 15px 30px rgba(0,0,0,0.08);
    transform: translateY(-5px);
}

.project-timeline .project-card:hover::before {
    background-color: var(--accent);
    transform: scale(1.2);
    transition: all 0.3s ease;
}

.project-card h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.project-card p {
    margin-bottom: 1.5rem;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.tags span {
    padding: 0.4rem 1rem;
    background: var(--bg-main);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* Achievements */
.achievements {
    background: var(--bg-card);
    padding: 3rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.achievements h3 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.achievements ul {
    list-style-position: inside;
    color: var(--text-secondary);
}

.achievements li {
    margin-bottom: 0.8rem;
    font-size: 1.1rem;
}

.achievements strong {
    color: var(--text-primary);
}

/* Contact */
.contact {
    background-color: var(--bg-card);
}

.contact-card {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-main);
    padding: 4rem;
    border-radius: 8px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.contact-info {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin: 3rem 0;
    flex-wrap: wrap;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.info-item a, .info-item span {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
}

.info-item a:hover {
    color: var(--accent);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.social-icon {
    padding: 0.8rem 2rem;
    background: var(--bg-card);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.social-icon:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
}

/* Hamburger */
.hamburger {
    display: none;
    cursor: pointer;
}

.hamburger .line {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 5px;
    transition: all 0.3s;
}

/* Animations */
.fade-up, .fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in {
    transform: translateY(0);
}

.fade-up.visible, .fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }

/* Responsive */
@media (max-width: 968px) {
    .hero {
        padding-top: calc(var(--nav-height) + 4rem);
    }
    
    .hero .hero-content {
        flex-direction: column-reverse;
        text-align: center;
        padding-top: 2rem;
    }

    .hero-buttons {
        justify-content: center;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }

    .contact-info {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        right: -100%;
        top: var(--nav-height);
        flex-direction: column;
        background: var(--bg-card);
        width: 100%;
        text-align: center;
        padding: 2rem 0;
        transition: 0.3s;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.active {
        right: 0;
    }

    .hamburger {
        display: block;
    }

    .hamburger.active .line:nth-child(1) {
        transform: rotate(-45deg) translate(-5px, 6px);
    }
    
    .hamburger.active .line:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active .line:nth-child(3) {
        transform: rotate(45deg) translate(-5px, -6px);
    }

    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }

    .profile-placeholder {
        width: 250px;
        height: 250px;
    }
}

/* Contact Cards Grid Layout */
.contact-method-card:hover {
    transform: translateY(-10px) !important;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.5) !important;
    border-color: var(--accent) !important;
}

/* Home Page Overview Cards */
.overview-card:hover, .project-card:hover, .skill-card:hover, .collaborator-card:hover {
    transform: translateY(-5px) !important;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.5) !important;
    border-color: var(--accent) !important;
}

/* Custom Cursor */
@media (pointer: fine) {
    body, a, button, input, textarea, .btn, .project-card, .overview-card, .contact-method-card {
        cursor: none !important;
    }
}

.cursor-minimal {
    position: fixed;
    top: 0;
    left: 0;
    width: 6px;
    height: 6px;
    background-color: var(--text-primary);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 9999;
    transition: transform 0.15s ease, background-color 0.15s ease;
}

.cursor-minimal.hover {
    transform: translate(-50%, -50%) scale(2);
    background-color: var(--accent);
}