:root {
    --bg-color: #0f172a; /* Soft dark background */
    --surface-color: #1e293b; /* Slightly lighter for cards */
    --accent-color: #38bdf8; /* Soft blue/cyan */
    --accent-hover: #0ea5e9;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    
    --font-stack: 'Inter', system-ui, -apple-system, sans-serif;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 4rem;
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-stack);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4 {
    color: var(--text-main);
    font-weight: 600;
    line-height: 1.2;
}

p {
    color: var(--text-muted);
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: var(--transition);
}

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

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: 6rem 0;
}

.section-title {
    font-size: 2rem;
    margin-bottom: var(--spacing-xl);
    text-align: center;
    position: relative;
    background: linear-gradient(135deg, var(--accent-color), #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
    width: 100%;
}

.section-desc {
    text-align: center;
    margin-top: -2rem;
    margin-bottom: 3rem;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: transparent;
    transition: background-color 0.3s ease, backdrop-filter 0.3s ease, border-color 0.3s ease;
    z-index: 100;
    border-bottom: 1px solid transparent;
}

.navbar.scrolled {
    background-color: rgba(15, 23, 42, 0.85);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent-color);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: var(--spacing-lg);
}

.nav-links a {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.nav-links a:hover, .nav-links a.active-link {
    color: var(--text-main);
    text-shadow: 0 0 10px rgba(56, 189, 248, 0.6);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.nav-toggle .bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-main);
    border-radius: 3px;
    transition: all 0.3s ease-in-out;
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    #nav-menu {
        position: absolute;
        top: 70px;
        right: -100%;
        background-color: rgba(15, 23, 42, 0.95);
        -webkit-backdrop-filter: blur(10px);
        backdrop-filter: blur(10px);
        width: 100%;
        height: calc(100vh - 70px);
        transition: right 0.3s ease;
        border-top: 1px solid var(--border-color);
        display: flex;
        justify-content: center;
        align-items: flex-start;
        padding-top: 2rem;
    }
    
    #nav-menu.nav-active {
        right: 0;
    }
    
    .nav-links {
        flex-direction: column;
        align-items: center;
        gap: var(--spacing-xl);
    }
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #0f172a;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    color: #0f172a;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.btn-secondary {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
}

.btn-secondary:hover {
    border-color: var(--text-muted);
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
    position: relative;
}

.hero-orb {
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(56,189,248,0.15) 0%, rgba(168,85,247,0.05) 50%, rgba(0,0,0,0) 70%);
    border-radius: 50%;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    filter: blur(40px);
    z-index: -1;
    pointer-events: none;
}

.hero-content {
    max-width: 800px;
    position: relative;
    z-index: 1;
}

.greeting {
    color: var(--accent-color);
    font-weight: 500;
    margin-bottom: 0;
}

.display-name {
    font-size: clamp(3rem, 5vw, 4.5rem);
    margin-bottom: 0;
    line-height: 1.1;
    background: linear-gradient(135deg, var(--accent-color), #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.role {
    font-size: clamp(1.5rem, 3vw, 2.5rem);
    color: var(--text-muted);
    margin-bottom: var(--spacing-sm);
}

.tagline {
    font-size: 1.1rem;
    max-width: 600px;
    margin-bottom: var(--spacing-lg);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
}

/* About Section */
.about-content {
    background: var(--surface-color);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

/* Projects Section */
.projects-grid {
    display: grid;
    gap: var(--spacing-lg);
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .project-card.featured {
        grid-column: 1 / -1;
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-lg);
        align-items: center;
    }
}

.project-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(56, 189, 248, 0.2);
    border-color: var(--accent-color);
}

.project-img-placeholder {
    height: 200px;
    background: #253347;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
}

.featured .project-img-placeholder {
    height: 100%;
    min-height: 300px;
}

.project-info {
    padding: var(--spacing-lg);
}

.featured-badge {
    display: inline-block;
    font-size: 0.8rem;
    color: var(--accent-color);
    background: rgba(56, 189, 248, 0.1);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    margin-bottom: var(--spacing-sm);
}

.problem, .solution {
    font-size: 0.9rem;
    margin: var(--spacing-sm) 0;
}

.tech-stack {
    display: flex;
    gap: var(--spacing-sm);
    margin: var(--spacing-md) 0;
}

.tech-stack span {
    font-size: 0.8rem;
    color: var(--text-muted);
    background: #0f172a;
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
}

.project-link {
    font-size: 0.9rem;
    font-weight: 500;
}

/* Learning Log */
.timeline {
    border-left: 2px solid var(--border-color);
    padding-left: var(--spacing-lg);
    margin-left: var(--spacing-md);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-lg);
}

.timeline-item::before {
    content: '';
    position: absolute;
    width: 12px;
    height: 12px;
    background: var(--accent-color);
    border-radius: 50%;
    left: calc(-2rem - 7px);
    top: 5px;
}

.timeline-date {
    font-size: 0.85rem;
    color: var(--accent-color);
    margin-bottom: var(--spacing-sm);
}

.timeline-content {
    background: var(--surface-color);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.timeline-content h4 {
    margin-bottom: var(--spacing-sm);
}

.timeline-content p {
    font-size: 0.9rem;
}

/* Skills */
.skills-wrapper {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.skill-category {
    background: var(--surface-color);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.skill-category h3 {
    margin-bottom: var(--spacing-md);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-tag {
    background: #0f172a;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.9rem;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.skill-tag:hover {
    border-color: var(--accent-color);
    color: var(--text-main);
}

.skill-tag.highlight {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background: rgba(56, 189, 248, 0.05);
}

/* Certificates */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.cert-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
}

.cert-card:hover {
    transform: scale(1.02);
    border-color: var(--accent-color);
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.15);
}

.cert-img-placeholder {
    height: 160px;
    background: #253347;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
}

.cert-info {
    padding: var(--spacing-md);
}

.cert-info h4 {
    font-size: 1rem;
}

.cert-info p {
    font-size: 0.85rem;
}

/* Experiment Zone */
.experiment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: var(--spacing-md);
}

.exp-card {
    background: var(--surface-color);
    padding: 1.25rem;
    border-radius: var(--border-radius);
    border: 1px dashed var(--border-color);
    transition: var(--transition);
    text-decoration: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    cursor: pointer;
}

.exp-card:hover {
    border-color: var(--accent-color);
    border-style: solid;
    background: #1e293b;
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(56, 189, 248, 0.15);
}

.exp-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 0.5rem;
    margin-bottom: 0.6rem;
}

.exp-card h4 {
    font-size: 1rem;
    color: var(--text-main);
    word-break: break-word;
    line-height: 1.3;
}

.exp-stars {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    background: rgba(234, 179, 8, 0.15);
    color: #facc15;
    font-size: 0.8rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 12px;
    white-space: nowrap;
    border: 1px solid rgba(234, 179, 8, 0.25);
}

.exp-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.5;
    margin-bottom: 0.75rem;
    flex-grow: 1;
}

.exp-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    margin-top: auto;
    padding-top: 0.6rem;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.exp-lang {
    background: #0f172a;
    color: var(--accent-color);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
}

.exp-link-icon {
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: transform 0.2s ease, color 0.2s ease;
}

.exp-card:hover .exp-link-icon {
    color: var(--accent-color);
    transform: translateX(4px);
}

/* Resources */
.resource-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.resource-link {
    font-size: 1.1rem;
    color: var(--text-muted);
    padding-bottom: 4px;
    position: relative;
}

.resource-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width 0.3s ease;
}

.resource-link:hover {
    color: var(--text-main);
}

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

/* Contact */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
}

@media (min-width: 768px) {
    .contact-wrapper {
        grid-template-columns: 1fr 1fr;
    }
}

.contact-email {
    font-size: 1.2rem;
    display: inline-block;
    margin-top: var(--spacing-md);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-form input,
.contact-form textarea {
    background: #0f172a;
    border: 1px solid var(--border-color);
    padding: 0.8rem;
    border-radius: 6px;
    color: var(--text-main);
    font-family: inherit;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

/* Footer */
footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Utilities & Animations */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

.fade-in {
    animation: fadeIn 1s ease-out forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.cursor {
    display: inline-block;
    width: 3px;
    height: 1em;
    background-color: var(--accent-color);
    margin-left: 2px;
    vertical-align: text-bottom;
    animation: blink 1s step-end infinite;
}

@keyframes blink {
    from, to { opacity: 1; }
    50% { opacity: 0; }
}