:root {
    --dark-navy: #121212;
    --navy: #1e1e1e;
    --light-navy: #2a2a2a;
    --slate: #8892b0;
    --light-slate: #a8b2d1;
    --white: #e6f1ff;
    --cyan: #64ffda;
    --purple: #bd34fe;

    --font-sans: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    --transition: all 0.25s cubic-bezier(0.645, 0.045, 0.355, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--dark-navy);
    color: var(--slate);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
    cursor: none;
}

/* Custom Cursor */
.cursor-dot,
.cursor-outline {
    position: fixed;
    top: 0;
    left: 0;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    z-index: 9999;
    pointer-events: none;
}

.cursor-dot {
    width: 8px;
    height: 8px;
    background-color: var(--cyan);
}

.cursor-outline {
    width: 40px;
    height: 40px;
    border: 2px solid var(--cyan);
    transition: width 0.2s, height 0.2s, background-color 0.2s;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 12px;
}

::-webkit-scrollbar-track {
    background: var(--dark-navy);
}

::-webkit-scrollbar-thumb {
    background-color: var(--navy);
    border: 3px solid var(--dark-navy);
    border-radius: 10px;
}

/* Navigation */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 50px;
    background-color: rgba(18, 18, 18, 0.9);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
    transition: var(--transition);
}

.logo {
    color: var(--cyan);
    font-family: var(--font-mono);
    font-size: 24px;
    font-weight: 700;
    cursor: pointer;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links li {
    margin: 0 5px;
}

.nav-links a {
    color: var(--light-slate);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 13px;
    transition: var(--transition);
}

.nav-links a:hover {
    color: var(--cyan);
}

.nav-links a::before {
    content: '<';
    color: var(--cyan);
    margin-right: 5px;
    opacity: 0;
    transition: var(--transition);
}

.nav-links a::after {
    content: '/>';
    color: var(--cyan);
    margin-left: 5px;
    opacity: 0;
    transition: var(--transition);
}

.nav-links a:hover::before,
.nav-links a:hover::after {
    opacity: 1;
}

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

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background-color: var(--cyan);
    transition: var(--transition);
}

/* Sections */
main {
    padding: 0 150px;
}

.section {
    padding: 100px 0;
    max-width: 1000px;
    margin: 0 auto;
}

.section-header {
    display: flex;
    align-items: center;
    margin-bottom: 40px;
}

.section-number {
    font-family: var(--font-mono);
    color: var(--cyan);
    font-size: 20px;
    margin-right: 10px;
}

.section-header h3 {
    color: var(--white);
    font-size: 32px;
    white-space: nowrap;
}

.line {
    height: 1px;
    background-color: var(--light-navy);
    width: 300px;
    margin-left: 20px;
}

/* Hero Section */
#hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding-top: 50px;
}

.hero-content {
    max-width: 1000px;
}

.profile-container {
    margin-bottom: 30px;
    margin-top: 40px;
    position: relative;
    width: 150px;
    height: 150px;
}

.profile-img {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--cyan);
    position: relative;
    z-index: 2;
    filter: grayscale(100%);
    transition: var(--transition);
}

.profile-container:hover .profile-img {
    filter: none;
}

.profile-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 160px;
    height: 160px;
    border-radius: 50%;
    background: var(--cyan);
    opacity: 0.2;
    filter: blur(20px);
    z-index: 1;
    animation: pulse 3s infinite;
}

@keyframes pulse {
    0% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 0.2;
    }

    50% {
        transform: translate(-50%, -50%) scale(1.1);
        opacity: 0.4;
    }

    100% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 0.2;
    }
}

h1 {
    font-size: 70px;
    color: var(--white);
    font-weight: 600;
    margin-bottom: 10px;
    position: relative;
}

h2 {
    font-size: 50px;
    color: var(--slate);
    font-weight: 600;
    margin-bottom: 20px;
}

.hero-tagline {
    font-size: 18px;
    max-width: 540px;
    margin-bottom: 40px;
    color: var(--slate);
}

.cta-buttons {
    display: flex;
    gap: 20px;
}

.btn {
    padding: 1.25rem 1.75rem;
    font-family: var(--font-mono);
    font-size: 14px;
    text-decoration: none;
    border-radius: 4px;
    transition: var(--transition);
    cursor: pointer;
}

.btn.primary {
    color: var(--cyan);
    border: 1px solid var(--cyan);
    background: transparent;
}

.btn.primary:hover {
    background: rgba(100, 255, 218, 0.1);
}

.btn.secondary {
    color: var(--slate);
    border: 1px solid var(--light-navy);
}

.btn.secondary:hover {
    color: var(--cyan);
    border-color: var(--cyan);
}

/* About Section */
.about-content {
    display: block;
    max-width: 800px;
}

.text-block p {
    margin-bottom: 15px;
    font-size: 17px;
}

.education-block {
    margin: 30px 0;
    padding: 20px;
    background: var(--navy);
    border-radius: 4px;
    border-left: 3px solid var(--cyan);
}

.education-block h4 {
    color: var(--white);
    margin-bottom: 5px;
    font-size: 18px;
}

.education-block .school {
    color: var(--cyan);
    font-family: var(--font-mono);
    font-size: 14px;
    margin-bottom: 2px;
}

.education-block .degree,
.education-block .gpa {
    font-size: 14px;
    color: var(--light-slate);
    margin-bottom: 0px;
}

.highlight {
    color: var(--cyan);
}

.tech-stack {
    display: grid;
    grid-template-columns: repeat(2, minmax(140px, 200px));
    gap: 15px;
    margin-top: 20px;
    list-style: none;
}

.tech-stack li {
    font-family: var(--font-mono);
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.tech-stack li i {
    color: var(--cyan);
    font-size: 12px;
}

/* Experience Section */
.timeline {
    border-left: 2px solid var(--light-navy);
    margin-left: 10px;
    padding-left: 20px;
}

.timeline-item {
    margin-bottom: 40px;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -26px;
    top: 5px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--cyan);
    border: 2px solid var(--dark-navy);
}

.timeline-header h4 {
    color: var(--white);
    font-size: 20px;
    margin-bottom: 5px;
}

.company {
    color: var(--cyan);
}

.date {
    display: block;
    font-family: var(--font-mono);
    font-size: 13px;
    margin-bottom: 15px;
}

.job-description li {
    margin-bottom: 10px;
    list-style-type: none;
    position: relative;
    padding-left: 20px;
}

.job-description li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--cyan);
    line-height: 1.6;
}

/* ═══════════════════════════════════════════
   Problems Solved — Two-Level Accordion
   ═══════════════════════════════════════════ */
.problems-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* ── Level 1: Problem Card ── */
.problem-card {
    background: var(--navy);
    border: 1px solid var(--light-navy);
    border-radius: 6px;
    overflow: hidden;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.problem-card:hover {
    border-color: rgba(100, 255, 218, 0.3);
}

.problem-card.active {
    border-color: var(--cyan);
    box-shadow: 0 4px 20px rgba(100, 255, 218, 0.05);
}

.problem-header {
    padding: 22px 28px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    gap: 20px;
}

.problem-title-row {
    display: flex;
    align-items: flex-start;
    gap: 18px;
}

.problem-num {
    font-family: var(--font-mono);
    color: var(--cyan);
    font-size: 14px;
    font-weight: 700;
    min-width: 24px;
    padding-top: 2px;
}

.problem-header h4 {
    color: var(--light-slate);
    font-size: 17px;
    font-weight: 600;
    margin: 0;
    line-height: 1.4;
    transition: color 0.3s ease;
}

.problem-card.active .problem-header h4 {
    color: var(--white);
}

.problem-context {
    display: block;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--slate);
    margin-top: 4px;
}

.problem-chevron {
    color: var(--cyan);
    font-size: 14px;
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.problem-card.active .problem-chevron {
    transform: rotate(180deg);
}

.problem-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Level 2: Nested Sections ── */
.nested-section {
    margin: 0 28px;
    border-top: 1px solid var(--light-navy);
}

.nested-section:last-of-type {
    border-bottom: 1px solid var(--light-navy);
}

.nested-header {
    padding: 16px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
}

.nested-header h5 {
    color: var(--light-slate);
    font-size: 14px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 0;
    transition: color 0.3s ease;
}

.nested-section.active .nested-header h5 {
    color: var(--white);
}

.nested-header h5 .fa-exclamation-circle {
    color: #f87171;
    font-size: 13px;
}

.nested-header h5 .fa-lightbulb {
    color: var(--cyan);
    font-size: 13px;
}

.nested-header h5 .fa-chart-line {
    color: var(--purple);
    font-size: 13px;
}

.nested-icon {
    color: var(--slate);
    font-size: 12px;
    transition: transform 0.3s ease, color 0.3s ease;
}

.nested-section.active .nested-icon {
    transform: rotate(45deg);
    color: var(--cyan);
}

.nested-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.nested-body p {
    font-size: 14px;
    color: var(--light-slate);
    margin-bottom: 12px;
    line-height: 1.6;
}

.nested-body ul {
    list-style: none;
    padding: 0;
    margin: 0 0 20px 0;
}

.nested-body ul li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
    font-size: 14px;
    color: var(--slate);
    line-height: 1.6;
}

.nested-body ul li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--cyan);
}

.nested-body ul li strong {
    color: var(--white);
    font-weight: 600;
}

/* Tech Tags (shared) */
.problem-tags,
.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 18px 28px;
}

.problem-tags span,
.project-tags span {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--cyan);
    background: rgba(100, 255, 218, 0.08);
    padding: 4px 12px;
    border-radius: 20px;
    border: 1px solid rgba(100, 255, 218, 0.15);
}

/* ═══════════════════════════════════════════
   Projects — Clean Expandable Cards
   ═══════════════════════════════════════════ */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    align-items: start;
}

.project-item {
    background: var(--navy);
    border: 1px solid var(--light-navy);
    border-radius: 6px;
    overflow: hidden;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.project-item:hover {
    border-color: rgba(100, 255, 218, 0.3);
}

.project-item.active {
    border-color: var(--cyan);
    box-shadow: 0 4px 20px rgba(100, 255, 218, 0.05);
}

.project-item-header {
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    gap: 16px;
}

.project-item-header .project-title-row {
    display: flex;
    align-items: center;
    gap: 14px;
}

.project-num {
    font-family: var(--font-mono);
    color: var(--slate);
    font-size: 12px;
    font-weight: 700;
}

.project-item-header h4 {
    color: var(--light-slate);
    font-size: 16px;
    font-weight: 600;
    margin: 0;
    transition: color 0.3s ease;
}

.project-item.active .project-item-header h4 {
    color: var(--white);
}

.project-header-right {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-shrink: 0;
}

.project-badge {
    font-family: var(--font-mono);
    font-size: 10px;
    font-weight: 700;
    padding: 3px 10px;
    border-radius: 20px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-badge.deployed {
    color: var(--cyan);
    border: 1px solid rgba(100, 255, 218, 0.3);
}

.project-badge.optimized {
    color: #60a5fa;
    border: 1px solid rgba(96, 165, 250, 0.3);
}

.project-badge.research {
    color: var(--purple);
    border: 1px solid rgba(189, 52, 254, 0.3);
}

.project-badge.complete {
    color: var(--light-slate);
    border: 1px solid rgba(168, 178, 209, 0.3);
}

.project-chevron {
    color: var(--cyan);
    font-size: 13px;
    transition: transform 0.3s ease;
}

.project-item.active .project-chevron {
    transform: rotate(180deg);
}

.project-item-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 0 24px;
}

.project-item.active .project-item-body {
    padding-bottom: 20px;
}

.project-item-body p {
    font-size: 14px;
    color: var(--slate);
    line-height: 1.6;
    padding-top: 4px;
    border-top: 1px solid var(--light-navy);
    margin-bottom: 16px;
}

.project-item-body p strong {
    color: var(--white);
}

.project-tags {
    padding: 0;
}

/* Achievements Section */
.achievements-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
}

.achievement-card {
    background-color: var(--navy);
    padding: 20px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: var(--transition);
    border: 1px solid transparent;
}

.achievement-card:hover {
    border-color: var(--cyan);
    transform: translateY(-5px);
}

.achievement-icon {
    font-size: 24px;
    color: var(--cyan);
    background: rgba(100, 255, 218, 0.1);
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.achievement-text h4 {
    color: var(--white);
    font-size: 14px;
    margin-bottom: 2px;
}

.achievement-text p {
    color: var(--light-slate);
    font-size: 13px;
    font-family: var(--font-mono);
}

/* Contact Section */
.contact-section {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 100px;
}

.contact-section p {
    margin-bottom: 30px;
    font-size: 18px;
}

.contact-section .btn {
    display: inline-block;
    margin-bottom: 10px;
}

.centered {
    justify-content: center;
}

.title {
    font-size: 40px;
    color: var(--white);
    margin-bottom: 20px;
}

.contact-text {
    margin-bottom: 40px;
    font-size: 18px;
}

.big-btn {
    padding: 1.25rem 2rem;
    font-size: 16px;
}

.social-links {
    margin-top: 50px;
    display: flex;
    justify-content: center;
    gap: 30px;
}

.social-links a {
    color: var(--slate);
    font-size: 22px;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--cyan);
    transform: translateY(-3px);
}

/* Footer */
footer {
    display: flex;
    justify-content: center;
    padding: 20px;
    background-color: var(--dark-navy);
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--slate);
}

/* Responsive */
@media (max-width: 1080px) {
    main {
        padding: 0 100px;
    }
}

@media (max-width: 768px) {
    main {
        padding: 0 50px;
    }

    .navbar {
        padding: 20px 30px;
    }

    .nav-links {
        display: none;
    }

    .hamburger {
        display: block;
    }

    .section-header h3 {
        font-size: 24px;
    }

    h1 {
        font-size: 40px;
    }

    h2 {
        font-size: 30px;
    }

    .achievements-container {
        grid-template-columns: 1fr;
    }

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

    .problem-header {
        padding: 18px 20px;
    }

    .nested-section {
        margin: 0 20px;
    }

    .problem-tags {
        padding: 16px 20px;
    }

    .problem-header h4 {
        font-size: 15px;
    }
}

@media (max-width: 480px) {
    main {
        padding: 0 25px;
    }

    .section {
        padding: 60px 0;
    }

    h1 {
        font-size: 32px;
    }

    h2 {
        font-size: 24px;
    }

    .problem-title-row {
        gap: 12px;
    }

    .problem-num {
        font-size: 12px;
    }
}