:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary: #0f172a;
  --accent: #06b6d4;
  --bg-light: #f8fafc;
  --bg-dark: #0f172a;
  --text-light: #334155;
  --text-dark: #e2e8f0;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --font: Inter, system-ui, sans-serif;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; overflow-x: hidden; }
body { overflow-x: hidden; }
body { font-family: var(--font); color: var(--text-light); line-height: 1.6; background: var(--bg-light); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section { padding: 100px 0; }
.section-dark { background: var(--bg-dark); color: var(--text-dark); }
.section-gradient { background: linear-gradient(135deg, #1e3a5f 0%, #0f172a 100%); color: #fff; }
.section-header { margin-bottom: 60px; text-align: center; }
.section-label { display: inline-block; background: var(--primary); color: #fff; padding: 4px 16px; border-radius: 20px; font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 16px; }
.section-header h2 { font-size: 36px; font-weight: 700; }
.navbar { position: fixed; top: 0; left: 0; right: 0; background: rgba(255,255,255,0.95); backdrop-filter: blur(10px); z-index: 1000; padding: 16px 0; border-bottom: 1px solid var(--border); }
.nav-container { max-width: 1200px; margin: 0 auto; padding: 0 24px; display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 24px; font-weight: 800; color: var(--primary); text-decoration: none; }
.nav-links { display: flex; gap: 32px; list-style: none; }
.nav-links a { color: var(--text-light); text-decoration: none; font-weight: 500; font-size: 14px; transition: color 0.2s; }
.nav-links a:hover { color: var(--primary); }
.mobile-menu-btn { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 5px; }
.mobile-menu-btn span { width: 24px; height: 2px; background: var(--secondary); }
.hero { min-height: 100vh; padding: 120px 0 80px; background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%); }
.hero .container { display: flex; align-items: center; }
.hero-content { flex: 1; max-width: 600px; }
.hero-badge { display: inline-block; background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%); color: #fff; padding: 8px 20px; border-radius: 25px; font-size: 13px; font-weight: 600; margin-bottom: 24px; }
.hero h1 { font-size: 56px; font-weight: 800; line-height: 1.1; margin-bottom: 16px; color: var(--secondary); }
.hero-subtitle { font-size: 20px; color: var(--primary); font-weight: 600; margin-bottom: 24px; }
.hero-tagline { font-size: 18px; color: var(--text-light); margin-bottom: 32px; line-height: 1.7; }
.hero-cta { display: flex; gap: 16px; }
.btn { padding: 14px 28px; border-radius: 8px; font-weight: 600; font-size: 15px; text-decoration: none; transition: all 0.2s; display: inline-block; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); }
.btn-secondary { background: #fff; color: var(--secondary); border: 2px solid var(--border); }
.btn-secondary:hover { border-color: var(--primary); color: var(--primary); }
.hero-visual { flex: 1; display: flex; justify-content: center; align-items: center; }
.code-window { background: #1e1e1e; border-radius: 12px; padding: 0; width: 100%; max-width: 400px; box-shadow: 0 25px 50px rgba(0,0,0,0.25); }
.window-header { display: flex; gap: 8px; padding: 12px 16px; background: #2d2d2d; border-radius: 12px 12px 0 0; }
.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot.red { background: #ff5f56; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #27c93f; }
.code-content { padding: 20px; font-family: monospace; font-size: 13px; line-height: 1.8; color: #d4d4d4; }
.keyword { color: #c586c0; }
.variable { color: #9cdcfe; }
.property { color: #9cdcfe; }
.string { color: #ce9178; }
.comment { color: #6a9955; }
.about-content p { font-size: 18px; line-height: 1.8; margin-bottom: 24px; }
.about-content strong { color: var(--primary); }
.about-highlights { display: flex; gap: 48px; margin-top: 48px; padding-top: 48px; border-top: 1px solid var(--border); }
.highlight-item { text-align: center; }
.highlight-number { font-size: 48px; font-weight: 800; color: var(--primary); display: block; }
.highlight-label { font-size: 14px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }

.expertise-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.expertise-card { background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); border-radius: 16px; padding: 32px; transition: all 0.3s; position: relative; }
.expertise-card:hover { transform: translateY(-8px); border-color: var(--accent); }
.expertise-card.featured { border-color: var(--accent); background: linear-gradient(135deg, rgba(6,182,212,0.1) 0%, rgba(37,99,235,0.1) 100%); }
.expertise-icon { width: 56px; height: 56px; background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%); border-radius: 12px; display: flex; align-items: center; justify-content: center; margin-bottom: 24px; }
.expertise-icon svg { width: 28px; height: 28px; color: #fff; }
.expertise-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 16px; }
.expertise-card ul { list-style: none; }
.expertise-card li { color: var(--text-muted); padding: 8px 0; border-bottom: 1px solid rgba(255,255,255,0.05); font-size: 14px; }
.expertise-card li:last-child { border: none; }
.card-badge { position: absolute; top: 16px; right: 16px; background: var(--accent); color: #fff; font-size: 10px; font-weight: 700; padding: 4px 12px; border-radius: 12px; text-transform: uppercase; }
.timeline { position: relative; max-width: 800px; margin: 0 auto; }
.timeline::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 2px; background: linear-gradient(180deg, var(--primary) 0%, var(--accent) 100%); }
.timeline-item { position: relative; padding-left: 48px; padding-bottom: 48px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-marker { position: absolute; left: -7px; top: 0; width: 16px; height: 16px; background: var(--primary); border-radius: 50%; border: 3px solid var(--bg-light); }
.timeline-content { background: #fff; border-radius: 12px; padding: 24px; box-shadow: 0 4px 20px rgba(0,0,0,0.08); }
.timeline-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 8px; flex-wrap: wrap; gap: 8px; }
.timeline-header h3 { font-size: 18px; font-weight: 700; }
.timeline-company { color: var(--primary); font-weight: 600; font-size: 14px; }
.timeline-date { color: var(--text-muted); font-size: 14px; }
.timeline-location { color: var(--text-muted); font-size: 13px; margin-bottom: 16px; }
.timeline-achievements { list-style: disc; padding-left: 20px; margin-bottom: 16px; }
.timeline-achievements li { font-size: 14px; color: var(--text-light); margin-bottom: 8px; }
.timeline-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.timeline-tags span { background: var(--bg-light); color: var(--text-light); padding: 4px 12px; border-radius: 20px; font-size: 12px; font-weight: 500; }
.achievements-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.achievement-card { text-align: center; padding: 40px 24px; background: rgba(255,255,255,0.1); border-radius: 16px; backdrop-filter: blur(10px); border: 1px solid rgba(255,255,255,0.1); }
.achievement-icon { width: 64px; height: 64px; margin: 0 auto 24px; background: rgba(255,255,255,0.1); border-radius: 50%; display: flex; align-items: center; justify-content: center; }
.achievement-icon svg { width: 32px; height: 32px; color: var(--accent); }
.achievement-stat { font-size: 56px; font-weight: 800; line-height: 1; }
.achievement-unit { font-size: 14px; color: var(--accent); text-transform: uppercase; letter-spacing: 2px; margin-top: 8px; }
.achievement-label { font-size: 18px; font-weight: 600; margin: 16px 0 8px; }
.achievement-desc { font-size: 14px; color: rgba(255,255,255,0.6); }
.innovation-content { display: grid; grid-template-columns: 300px 1fr; gap: 60px; align-items: center; }
.book-cover { background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%); border-radius: 8px; padding: 32px; text-align: center; color: #fff; aspect-ratio: 3/4; display: flex; flex-direction: column; justify-content: center; box-shadow: 0 20px 40px rgba(0,0,0,0.3); }
.book-title { font-size: 24px; font-weight: 800; margin-bottom: 8px; }
.book-subtitle { font-size: 12px; opacity: 0.8; margin-bottom: 24px; }
.book-author { font-size: 14px; font-style: italic; opacity: 0.7; }
.book-cta { font-size: 11px; background: rgba(255,255,255,0.2); padding: 6px 12px; border-radius: 12px; margin-top: 16px; text-transform: uppercase; letter-spacing: 1px; }
.book-link { text-decoration: none; transition: transform 0.3s, box-shadow 0.3s; }
.book-link:hover { transform: translateY(-8px); box-shadow: 0 28px 50px rgba(0,0,0,0.4); }
.amazon-link { display: inline-flex; align-items: center; gap: 10px; margin-top: 24px; padding: 12px 24px; background: #ff9900; color: #000; text-decoration: none; border-radius: 8px; font-weight: 600; font-size: 14px; transition: all 0.2s; }
.amazon-link:hover { background: #e68a00; transform: translateY(-2px); }
.amazon-link svg { flex-shrink: 0; }
.notify-section { margin-top: 24px; padding: 24px; background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); border-radius: 12px; }
.notify-badge { display: inline-block; background: linear-gradient(135deg, var(--accent) 0%, var(--primary) 100%); color: #fff; font-size: 11px; font-weight: 700; padding: 4px 12px; border-radius: 12px; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 12px; }
.notify-text { font-size: 14px; color: var(--text-muted); margin-bottom: 16px; }
.notify-form { display: flex; gap: 8px; }
.notify-form input { flex: 1; padding: 12px 16px; background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); border-radius: 8px; color: #fff; font-size: 14px; }
.notify-form input::placeholder { color: rgba(255,255,255,0.4); }
.notify-form input:focus { outline: none; border-color: var(--accent); }
.notify-form button { padding: 12px 20px; background: var(--primary); color: #fff; border: none; border-radius: 8px; font-weight: 600; font-size: 14px; cursor: pointer; transition: all 0.2s; }
.notify-form button:hover { background: var(--primary-dark); }
.notify-form button:disabled { background: #10b981; cursor: default; }
.research-areas h4 { font-size: 16px; margin: 24px 0 16px; color: var(--accent); }
.research-areas ul { list-style: none; }
.research-areas li { font-size: 14px; color: var(--text-muted); padding: 12px 0; border-bottom: 1px solid rgba(255,255,255,0.05); }
.research-areas strong { color: #fff; }

.education-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.education-card { background: #fff; border: 1px solid var(--border); border-radius: 12px; padding: 24px; position: relative; }
.education-card.featured { border-color: var(--primary); background: linear-gradient(135deg, rgba(37,99,235,0.05) 0%, rgba(6,182,212,0.05) 100%); }
.education-badge { position: absolute; top: -8px; right: 16px; background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%); color: #fff; font-size: 10px; font-weight: 700; padding: 4px 12px; border-radius: 12px; text-transform: uppercase; }
.education-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.education-institution { display: block; color: var(--primary); font-weight: 500; font-size: 14px; }
.education-date { color: var(--text-muted); font-size: 13px; }
.contact-intro { text-align: center; max-width: 600px; margin: 0 auto 48px; font-size: 18px; }
.contact-links { display: flex; flex-direction: column; gap: 16px; max-width: 500px; margin: 0 auto; }
.contact-link { display: flex; align-items: center; gap: 20px; background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); padding: 20px 24px; border-radius: 12px; text-decoration: none; color: var(--text-dark); transition: all 0.2s; }
a.contact-link:hover { background: rgba(255,255,255,0.1); border-color: var(--accent); }
.contact-icon { width: 48px; height: 48px; background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%); border-radius: 12px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.contact-icon svg { width: 24px; height: 24px; color: #fff; }
.contact-info { display: flex; flex-direction: column; }
.contact-label { font-size: 12px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }
.contact-value { font-size: 16px; font-weight: 600; }
.footer { background: var(--secondary); color: var(--text-dark); padding: 48px 0; text-align: center; }
.footer-logo { font-size: 32px; font-weight: 800; color: var(--primary); margin-bottom: 16px; }
.footer-text { font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
.footer-copyright { font-size: 12px; color: var(--text-muted); }
@media (max-width: 768px) {
  .nav-container { position: relative; }
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: #fff; flex-direction: column; padding: 24px; gap: 16px; border-bottom: 1px solid var(--border); }
  .nav-links.active { display: flex; }
  .mobile-menu-btn { 
    display: flex; 
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1001;
  }
  .logo { margin-left: 60px; }
  .nav-links { margin-left: 0; }
  .hero .container { flex-direction: column; }
  .hero { text-align: center; padding-top: 100px; }
  .hero h1 { font-size: 36px; }
  .hero-cta { justify-content: center; flex-wrap: wrap; }
  .hero-content, .hero-visual { width: 100%; }
  .hero-visual { order: -1; margin-bottom: 32px; }
  .hero-visual .code-window { max-width: 100%; }
  .about-highlights { flex-direction: column; gap: 24px; }
  .expertise-grid { grid-template-columns: 1fr; }
  .achievements-grid { grid-template-columns: 1fr; }
  .innovation-content { grid-template-columns: 1fr; }
  .innovation-content .book-preview { max-width: 200px; margin: 0 auto; }
  .education-grid { grid-template-columns: 1fr; }
  .timeline-header { flex-direction: column; }
  .projects-grid { grid-template-columns: 1fr; }
  .section { padding: 60px 0; }
  .section-header h2 { font-size: 28px; }
  
  /* Contact Section - Fixed for Mobile */
  .contact-wrapper {
    display: flex;
    flex-direction: column;
    gap: 32px;
    max-width: 100%;
    overflow-x: hidden;
  }
  .contact-info-column,
  .contact-form-column {
    width: 100%;
    min-width: 0;
  }
  .contact-form-column {
    padding: 24px;
    overflow-x: hidden;
  }
  .contact-form {
    width: 100%;
    box-sizing: border-box;
  }
  .contact-form h3 {
    font-size: 18px;
  }
  .form-group {
    width: 100%;
    box-sizing: border-box;
    margin-bottom: 16px;
  }
  .form-group input,
  .form-group textarea {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
  }
}

/* Large phones (600px and below) */
@media (max-width: 600px) {
  .container { padding: 0 20px; }
  .contact-wrapper { gap: 24px; }
  .contact-form-column { padding: 20px; }
}

/* Regular phones (420px and below) - Motorola Edge ~414px */
@media (max-width: 420px) {
  .container { padding: 0 16px; }
  .contact-form-column { padding: 16px; }
  .contact-form h3 { font-size: 18px; }
  .form-group input,
  .form-group textarea { padding: 12px; }
}

/* Small phones (360px and below) */
@media (max-width: 360px) {
  .container { padding: 0 12px; }
  .contact-form-column { padding: 14px; }
  .form-group { margin-bottom: 12px; }
  .form-group label { font-size: 11px; }
  .btn-submit { padding: 12px; font-size: 14px; }
}

/* Very small phones (320px and below) */
@media (max-width: 320px) {
  .container { padding: 0 8px; }
  .contact-form-column { padding: 10px; }
  .form-group { margin-bottom: 10px; }
}

/* Tiny phones (280px and below) */
@media (max-width: 280px) {
  .container { padding: 0 6px; }
  .contact-form-column { padding: 8px; }
  .contact-form h3 { font-size: 16px; }
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  margin-bottom: 48px;
}

.project-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  text-decoration: none;
  color: inherit;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0,0,0,0.1);
  border-color: var(--primary);
}

.project-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  color: var(--secondary);
}

.project-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--primary);
}

.project-desc {
  font-size: 14px;
  color: var(--text-muted);
  flex-grow: 1;
  margin-bottom: 16px;
  line-height: 1.6;
}

.project-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--text-muted);
}

.project-lang {
  display: flex;
  align-items: center;
  gap: 6px;
}

.lang-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #f1e05a;
}

.project-stars {
  color: #eab308;
}

.no-repos {
  text-align: center;
  color: var(--text-muted);
  grid-column: 1 / -1;
  padding: 40px;
}

.projects-cta {
  text-align: center;
  margin-top: 40px;
}

.featured-projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.featured-project-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  text-align: center;
  transition: all 0.3s ease;
}

.featured-project-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.1);
  border-color: var(--primary);
}

.featured-project-icon {
  width: 72px;
  height: 72px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
}

.featured-project-icon svg {
  width: 36px;
  height: 36px;
  color: #fff;
}

.featured-project-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--secondary);
}

.featured-project-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.featured-project-tag {
  display: inline-block;
  background: var(--bg-light);
  color: var(--text-light);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
}

.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.contact-info-column .contact-intro {
  text-align: left;
  margin-bottom: 32px;
}

.contact-form-column {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 16px;
  padding: 32px;
}

.contact-form h3 {
  font-size: 20px;
  margin-bottom: 24px;
  color: #fff;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 14px 16px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 8px;
  color: #fff;
  font-size: 15px;
  font-family: var(--font);
  transition: all 0.2s;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: rgba(255,255,255,0.3);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  background: rgba(255,255,255,0.08);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.btn-submit {
  width: 100%;
  padding: 16px;
  font-size: 16px;
  cursor: pointer;
}

.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  background: #2563eb;
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  z-index: 9999;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

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

.back-to-top:hover {
  background: #1d4ed8;
  transform: translateY(-2px);
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-4px);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

.back-home-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  color: var(--primary);
  background: rgba(37, 99, 235, 0.1);
  border-radius: 50%;
  text-decoration: none;
  margin-bottom: 16px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.back-home-link.visible {
  opacity: 1;
  visibility: visible;
}

.back-home-link:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
}

.back-home-link-light {
  color: rgba(255, 255, 255, 0.8);
  background: rgba(255, 255, 255, 0.1);
}

.back-home-link-light:hover {
  background: #fff;
  color: var(--primary);
}