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

    :root {
      --bg-primary: #0a0e1a;
      --bg-secondary: #111827;
      --bg-card: #1a1f35;
      --text-primary: #e5e7eb;
      --text-secondary: #9ca3af;
      --accent: #3b82f6;
      --accent-hover: #2563eb;
      --accent-glow: rgba(59, 130, 246, 0.3);
      --border: rgba(255, 255, 255, 0.1);
      --shadow: rgba(0, 0, 0, 0.3);
    }

    body {
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
      background: var(--bg-primary);
      color: var(--text-primary);
      line-height: 1.6;
      overflow-x: hidden;
    }

    /* ========== Intro ============ */
    #intro {
      position: fixed;
      inset: 0;
      background: #000000;
      display: flex;
      justify-content: center;
      align-items: center;
      z-index: 1000;
      flex-direction: column;
      overflow: hidden;
      transition: opacity 0.8s ease, transform 0.8s ease;
    }
    #intro.fade-out {
      opacity: 0;
      transform: scale(1.1);
      pointer-events: none;
    }
    .intro-text {
      text-align: center;
      position: relative;
      z-index: 10;
    }
    .line {
      display: block;
      opacity: 0;
      font-size: clamp(3rem, 10vw, 7rem);
      font-family: 'Inter', sans-serif;
      font-weight: 900;
      color: #ffffff;
      letter-spacing: 0.15em;
      animation: fadeInUpGlitch 1s forwards;
      position: relative;
    }
    .line::before,
    .line::after {
      content: attr(data-text);
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      opacity: 0;
    }
    .line::before {
      color: #ff00ff;
      animation: glitchBefore 2.5s infinite;
      clip-path: polygon(0 0, 100% 0, 100% 45%, 0 45%);
    }
    .line::after {
      color: #00ffff;
      animation: glitchAfter 2.5s infinite;
      clip-path: polygon(0 55%, 100% 55%, 100% 100%, 0 100%);
    }
    @keyframes fadeInUpGlitch {
      0% {
        opacity: 0;
        transform: translateY(30px);
        letter-spacing: 0.3em;
      }
      60% {
        opacity: 1;
        transform: translateY(0);
        letter-spacing: 0.15em;
      }
      100% {
        opacity: 1;
        transform: translateY(0);
        letter-spacing: 0.1em;
      }
    }
    @keyframes glitchBefore {
      0%, 3%, 5%, 42%, 44%, 100% {
        opacity: 0;
        transform: translateX(0);
      }
      4% {
        opacity: 0.7;
        transform: translateX(-2px);
      }
      43% {
        opacity: 0.7;
        transform: translateX(3px);
      }
    }
    @keyframes glitchAfter {
      0%, 3%, 5%, 42%, 44%, 100% {
        opacity: 0;
        transform: translateX(0);
      }
      4% {
        opacity: 0.7;
        transform: translateX(2px);
      }
      43% {
        opacity: 0.7;
        transform: translateX(-3px);
      }
    }
    .subtitle {
      display: block;
      opacity: 0;
      font-size: clamp(12.8px, 2vw, 19.2px);
      font-family: 'Inter', sans-serif;
      font-weight: 400;
      color: #ffffff;
      letter-spacing: 0.3em;
      margin-top: 24px;
      text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
      animation: fadeInUp 1s 0.5s forwards;
    }
    @keyframes fadeInUp {
      from {
        opacity: 0;
        transform: translateY(30px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }
    .loading-bar {
      position: absolute;
      bottom: 80px;
      width: 300px;
      height: 3px;
      background: rgba(255, 255, 255, 0.2);
      border-radius: 10px;
      overflow: hidden;
      opacity: 0;
      animation: fadeIn 0.5s 1s forwards;
    }
    @keyframes fadeIn {
      to { opacity: 1; }
    }
    .loading-progress {
      height: 100%;
      width: 0;
      background: #ffffff;
      border-radius: 10px;
      animation: loadProgress 2.5s ease-out forwards;
      box-shadow: 0 0 20px rgba(255, 255, 255, 0.8);
    }
    @keyframes loadProgress {
      to { width: 100%; }
    }

    /* ========== Project Modal/Popup ========== */
    .project-modal {
      display: none;
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.9);
      z-index: 2000;
      justify-content: center;
      align-items: center;
      padding: 2rem;
      backdrop-filter: blur(10px);
      animation: fadeInModal 0.3s ease;
    }

    .project-modal.active {
      display: flex;
    }

    @keyframes fadeInModal {
      from {
        opacity: 0;
      }
      to {
        opacity: 1;
      }
    }

    .modal-content {
      background: var(--bg-card);
      border-radius: 20px;
      max-width: 900px;
      width: 100%;
      max-height: 90vh;
      overflow-y: auto;
      position: relative;
      border: 2px solid var(--border);
      box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
      animation: slideInModal 0.4s ease;
    }

    @keyframes slideInModal {
      from {
        transform: translateY(-50px) scale(0.9);
        opacity: 0;
      }
      to {
        transform: translateY(0) scale(1);
        opacity: 1;
      }
    }

    .modal-close {
      position: absolute;
      top: 1.5rem;
      right: 1.5rem;
      background: var(--bg-secondary);
      border: 2px solid var(--border);
      width: 40px;
      height: 40px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: all 0.3s;
      z-index: 10;
      color: var(--text-primary);
      font-size: 1.5rem;
      font-weight: bold;
    }

    .modal-close:hover {
      background: var(--accent);
      border-color: var(--accent);
      transform: rotate(90deg);
      color: white;
    }

    .modal-image {
      width: 100%;
      height: 300px;
      object-fit: cover;
      border-radius: 18px 18px 0 0;
      background: var(--bg-secondary);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-secondary);
    }

    .modal-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .modal-body {
      padding: 2rem;
    }

    .modal-title {
      font-size: 1.75rem;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 1rem;
      background: linear-gradient(135deg, var(--accent), #8b5cf6);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .modal-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem;
      margin-bottom: 1.5rem;
    }

    .modal-tag {
      padding: 0.35rem 0.85rem;
      background: var(--accent-glow);
      color: var(--accent);
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
    }

    .modal-description {
      color: var(--text-secondary);
      line-height: 1.8;
      margin-bottom: 2rem;
      font-size: 1rem;
    }

    .modal-actions {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }

    .modal-btn {
      padding: 0.875rem 1.75rem;
      border-radius: 10px;
      font-weight: 600;
      text-decoration: none;
      transition: all 0.3s;
      border: 2px solid transparent;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      cursor: pointer;
      font-size: 0.95rem;
    }

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

    .modal-btn-primary:hover {
      background: var(--accent-hover);
      box-shadow: 0 0 20px var(--accent-glow);
      transform: translateY(-2px);
    }

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

    .modal-btn-secondary:hover {
      border-color: var(--accent);
      background: var(--accent-glow);
    }

    /* Responsive modal */
    @media (max-width: 768px) {
      .project-modal {
        padding: 1rem;
      }

      .modal-content {
        max-height: 95vh;
      }

      .modal-image {
        height: 200px;
      }

      .modal-body {
        padding: 1.5rem;
      }

      .modal-title {
        font-size: 1.5rem;
      }

      .modal-actions {
        flex-direction: column;
      }

      .modal-btn {
        width: 100%;
        justify-content: center;
      }
    }

    /* Header */
    header {
      position: fixed;
      top: 0;
      width: 100%;
      background: rgba(10, 14, 26, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border);
      z-index: 1000;
      transition: all 0.3s ease;
    }

    header.scrolled {
      box-shadow: 0 4px 20px var(--shadow);
    }

    nav {
      max-width: 1200px;
      margin: 0 auto;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1.2rem 2rem;
    }

    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      background: linear-gradient(135deg, var(--accent), #8b5cf6);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

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

    nav a {
      color: var(--text-secondary);
      text-decoration: none;
      font-weight: 500;
      transition: color 0.3s;
      position: relative;
    }

    nav a::after {
      content: '';
      position: absolute;
      bottom: -5px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width 0.3s;
    }

    nav a:hover {
      color: var(--text-primary);
    }

    nav a:hover::after {
      width: 100%;
    }

    /* Hero Section */
    .hero {
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      text-align: center;
      padding: 6rem 2rem 4rem;
      position: relative;
      overflow: hidden;
    }

    .hero::before {
      content: '';
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, var(--accent-glow), transparent 70%);
      opacity: 0.3;
      animation: pulse 4s ease-in-out infinite;
    }

    @keyframes pulse {
      0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.3; }
      50% { transform: translate(-50%, -50%) scale(1.1); opacity: 0.5; }
    }

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

    .hero h1 {
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 700;
      margin-bottom: 1rem;
      background: linear-gradient(135deg, var(--text-primary), var(--accent));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .hero p {
      font-size: 1.25rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      line-height: 1.8;
    }

    .hero-buttons {
      display: flex;
      gap: 1rem;
      justify-content: center;
      flex-wrap: wrap;
    }

    .btn {
      padding: 0.875rem 2rem;
      border-radius: 8px;
      font-weight: 600;
      text-decoration: none;
      transition: all 0.3s;
      border: 2px solid transparent;
      display: inline-block;
    }

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

    .btn-primary:hover {
      background: var(--accent-hover);
      box-shadow: 0 0 20px var(--accent-glow);
      transform: translateY(-2px);
    }

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

    .btn-secondary:hover {
      background: var(--accent-glow);
    }

    /* Section styles */
    section {
      padding: 5rem 2rem;
      max-width: 1200px;
      margin: 0 auto;
    }

    .section-title {
      font-size: 2.5rem;
      text-align: center;
      margin-bottom: 3rem;
      position: relative;
      padding-bottom: 1rem;
    }

    .section-title::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 80px;
      height: 4px;
      background: linear-gradient(90deg, var(--accent), #8b5cf6);
      border-radius: 2px;
    }

    /* Timeline */
    .timeline {
      position: relative;
      max-width: 900px;
      margin: 0 auto;
      padding: 2rem 0;
    }

    .timeline::before {
      content: '';
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      width: 4px;
      height: 100%;
      background: linear-gradient(180deg, var(--accent), transparent);
    }

    .timeline-item {
      display: flex;
      margin-bottom: 3rem;
      position: relative;
    }

    .timeline-item:nth-child(odd) {
      flex-direction: row-reverse;
    }

    .timeline-content {
      width: calc(50% - 40px);
      padding: 1.5rem;
      background: var(--bg-card);
      border-radius: 12px;
      border: 1px solid var(--border);
      position: relative;
      transition: all 0.3s;
    }

    .timeline-content:hover {
      transform: translateY(-5px);
      box-shadow: 0 10px 30px var(--shadow);
      border-color: var(--accent);
    }

    .timeline-dot {
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      width: 20px;
      height: 20px;
      background: var(--accent);
      border: 4px solid var(--bg-primary);
      border-radius: 50%;
      z-index: 1;
      box-shadow: 0 0 0 4px var(--accent-glow);
    }

    .timeline-date {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      background: var(--accent-glow);
      color: var(--accent);
      border-radius: 20px;
      font-size: 0.875rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
    }

    .timeline-content h3 {
      font-size: 1.25rem;
      margin-bottom: 0.5rem;
      color: var(--text-primary);
    }

    .timeline-content p {
      color: var(--text-secondary);
      font-size: 0.95rem;
    }

    /* BTS Card */
    .bts-presentation {
      background: linear-gradient(135deg, var(--bg-card), var(--bg-secondary));
      padding: 2.5rem;
      border-radius: 16px;
      border: 1px solid var(--border);
      margin-bottom: 3rem;
    }

    .bts-presentation h3 {
      font-size: 1.75rem;
      margin-bottom: 1.5rem;
      color: var(--accent);
    }

    .bts-description {
      color: var(--text-secondary);
      margin-bottom: 2rem;
      line-height: 1.8;
    }

    .bts-options {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 1.5rem;
      margin-top: 2rem;
    }

    .bts-option {
      background: var(--bg-secondary);
      padding: 1.5rem;
      border-radius: 12px;
      border-left: 4px solid var(--border);
      transition: all 0.3s;
    }

    .bts-option.highlight {
      border-left-color: var(--accent);
      background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), transparent);
    }

    .bts-option:hover {
      transform: translateX(5px);
    }

    .bts-option-title {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 0.75rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .badge {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      background: var(--accent);
      color: white;
      border-radius: 20px;
      font-size: 0.75rem;
      font-weight: 600;
    }

    /* Skills Grid */
    .skills-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
      gap: 1rem;
      margin-top: 2rem;
    }

    .skill-item {
      background: var(--bg-card);
      padding: 1rem;
      border-radius: 12px;
      text-align: center;
      border: 1px solid var(--border);
      transition: all 0.3s;
      cursor: pointer;
    }

    .skill-item:hover {
      transform: translateY(-5px);
      border-color: var(--accent);
      box-shadow: 0 10px 20px var(--shadow);
    }

    .skill-icon {
      font-size: 2rem;
      margin-bottom: 0.5rem;
      display: block;
    }

    .skill-name {
      font-size: 0.9rem;
      font-weight: 500;
      color: var(--text-secondary);
    }

    /* Certifications */
    .cert-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 2rem;
    }

    .cert-card {
      background: var(--bg-card);
      padding: 2rem;
      border-radius: 16px;
      border: 1px solid var(--border);
      text-align: center;
      transition: all 0.3s;
      position: relative;
      overflow: hidden;
    }

    .cert-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 4px;
      background: linear-gradient(90deg, var(--accent), #8b5cf6);
    }

    .cert-card:hover {
      transform: translateY(-10px);
      box-shadow: 0 20px 40px var(--shadow);
      border-color: var(--accent);
    }

    .cert-icon {
      font-size: 3rem;
      margin-bottom: 1rem;
    }

    .cert-card h4 {
      font-size: 1.5rem;
      margin-bottom: 0.5rem;
      color: var(--text-primary);
    }

    .cert-issuer {
      color: var(--accent);
      font-size: 0.9rem;
      margin-bottom: 1rem;
    }

    .cert-description {
      color: var(--text-secondary);
      font-size: 0.95rem;
      line-height: 1.6;
      margin-bottom: 1rem;
    }

    .cert-date {
      display: inline-block;
      padding: 0.5rem 1rem;
      background: var(--accent-glow);
      color: var(--accent);
      border-radius: 20px;
      font-weight: 600;
      font-size: 0.875rem;
    }

    /* Tools Grid */
    .tools-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
      gap: 1.5rem;
    }

    .tool-card {
      background: var(--bg-card);
      padding: 1.5rem;
      border-radius: 12px;
      border: 1px solid var(--border);
      text-align: center;
      transition: all 0.3s;
    }

    .tool-card:hover {
      transform: translateY(-5px);
      border-color: var(--accent);
      box-shadow: 0 10px 20px var(--shadow);
    }

    .tool-icon {
      width: 60px;
      height: 60px;
      margin: 0 auto 1rem;
      display: flex;
      align-items: center;
      justify-content: center;
      background: var(--bg-secondary);
      border-radius: 12px;
    }

    .tool-icon img {
      max-width: 40px;
      max-height: 40px;
      object-fit: contain;
    }

    .tool-card h4 {
      font-size: 1.1rem;
      margin-bottom: 0.5rem;
    }

    .tool-card p {
      color: var(--text-secondary);
      font-size: 0.875rem;
    }

    /* Projects */
    .project-filters {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 1rem;
      margin-bottom: 3rem;
    }

    .filter-btn {
      padding: 0.75rem 1.5rem;
      background: var(--bg-card);
      border: 2px solid var(--border);
      border-radius: 8px;
      color: var(--text-secondary);
      cursor: pointer;
      transition: all 0.3s;
      font-weight: 500;
      font-size: 0.95rem;
    }

    .filter-btn:hover {
      border-color: var(--accent);
      color: var(--text-primary);
    }

    .filter-btn.active {
      background: var(--accent);
      border-color: var(--accent);
      color: white;
    }

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

    .project-card {
      background: var(--bg-card);
      border-radius: 16px;
      overflow: hidden;
      border: 1px solid var(--border);
      transition: all 0.3s;
      display: flex;
      flex-direction: column;
      cursor: pointer;
    }

    .project-card:hover {
      transform: translateY(-10px);
      box-shadow: 0 20px 40px var(--shadow);
      border-color: var(--accent);
    }

    .project-content {
      padding: 1.5rem;
      flex: 1;
      display: flex;
      flex-direction: column;
    }

    .project-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem;
      margin-bottom: 1rem;
    }

    .project-tag {
      padding: 0.25rem 0.75rem;
      background: var(--accent-glow);
      color: var(--accent);
      border-radius: 20px;
      font-size: 0.75rem;
      font-weight: 600;
    }

    .project-card h4 {
      font-size: 1.25rem;
      margin-bottom: 0.75rem;
      color: var(--text-primary);
    }

    .project-card p {
      color: var(--text-secondary);
      font-size: 0.95rem;
      line-height: 1.6;
      flex: 1;
    }

    .project-meta {
      display: flex;
      gap: 0.5rem;
      margin-top: 1rem;
      flex-wrap: wrap;
    }

    .project-meta span {
      padding: 0.5rem 1rem;
      background: var(--bg-secondary);
      border-radius: 6px;
      font-size: 0.875rem;
      color: var(--text-secondary);
    }

    /* Contact Form */
    .contact-form {
      max-width: 600px;
      margin: 0 auto;
    }

    .form-group {
      margin-bottom: 1.5rem;
    }

    .form-group label {
      display: block;
      margin-bottom: 0.5rem;
      color: var(--text-secondary);
      font-weight: 500;
    }

    .form-group input,
    .form-group textarea {
      width: 100%;
      padding: 1rem;
      background: var(--bg-card);
      border: 2px solid var(--border);
      border-radius: 8px;
      color: var(--text-primary);
      font-family: inherit;
      transition: all 0.3s;
    }

    .form-group input:focus,
    .form-group textarea:focus {
      outline: none;
      border-color: var(--accent);
      box-shadow: 0 0 0 4px var(--accent-glow);
    }

    .form-group textarea {
      resize: vertical;
      min-height: 150px;
    }

    .form-message {
      margin-top: 1rem;
      padding: 1rem;
      background: rgba(34, 197, 94, 0.1);
      border: 1px solid rgba(34, 197, 94, 0.3);
      border-radius: 8px;
      color: #22c55e;
      text-align: center;
      display: none;
    }

    .form-message.show {
      display: block;
    }

    /* Footer */
    footer {
      text-align: center;
      padding: 3rem 2rem;
      border-top: 1px solid var(--border);
      color: var(--text-secondary);
    }

    /* Responsive */
    @media (max-width: 768px) {
      nav ul {
        display: none;
      }

      #presentation > div > div {
        grid-template-columns: 1fr !important;
        gap: 2rem !important;
      }

      #presentation > div > div > div:last-child {
        order: -1;
      }

      #presentation > div > div > div:last-child > div {
        height: 300px !important;
      }

      .timeline::before {
        left: 30px;
      }

      .timeline-item {
        flex-direction: row !important;
      }

      .timeline-content {
        width: calc(100% - 60px);
        margin-left: 60px;
      }

      .timeline-dot {
        left: 30px;
      }

      .hero h1 {
        font-size: 2rem;
      }

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

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

    /* Animations */
    @keyframes fadeInUp {
      from {
        opacity: 0;
        transform: translateY(30px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    .fade-in-up {
      animation: fadeInUp 0.6s ease-out;
    }