/* ===== RESET & BASE ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #111118;
  --bg-card: #16161d;
  --bg-card-hover: #1c1c25;
  --text-primary: #e8e8ed;
  --text-secondary: #9898a6;
  --text-muted: #6b6b7b;
  --accent: #6c63ff;
  --accent-hover: #5a52e0;
  --accent-glow: rgba(108, 99, 255, 0.15);
  --border: #2a2a35;
  --border-light: #3a3a48;
  --success: #4ade80;
  --error: #f87171;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --nav-height: 72px;
  --container-max: 1100px;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

img {
  max-width: 100%;
  display: block;
}

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== NAVIGATION ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid transparent;
  z-index: 1000;
  transition: border-color var(--transition), background var(--transition);
}

.navbar.scrolled {
  border-bottom-color: var(--border);
  background: rgba(10, 10, 15, 0.95);
}

.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  transition: color var(--transition);
}

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

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-menu a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition);
}

.lang-toggle:hover {
  border-color: var(--accent);
  color: var(--text-primary);
}

.lang-flag {
  display: inline-block;
  vertical-align: middle;
  border-radius: 2px;
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 40px) 24px 60px;
  position: relative;
  background:
    radial-gradient(ellipse at 50% 0%, rgba(108, 99, 255, 0.08) 0%, transparent 60%),
    var(--bg-primary);
}

.hero-content {
  max-width: 700px;
}

.hero-greeting {
  font-size: 1.1rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-title {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 500px;
  margin: 0 auto 36px;
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-socials {
  display: flex;
  gap: 20px;
  justify-content: center;
}

.hero-socials a {
  color: var(--text-muted);
  transition: color var(--transition), transform var(--transition);
}

.hero-socials a:hover {
  color: var(--accent);
  transform: translateY(-2px);
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.hero-scroll a {
  color: var(--text-muted);
  transition: color var(--transition);
}

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

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-8px); }
  60% { transform: translateX(-50%) translateY(-4px); }
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 0.95rem;
  font-weight: 500;
  font-family: var(--font-sans);
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 24px rgba(108, 99, 255, 0.25);
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 6px 32px rgba(108, 99, 255, 0.35);
}

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

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

.btn-full {
  width: 100%;
}

/* ===== SECTIONS ===== */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--bg-secondary);
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
  margin-bottom: 16px;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
  margin: 16px auto 0;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto 60px;
}

/* ===== ABOUT ===== */
.about-grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 60px;
  align-items: center;
  margin-top: 60px;
}

.photo-placeholder {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-card-hover) 100%);
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
  overflow: hidden;
}

.photo-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  font-size: 1.02rem;
}

.about-stats {
  display: flex;
  gap: 40px;
  margin-top: 32px;
}

.stat {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ===== SKILLS ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 60px;
}

.skill-category {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color var(--transition), transform var(--transition);
}

.skill-category:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.skill-category h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 6px 14px;
  background: rgba(108, 99, 255, 0.08);
  border: 1px solid rgba(108, 99, 255, 0.15);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
  transition: all var(--transition);
}

.tag:hover {
  background: rgba(108, 99, 255, 0.15);
  color: var(--text-primary);
  border-color: rgba(108, 99, 255, 0.3);
}

/* Language progress bars */
.language-bars {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.language-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.language-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.language-name {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-primary);
}

.language-level {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #9b8aff);
  border-radius: 3px;
  transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== PROJECTS ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 60px;
}

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

.project-card:hover {
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.project-image {
  height: 200px;
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-card-hover) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid var(--border);
}

.project-placeholder {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.project-info {
  padding: 24px;
}

.project-info h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.project-info p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  margin-bottom: 16px;
  line-height: 1.6;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}

.tag-sm {
  padding: 3px 10px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 14px;
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
}

.project-links {
  display: flex;
  gap: 16px;
}

.project-link {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.project-link:hover {
  color: var(--accent-hover);
}

/* ===== EXPERIENCE / TIMELINE ===== */
.timeline {
  position: relative;
  margin-top: 60px;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  margin-bottom: 48px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-marker {
  position: absolute;
  left: -40px;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 3px solid var(--accent);
  z-index: 1;
}

.timeline-item:first-child .timeline-marker {
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-glow);
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color var(--transition);
}

.timeline-content:hover {
  border-color: var(--border-light);
}

.timeline-date {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--accent);
  font-family: var(--font-mono);
  margin-bottom: 10px;
}

.timeline-content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.timeline-content h4 {
  font-size: 0.95rem;
  font-weight: 400;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.timeline-location {
  display: inline-block;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.timeline-content p {
  color: var(--text-muted);
  font-size: 0.92rem;
}

.timeline-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.timeline-list li {
  position: relative;
  padding-left: 16px;
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
  margin-bottom: 8px;
}

.timeline-list li:last-child {
  margin-bottom: 0;
}

.timeline-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}

/* ===== EDUCATION ===== */
.education-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 60px;
}

.education-subsection {
  margin-top: 56px;
}

.education-subtitle {
  font-size: 1.35rem;
  font-weight: 600;
  text-align: center;
  margin-bottom: 28px;
  color: var(--text-primary);
}

.certifications-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.edu-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  text-align: center;
  transition: all var(--transition);
}

.edu-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.edu-icon {
  color: var(--accent);
  margin-bottom: 20px;
}

.edu-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.edu-card h4 {
  font-size: 0.92rem;
  font-weight: 400;
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.5;
}

.edu-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.certification-card h3 {
  min-height: 2.8em;
}

.certification-period {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

/* ===== CONTACT ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  margin-top: 60px;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  padding: 12px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

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

.form-status {
  font-size: 0.88rem;
  text-align: center;
  min-height: 1.4em;
}

.form-status.success {
  color: var(--success);
}

.form-status.error {
  color: var(--error);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 28px;
  justify-content: center;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-item svg {
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 2px;
}

.contact-item h4 {
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.contact-item a,
.contact-item p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

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

/* ===== FOOTER ===== */
.footer {
  padding: 32px 0;
  text-align: center;
  border-top: 1px solid var(--border);
}

.footer p {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ===== BACK TO TOP ===== */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--accent);
  border: none;
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all var(--transition);
  box-shadow: 0 4px 16px rgba(108, 99, 255, 0.3);
  z-index: 900;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
}

/* ===== SCROLL REVEAL ANIMATION ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .about-photo {
    display: flex;
    justify-content: center;
  }

  .photo-placeholder {
    width: 200px;
    height: 200px;
    font-size: 3rem;
  }

  .about-stats {
    justify-content: center;
  }

  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

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

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

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 10, 15, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition);
  }

  .nav-menu.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-menu a {
    font-size: 1.2rem;
    padding: 12px 24px;
  }

  .section {
    padding: 72px 0;
  }

  .hero {
    padding-top: calc(var(--nav-height) + 20px);
  }

  .timeline {
    padding-left: 32px;
  }

  .timeline-marker {
    left: -32px;
  }

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

@media (max-width: 480px) {
  .hero-name {
    font-size: 2rem;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 260px;
  }
}