*, *::before, *::after {
  box-sizing: border-box;
}

:root {
  --primary: #007aff;
  --bg: #fafafa;
  --card-bg: #ffffff;
  --text-main: #111111;
  --text-muted: #666666;
  --radius: 40px;
  --shadow: 0 40px 100px -20px rgba(0, 0, 0, 0.06);
  --border: 1px solid rgba(0, 0, 0, 0.05);
  --nav-bg: rgba(255, 255, 255, 0.75);
  --transition: background-color 0.5s ease;
}

body.dark-theme {
  --bg: #1a1a1a;
  --card-bg: #2a2a2a;
  --text-main: #f0f0f0;
  --text-muted: #a0a0a0;
  --border: 1px solid rgba(255, 255, 255, 0.1);
  --shadow: 0 40px 100px -20px rgba(0, 0, 0, 0.3);
  --nav-bg: rgba(42, 42, 42, 0.85);
}

* {
  transition: background-color 0.5s ease, color 0.5s ease, border-color 0.5s ease, box-shadow 0.5s ease;
}

html, body {
  overflow-x: hidden;
  width: 100%;
  position: relative;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg);
  color: var(--text-main);
  margin: 0;
  padding: 0;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.5s ease, color 0.5s ease;
}

ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

a {
  text-decoration: none;
  color: inherit;
  transition: all 0.5s ease;
}

/* Navbar */
.main-nav {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: auto;
  max-width: 95%;
  background: var(--nav-bg);
  backdrop-filter: blur(25px) saturate(180%);
  -webkit-backdrop-filter: blur(25px) saturate(180%);
  z-index: 1000;
  border-radius: 100px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.1);
  padding: 6px 12px;
  transition: all 0.5s ease;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  height: 48px;
  padding: 0 0.5rem;
}

.logo {
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--text-main);
  letter-spacing: -0.02em;
  padding-right: 1rem;
  border-right: var(--border);
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  gap: 0.25rem;
}

.nav-links li a {
  display: block;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  border-radius: 100px;
  transition: all 0.5s ease;
  white-space: nowrap;
}

.nav-links li a:hover {
  background: var(--border);
  color: var(--primary);
}

.lang-switch-container {
  display: flex;
  align-items: center;
  margin-left: 0.5rem;
}

.lang-switch {
  display: flex;
  gap: 0.25rem;
  align-items: center;
  font-size: 0.8rem;
  border-left: var(--border);
  padding-left: 1rem;
}

.lang-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-weight: 600;
  color: var(--text-muted);
  padding: 4px 8px;
  border-radius: 4px;
  transition: background-color 0.5s ease, color 0.5s ease;
}

.lang-btn.active {
  background: var(--border);
  color: var(--text-main);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.theme-btn {
  background: none;
  border: 1px solid transparent;
  cursor: pointer;
  color: var(--text-main);
  padding: 8px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.theme-btn svg,
.hamburger span {
  transition: all 0.5s ease;
}

.theme-btn:hover {
  background: rgba(0, 0, 0, 0.05);
  transform: scale(1.1);
}

body.dark-theme .theme-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.sun-icon { display: none; }
.moon-icon { display: block; }

body.dark-theme .sun-icon { display: block; }
body.dark-theme .moon-icon { display: none; }

.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 4px;
}

.hamburger span {
  width: 22px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
  transition: background-color 0.5s ease;
}

/* Hero */
.hero {
  min-height: 95vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 0 1.5rem;
  background-color: var(--bg);
}

.avatar-container {
  width: 170px;
  height: 170px;
  margin-bottom: 1.5rem;
  border-radius: 50%;
  background: var(--card-bg);
  padding: 8px;
  box-shadow: var(--shadow);
  border: var(--border);
  pointer-events: none;
}

.avatar-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 20%;
  border-radius: 50%;
  pointer-events: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
}

h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  margin: 0 0 1rem;
  letter-spacing: -0.04em;
  color: var(--text-main);
  line-height: 1.1;
}

.subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}

/* Sections */
.section {
  padding: 4rem 1.5rem;
  scroll-margin-top: 100px;
}

.container {
  max-width: 1050px;
  margin: 0 auto;
}

h2 {
  font-size: 1.75rem;
  text-align: center;
  margin-bottom: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-main);
}

/* Cards */
.card {
  background: var(--card-bg);
  border: var(--border);
  padding: 2rem;
  border-radius: var(--radius);
  transition: all 0.5s ease;
  box-shadow: var(--shadow);
  will-change: transform;
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 122, 255, 0.15);
}

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.card p {
  color: var(--text-muted);
  font-size: 1rem;
}

/* About */
.about-card {
  max-width: 900px;
  margin: 0 auto;
}

.about-description {
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.skills-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.skills-highlight {
  padding: 2.5rem;
  background: var(--card-bg);
  border-radius: 24px;
  border: var(--border);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.03);
  transition: all 0.5s ease;
}

body.dark-theme .skills-highlight {
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.skills-highlight:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
}

.skills-highlight h4 {
  margin: 0 0 1rem;
  color: var(--text-main);
  font-size: 1.2rem;
  font-weight: 800;
}

.skills-highlight p {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Education / Cert grids */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
}

.date {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: var(--bg);
  color: var(--primary);
  font-weight: 600;
  font-size: 0.85rem;
  border-radius: 100px;
  margin-bottom: 1rem;
}

/* Services */
.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  max-width: 900px;
  margin: 0 auto;
}

.service-card {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2.5rem 1.5rem;
}

.service-icon {
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  color: var(--primary);
  border-radius: 24px;
  margin-bottom: 2.5rem;
  transition: transform 0.2s ease, background-color 0.5s ease;
}

.service-card:hover .service-icon {
  transform: scale(1.1);
}

/* Timeline */
.timeline {
  max-width: 1000px;
  margin: 4rem auto;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 150px;
  top: 40px;
  bottom: 40px;
  width: 2px;
  background: rgba(0, 122, 255, 0.2);
  z-index: 1;
}

body.dark-theme .timeline::before {
  background: rgba(0, 122, 255, 0.3);
}

.timeline-item {
  display: grid;
  grid-template-columns: 130px 40px 1fr;
  gap: 0;
  margin-bottom: 3.5rem;
  align-items: start;
}

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

.timeline-date {
  text-align: right;
  padding-right: 2rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  padding-top: 32px;
}

.timeline-dot {
  position: relative;
  width: 20px;
  height: 20px;
  background: var(--bg);
  border: 4px solid var(--primary);
  border-radius: 50%;
  margin-top: 30px;
  z-index: 2;
  box-shadow: 0 0 0 6px rgba(0, 122, 255, 0.05);
  transition: all 0.5s ease;
  margin-left: 10px;
}

.timeline-item:hover .timeline-dot {
  background: var(--primary);
  transform: scale(1.2);
  box-shadow: 0 0 0 10px rgba(0, 122, 255, 0.1);
}

.timeline-content {
  background: var(--card-bg);
  padding: 2rem;
  border-radius: var(--radius);
  border: var(--border);
  box-shadow: var(--shadow);
  transition: all 0.5s ease;
  margin-left: 1.5rem;
}

.timeline-content:hover {
  transform: translateX(10px);
  box-shadow: 0 50px 100px -30px rgba(0, 0, 0, 0.1);
}

.timeline-content .date {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(0, 122, 255, 0.1);
  font-size: 0.85rem;
  font-weight: 700;
  color: #007aff;
  border-radius: 100px;
  margin-bottom: 1rem;
}

.experience-actions {
  margin-top: 1rem;
}

.link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 8px 16px;
  background: var(--bg);
  color: var(--primary);
  text-decoration: none;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.5s ease;
  border: 1px solid rgba(0, 122, 255, 0.1);
}

.link-btn:hover {
  background: #007aff;
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 122, 255, 0.2);
}

.timeline-content h3 {
  font-size: 1.4rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
  font-weight: 700;
}

.timeline-content p {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.6;
}

/* Contacts */
.contacts-section {
  padding: 6rem 1.5rem;
  background: var(--bg);
}

.contacts-card {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  background: var(--card-bg);
  border-radius: 40px;
  overflow: hidden;
  box-shadow: var(--shadow);
  border: var(--border);
}

.contacts-info-panel {
  padding: 5rem;
  background: #111;
  color: #fff;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

body.dark-theme .contacts-info-panel {
  background: #2a2a2a;
}

.contacts-info-panel h2 {
  text-align: left;
  font-size: 2.5rem;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, #e5e5e5 0%, #999999 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

body.dark-theme .contacts-info-panel h2 {
  background: linear-gradient(135deg, #f5f5f7 0%, #8e8e93 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.contacts-subtitle {
  font-size: 1.2rem;
  color: #888888;
  margin-bottom: 4rem;
}

body.dark-theme .contacts-subtitle,
body.dark-theme .contact-item span,
body.dark-theme .contact-item p {
  color: var(--text-muted);
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.contact-icon {
  width: 54px;
  height: 54px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #007aff;
}

body.dark-theme .contact-icon {
  background: rgba(255, 255, 255, 0.05);
}

.contact-item span {
  display: block;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #666666;
  margin-bottom: 0.25rem;
}

.contact-item p {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: #888888;
}

.contacts-form-panel {
  padding: 4rem;
  background: var(--card-bg);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* Contact Form */
.form-field {
  position: relative;
  margin-bottom: 2.5rem;
}

.form-field input,
.form-field textarea {
  width: 100%;
  padding: 1rem 0;
  background: transparent;
  border: none;
  border-bottom: var(--border);
  font-size: 1rem;
  font-family: inherit;
  transition: all 0.5s ease;
  color: var(--text-main);
}

.form-field textarea {
  resize: none;
  overflow-y: hidden;
  min-height: 100px;
}

.form-field label {
  position: absolute;
  top: 1rem;
  left: 0;
  font-size: 1rem;
  color: var(--text-muted);
  pointer-events: none;
  transition: top 0.3s ease, font-size 0.3s ease, color 0.3s ease;
}

.form-field input:focus ~ label,
.form-field textarea:focus ~ label,
.form-field input:not(:placeholder-shown) ~ label,
.form-field textarea:not(:placeholder-shown) ~ label {
  top: -1rem;
  font-size: 0.75rem;
  color: #007aff;
  font-weight: 700;
}

.form-field input:focus,
.form-field textarea:focus {
  outline: none;
  border-bottom-color: #007aff;
}

.contacts-form-panel .submit-btn {
  width: 100%;
  margin-top: 1rem;
}

.submit-btn {
  width: 100%;
  padding: 1.25rem;
  background: #007aff;
  color: #fff;
  border: none;
  border-radius: 16px;
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.5s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  box-shadow: 0 10px 20px -5px rgba(0, 122, 255, 0.3);
}

.submit-btn:hover {
  background: #0056b3;
  transform: translateY(-2px);
  box-shadow: 0 15px 25px -5px rgba(0, 122, 255, 0.4);
}

/* Footer */
footer {
  text-align: center;
  padding: 4rem 1.5rem;
  color: var(--text-muted);
  font-size: 0.9rem;
  border-top: var(--border);
  background: var(--bg);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
}

.footer-socials {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
}

.social-box {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--card-bg);
  border: var(--border);
  color: var(--text-muted);
  transition: all 0.5s ease;
}

.social-box:hover {
  background: var(--bg);
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

/* Lock Button & Modal */
.lock-btn svg {
  transition: transform 0.3s ease;
}

.lock-btn:hover svg {
  transform: scale(1.15);
}

.lock-modal.hidden {
  display: none;
}

.lock-modal {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lock-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.lock-modal-content {
  position: relative;
  background: var(--card-bg);
  border: var(--border);
  border-radius: 24px;
  padding: 3rem 2.5rem;
  width: 90%;
  max-width: 380px;
  text-align: center;
  box-shadow: 0 40px 100px -20px rgba(0, 0, 0, 0.2);
  animation: lockModalIn 0.3s ease;
}

@keyframes lockModalIn {
  from { opacity: 0; transform: scale(0.95) translateY(10px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.lock-modal-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 122, 255, 0.1);
  color: var(--primary);
  border-radius: 50%;
}

.lock-modal-content h3 {
  font-size: 1.4rem;
  font-weight: 800;
  margin: 0 0 0.5rem;
  color: var(--text-main);
}

.lock-modal-content p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0 0 2rem;
}

.lock-modal-content input[type="password"] {
  width: 100%;
  padding: 1rem 1.25rem;
  font-size: 1rem;
  font-family: inherit;
  background: var(--bg);
  border: var(--border);
  border-radius: 12px;
  color: var(--text-main);
  outline: none;
  transition: border-color 0.3s ease;
  box-sizing: border-box;
}

.lock-modal-content input[type="password"]:focus {
  border-color: var(--primary);
}

.lock-error {
  color: #ff3b30;
  font-size: 0.85rem;
  margin: 0.75rem 0 0 !important;
  font-weight: 600;
}

.lock-submit-btn {
  width: 100%;
  padding: 1rem;
  margin-top: 1.25rem;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.3s ease;
}

.lock-submit-btn:hover {
  background: #0056b3;
  transform: translateY(-1px);
}

/* Desktop nav show, hide hamburger */
@media (min-width: 769px) {
  .hamburger {
    display: none;
  }
}

/* Mobile */
@media (max-width: 768px) {
  :root {
    --radius: 24px;
  }

  .section {
    padding: 5rem 1.5rem;
  }

  h1 {
    font-size: clamp(2.5rem, 10vw, 3.5rem);
  }

  h2 {
    font-size: 1.75rem !important;
    margin-bottom: 2.5rem;
  }

  .main-nav {
    top: 0;
    left: 0;
    transform: translateY(0);
    width: 100%;
    max-width: none;
    background: var(--nav-bg);
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
    padding: 12px 1.5rem;
    border-radius: 0;
    border: none;
    border-bottom: var(--border);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
    pointer-events: auto;
  }

  .main-nav.nav-hidden {
    transform: translateY(-100%);
    transition: transform 0.5s ease;
  }

  .nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: 0;
    height: 100%;
  }

  .logo {
    font-size: 1.5rem;
    color: var(--text-main);
    font-weight: 800;
    border-right: none;
    padding-right: 0;
    letter-spacing: -0.04em;
  }

  .hamburger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 4px;
    background: none;
    border: none;
    padding: 8px;
    z-index: 1001;
    pointer-events: auto;
  }

  .hamburger span {
    transition: transform 0.3s ease, opacity 0.3s ease;
  }

  .main-nav.open .hamburger span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .main-nav.open .hamburger span:nth-child(2) {
    opacity: 0;
  }

  .main-nav.open .hamburger span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .lang-switch-container {
    order: -1;
    width: 100%;
    display: flex;
    justify-content: center;
    padding-bottom: 1.5rem;
    border-bottom: var(--border);
    margin-left: 0;
    margin-bottom: 1rem;
  }

  .lang-switch {
    border-left: none;
    padding-left: 0;
    margin-left: 0;
  }

  .lang-btn {
    color: var(--text-muted);
  }

  .lang-btn.active {
    background: var(--border);
    color: var(--text-main);
  }

  .lang-switch span {
    color: var(--text-muted);
    font-size: 0.8rem;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    left: auto;
    width: 85%;
    max-width: 280px;
    height: 100vh;
    background: var(--card-bg);
    backdrop-filter: blur(25px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 6rem 2rem 2rem 2rem;
    gap: 1.5rem;
    z-index: 1000;
    transform: translateX(100%);
    transition: transform 0.5s ease, background-color 0.5s ease;
    border-radius: 0;
    box-shadow: -20px 0 40px rgba(0, 0, 0, 0.08);
    border: none;
    border-left: var(--border);
    pointer-events: auto;
  }

  .main-nav.open .nav-links {
    transform: translateX(0);
  }

  .nav-links li a {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
  }

  .timeline::before {
    left: 15px;
    top: 0;
    bottom: 0;
  }

  .timeline-item {
    display: block;
    padding-left: 40px;
    position: relative;
    margin-bottom: 4rem;
  }

  .timeline-date {
    text-align: left;
    padding-right: 0;
    padding-top: 0;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    display: block;
  }

  .timeline-dot {
    position: absolute;
    left: 15px;
    top: 10px;
    margin-left: -10px;
    margin-top: 0;
    width: 20px;
    height: 20px;
  }

  .timeline-content {
    margin-left: 0;
    padding: 2rem;
  }

  .timeline-content h3 {
    font-size: 1.25rem;
  }

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

  .contacts-card {
    grid-template-columns: 1fr;
  }

  .contacts-info-panel,
  .contacts-form-panel {
    padding: 2.5rem 1.5rem;
  }

  .contacts-info-panel h2 {
    font-size: 2rem;
  }

  body.dark-theme .contacts-info-panel {
    background: #2a2a2a;
  }

  body.dark-theme .contacts-info-panel h2 {
    background: linear-gradient(135deg, #f5f5f7 0%, #8e8e93 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }

  body.dark-theme .contacts-subtitle {
    color: var(--text-muted);
  }
}