:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-tertiary: #1a1a1a;
  --text-primary: #ffffff;
  --text-secondary: #a3a3a3;
  --text-muted: #737373;
  --accent: #f5f5f5;
  --accent-secondary: #e5e5e5;
  --border: #262626;
  --border-light: #404040;
  --shadow: rgba(0, 0, 0, 0.5);
  --shadow-light: rgba(0, 0, 0, 0.2);

  --card-bg: #0f0f0f;
  --card-bg-back: #141414; 
  --card-border: #1f1f1f;
  --card-hover-border: #2a2a2a;
  --progress-bg: #1a1a1a;
  --progress-fill: #ffffff;
  --card-shadow: 0 8px 25px -5px rgba(0, 0, 0, 0.3), 0 4px 10px -2px rgba(0, 0, 0, 0.2);
  --card-hover-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.4), 0 12px 20px -8px rgba(0, 0, 0, 0.3);
  --hover-lift: -8px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

.hero {
  text-align: center;
  padding: 3rem 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--space-3);
  font-weight: 700;
  font-size: 50px;
}

.text-blue {
  color: #2563eb;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.navbar {
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  backdrop-filter: blur(20px);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1.25rem;
  transition: transform 0.3s ease;
}

.nav-logo:hover {
  transform: translateY(-1px);
}

.logo-icon {
  width: 2rem;
  height: 2rem;
  color: var(--accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 3rem;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
  padding: 0.5rem 0;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--accent);
  transition: width 0.3s ease;
}

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

.nav-link:hover::after {
  width: 100%;
}

.nav-link.active {
  color: var(--text-primary);
}

.nav-link.active::after {
  width: 100%;
}

.language-switcher {
  display: flex;
  gap: 0.25rem;
  background-color: var(--bg-tertiary);
  border-radius: 0.75rem;
  padding: 0.25rem;
  border: 1px solid var(--border);
}

.lang-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  border-radius: 0.5rem;
  transition: all 0.3s ease;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 500;
}

.lang-btn:hover {
  color: var(--text-primary);
  background-color: var(--border);
}

.lang-btn.active {
  background-color: var(--accent);
  color: var(--bg-primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 0.5rem;
  transition: background-color 0.3s ease;
}

.mobile-menu-btn:hover {
  background-color: var(--bg-tertiary);
}

.mobile-menu-btn svg {
  width: 1.5rem;
  height: 1.5rem;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 1rem;
    gap: 1rem;
  }

  .nav-links.active {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }

  .language-switcher {
    margin-top: 1rem;
  }
}

.main-content {
  margin-top: 5rem;
  min-height: calc(100vh - 10rem);
  padding: 3rem 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.page-header {
  text-align: center;
  margin-bottom: 5rem;
}

.page-title {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.page-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
  font-weight: 400;
}

.category-section {
  margin-bottom: 4rem;
}

.category-header {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.category-title {
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  letter-spacing: -0.01em;
}

.category-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--border-light), transparent);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.skill-card {
  position: relative;
  height: auto; 
  min-height: 280px; 
  cursor: default; 
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  padding: 2.5rem 2rem; 
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  animation: fadeInUp 0.6s ease forwards;
  opacity: 0;
  
  background: radial-gradient(circle at top left, rgba(255, 255, 255, 0.03) 0%, transparent 60%), var(--card-bg);
}

.skill-card:hover {
  transform: translateY(var(--hover-lift)) scale(1.02);
  box-shadow: var(--card-hover-shadow);
}

.progress-container {
  position: relative;
  width: 120px;
  height: 120px;
  margin-bottom: 1.5rem;
}

.progress-svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
  filter: drop-shadow(0 0 10px rgba(255, 255, 255, 0.1));
}

.progress-bg {
  fill: none;
  stroke: var(--progress-bg);
  stroke-width: 6;
  stroke-linecap: round;
}

.progress-fill {
  fill: none;
  stroke: var(--progress-fill);
  stroke-width: 6;
  stroke-linecap: round;
  transition: stroke-dashoffset 1.8s cubic-bezier(0.4, 0, 0.2, 1);
  filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.3));
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  text-shadow: 0 0 8px rgba(255, 255, 255, 0.2);
}

.skill-title {
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 1rem 0; 
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.skill-description {
  color: var(--text-secondary);
  line-height: 1.6;
  text-align: center;
  font-size: 0.95rem;
  max-width: 280px;
  margin: 0;
  font-weight: 400;
  opacity: 0.85;
}

footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 5rem;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  text-align: center;
}

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

@media (max-width: 768px) {
  .main-content {
    margin-top: 4rem;
    padding: 2rem 0;
  }

  .container {
    padding: 0 1rem;
  }

  .page-title {
    font-size: 2.5rem;
  }

  .page-subtitle {
    font-size: 1.125rem;
  }

  .page-header {
    margin-bottom: 3rem;
  }

  .category-header {
    gap: 1rem;
    margin-bottom: 2rem;
  }

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

  .skills-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .skill-card {
    min-height: 260px; 
    padding: 2rem 1.5rem;
    --hover-lift: -4px;
  }

  .progress-container {
    width: 100px;
    height: 100px;
    margin-bottom: 1.25rem;
  }

  .progress-text {
    font-size: 1.3rem;
  }

  .skill-title {
    font-size: 1.4rem;
  }

  .skill-description {
    font-size: 0.9rem;
    max-width: 240px;
  }
}

@media (max-width: 480px) {
  .skill-card {
    min-height: 240px; 
    padding: 1.75rem 1.25rem;
  }
  .progress-container {
    width: 90px;
    height: 90px;
    margin-bottom: 1rem;
  }

  .progress-text {
    font-size: 1.1rem;
  }

  .skill-title {
    font-size: 1.25rem;
  }

  .skill-description {
    font-size: 0.85rem;
    max-width: 220px;
    line-height: 1.6;
  }
}

.skill-card,
.progress-fill {
  will-change: transform, opacity;
}

@media (prefers-reduced-motion: reduce) {
  .skill-card {
    transition-duration: 0.3s;
  }

  .progress-fill {
    transition-duration: 1s;
  }

  .skill-card:hover {
    transform: translateY(-2px);
  }
}

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

.skill-card:nth-child(1) {
  animation-delay: 0.1s;
}
.skill-card:nth-child(2) {
  animation-delay: 0.2s;
}
.skill-card:nth-child(3) {
  animation-delay: 0.3s;
}
.skill-card:nth-child(4) {
  animation-delay: 0.4s;
}
.skill-card:nth-child(5) {
  animation-delay: 0.5s;
}

.contact-section {
  width: 100%;
  max-width: 40rem;
  margin-left: auto;
  margin-right: auto;
  margin-top: 100px;
  padding: 3rem 1rem;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.contact-intro > * + * {
  margin-top: 1rem;
}

.contact-title {
  font-size: 1.875rem;
  line-height: 2.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.contact-description {
  color: var(--text-secondary);
  font-size: 1.125rem;
  line-height: 1.7;
}

.form-group-container {
  display: grid;
  gap: 1.5rem;
  margin-top: 2rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  position: relative;
}

.form-group.focused .form-label {
  color: var(--text-primary);
  transform: translateY(-2px);
}

.form-label {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-weight: 500;
  transition: all 0.3s ease;
}

.form-input,
.form-textarea {
  padding: 0.875rem;
  border: 1px solid var(--border);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  height: 2.75rem;
  width: 100%;
  border-radius: 0.5rem;
  font-size: 0.875rem;
  line-height: 1.25rem;
  transition: all 0.3s ease;
}

.form-input:focus,
.form-textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(245, 245, 255, 0.1);
  outline: none;
  transform: translateY(-1px);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--text-muted);
  opacity: 0.8;
}

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

.form-submit {
  width: 100%;
  margin-top: 1.5rem;
  background-color: var(--accent);
  color: var(--bg-primary);
  padding: 1rem;
  border-radius: 0.5rem;
  border: none;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.form-submit:hover {
  background-color: #2563eb;
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(37, 99, 235, 0.3);
}

.form-submit:active {
  transform: translateY(0);
}

.form-submit.loading {
  pointer-events: none;
  opacity: 0.8;
}

.form-submit.loading::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1rem;
  height: 1rem;
  border: 2px solid transparent;
  border-top: 2px solid currentColor;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  transform: translate(-50%, -50%);
}

@keyframes spin {
  0% {
    transform: translate(-50%, -50%) rotate(0deg);
  }
  100% {
    transform: translate(-50%, -50%) rotate(360deg);
  }
}

.contact-info-block {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  color: var(--text-secondary);
  font-size: 1.125rem;
}

.contact-info-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.contact-info-item a {
  color: var(--accent); 
  text-decoration: none;
  transition: color 0.3s ease;
}

.contact-info-item a:hover {
  color: #2563eb; 
}

.contact-icon {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--accent); 
}

@media (max-width: 768px) {
  .contact-info-block {
    font-size: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

.nav-link:focus-visible,
.lang-btn:focus-visible,
.form-input:focus-visible,
.form-textarea:focus-visible,
.form-submit:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}