:root {
  --bg: #1a1d24;
  --text: #f4f4f4;
  --accent: #00ffe7;
  --card: #242833;
  --bg-light: #f7f7f7;
  --text-light: #1a1d24;
  --accent-light: #00bfa6;
  --bg-cyber: #0f0f1b;
  --text-cyber: #00ffea;
  --accent-cyber: #ff00ff;
  --card-cyber: #1a1a2e;
  --terminal-bg: #000;
  --terminal-text: #0f0;
  --terminal-cursor: #0f0;
  --mobile-padding: 20px;
}

[data-theme="light"] {
  --bg: var(--bg-light);
  --text: var(--text-light);
  --accent: var(--accent-light);
  --card: #ffffff;
  --terminal-bg: #f0f0f0;
  --terminal-text: #333;
  --terminal-cursor: #00bfa6;
}

[data-theme="cyber"] {
  --bg: var(--bg-cyber);
  --text: var(--text-cyber);
  --accent: var(--accent-cyber);
  --card: var(--card-cyber);
  --terminal-bg: #000;
  --terminal-text: #ff00ff;
  --terminal-cursor: #ff00ff;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Rubik', sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background 0.5s ease, color 0.5s ease;
  overflow-x: hidden;
}

/* Header (шапка) */
header {
  background: var(--bg);
  padding: 20px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 4px 20px rgba(0, 255, 204, 0.1);
  transition: all 0.5s ease;
}

.logo {
  cursor: pointer;
  position: relative;
  font-size: 24px;
  color: var(--accent);
  animation: glow 2s infinite alternate;
  padding: 5px 10px;
  border-radius: 8px;
  transition: all 0.3s ease;
}

.logo:hover {
  transform: scale(1.05);
  background: rgba(0, 255, 231, 0.1);
}

@keyframes glow {
  from { text-shadow: 0 0 5px var(--accent); }
  to { text-shadow: 0 0 15px var(--accent), 0 0 20px var(--accent); }
}

nav {
  display: flex;
  align-items: center;
}

nav a {
  color: var(--text);
  margin-left: 20px;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

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

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

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

.theme-toggle {
  background: none;
  border: 2px solid var(--accent);
  color: var(--accent);
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 120px;
}

.theme-toggle::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 255, 231, 0.2), transparent);
  transition: 0.5s;
}

.theme-toggle:hover::before {
  left: 100%;
}

.theme-toggle:hover {
  transform: scale(1.05);
  box-shadow: 0 0 10px var(--accent);
}

.theme-icon {
  margin-right: 8px;
  transition: all 0.3s ease;
}

/* Герой-секция */
.hero {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  padding: 60px 10%;
  position: relative;
}

.hero-text {
  max-width: 600px;
}

.hero-text h2 {
  font-size: 48px;
  margin-bottom: 20px;
  color: var(--accent);
  line-height: 1.2;
}

.hero-text p {
  font-size: 20px;
  color: #aaa;
  margin-bottom: 30px;
}

.buttons {
  display: flex;
  flex-wrap: wrap;
}

.buttons a {
  background: var(--accent);
  color: var(--bg);
  padding: 14px 28px;
  margin: 5px;
  border-radius: 12px;
  text-decoration: none;
  display: inline-block;
  font-weight: 500;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.buttons a::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.1);
  transition: width 0.3s;
  z-index: -1;
}

.buttons a:hover::before {
  width: 100%;
}

.buttons a:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 20px rgba(0, 255, 231, 0.3);
}

.hero-img {
  max-width: 400px;
  flex: 1;
  margin-top: 30px;
}

/* Терминал */
.terminal {
  background-color: var(--terminal-bg);
  color: var(--terminal-text);
  font-family: 'Fira Code', monospace;
  padding: 16px;
  border-radius: 12px;
  max-height: 250px;
  overflow-y: auto;
  white-space: pre-wrap;
  box-shadow: 0 0 20px rgba(0, 255, 204, 0.2);
  font-size: 14px;
  transition: all 0.5s ease;
  border: 1px solid var(--accent);
}

.terminal-header {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}

.terminal-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  margin-right: 6px;
}

.terminal-dot.red {
  background-color: #ff5f56;
}

.terminal-dot.yellow {
  background-color: #ffbd2e;
}

.terminal-dot.green {
  background-color: #27c93f;
}

.terminal-title {
  flex-grow: 1;
  text-align: center;
  font-weight: bold;
  color: var(--terminal-text);
}

.terminal-input-line {
  display: flex;
  align-items: center;
}

.terminal-prompt {
  color: var(--accent);
  margin-right: 8px;
}

.terminal-input {
  background: transparent;
  border: none;
  outline: none;
  color: var(--terminal-text);
  width: 100%;
  font-family: inherit;
  caret-color: var(--terminal-cursor);
}

.terminal-output {
  margin-bottom: 10px;
}

/* Секции */
section {
  padding: 60px 10%;
}

.section-title {
  font-size: 32px;
  margin-bottom: 30px;
  text-align: center;
  color: var(--accent);
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

/* Карточки */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
}

.card {
  background: var(--card);
  border-radius: 16px;
  padding: 30px;
  box-shadow: 0 0 20px rgba(0,255,204,0.05);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent);
  transition: height 0.3s ease;
}

.card:hover::before {
  height: 100%;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(0, 255, 231, 0.2);
}

.card h3 {
  margin-bottom: 15px;
  color: var(--accent);
  position: relative;
  z-index: 1;
}

.card p {
  color: #ccc;
  position: relative;
  z-index: 1;
}

/* Подвал */
footer {
  text-align: center;
  padding: 20px;
  color: #888;
  background: var(--bg);
  border-top: 1px solid #333;
  transition: all 0.5s ease;
}

/* Лого-анимация */
.logo-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 9999;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s ease;
}

.logo-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.logo-animation {
  font-size: 5rem;
  color: var(--accent);
  text-shadow: 0 0 20px var(--accent);
  animation: pulse 1.5s infinite alternate, glow 2s infinite alternate;
}

@keyframes pulse {
  0% { transform: scale(1); }
  100% { transform: scale(1.1); }
}

/* Партиклы */
.particles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
}

.particle {
  position: absolute;
  background: var(--accent);
  border-radius: 50%;
  opacity: 0.3;
  animation: float linear infinite;
}

@keyframes float {
  0% { transform: translateY(0) translateX(0); }
  50% { transform: translateY(-100px) translateX(100px); }
  100% { transform: translateY(0) translateX(0); }
}

/* Кнопка "Наверх" */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--accent);
  color: var(--bg);
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
  box-shadow: 0 0 10px rgba(0, 255, 231, 0.5);
}

.scroll-top.active {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 0 20px rgba(0, 255, 231, 0.8);
}

/* Мобильная адаптация */
@media (max-width: 768px) {
  header {
    padding: 15px var(--mobile-padding);
    flex-direction: column;
    align-items: flex-start;
  }
  
  nav {
    margin-top: 15px;
    width: 100%;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
  }
  
  nav a {
    margin: 0 5px;
    font-size: 14px;
  }
  
  .theme-toggle {
    padding: 6px 12px;
    min-width: auto;
    font-size: 14px;
    margin-top: 15px;
    align-self: center;
  }
  
  .hero {
    padding: 40px var(--mobile-padding);
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .hero-text h2 {
    font-size: 32px;
  }
  
  .hero-text p {
    font-size: 16px;
  }
  
  .buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .buttons a {
    width: 100%;
    max-width: 250px;
    margin: 5px 0;
    padding: 12px 20px;
  }
  
  .hero-img {
    margin-top: 40px;
    max-width: 100%;
  }
  
  section {
    padding: 40px var(--mobile-padding);
  }
  
  .section-title {
    font-size: 28px;
    width: 100%;
  }
  
  .cards {
    grid-template-columns: 1fr;
  }
  
  .card {
    padding: 20px;
  }
  
  .terminal {
    font-size: 12px;
    max-height: 200px;
  }
  
  .logo-animation {
    font-size: 3rem;
  }
  
  .section-title::after {
    bottom: -5px;
    height: 2px;
  }
  
  .scroll-top {
    width: 40px;
    height: 40px;
    bottom: 20px;
    right: 20px;
  }
}

@media (max-width: 480px) {
  :root {
    --mobile-padding: 15px;
  }
  
  .hero-text h2 {
    font-size: 28px;
  }
  
  nav {
    justify-content: center;
  }
  
  nav a {
    margin: 5px;
    font-size: 12px;
  }
  
  .terminal {
    padding: 12px;
    font-size: 11px;
  }
  
  .logo {
    font-size: 20px;
  }
  
  .section-title {
    font-size: 24px;
  }
}