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

:root {
  --color-primary-main: #6366f1;
  --color-primary-light: #818cf8;
  --color-primary-dark: #4f46e5;
  --color-primary-gradient-start: #6366f1;
  --color-primary-gradient-end: #8b5cf6;

  --color-secondary-main: #ec4899;
  --color-secondary-light: #f472b6;
  --color-secondary-dark: #db2777;

  --color-bg-primary: #0f0f1a;
  --color-bg-secondary: #1a1a2e;
  --color-bg-tertiary: #252542;
  --color-bg-elevated: #32325a;

  --color-text-primary: #ffffff;
  --color-text-secondary: #a1a1aa;
  --color-text-tertiary: #71717a;
  --color-text-muted: #52525b;

  --color-mode-natural: #10b981;
  --color-mode-formal: #6366f1;
  --color-mode-casual: #f59e0b;
  --color-mode-adventure: #ef4444;

  --color-success: #22c55e;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;

  --border-light: rgba(255, 255, 255, 0.1);
  --border-medium: rgba(255, 255, 255, 0.2);
  --border-strong: rgba(255, 255, 255, 0.3);

  --spacing-0: 0;
  --spacing-1: 4px;
  --spacing-2: 8px;
  --spacing-3: 12px;
  --spacing-4: 16px;
  --spacing-5: 20px;
  --spacing-6: 24px;
  --spacing-8: 32px;
  --spacing-10: 40px;
  --spacing-12: 48px;
  --spacing-16: 64px;
  --spacing-20: 80px;
  --spacing-24: 96px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;
  --radius-3xl: 24px;
  --radius-full: 9999px;

  --font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI',
    Roboto, Helvetica, Arial, sans-serif;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-base: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 6px 10px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 10px 16px rgba(0, 0, 0, 0.2);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.5);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: linear-gradient(
    135deg,
    var(--color-bg-primary) 0%,
    var(--color-bg-secondary) 50%,
    var(--color-bg-tertiary) 100%
  );
  color: var(--color-text-primary);
  line-height: 1.5;
  min-height: 100vh;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-5);
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-4);
  }
}

a {
  color: var(--color-primary-light);
  text-decoration: none;
  transition: color 0.2s;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

img {
  max-width: 100%;
  height: auto;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.header {
  padding: var(--spacing-5) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  background: rgba(15, 15, 26, 0.8);
  border-bottom: 1px solid var(--border-light);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  text-decoration: none;
  color: var(--color-text-primary);
}

.logo-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-xl);
  background: linear-gradient(
    135deg,
    var(--color-primary-gradient-start),
    var(--color-primary-gradient-end)
  );
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
}

.logo-icon svg {
  width: 24px;
  height: 24px;
  color: var(--color-text-primary);
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-title {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.logo-subtitle {
  font-size: 11px;
  color: var(--color-text-secondary);
  letter-spacing: 0.05em;
  line-height: 1.2;
}

.nav-links {
  display: flex;
  gap: var(--spacing-6);
  align-items: center;
}

.nav-link {
  color: var(--color-text-secondary);
  font-size: 14px;
  font-weight: 500;
  padding: var(--spacing-2) var(--spacing-3);
  border-radius: var(--radius-md);
  transition: all 0.2s;
}

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

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

.lang-switch {
  display: flex;
  gap: var(--spacing-1);
  background: var(--border-light);
  padding: 2px;
  border-radius: var(--radius-md);
}

.lang-switch a {
  padding: var(--spacing-2) var(--spacing-3);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: all 0.2s;
}

.lang-switch a:hover {
  color: var(--color-text-primary);
}

.lang-switch a.active {
  background: var(--color-primary-main);
  color: var(--color-text-primary);
}

.hero {
  padding: var(--spacing-24) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(
    circle,
    rgba(99, 102, 241, 0.15) 0%,
    transparent 70%
  );
  z-index: -1;
}

.hero-icon {
  width: 120px;
  height: 120px;
  border-radius: var(--radius-3xl);
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.2),
    rgba(139, 92, 246, 0.1)
  );
  border: 1px solid var(--border-light);
  margin: 0 auto var(--spacing-6);
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-icon svg {
  width: 56px;
  height: 56px;
  color: var(--color-text-primary);
}

.hero-title {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: var(--spacing-4);
  background: linear-gradient(
    135deg,
    var(--color-text-primary) 0%,
    var(--color-text-secondary) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 32px;
  }
}

.hero-subtitle {
  font-size: 18px;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto var(--spacing-8);
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-3);
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: var(--spacing-3) var(--spacing-6);
  border-radius: var(--radius-lg);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  letter-spacing: 0.02em;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--color-primary-gradient-start),
    var(--color-primary-gradient-end)
  );
  color: var(--color-text-primary);
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

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

.btn-outline:hover {
  background: var(--border-light);
  border-color: var(--color-primary-light);
}

.btn-icon {
  width: 18px;
  height: 18px;
}

.section {
  padding: var(--spacing-20) 0;
}

.section-title {
  font-size: 28px;
  font-weight: 600;
  text-align: center;
  margin-bottom: var(--spacing-4);
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 15px;
  color: var(--color-text-secondary);
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--spacing-10);
}

.modes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-4);
}

@media (max-width: 768px) {
  .modes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .modes-grid {
    grid-template-columns: 1fr;
  }
}

.mode-card {
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.05),
    rgba(255, 255, 255, 0.02)
  );
  border: 1px solid var(--border-light);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-6);
  text-align: center;
  transition: all 0.3s;
}

.mode-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-medium);
  box-shadow: var(--shadow-lg);
}

.mode-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-xl);
  margin: 0 auto var(--spacing-4);
  display: flex;
  align-items: center;
  justify-content: center;
}

.mode-icon svg {
  width: 32px;
  height: 32px;
}

.mode-natural .mode-icon {
  background: linear-gradient(
    135deg,
    rgba(16, 185, 129, 0.2),
    rgba(52, 211, 153, 0.1)
  );
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.mode-natural .mode-icon svg {
  color: var(--color-mode-natural);
}

.mode-formal .mode-icon {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.2),
    rgba(139, 92, 246, 0.1)
  );
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.mode-formal .mode-icon svg {
  color: var(--color-mode-formal);
}

.mode-casual .mode-icon {
  background: linear-gradient(
    135deg,
    rgba(245, 158, 11, 0.2),
    rgba(251, 191, 36, 0.1)
  );
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.mode-casual .mode-icon svg {
  color: var(--color-mode-casual);
}

.mode-adventure .mode-icon {
  background: linear-gradient(
    135deg,
    rgba(239, 68, 68, 0.2),
    rgba(249, 115, 22, 0.1)
  );
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.mode-adventure .mode-icon svg {
  color: var(--color-mode-adventure);
}

.mode-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--spacing-2);
}

.mode-description {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-4);
}

@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
}

.feature-card {
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.05),
    rgba(255, 255, 255, 0.02)
  );
  border: 1px solid var(--border-light);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-6);
  text-align: center;
  transition: all 0.3s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-medium);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.2),
    rgba(139, 92, 246, 0.1)
  );
  border: 1px solid var(--border-light);
  margin: 0 auto var(--spacing-4);
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  color: var(--color-text-primary);
}

.feature-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--spacing-2);
}

.feature-description {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.footer {
  border-top: 1px solid var(--border-light);
  padding: var(--spacing-8) 0 var(--spacing-6);
  background: var(--color-bg-secondary);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-4);
}

.footer-links {
  display: flex;
  gap: var(--spacing-6);
}

.footer-link {
  color: var(--color-text-secondary);
  font-size: 14px;
  transition: color 0.2s;
}

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

.footer-copyright {
  color: var(--color-text-tertiary);
  font-size: 13px;
}

.footer-contact {
  color: var(--color-text-secondary);
  font-size: 14px;
}

@media (max-width: 768px) {
  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
  }

  .nav-links {
    display: none;
  }
}