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

:root {
  --primary-green: #166534;
  --primary-green-light: #22c55e;
  --primary-green-dark: #15803d;
  --accent-yellow: #f59e0b;
  --accent-yellow-light: #fbbf24;

  --bg-main: #f0fdf4;
  --bg-white: #ffffff;
  --bg-gray: #f9fafb;

  --text-dark: #1a1a1a;
  --text-gray: #6b7280;
  --text-light: #9ca3af;

  --fd-color: #3b82f6;
  --fd-bg: #dbeafe;
  --bonds-color: #f59e0b;
  --bonds-bg: #fef3c7;
  --mf-color: #8b5cf6;
  --mf-bg: #e0e7ff;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-dark);
  line-height: 1.6;
  min-height: 100vh;
}

.header {
  background: linear-gradient(
    135deg,
    var(--primary-green) 0%,
    var(--primary-green-dark) 100%
  );
  color: white;
  padding: 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 600px;
  margin: 0 auto;
}

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

.logo-icon {
  font-size: 1.75rem;
  animation: pulse-grow 2s ease-in-out infinite;
}

@keyframes pulse-grow {
  0%,
  100% {
    transform: scale(1);
  }

  50% {
    transform: scale(1.1);
  }
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.language-toggle {
  display: flex;
  gap: 0.25rem;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  padding: 0.25rem;
}

.lang-btn {
  background: transparent;
  border: none;
  color: white;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.875rem;
  transition: all 0.2s ease;
}

.lang-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

.lang-btn.active {
  background: white;
  color: var(--primary-green);
}

.tagline {
  text-align: center;
  font-size: 0.875rem;
  opacity: 0.9;
  margin-top: 0.5rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.lang-btn:focus {
  outline: 3px solid var(--accent-yellow);
  outline-offset: 2px;
}

/* Large screens */
@media (min-width: 768px) {
  .header {
    padding: 1.25rem 2rem;
  }

  .logo-text {
    font-size: 1.75rem;
  }

  .tagline {
    font-size: 1rem;
  }
}