* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', sans-serif;
}
/* BACK BUTTON */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  transition: color 0.25s ease, background 0.25s ease, transform 0.25s ease;
}
/* Hover */
.back-btn:hover {
  color: var(--text);
  background: rgba(198, 43, 111, 0.15);
  transform: translateX(-3px);
}

/* Active (click) */
.back-btn:active {
  transform: translateX(-6px) scale(0.98);
  background: rgba(198, 43, 111, 0.25);
}

/* Keyboard accessibility */
.back-btn:focus-visible {
  outline: 2px solid rgba(198, 43, 111, 0.6);
  outline-offset: 4px;
}

body {
  background: linear-gradient(135deg, #0f172a, #111827);
  color: #e5e7eb;
  line-height: 1.8;
}

.progress-bar {
  height: 4px;
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  width: 0%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 9999;
}

.hero {
  padding: 120px 20px 60px;
  text-align: center;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  margin-top: 15px;
  color: #94a3b8;
}

.container {
  max-width: 900px;
  margin: auto;
  padding: 40px 20px;
  background: rgba(255,255,255,0.03);
  backdrop-filter: blur(12px);
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.4);
}

.section {
  margin-bottom: 60px;
  animation: fadeUp 1s ease forwards;
}

.section h2 {
  color: #3b82f6;
  margin-bottom: 20px;
}

.highlight {
  background: rgba(59,130,246,0.1);
  padding: 20px;
  border-radius: 12px;
  margin-top: 20px;
}

.image-placeholder {
  border: 2px dashed #3b82f6;
  padding: 10px;
  text-align: center;
  border-radius: 15px;
  color: #94a3b8;
  margin-bottom: 40px;
}

.code-block {
  background: #0f172a;
  padding: 20px;
  border-radius: 12px;
  margin: 20px 0;
  overflow-x: auto;
}

.cost-card {
  background: rgba(255,255,255,0.05);
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 20px;
  border: 1px solid rgba(255,255,255,0.1);
  transition: 0.3s;
}

.cost-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(59,130,246,0.3);
}

.cta {
  text-align: center;
  padding: 80px 20px;
  background: linear-gradient(135deg, #1e293b, #0f172a);
  margin-top: 80px;
}

.buttons {
  margin-top: 30px;
}

.btn {
  padding: 14px 28px;
  border-radius: 30px;
  text-decoration: none;
  margin: 10px;
  display: inline-block;
  transition: 0.3s;
}

.primary {
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  color: white;
}

.secondary {
  border: 1px solid #3b82f6;
  color: #3b82f6;
}

.btn:hover {
  transform: translateY(-3px);
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}