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

body {
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #0f172a, #111827, #1e293b);
  color: white;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

.bg {
  position: fixed;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.35;
  z-index: 0;
}

.bg.one {
  background: #8b5cf6;
  top: 40px;
  left: 40px;
}

.bg.two {
  background: #06b6d4;
  bottom: 40px;
  right: 40px;
}

.hero {
  text-align: center;
  padding: 40px 20px 20px;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 10px;
}

.hero p {
  color: #cbd5e1;
  margin-bottom: 14px;
}

.meta {
  display: flex;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  color: #e2e8f0;
}

.container {
  width: 92%;
  max-width: 1100px;
  margin: 20px auto 50px;
  position: relative;
  z-index: 1;
}

.card {
  background: rgba(30, 41, 59, 0.88);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 22px;
  padding: 25px;
  margin-bottom: 25px;
  box-shadow: 0 12px 35px rgba(0,0,0,0.28);
}

.card h2 {
  margin-bottom: 18px;
}

label {
  display: block;
  margin: 12px 0 8px;
  font-weight: bold;
}

textarea,
input {
  width: 100%;
  padding: 14px;
  border-radius: 14px;
  border: 1px solid rgba(255,255,255,0.15);
  background: rgba(255,255,255,0.07);
  color: white;
  outline: none;
}

textarea::placeholder,
input::placeholder {
  color: #cbd5e1;
}

button {
  margin-top: 18px;
  padding: 14px 22px;
  border: none;
  border-radius: 14px;
  background: linear-gradient(135deg, #8b5cf6, #06b6d4);
  color: white;
  font-weight: bold;
  cursor: pointer;
}

button:hover {
  transform: translateY(-1px);
}

.examples {
  margin-top: 20px;
  background: rgba(255,255,255,0.05);
  padding: 16px;
  border-radius: 16px;
}

.examples h3 {
  margin-bottom: 8px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
  margin-bottom: 20px;
}

.small-card {
  background: rgba(255,255,255,0.05);
  padding: 16px;
  border-radius: 16px;
}

.small-card h3 {
  margin-bottom: 8px;
  color: #c4b5fd;
}

.success {
  border: 1px solid rgba(34,197,94,0.4);
}

.block {
  margin-top: 22px;
  background: rgba(255,255,255,0.05);
  padding: 18px;
  border-radius: 18px;
}

.block h3 {
  margin-bottom: 12px;
  color: #67e8f9;
}

#grammarList li,
#exploredList li {
  margin-bottom: 8px;
  line-height: 1.6;
}

.derivation-box,
.tree-box {
  background: rgba(255,255,255,0.06);
  padding: 16px;
  border-radius: 16px;
  margin-bottom: 14px;
}

.derivation-box h4,
.tree-box h4 {
  margin-bottom: 10px;
  color: #facc15;
}

.step {
  padding: 8px 12px;
  margin-bottom: 8px;
  border-radius: 10px;
  background: rgba(255,255,255,0.05);
}

@media (max-width: 700px) {
  .hero h1 {
    font-size: 2.1rem;
  }
}