* {
  box-sizing: border-box;
  font-family: "Segoe UI", system-ui, sans-serif;
}

body {
  margin: 0;
  background: #020617;
  color: #e5e7eb;
}

header {
  padding: 30px;
  background: linear-gradient(135deg, #020617, #020617);
  border-bottom: 1px solid #1e293b;
}

header h1 {
  margin: 0;
  color: #38bdf8;
}

main {
  max-width: 900px;
  margin: auto;
  padding: 30px;
}

.card {
  background: #0b1220;
  padding: 25px;
  border-radius: 12px;
  margin-bottom: 25px;
  border-left: 4px solid #38bdf8;
}

label {
  font-size: 16px;
  display: block;
  margin-bottom: 10px;
}

select {
  width: 100%;
  padding: 12px;
  background: #020617;
  color: white;
  border: 1px solid #334155;
  border-radius: 8px;
  font-size: 15px;
}

.hidden {
  display: none;
}

.step {
  margin-bottom: 25px;
}

.step h3 {
  color: #38bdf8;
  margin-bottom: 5px;
}

.step p {
  margin: 8px 0;
}

pre {
  background: #020617;
  padding: 15px;
  border-radius: 8px;
  overflow-x: auto;
  border: 1px solid #334155;
}

code {
  color: #a5f3fc;
}

.ethics {
  font-size: 13px;
  opacity: 0.7;
  margin-top: 30px;
}

footer {
  text-align: center;
  padding: 20px;
  font-size: 13px;
  opacity: 0.5;
}

.intro-box {
  margin-top: 30px;
  padding: 25px;
  background: #020617;
  border-radius: 12px;
  border: 1px solid #1e293b;
}

.intro-box h2 {
  margin-bottom: 10px;
}

.intro-box ol {
  margin-left: 20px;
}

.beginner-note {
  margin-top: 20px;
  padding: 15px;
  background: #020617;
  border-left: 4px solid #38bdf8;
  border-radius: 8px;
  opacity: 0.9;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 15px;
  margin-top: 30px;
}

.feature-card {
  background: #020617;
  padding: 15px;
  border-radius: 10px;
  text-align: center;
  border: 1px solid #1e293b;
  font-size: 14px;
}

.tip-box {
  margin-top: 25px;
  padding: 15px;
  background: #020617;
  border-radius: 10px;
  border-left: 4px solid #22c55e;
  font-size: 14px;
  opacity: 0.9;
}

.why-box {
  margin-top: 20px;
  background: #020617;
  padding: 15px;
  border-radius: 10px;
  border: 1px solid #1e293b;
  cursor: pointer;
}

.why-box summary {
  font-weight: bold;
  margin-bottom: 8px;
}

.why-box p {
  font-size: 14px;
  opacity: 0.85;
}