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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: #0f172a;
  color: #e2e8f0;
  min-height: 100vh;
  line-height: 1.6;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

header {
  text-align: center;
  margin-bottom: 2.5rem;
}

header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: #f8fafc;
  margin-bottom: 0.5rem;
}

.highlight {
  color: #38bdf8;
}

.subtitle {
  font-size: 1.1rem;
  color: #94a3b8;
}

.card {
  background: #1e293b;
  border-radius: 12px;
  padding: 2rem;
  border: 1px solid #334155;
  margin-bottom: 3rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #cbd5e1;
}

input[type="text"] {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid #475569;
  border-radius: 8px;
  background: #0f172a;
  color: #f1f5f9;
  font-size: 1rem;
  transition: border-color 0.2s;
}

input[type="text"]:focus {
  outline: none;
  border-color: #38bdf8;
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

input[type="text"]::placeholder {
  color: #64748b;
}

small {
  display: block;
  margin-top: 0.35rem;
  color: #64748b;
  font-size: 0.85rem;
}

.radio-group {
  display: flex;
  gap: 1.5rem;
  margin-top: 0.25rem;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-weight: 400;
  color: #e2e8f0;
}

input[type="radio"] {
  accent-color: #38bdf8;
  width: 18px;
  height: 18px;
}

button[type="submit"] {
  width: 100%;
  padding: 0.85rem;
  background: #38bdf8;
  color: #0f172a;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.2s;
}

button[type="submit"]:hover {
  background: #7dd3fc;
}

button[type="submit"]:disabled {
  background: #475569;
  cursor: not-allowed;
}

.result {
  margin-top: 1.5rem;
  padding: 1.25rem;
  background: #0f172a;
  border-radius: 8px;
  border: 1px solid #22d3ee;
}

.result p {
  color: #94a3b8;
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}

.url-box {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: #1e293b;
  padding: 0.75rem 1rem;
  border-radius: 6px;
  margin-bottom: 0.75rem;
}

.url-box a {
  flex: 1;
  color: #38bdf8;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.05rem;
  word-break: break-all;
}

.url-box a:hover {
  text-decoration: underline;
}

#copyBtn {
  padding: 0.5rem 1rem;
  background: #334155;
  color: #e2e8f0;
  border: 1px solid #475569;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background 0.2s;
}

#copyBtn:hover {
  background: #475569;
}

.info {
  color: #64748b !important;
  font-size: 0.82rem !important;
  margin-bottom: 0 !important;
}

.error {
  margin-top: 1rem;
  padding: 1rem;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid #ef4444;
  border-radius: 8px;
  color: #fca5a5;
}

.hidden {
  display: none;
}

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.feature {
  background: #1e293b;
  padding: 1.5rem;
  border-radius: 10px;
  border: 1px solid #334155;
}

.feature h3 {
  color: #38bdf8;
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.feature p {
  color: #94a3b8;
  font-size: 0.9rem;
}

.how-it-works {
  margin-bottom: 3rem;
}

.how-it-works h2 {
  text-align: center;
  font-size: 1.5rem;
  color: #f8fafc;
  margin-bottom: 1.5rem;
}

.steps {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.step {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: #1e293b;
  padding: 1.25rem;
  border-radius: 10px;
  border: 1px solid #334155;
}

.step-number {
  width: 36px;
  height: 36px;
  min-width: 36px;
  border-radius: 50%;
  background: #38bdf8;
  color: #0f172a;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}

.step p {
  color: #cbd5e1;
  font-size: 0.95rem;
}

footer {
  text-align: center;
  color: #475569;
  font-size: 0.85rem;
  border-top: 1px solid #1e293b;
  padding-top: 1.5rem;
}

@media (max-width: 640px) {
  header h1 {
    font-size: 1.8rem;
  }

  .features {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 1.5rem;
  }

  .radio-group {
    flex-direction: column;
    gap: 0.75rem;
  }
}