:root {
  --bg1: #0f172a;
  --bg2: #1e293b;
  --accent: #60a5fa;
  --card: rgba(255,255,255,0.08);
  --text: #e5e7eb;
  --muted: #94a3b8;
  --ring: rgba(96,165,250,0.5);
  --success: #10b981;
  --error: #ef4444;
  --warning: #f59e0b;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 800px at 10% -10%, #1d4ed8 0%, transparent 60%),
    radial-gradient(800px 600px at 100% 20%, #22d3ee 0%, transparent 60%),
    linear-gradient(180deg, var(--bg1), var(--bg2));
  min-height: 100vh;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px 80px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 36px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, #60a5fa, #22d3ee);
  box-shadow: 0 10px 30px rgba(34,211,238,0.3), inset 0 0 20px rgba(255,255,255,0.2);
  position: relative;
}

.logo::after {
  content: "HTTP";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-weight: 800;
  color: #0b132b;
  font-size: 11px;
  letter-spacing: 0.5px;
}

h1 {
  font-family: Poppins, Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  font-weight: 600;
  margin: 0;
  font-size: 28px;
  letter-spacing: 0.4px;
}

.subtitle {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.hero {
  margin: 32px 0 24px;
  padding: 24px;
  border-radius: 16px;
  background: linear-gradient(180deg, rgba(255,255,255,0.10), rgba(255,255,255,0.06));
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.12);
  box-shadow: 0 20px 60px rgba(2,6,23,0.6), inset 0 1px 0 rgba(255,255,255,0.06);
}

.hero p {
  margin: 0;
  line-height: 1.6;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.card {
  position: relative;
  border-radius: 14px;
  background: var(--card);
  padding: 24px;
  border: 1px solid rgba(255,255,255,0.12);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
  overflow: hidden;
  color: var(--text);
  text-decoration: none;
}

.card:visited {
  color: var(--text);
}

.card .title {
  color: var(--text);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(2,6,23,0.45);
  border-color: var(--ring);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: .3px;
  color: #0b132b;
  background: linear-gradient(135deg, #22d3ee, #60a5fa);
  padding: 6px 12px;
  border-radius: 999px;
  font-weight: 700;
  margin-bottom: 16px;
}

.title {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.desc {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.lab-section {
  background: rgba(255,255,255,0.05);
  border-radius: 12px;
  padding: 20px;
  margin: 20px 0;
  border: 1px solid rgba(255,255,255,0.1);
}

.lab-section h3 {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 18px;
}

.button-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
  margin: 16px 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 16px;
  border-radius: 10px;
  background: rgba(96,165,250,0.15);
  color: #dbeafe;
  text-decoration: none;
  font-weight: 600;
  border: 1px solid rgba(96,165,250,0.35);
  transition: all .2s ease;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 14px;
  cursor: pointer;
}

.btn:hover {
  background: rgba(96,165,250,0.25);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(96,165,250,0.2);
}

.btn.btn-success {
  background: rgba(16,185,129,0.15);
  border-color: rgba(16,185,129,0.35);
  color: #10b981;
}

.btn.btn-success:hover {
  background: rgba(16,185,129,0.25);
}

.btn.btn-error {
  background: rgba(239,68,68,0.15);
  border-color: rgba(239,68,68,0.35);
  color: #ef4444;
}

.btn.btn-error:hover {
  background: rgba(239,68,68,0.25);
}

.btn.btn-warning {
  background: rgba(245,158,11,0.15);
  border-color: rgba(245,158,11,0.35);
  color: #f59e0b;
}

.btn.btn-warning:hover {
  background: rgba(245,158,11,0.25);
}

.form-group {
  margin: 16px 0;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  color: var(--text);
  font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.05);
  color: var(--text);
  font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(96,165,250,0.1);
}

.response-display {
  background: rgba(0,0,0,0.3);
  border-radius: 8px;
  padding: 16px;
  margin: 16px 0;
  border-left: 4px solid var(--accent);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 14px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-all;
}

.response-display.success {
  border-left-color: var(--success);
}

.response-display.error {
  border-left-color: var(--error);
}

.status-indicator {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: 8px;
}

.status-indicator.success {
  background: var(--success);
}

.status-indicator.error {
  background: var(--error);
}

.status-indicator.warning {
  background: var(--warning);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--accent);
  text-decoration: none;
  margin-bottom: 24px;
  font-weight: 500;
}

.back-link:hover {
  text-decoration: underline;
}

footer {
  margin-top: 48px;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

@media (max-width: 768px) {
  .container {
    padding: 24px 16px;
  }

  h1 {
    font-size: 24px;
  }

  .hero {
    padding: 20px;
  }

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

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