:root {
  --bg: #0f1221;
  --body-bg: #0b0f1d;
  --panel: #14182b;
  --muted: #8b93a7;
  --txt: #e9ecf1;
  --brand: #7dd3fc;
  --brand-2: #60a5fa;
  --ok: #22c55e;
  --warn: #eab308;
  --err: #ef4444;
  --radius: 18px;
  --gap: 14px;
}

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

html, body {
  height: 100%;
}

body {
  font-family: sans-serif;
  background: linear-gradient(180deg, var(--body-bg), var(--bg) 35%);
  color: var(--txt);
}

header {
  padding: 20px;
  background: linear-gradient(90deg, rgba(96, 165, 250, 0.15), rgba(125, 211, 252, 0.1));
  border-bottom: 1px solid rgba(255, 255,255, 0.06);
}

.container {
  max-width: 1200px;
  margin-inline: auto;
  padding: 14px;
  justify-content: space-between;
}

.brand {
  display: flex; /* Suitable for 1-D layout structure */
  align-items: center;
  gap: 10px;
  font-weight: 700;
}

.brand .logo {
  inline-size: 36px;
  block-size: 36px;
  border-radius: 10px;

  background: url(https://avatars.githubusercontent.com/u/213578506?v=4) center / cover no-repeat;
}

.title {
  font-size: clamp(18px, 2vw, 22px);
}

main {
  max-width: 1516px;
  margin-inline: auto;
  padding: 18px;
  display: grid; /* suitable for designing and structuring 2-d Layouts in CSS */
  grid-template-columns: 280px 1fr 360px;
  gap: var(--gap);
}

@media (max-width: 1100px) {
  main {
    grid-template-columns: 1fr;
  }
}

.card {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.03));
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

.panel {
  padding: 16px;
}

h2, h3 {
  margin: 0 0 12px;
}

.muted {
  color: var(--muted);
  font-size: 13px;
}

.stack {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: space-between;
}

.btn {
  appearance: none;
  border: none;
  background: linear-gradient(180deg, var(--brand-2), var(--brand));
  color: #0b111f;
  font-weight: 700;
  padding: 10px 14px;
  cursor: pointer;
  box-shadow: 0 10px 24px rgba(96, 165, 250, 0.35);
}

.btn.secondary {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--txt);
  box-shadow: none;
}

.btn.warn{
  background: linear-gradient(180deg, #f59e0b, #eab308);
}

.btn.ok {
  background: linear-gradient(180deg, #34d399, #22c55e);
}

.btn.err {
  background: linear-gradient(180deg, #fb7185, #ef4444);
}

.select, select, .text {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: var(--txt);
  padding: 10px 12px;
  border-radius: 12px;
}

textarea.text {
  width: 100%;
  min-height: 120px;
}

.tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.tab {
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.03);
  cursor: pointer;
  font-weight: 700;
  color: #fff;
}

.tab.active {
  background: linear-gradient(180deg, rgba(125, 211, 252, 0.18), rgba(96, 165, 250, 0.18));
  color: #00ff00 !important;
}

.editor-wrap {
  position: relative;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  overflow: hidden;
  min-height: 280px;
  background-color: #0b1020;
}

.editor {
  inline-size: 100%;
  block-size: 380px;
}

iframe.preview {
  inline-size: 100%;
  block-size: 380px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  background-color: #fff;
}

.out {
  background-color: #0a0e1a;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  padding: 10px;
  min-height: 160px;
  overflow: auto;
  white-space: pre-wrap;
}

.footer {
  opacity: 0.7;
  font-size: 12px;
  text-align: center;
  padding: 12px;
}

.kbd {
  font-family: ui-monospace, SFMono-Regular, Melno, Consolas, "Cascadia Code", monospace;
  background-color: #0e1324;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  padding: 2px 6px;
}

.label {
  font-size: 13px;
  color: var(--muted);
}