:root {
  --bg: #f6f2ea;
  --paper: #fffaf2;
  --ink: #1f2a39;
  --muted: #5e6b76;
  --line: #d8c8b4;
  --accent: #1f6f5d;
  --accent-2: #c46b39;
  --shadow: 0 12px 30px rgba(36, 32, 26, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Noto Serif SC", serif;
  color: var(--ink);
  background: radial-gradient(circle at 20% 20%, #fef5dd, var(--bg) 50%),
    linear-gradient(135deg, #f9f3e8 0%, #f1ebe2 100%);
  min-height: 100vh;
}

.bg-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(50px);
  z-index: 0;
  pointer-events: none;
}

.orb-1 {
  width: 280px;
  height: 280px;
  background: rgba(196, 107, 57, 0.28);
  top: -100px;
  right: -80px;
}

.orb-2 {
  width: 220px;
  height: 220px;
  background: rgba(31, 111, 93, 0.24);
  bottom: -70px;
  left: -60px;
}

.app {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 100vh;
}

.sidebar {
  background: linear-gradient(180deg, #20343a 0%, #132026 100%);
  color: #ecf7f2;
  padding: 24px 18px;
  border-right: 1px solid rgba(255, 255, 255, 0.1);
}

.brand {
  margin-bottom: 18px;
  animation: fadeUp 500ms ease forwards;
}

.brand h1 {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.brand p {
  margin: 10px 0 0;
  font-family: "LXGW WenKai Mono TC", monospace;
  opacity: 0.85;
}

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

.nav button {
  border: 1px solid rgba(236, 247, 242, 0.25);
  background: rgba(236, 247, 242, 0.04);
  color: inherit;
  border-radius: 12px;
  text-align: left;
  padding: 10px 12px;
  font-size: 15px;
  cursor: pointer;
  transition: transform 150ms ease, background-color 150ms ease;
  font-family: "Noto Serif SC", serif;
}

.nav button:hover {
  transform: translateX(4px);
  background: rgba(236, 247, 242, 0.15);
}

.nav button.active {
  background: linear-gradient(90deg, rgba(196, 107, 57, 0.95), rgba(196, 107, 57, 0.7));
  border-color: transparent;
  color: #fff7ef;
}

.content {
  padding: 24px;
}

.content-header {
  margin-bottom: 14px;
  border-bottom: 2px dashed rgba(31, 42, 57, 0.15);
  padding-bottom: 10px;
  animation: fadeUp 600ms ease forwards;
}

.content-header h2 {
  margin: 0;
  font-size: 30px;
}

.content-header p {
  margin: 6px 0 0;
  color: var(--muted);
  font-family: "LXGW WenKai Mono TC", monospace;
}

.view-body {
  display: grid;
  gap: 16px;
  animation: fadeUp 700ms ease forwards;
}

.panel {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.panel-header {
  background: linear-gradient(90deg, rgba(31, 111, 93, 0.13), rgba(196, 107, 57, 0.08));
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  font-family: "LXGW WenKai Mono TC", monospace;
  font-size: 14px;
}

.panel-body {
  padding: 14px 16px;
}

.tab-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.tab-row button {
  border: 1px solid var(--line);
  background: #fff;
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  font-family: "LXGW WenKai Mono TC", monospace;
}

.tab-row button.active {
  border-color: transparent;
  background: linear-gradient(120deg, var(--accent) 0%, #2f8e78 100%);
  color: #ffffff;
}

.markdown {
  line-height: 1.7;
}

.markdown h1,
.markdown h2,
.markdown h3 {
  margin-top: 1.1em;
  margin-bottom: 0.45em;
  color: #142731;
}

.markdown p,
.markdown li {
  color: #253340;
}

.markdown code {
  background: #f3ede2;
  border: 1px solid #e5d6bf;
  border-radius: 5px;
  padding: 1px 4px;
}

.markdown pre {
  background: #f0eadf;
  border: 1px solid #dfcfb6;
  border-radius: 12px;
  padding: 10px;
  overflow-x: auto;
}

.markdown blockquote {
  margin: 0;
  border-left: 4px solid var(--accent-2);
  padding-left: 12px;
  color: #4a5966;
}

.markdown table {
  border-collapse: collapse;
  width: 100%;
}

.markdown th,
.markdown td {
  border: 1px solid #dac8ac;
  padding: 6px 8px;
}

.markdown th {
  background: #f2e8d6;
}

.error {
  color: #7a1c1c;
  background: #ffefef;
  border: 1px solid #eababa;
  border-radius: 10px;
  padding: 10px;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 900px) {
  .app {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: sticky;
    top: 0;
    z-index: 5;
    padding-bottom: 12px;
  }

  .nav {
    flex-direction: row;
    overflow-x: auto;
    padding-bottom: 8px;
  }

  .nav button {
    white-space: nowrap;
  }

  .content {
    padding: 16px;
  }

  .content-header h2 {
    font-size: 24px;
  }
}