:root {
  --ink: #1a1f1c;
  --ink-soft: #3d4741;
  --muted: #6b756f;
  --line: #d5ddd6;
  --paper: #f3f0e8;
  --paper-deep: #e8e3d6;
  --panel: #faf8f3;
  --accent: #1f5c45;
  --accent-soft: #d8ebe2;
  --warn: #8a5a2b;
  --preview-bg: #1e2421;
  --preview-ink: #e8efe9;
  --preview-dim: #9aaba0;
  --shadow: 0 18px 40px rgba(26, 31, 28, 0.08);
  --radius: 14px;
  --font: "DM Sans", system-ui, sans-serif;
  --serif: "Libre Baskerville", Georgia, serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 100% -10%, rgba(31, 92, 69, 0.12), transparent 55%),
    radial-gradient(ellipse 60% 40% at 0% 100%, rgba(138, 90, 43, 0.08), transparent 50%),
    linear-gradient(165deg, #efebe1 0%, var(--paper) 45%, #e9efe9 100%);
  background-attachment: fixed;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.hidden {
  display: none !important;
}

.app {
  display: grid;
  grid-template-columns: 300px 1fr;
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  padding: 1.5rem 1.1rem 1.5rem 1.25rem;
  background: rgba(250, 248, 243, 0.92);
  border-right: 1px solid var(--line);
  backdrop-filter: blur(10px);
  overflow: hidden;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.25rem 0.35rem;
}

.tool-link {
  display: block;
  margin: 0 0.35rem;
  padding: 0.55rem 0.7rem;
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid #c2ddd0;
}

.tool-link:hover {
  background: #cfe6db;
}

.brand-mark {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 8px;
  background:
    linear-gradient(135deg, var(--accent) 0%, #2f7a5c 55%, #8a5a2b 100%);
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.2);
}

.brand-name {
  margin: 0;
  font-family: var(--serif);
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.brand-tag {
  margin: 0.1rem 0 0;
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.search-wrap input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.7rem 0.85rem;
  font: inherit;
  font-size: 0.92rem;
  background: #fff;
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.search-wrap input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.nav {
  overflow-y: auto;
  padding-right: 0.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.nav-group h2 {
  margin: 0 0 0.4rem 0.35rem;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.nav-group ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.nav-link {
  display: block;
  width: 100%;
  text-align: left;
  border: 0;
  background: transparent;
  color: var(--ink-soft);
  font: inherit;
  font-size: 0.92rem;
  padding: 0.55rem 0.7rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}

.nav-link:hover {
  background: var(--paper-deep);
  color: var(--ink);
}

.nav-link.active {
  background: var(--accent);
  color: #f5faf7;
  font-weight: 600;
}

.main-wrap {
  min-width: 0;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.75rem 0;
}

.menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  cursor: pointer;
}

.menu-btn span {
  display: block;
  width: 1rem;
  height: 2px;
  margin: 0 auto;
  background: var(--ink);
}

.topbar-hint {
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.main {
  padding: 1.25rem 1.75rem 3rem;
}

.home h1 {
  margin: 0.35rem 0 0.85rem;
  font-family: var(--serif);
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
  font-weight: 700;
}

.eyebrow {
  margin: 0;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

.lede {
  margin: 0 0 2rem;
  max-width: 38rem;
  font-size: 1.05rem;
  line-height: 1.55;
  color: var(--ink-soft);
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.cat-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(250, 248, 243, 0.85);
  padding: 1.15rem 1.2rem 1.25rem;
  box-shadow: var(--shadow);
  transition: transform 0.15s, border-color 0.15s;
}

.cat-card:hover {
  transform: translateY(-2px);
  border-color: #b7c7bc;
}

.cat-card h2 {
  margin: 0 0 0.75rem;
  font-family: var(--serif);
  font-size: 1.15rem;
}

.cat-card ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.cat-card button {
  border: 0;
  background: transparent;
  color: var(--accent);
  font: inherit;
  font-size: 0.92rem;
  text-align: left;
  padding: 0.35rem 0;
  cursor: pointer;
}

.cat-card button:hover {
  text-decoration: underline;
}

.detail {
  animation: fade-in 0.25s ease;
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.detail-header {
  margin-bottom: 1.5rem;
}

.detail-header .back {
  border: 0;
  background: transparent;
  color: var(--accent);
  font: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  padding: 0;
  margin-bottom: 0.85rem;
  cursor: pointer;
}

.detail-header h1 {
  margin: 0.25rem 0 0.6rem;
  font-family: var(--serif);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  letter-spacing: -0.02em;
}

.detail-header .summary {
  margin: 0;
  max-width: 42rem;
  color: var(--ink-soft);
  line-height: 1.55;
  font-size: 1.02rem;
}

.download-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  margin-top: 1.1rem;
}

.home-downloads {
  margin: 0 0 1.75rem;
}

.dl-label {
  width: 100%;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.15rem;
}

@media (min-width: 700px) {
  .dl-label {
    width: auto;
    margin: 0 0.35rem 0 0;
  }
}

.dl-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink-soft);
  font: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.45rem 0.7rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, color 0.12s;
}

.dl-btn:hover {
  border-color: #b7c7bc;
  color: var(--ink);
  background: var(--panel);
}

.dl-btn:disabled {
  opacity: 0.65;
  cursor: wait;
}

.dl-btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #f5faf7;
}

.dl-btn-primary:hover {
  background: #184a37;
  border-color: #184a37;
  color: #fff;
}

.dl-btn-accent {
  background: var(--warn);
  border-color: var(--warn);
  color: #fff;
}

.dl-btn-accent:hover {
  filter: brightness(0.95);
  color: #fff;
}

.preview-actions {
  display: flex;
  gap: 0.4rem;
}

.detail-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
  gap: 1.25rem;
  align-items: start;
}

.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(250, 248, 243, 0.9);
  padding: 1.2rem 1.25rem 1.35rem;
  box-shadow: var(--shadow);
}

.panel h2 {
  margin: 0 0 0.85rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.parts {
  margin: 0;
  padding-left: 1.15rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  color: var(--ink-soft);
  line-height: 1.4;
}

.tips {
  margin: 1.15rem 0 0;
  padding: 0.9rem 1rem;
  border-radius: 10px;
  background: var(--accent-soft);
  border: 1px solid #c2ddd0;
}

.tips h3 {
  margin: 0 0 0.45rem;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

.tips ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
  line-height: 1.45;
}

.preview-panel {
  background: var(--preview-bg);
  border-color: #2c3530;
  color: var(--preview-ink);
}

.preview-panel h2 {
  color: var(--preview-dim);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.copy-btn {
  border: 1px solid #3d4a43;
  background: #2a322e;
  color: var(--preview-ink);
  font: inherit;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.35rem 0.6rem;
  border-radius: 6px;
  cursor: pointer;
}

.copy-btn:hover {
  background: #35413b;
}

.preview {
  margin: 0;
  white-space: pre-wrap;
  font-family: var(--mono);
  font-size: 0.78rem;
  line-height: 1.55;
  color: var(--preview-ink);
  overflow-x: auto;
}

.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(20, 24, 22, 0.45);
  z-index: 20;
}

@media (max-width: 960px) {
  .detail-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 800px) {
  .app {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: min(300px, 88vw);
    z-index: 30;
    transform: translateX(-105%);
    transition: transform 0.2s ease;
    box-shadow: var(--shadow);
  }

  .sidebar.open {
    transform: none;
  }

  .menu-btn {
    display: flex;
  }

  .main {
    padding: 1rem 1.1rem 2.5rem;
  }

  .topbar {
    padding: 0.85rem 1.1rem 0;
  }

  .topbar-hint {
    display: none;
  }
}