:root {
  color-scheme: dark;
  --bg: #101114;
  --surface: #181a1f;
  --surface-soft: #20232a;
  --surface-strong: #272b33;
  --line: #343945;
  --text: #f2f0ea;
  --muted: #a9a59c;
  --quiet: #7d7a73;
  --accent: #8fd14f;
  --accent-strong: #b8e986;
  --amber: #f0b45b;
  --rose: #e27a7a;
  --ink: #08090b;
  --radius: 8px;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.36);
}

* {
  box-sizing: border-box;
}

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

body {
  min-height: 100vh;
  background:
    linear-gradient(180deg, rgba(143, 209, 79, 0.06), transparent 280px),
    var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.45;
  overflow-x: hidden;
}

button,
input,
select,
textarea {
  font: inherit;
  min-width: 0;
}

.app-shell {
  width: min(1440px, 100%);
  margin: 0 auto;
  padding: 24px 24px 72px;
}

.topbar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 20px;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--accent-strong);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-size: 2.15rem;
  line-height: 1;
  letter-spacing: 0;
}

.intro {
  max-width: 720px;
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.98rem;
}

h2 {
  font-size: 0.95rem;
  letter-spacing: 0;
}

h3 {
  margin: 0;
  font-size: 0.86rem;
  letter-spacing: 0;
}

.mode-switch {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
  padding: 4px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.mode-btn,
.btn {
  border: 0;
  border-radius: 6px;
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
}

.mode-btn {
  min-width: 104px;
  padding: 9px 14px;
  background: transparent;
  color: var(--muted);
  font-weight: 800;
}

.mode-btn.is-active {
  background: var(--accent);
  color: var(--ink);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 520px);
  gap: 18px;
  align-items: start;
}

.composer {
  display: grid;
  gap: 14px;
}

.panel,
.preview-panel {
  background: var(--surface);
  background: color-mix(in srgb, var(--surface) 94%, black);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 38px rgba(0, 0, 0, 0.28);
  min-width: 0;
}

.panel {
  padding: 18px;
}

.panel-heading,
.preview-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.panel-heading {
  flex-wrap: wrap;
}

.hint,
.counter,
.preview-head p {
  color: var(--quiet);
  font-size: 0.78rem;
  font-weight: 700;
}

.grid {
  display: grid;
  gap: 12px;
}

.grid.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: stretch;
}

.field {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 7px;
  margin-bottom: 13px;
}

.grid .field {
  margin-bottom: 0;
}

.field:last-child {
  margin-bottom: 0;
}

.field > span,
.slider-field > span {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 800;
}

input[type="text"],
select,
textarea {
  width: 100%;
  min-height: 42px;
  background: var(--surface-soft);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px 11px;
  outline: none;
}

textarea {
  min-height: 74px;
  resize: vertical;
}

.grid.two textarea {
  min-height: 116px;
}

select {
  appearance: none;
  background-image:
    linear-gradient(45deg, transparent 50%, var(--accent-strong) 50%),
    linear-gradient(135deg, var(--accent-strong) 50%, transparent 50%);
  background-position:
    calc(100% - 17px) 50%,
    calc(100% - 12px) 50%;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 34px;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(143, 209, 79, 0.15);
}

.slider-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 14px;
}

.slider-field {
  display: grid;
  grid-template-columns: minmax(78px, 96px) minmax(0, 1fr) 28px;
  align-items: center;
  gap: 10px;
  padding: 10px;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.slider-field strong {
  color: var(--accent-strong);
  text-align: right;
}

.sample-card,
.advanced-banner,
.advanced-guide article,
.helper-block {
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.sample-card {
  display: grid;
  gap: 14px;
  margin-bottom: 14px;
  padding: 14px;
}

.sample-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.sample-head p,
.sample-dialog p,
.advanced-banner p,
.advanced-guide p,
.helper-block p {
  color: var(--muted);
  font-size: 0.84rem;
}

.sample-head p {
  margin-top: 3px;
}

.sample-head span,
.advanced-banner span {
  flex: 0 0 auto;
  padding: 4px 8px;
  background: rgba(143, 209, 79, 0.14);
  color: var(--accent-strong);
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 900;
}

.sample-dialog {
  display: grid;
  gap: 8px;
  padding: 12px;
  background: #101216;
  border: 1px solid rgba(255, 255, 255, 0.04);
  border-radius: 6px;
}

.sample-dialog strong {
  display: inline-block;
  min-width: 50px;
  color: var(--accent-strong);
}

.helper-block {
  margin-bottom: 14px;
  padding: 0;
}

.helper-block summary {
  cursor: pointer;
  padding: 11px 12px;
  color: var(--text);
  font-size: 0.84rem;
  font-weight: 900;
}

.helper-block p {
  padding: 0 12px 12px;
}

input[type="range"] {
  appearance: none;
  width: 100%;
  height: 5px;
  background: var(--surface-strong);
  border-radius: 999px;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--surface-soft);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--surface-soft);
}

.advanced-banner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 14px;
  padding: 14px;
  border-color: rgba(143, 209, 79, 0.42);
  box-shadow: inset 3px 0 0 var(--accent);
}

.advanced-banner strong {
  display: block;
  margin-bottom: 4px;
}

.advanced-guide {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 14px;
}

.advanced-guide article {
  padding: 12px;
}

.advanced-guide h3 {
  margin-bottom: 5px;
}

.checkbox-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 14px;
}

.checkbox-grid label {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  min-height: 42px;
  padding: 9px 10px;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 700;
}

input[type="checkbox"] {
  flex: 0 0 auto;
  width: 17px;
  height: 17px;
  margin-top: 2px;
  accent-color: var(--accent);
}

.preview-column {
  position: sticky;
  top: 18px;
}

.preview-panel {
  padding: 16px;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr) auto;
  max-height: calc(100vh - 36px);
}

.health {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: 12px;
}

.health span {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 3px 8px;
  border-radius: 999px;
  font-size: 0.74rem;
  font-weight: 800;
}

.health .ok {
  background: rgba(143, 209, 79, 0.16);
  color: var(--accent-strong);
}

.health .warn {
  background: rgba(240, 180, 91, 0.16);
  color: var(--amber);
}

.preview {
  min-height: 520px;
  max-height: none;
  overflow: auto;
  margin: 0;
  padding: 16px;
  background: #0b0c0f;
  color: #e9e6dc;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.83rem;
  line-height: 1.58;
  white-space: pre-wrap;
  word-break: break-word;
}

.actions {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.35fr) minmax(0, 1fr);
  gap: 9px;
  margin-top: 12px;
}

.btn {
  min-height: 42px;
  padding: 10px 12px;
  font-weight: 900;
  line-height: 1.1;
  overflow-wrap: anywhere;
}

.btn.primary {
  background: var(--accent);
  color: var(--ink);
}

.btn.secondary {
  background: var(--surface-strong);
  color: var(--text);
  border: 1px solid var(--line);
}

.btn.ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--line);
}

.btn:hover,
.mode-btn:hover {
  filter: brightness(1.08);
}

.seo-section {
  max-width: 780px;
  margin: 28px 0 0;
  padding-bottom: 18px;
  color: var(--muted);
}

.seo-section h2 {
  margin-bottom: 8px;
  color: var(--text);
}

body[data-mode="simple"] .advanced-only {
  display: none;
}

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

  .preview-column {
    position: static;
  }

  .preview {
    min-height: 420px;
    max-height: 560px;
  }

  .preview-panel {
    max-height: none;
  }
}

@media (max-width: 720px) {
  .app-shell {
    padding: 16px 16px 56px;
  }

  .topbar {
    align-items: stretch;
    flex-direction: column;
  }

  .mode-switch {
    width: 100%;
  }

  h1 {
    font-size: 1.7rem;
  }

  .intro {
    font-size: 0.92rem;
  }

  .grid.two,
  .slider-grid,
  .checkbox-grid,
  .advanced-guide,
  .actions {
    grid-template-columns: 1fr;
  }

  .sample-head,
  .advanced-banner {
    flex-direction: column;
  }

  .slider-field {
    grid-template-columns: minmax(72px, 84px) minmax(0, 1fr) 24px;
  }

  .panel,
  .preview-panel {
    padding: 14px;
  }

  .preview-head {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .preview {
    min-height: 360px;
    font-size: 0.78rem;
  }
}