:root {
  --ink: #13221a;
  --muted: #627168;
  --line: #d5dfd8;
  --surface: #ffffff;
  --surface-soft: #f5f9f6;
  --canvas: #eef4ef;
  --green-900: #174f35;
  --green-800: #216241;
  --green-700: #28744c;
  --green-200: #c9e6d3;
  --green-100: #e7f3eb;
  --danger: #b42318;
  --danger-soft: #fee4e2;
  --warning: #a15c00;
  --warning-soft: #fff2d8;
  --shadow: 0 22px 54px rgba(20, 56, 37, 0.09);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: light;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--canvas);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

button:focus-visible,
.svg-frame:focus-visible,
.point-handle:focus-visible,
.edge-target:focus-visible {
  outline: 3px solid rgba(40, 116, 76, 0.32);
  outline-offset: 3px;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.46;
}

.container {
  width: min(1450px, calc(100% - 34px));
  margin-inline: auto;
}

.hero {
  padding: 38px 0 40px;
  background:
    radial-gradient(circle at 86% -25%, rgba(89, 169, 121, 0.32), transparent 38%),
    linear-gradient(135deg, #103d29, #216241);
  color: white;
}

.hero-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 28px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 10px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.72rem;
  font-weight: 900;
}

.eyebrow {
  color: rgba(255, 255, 255, 0.7);
}

.section-kicker {
  color: var(--green-700);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.5rem, 5vw, 4.8rem);
  line-height: 0.98;
  letter-spacing: -0.055em;
}

.hero-copy {
  max-width: 760px;
  margin: 18px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: 1.05rem;
}

.version-pill {
  flex: 0 0 auto;
  min-width: 105px;
  padding: 13px 17px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.09);
  backdrop-filter: blur(12px);
}

.version-pill span,
.version-pill strong {
  display: block;
}

.version-pill span {
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.11em;
}

.version-pill strong {
  margin-top: 2px;
  font-size: 1.35rem;
}

.app-shell {
  padding: 27px 0 52px;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.toolbar-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.76);
}

.toolbar-group-push {
  margin-left: auto;
}

.tool-button {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 9px 13px;
  background: transparent;
  color: var(--ink);
  font-weight: 850;
}

.tool-button:hover:not(:disabled) {
  background: var(--surface);
  border-color: var(--line);
}

.tool-button-accent {
  color: var(--green-800);
}

.tool-button-accent.active {
  background: var(--green-800);
  color: white;
}

.tool-button-danger {
  color: var(--danger);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 315px;
  gap: 18px;
  align-items: stretch;
}

.editor-card,
.summary-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.editor-card {
  min-width: 0;
  padding: 20px;
}

.summary-card {
  padding: 22px;
}

.card-heading,
.summary-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 22px;
  margin-bottom: 16px;
}

.card-heading h2,
.summary-heading h2 {
  margin: 0;
  letter-spacing: -0.035em;
}

.card-heading h2 {
  font-size: 1.55rem;
}

.card-heading p:not(.section-kicker) {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.view-readout {
  flex: 0 0 auto;
  display: flex;
  gap: 12px;
  color: var(--muted);
  font-size: 0.8rem;
}

.view-readout span {
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--surface-soft);
}

.view-readout strong {
  color: var(--ink);
}

.svg-frame {
  position: relative;
  min-height: 420px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 15px;
  background: #f8fbf9;
  cursor: grab;
  touch-action: none;
  user-select: none;
}

.svg-frame.panning {
  cursor: grabbing;
}

.svg-frame.add-mode {
  cursor: crosshair;
}

#editorSvg {
  width: 100%;
  height: clamp(420px, 58vw, 680px);
  display: block;
}

.canvas-background {
  pointer-events: all;
}

.grid-minor {
  stroke: #e5eee8;
  stroke-width: 1;
}

.grid-major {
  stroke: #d4e2d8;
  stroke-width: 1.35;
}

.polygon-shape {
  fill: rgba(57, 135, 84, 0.31);
  stroke: var(--green-800);
  stroke-width: 5;
  vector-effect: non-scaling-stroke;
  pointer-events: visiblePainted;
}

.edge-target {
  stroke: transparent;
  stroke-linecap: round;
  pointer-events: none;
}

.edge-target.add-enabled {
  pointer-events: stroke;
  cursor: copy;
}

.edge-target.add-enabled:hover,
.edge-target.add-enabled:focus {
  stroke: rgba(40, 116, 76, 0.43);
}

.point-handle {
  cursor: grab;
}

.point-handle:active {
  cursor: grabbing;
}

.point-handle circle {
  fill: white;
  stroke: var(--green-900);
  vector-effect: non-scaling-stroke;
  filter: drop-shadow(0 4px 7px rgba(17, 60, 38, 0.18));
}

.point-handle text {
  fill: var(--ink);
}

.point-handle:hover circle,
.point-handle:focus circle {
  fill: var(--green-100);
  stroke: var(--green-700);
}

.point-handle.selected circle {
  fill: var(--green-800);
  stroke: white;
}

.point-handle.selected text {
  fill: white;
}

.mode-badge,
.selection-badge {
  position: absolute;
  z-index: 5;
  border-radius: 999px;
  padding: 8px 12px;
  font-size: 0.75rem;
  font-weight: 850;
  box-shadow: 0 8px 20px rgba(20, 56, 37, 0.14);
  pointer-events: none;
}

.mode-badge {
  top: 14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--green-800);
  color: white;
}

.selection-badge {
  left: 14px;
  bottom: 14px;
  background: white;
  color: var(--green-800);
  border: 1px solid var(--line);
}

.editor-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.72rem;
}

.editor-footer span::before {
  content: "•";
  margin-right: 7px;
  color: var(--green-700);
}

.validity-badge {
  border-radius: 999px;
  padding: 6px 9px;
  font-size: 0.7rem;
  font-weight: 900;
}

.validity-badge.valid {
  background: var(--green-100);
  color: var(--green-800);
}

.validity-badge.invalid {
  background: var(--danger-soft);
  color: var(--danger);
}

.stats-list {
  margin: 0;
}

.stats-list div {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.stats-list dt,
.stats-list dd {
  margin: 0;
  font-size: 0.84rem;
}

.stats-list dt {
  color: var(--muted);
}

.stats-list dd {
  max-width: 145px;
  font-weight: 900;
  text-align: right;
}

.instruction-card {
  margin-top: 17px;
  padding: 15px;
  border-radius: 13px;
  background: var(--green-100);
}

.instruction-card strong {
  font-size: 0.82rem;
}

.instruction-card p {
  margin: 6px 0 0;
  color: #40584a;
  font-size: 0.78rem;
}

.wide-button {
  width: 100%;
  min-height: 43px;
  margin-top: 17px;
  border: 1px solid var(--line);
  border-radius: 11px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 850;
}

.wide-button:hover:not(:disabled) {
  background: var(--surface-soft);
}

.site-footer {
  padding: 24px 0;
  border-top: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.8rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 50;
  max-width: min(500px, calc(100% - 32px));
  transform: translate(-50%, 120px);
  padding: 11px 15px;
  border-radius: 11px;
  background: var(--green-900);
  color: white;
  font-size: 0.82rem;
  font-weight: 800;
  box-shadow: 0 14px 35px rgba(19, 34, 26, 0.25);
  opacity: 0;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.toast.visible {
  transform: translate(-50%, 0);
  opacity: 1;
}

.toast.error {
  background: var(--danger);
}

[hidden] {
  display: none !important;
}

@media (max-width: 1050px) {
  .workspace {
    grid-template-columns: 1fr;
  }

  .summary-card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0 22px;
  }

  .summary-heading,
  .stats-list,
  .wide-button {
    grid-column: 1 / -1;
  }
}

@media (max-width: 760px) {
  .container {
    width: min(100% - 20px, 1450px);
  }

  .hero-inner,
  .card-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .version-pill {
    display: none;
  }

  .toolbar-group-push {
    margin-left: 0;
  }

  .view-readout {
    flex-wrap: wrap;
  }

  .summary-card {
    display: block;
  }

  .instruction-card {
    margin-top: 14px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 6px;
  }
}

@media (max-width: 520px) {
  .hero {
    padding: 31px 0;
  }

  .hero h1 {
    font-size: 2.45rem;
  }

  .tool-button {
    min-height: 42px;
    padding: 8px 10px;
  }

  .tool-button span {
    display: none;
  }

  .editor-card,
  .summary-card {
    padding: 15px;
  }

  #editorSvg {
    height: 440px;
  }

  .editor-footer {
    display: grid;
  }
}