/* ── Design Tokens ── */
:root {
  --color-accent: #e276801c;
  --color-bg: #f8fbfa;
  --color-bg-secondary: #dbe9e8;
  --color-link: #b44a55;
  --color-secondary: #5c8987;
  --color-secondary-accent: #9ececc26;
  --color-shadow: #f0f6f5;
  --color-table: #9ececc;
  --color-text: #222629;
  --color-text-secondary: #667174;
  --color-scrollbar: #9ececc;
  --radius: 7px;
  --radius-lg: 12px;
  --font-sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  color-scheme: light;
}

/* ── Reset ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ── Base Element Styles ── */
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Links — base underline & accent so individual components only override when different */
a {
  color: var(--color-link);
  text-decoration: underline;
  text-underline-offset: 0.18em;
  text-decoration-thickness: 1px;
  transition: opacity 0.15s ease;
}
a:hover { opacity: 0.75; }

code {
  font-family: var(--font-mono);
}

pre {
  font-family: var(--font-mono);
}

button, input, select, textarea { font: inherit; }

button:focus-visible, a:focus-visible, input:focus-visible,
select:focus-visible, textarea:focus-visible {
  outline: 2px solid #d90000;
  outline-offset: 3px;
}

/* ── Prerelease Banner ── */
.prerelease-banner {
  max-width: 1056px;
  margin: 0 auto;
  padding: 1rem 1.25rem;
  border: 1px solid #cfe1e0;
  border-radius: var(--radius);
  background: #fff;
  color: var(--color-text-secondary);
  text-align: left;
  font-size: 0.78rem;
  line-height: 1.6;
}
.prerelease-banner strong { color: var(--color-text); }
.prerelease-banner code {
  background: #edf6f5;
  color: var(--color-text);
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  font-size: 0.85rem;
  white-space: nowrap;
}
.prerelease-banner a {
  float: right;
  color: var(--color-link);
  text-decoration: none;
}
.prerelease-banner a:hover { color: #d90000; }

/* ── Header Navigation ── */
.top-nav {
  position: relative;
  max-width: 1120px;
  margin: 0 auto;
  padding: 1.2rem 2rem 1.1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.78rem;
  font-weight: 600;
}
.top-nav::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  height: 1px;
  background: linear-gradient(90deg, transparent, #9ececc 24%, #9ececc 76%, transparent);
  opacity: 0.38;
}
.top-nav-left a {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
}
.brand-mark {
  width: 2.35rem;
  height: 2.35rem;
  overflow: visible;
  fill: none;
}
.brand-frame {
  stroke: #8fbfbc;
  stroke-width: 1;
  stroke-linecap: square;
}
.brand-contour {
  stroke: var(--color-text);
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.brand-contour-secondary {
  stroke: #9ececc;
  stroke-width: 1;
}
.brand-point {
  fill: #b44a55;
  stroke: var(--color-bg);
  stroke-width: 1.5;
  transform-box: fill-box;
  transform-origin: center;
  animation: brand-point-breathe 4.8s ease-in-out infinite;
}
.brand-name {
  display: grid;
  gap: 0.18rem;
  font-size: 0.94rem;
  font-weight: 680;
  line-height: 1;
}
.brand-name small {
  color: #82908f;
  font: 500 0.48rem/1 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.top-nav-left a:hover { opacity: 1; }
.top-nav-left a:hover .brand-contour:not(.brand-contour-secondary) { stroke: #b44a55; }
.top-nav-right {
  position: relative;
  display: grid;
  width: min(47vw, 480px);
  grid-template-columns: repeat(4, minmax(0, 1fr));
  padding-bottom: 0.9rem;
}
.top-nav-right a {
  position: relative;
  z-index: 1;
  color: var(--color-text-secondary);
  text-align: center;
  text-decoration: none;
  font-size: 0.72rem;
  font-weight: 560;
}
.top-nav-right a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -1.03rem;
  width: 5px;
  height: 5px;
  border: 1px solid #8fbfbc;
  border-radius: 50%;
  background: var(--color-bg);
  transform: translateX(-50%);
  transition: border-color 160ms ease, background-color 160ms ease, transform 160ms ease;
}
.top-nav-right a:hover { color: var(--color-text); opacity: 1; }
.top-nav-right a:hover::after {
  border-color: #b44a55;
  background: #b44a55;
  transform: translateX(-50%) scale(1.25);
}
.top-nav-signal {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 18px;
  overflow: visible;
  pointer-events: none;
}
.top-nav-signal-base,
.top-nav-signal-pulse {
  fill: none;
  vector-effect: non-scaling-stroke;
}
.top-nav-signal-base { stroke: #b8d6d4; stroke-width: 1; }
.top-nav-signal-pulse {
  stroke: #b44a55;
  stroke-width: 1.4;
  stroke-linecap: round;
  stroke-dasharray: 18 402;
  animation: nav-signal-travel 9s linear infinite;
}
@keyframes nav-signal-travel {
  from { stroke-dashoffset: 42; }
  to { stroke-dashoffset: -378; }
}
@keyframes brand-point-breathe {
  0%, 70%, 100% { opacity: 0.72; transform: scale(0.86); }
  82% { opacity: 1; transform: scale(1.18); }
}

/* ── Hero Section ── */
.hero {
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(5.5rem, 10vw, 8.5rem) 2rem clamp(4.5rem, 8vw, 7rem);
  text-align: left;
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(250px, 0.65fr);
  gap: clamp(3rem, 9vw, 8rem);
  align-items: center;
}
.hero-copy { max-width: 680px; }
.hero-kicker {
  margin-bottom: 1.8rem;
  color: #b44a55;
  font: 600 0.7rem/1 var(--font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.hero h1 {
  max-width: 680px;
  margin-bottom: 1.6rem;
  color: var(--color-text);
  font: 560 clamp(2.8rem, 6vw, 5rem)/1.02 var(--font-sans);
  letter-spacing: -0.06em;
}
.hero h1 u {
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 2px;
}
.hero h1 em { color: var(--color-text); font-style: normal; font-weight: 560; }
.hero p {
  max-width: 590px;
  color: var(--color-text-secondary);
  font-size: clamp(1rem, 1.8vw, 1.15rem);
  line-height: 1.65;
}
.hero p strong { color: var(--color-text); font-weight: 600; }
.install-line {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
  padding: 0.75rem 1rem;
  border: 1px solid #cfe1e0;
  border-radius: 6px;
  background: #fff;
  color: var(--color-text);
  font: 0.78rem/1 var(--font-mono);
}
.install-line::before { content: "$"; color: #b44a55; }
.install-line span { color: var(--color-text-secondary); font-size: 0.65rem; }
.hero-sample {
  overflow: hidden;
  border: 1px solid #9ececc;
  border-radius: 9px;
  background: #fff;
}
.hero-sample-header {
  display: flex;
  justify-content: space-between;
  padding: 0.8rem 1rem;
  border-bottom: 1px solid #dcebea;
  color: var(--color-text-secondary);
  font: 0.61rem/1 var(--font-mono);
  text-transform: uppercase;
}
.hero-sample-header code { color: #b44a55; }
.hero-sample pre {
  margin: 0;
  padding: 1.4rem 1.2rem;
  overflow-x: auto;
  color: var(--color-text);
  font: 0.72rem/1.75 var(--font-mono);
}
.hero-sample .comment { color: #718b89; }
.hero-sample pre a {
  color: var(--color-link);
  text-decoration: none;
}
.hero-sample pre a:hover {
  text-decoration: underline;
}
.hero-sample .result {
  padding: 0.8rem 1rem;
  border-top: 1px solid #dcebea;
  background: #f1f8f7;
  color: #4e7775;
  font: 0.65rem/1 var(--font-mono);
}
.hero-sample-links {
  padding: 0.55rem 1rem;
  border-top: 1px solid #dcebea;
  background: #f1f8f7;
  font: 0.62rem/1 var(--font-mono);
}
.hero-sample-links a {
  color: var(--color-link);
  text-decoration: none;
}
.hero-sample-links a:hover {
  text-decoration: underline;
}
.browser-mark {
  background: linear-gradient(transparent 62%, #9ececc70 62%);
  color: var(--color-text);
  padding: 0 1px;
}

/* ── Capability Overview ── */
.capability-overview {
  max-width: 1120px;
  margin: 0 auto clamp(3rem, 6vw, 5rem);
  padding: clamp(4rem, 8vw, 7rem) 2rem;
  border: solid #cfe1e0;
  border-width: 1px 0;
  display: grid;
  grid-template-columns: minmax(210px, 0.65fr) minmax(0, 1.6fr);
  gap: clamp(3rem, 8vw, 7rem);
}
.capability-intro .section-label,
.runtime-contract .section-label {
  margin-bottom: 1rem;
  color: #b44a55;
  font: 600 0.65rem/1 var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.capability-intro h2 {
  margin-bottom: 1rem;
  color: var(--color-text);
  font-size: clamp(1.8rem, 3.5vw, 2.7rem);
  font-weight: 560;
  line-height: 1.12;
  letter-spacing: -0.045em;
}
.capability-intro > p:last-child { color: var(--color-text-secondary); font-size: 0.9rem; line-height: 1.7; }
.problem-types { display: grid; grid-template-columns: repeat(3, 1fr); }
.problem-type {
  min-width: 0;
  padding: 0.35rem clamp(1.2rem, 3vw, 2rem);
  border-left: 1px solid #9ececc;
}
.problem-type code { color: #d90000; font: 600 0.68rem/1 var(--font-mono); }
.problem-type h3 { margin: 1.1rem 0 0.65rem; font-size: 1rem; font-weight: 650; }
.problem-type p { color: var(--color-text-secondary); font-size: 0.8rem; line-height: 1.65; }
.runtime-contract {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: minmax(210px, 0.65fr) minmax(0, 1.6fr);
  gap: clamp(3rem, 8vw, 7rem);
  padding-top: clamp(2rem, 4vw, 3rem);
  border-top: 1px solid #dcebea;
}
.runtime-contract h3 { max-width: 230px; font-size: 1rem; font-weight: 600; line-height: 1.5; }
.runtime-contract dl { display: grid; grid-template-columns: 130px 1fr; margin: 0; }
.runtime-contract dt,
.runtime-contract dd { padding: 0.65rem 0; border-bottom: 1px solid #e4efee; }
.runtime-contract dt { color: var(--color-text-secondary); font: 0.65rem/1.6 var(--font-mono); text-transform: uppercase; }
.runtime-contract dd { margin: 0; color: var(--color-text); font: 0.75rem/1.6 var(--font-mono); }
.runtime-contract .limit { color: #a6434c; }

/* ── Divider & Section Title ── */
.section-divider { display: none; }

.demo-heading {
  max-width: 1440px;
  margin: clamp(5rem, 9vw, 8rem) auto 1.8rem;
  padding: 0 2rem;
  text-align: left;
  color: var(--color-text);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.demo-heading::after {
  content: " Each one exercises the package API directly.";
  color: var(--color-text-secondary);
  font-weight: 400;
}

/* ── Main Container ── */
.container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 2rem 9rem;
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: clamp(2rem, 4vw, 4rem);
  align-items: start;
}

#example-panels { min-width: 0; }

/* ── Example Card Component ── */
.example-card {
  padding: clamp(1.5rem, 3.5vw, 3.25rem);
  border: 1px solid #cfe1e0;
  border-radius: 14px;
  background: #fff;
  box-shadow: none;
  margin-bottom: 2rem;
}
.example-card > * { max-width: none; margin-left: auto; margin-right: auto; }

.tech-header-line {
  margin-bottom: clamp(2rem, 3vw, 2.75rem);
  padding-bottom: 0.8rem;
  border-bottom: 1px solid #cfe1e0;
  color: #b44a55;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ── Problem Header & Explanation Typography ── */
.problem-header { max-width: none; margin-bottom: clamp(2rem, 3vw, 2.75rem); }
.problem-header h3 {
  margin-bottom: 0.85rem;
  color: var(--color-text);
  font-size: clamp(1.7rem, 3.5vw, 2.55rem);
  font-weight: 560;
  line-height: 1.15;
  letter-spacing: -0.045em;
}
.problem-header p { max-width: 920px; color: var(--color-text-secondary); font-size: 0.93rem; line-height: 1.7; }
.problem-header code { font-family: var(--font-mono); font-size: 0.82em; }

.problem-header .api-reference-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem 0.8rem;
  margin-top: 0.8rem;
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
  font-size: 0.72rem;
}
.api-reference-links span {
  color: var(--color-text);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
/* .api-reference-links a inherits base <a> underline & accent */

/* ── Sparse Explorer ── */
.sparse-explorer {
  container-type: inline-size;
  margin-bottom: clamp(2rem, 3vw, 3rem) !important;
  overflow: hidden;
  border: 1px solid #cfe1e0;
  border-radius: 10px;
  background: #fbfdfd;
}
.sparse-explorer-header {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  align-items: flex-start;
  padding: 1.15rem 1.25rem;
  border-bottom: 1px solid #dcebea;
  background: #f1f8f7;
}
.sparse-explorer-header strong { display: block; margin-bottom: 0.25rem; font-size: 0.82rem; }
.sparse-explorer-header p { max-width: 650px; color: var(--color-text-secondary); font-size: 0.7rem; line-height: 1.55; }
.sparse-controls { display: flex; flex: 0 0 auto; gap: 0.35rem; }
.sparse-control {
  min-width: 34px;
  height: 32px;
  padding: 0 0.65rem;
  border: 1px solid #bad4d2;
  border-radius: 5px;
  background: #fff;
  color: var(--color-text);
  font: 0.62rem/1 var(--font-mono);
  cursor: pointer;
}
.sparse-control:hover { border-color: #e27680; }
.sparse-flow {
  display: grid;
  grid-template-columns: minmax(220px, 0.95fr) minmax(230px, 1fr) minmax(360px, 1.5fr);
}
.sparse-stage { position: relative; min-width: 0; padding: 1.2rem; }
.sparse-stage + .sparse-stage { border-left: 1px solid #dcebea; }
.sparse-stage + .sparse-stage::before {
  content: "\2192";
  position: absolute;
  top: 1.1rem;
  left: -0.7rem;
  display: grid;
  width: 1.4rem;
  height: 1.4rem;
  place-items: center;
  border: 1px solid #cfe1e0;
  border-radius: 50%;
  background: #fbfdfd;
  color: #b44a55;
  font-size: 0.7rem;
}
.sparse-stage-label {
  margin-bottom: 1rem;
  color: #718b89;
  font: 600 0.58rem/1 var(--font-mono);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.formula-list { display: grid; gap: 0.4rem; }
.formula-row {
  padding: 0.5rem 0.6rem;
  border-left: 2px solid transparent;
  color: var(--color-text-secondary);
  font: 0.67rem/1.5 var(--font-mono);
  transition: 160ms ease;
}
.formula-row.active { border-left-color: #e27680; background: #fff3f4; color: var(--color-text); }
.math-model-row {
  display: grid;
  grid-template-columns: 66px minmax(0, 1fr);
  gap: 0.5rem;
  align-items: baseline;
  padding-top: 0.4rem;
  padding-bottom: 0.4rem;
}
.math-role { color: #718b89; font-size: 0.56rem; text-transform: uppercase; }
.math-expression { color: var(--color-text); line-height: 1.8; }
.formula-term {
  display: inline-block;
  margin: -0.15rem -0.1rem;
  padding: 0.15rem 0.1rem;
  border-radius: 3px;
  cursor: default;
}
.formula-term:hover { box-shadow: 0 0 0 1px #e27680; }
.formula-term.active { background: #e27680; color: #fff; }
.matrix-wrap { overflow-x: auto; }
.matrix-table { border-spacing: 4px; border-collapse: separate; margin: -4px; font: 0.63rem/1 var(--font-mono); }
.matrix-table th { min-width: 34px; height: 24px; color: #718b89; font-weight: 500; text-align: center; }
.matrix-axis-name { display: block; font: 0.57rem/1 var(--font-mono); }
.matrix-table td {
  min-width: 34px;
  height: 32px;
  border: 1px solid #dcebea;
  border-radius: 4px;
  background: #fff;
  color: #889395;
  text-align: center;
  transition: 160ms ease;
}
.matrix-table td.nonzero { color: var(--color-text); }
.matrix-table td.active { border-color: #e27680; background: #e27680; color: #fff; transform: scale(1.08); }
.matrix-table td.mirror { border-color: #9ececc; background: #e4f3f2; color: #4e7775; }
.matrix-table td.zero-hover { border-style: dashed; border-color: #9ececc; background: #f2f8f7; color: #718b89; }
.array-stack { display: grid; gap: 0.7rem; padding-top: 0.35rem; }
.array-row { display: grid; grid-template-columns: 46px minmax(0, 1fr); gap: 0.3rem; align-items: start; }
.array-name { padding-top: 0.38rem; color: #718b89; font: 0.58rem/1 var(--font-mono); }
.array-cells { display: flex; width: 100%; min-width: 0; gap: 2px; padding: 2px; }
.array-cell {
  display: grid;
  flex: 1 1 30px;
  min-width: 16px;
  max-width: 34px;
  height: 30px;
  place-items: center;
  border: 1px solid #dcebea;
  border-radius: 4px;
  background: #fff;
  color: var(--color-text-secondary);
  font: 0.54rem/1 var(--font-mono);
  transition: 160ms ease;
}
.array-cell.active { border-color: #e27680; background: #fff1f2; color: #a6434c; font-weight: 700; }
.array-cell.boundary { border-color: #9ececc; background: #edf8f7; color: #4e7775; }
.array-cell:hover { box-shadow: 0 0 0 1px #e27680; }
.sparse-narration {
  min-height: 52px;
  padding: 0.85rem 1.2rem;
  border-top: 1px solid #dcebea;
  background: #fff;
  color: var(--color-text-secondary);
  font: 0.65rem/1.6 var(--font-mono);
}
.sparse-narration strong { color: #a6434c; }
.sparse-legend { color: #718b89; font-size: 0.62rem; }

@container (max-width: 840px) {
  .sparse-flow { grid-template-columns: 1fr; }
  .sparse-stage + .sparse-stage { border-left: 0; border-top: 1px solid #dcebea; }
  .sparse-stage + .sparse-stage::before { top: -0.7rem; left: 1.1rem; content: "\2193"; }
}

/* ── Code Section ── */
.code-section,
.visual-inputs,
.visual-solution,
.textual-solution { margin-bottom: 1.5rem; }

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.55rem;
  font: 600 0.65rem/1.4 var(--font-mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.code-header a {
  color: inherit;
  text-decoration-color: color-mix(in srgb, currentColor 35%, transparent);
  text-underline-offset: 0.2em;
}

.code-header a:hover { color: var(--color-link); }

.code-editor-box {
  padding: 1.3rem 1.4rem;
  border: 0;
  border-top: 3px solid #9ececc;
  border-radius: 5px;
  background: #222629;
  color: #edf5f4;
  font-family: var(--font-mono);
  font-size: 0.825rem;
  line-height: 1.5;
  overflow: hidden;
}
.code-editor-box textarea {
  width: 100%;
  background: transparent;
  border: none;
  outline: none;
  color: #edf5f4;
  font-family: var(--font-mono);
  font-size: 0.825rem;
  line-height: 1.5;
  resize: none;
  height: auto;
  field-sizing: content;
  overflow: hidden;
  padding: 0;
  margin: 0;
  display: block;
}
.highlighted-code {
  margin: 0;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  color: #edf5f4;
  font: 0.825rem/1.5 var(--font-mono);
}

/* ── Syntax Editor ── */
.syntax-editor {
  display: grid;
  overflow: hidden;
  border: 1px solid #d3e4e3;
  border-radius: 5px;
  background: #fff;
}
.syntax-editor:focus-within { border-color: #9ececc; box-shadow: 0 0 0 3px #9ececc30; }
.syntax-editor pre,
.syntax-editor textarea {
  grid-area: 1 / 1;
  width: 100%;
  min-height: inherit;
  margin: 0;
  padding: 0.75rem 0.85rem;
  border: 0;
  border-radius: 0;
  overflow: hidden;
  white-space: pre-wrap;
  overflow-wrap: normal;
  font: 0.825rem/1.5 var(--font-mono);
  tab-size: 2;
}
.syntax-editor pre { pointer-events: none; color: var(--color-text); }
.syntax-editor textarea {
  z-index: 1;
  resize: none;
  background: transparent;
  color: transparent;
  caret-color: var(--color-text);
  -webkit-text-fill-color: transparent;
}
.syntax-editor textarea:focus { background: transparent; box-shadow: none; }
.syntax-editor textarea::selection { background: #9ececc70; }

/* ── Syntax Tokens ── */
.token.comment { color: #718b89; font-style: italic; }
.token.keyword { color: #b13442; font-weight: 600; }
.token.string { color: #397c69; }
.token.number, .token.boolean { color: #9c5c23; }
.token.operator { color: #d90000; }
.token.property, .token.label { color: #476f9c; }
.token.variable { color: #3f6f6d; }
.code-editor-box .token.comment { color: #8baaa7; }
.code-editor-box .token.keyword { color: #f08b95; }
.code-editor-box .token.string { color: #9ececc; }
.code-editor-box .token.number { color: #f1c27d; }
.syntax-output .token.property { color: #476f9c; }

/* ── Interactive Visualizations ── */
.visual-inputs,
.visual-solution {
  padding: clamp(1.15rem, 3vw, 1.8rem);
  border: 1px solid #d6e6e5;
  border-radius: var(--radius);
  background: #f4f9f8;
}
.visual-inputs h4,
.visual-solution h4 {
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.85rem;
  letter-spacing: 0.035em;
  text-transform: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.visual-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(175px, 1fr));
  gap: 0.85rem;
}

.item-card,
.stat-box,
.capacity-packing { border-color: #d3e4e3; background: #fff; }

.item-card {
  border: 1px solid;
  border-radius: var(--radius);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  transition: all 0.15s ease;
}
.item-card.selected {
  border-color: #9ececc;
  background: #e8f5f4;
}
.item-card h5 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.stat-box {
  border: 1px solid;
  border-radius: var(--radius);
  min-height: 76px;
  padding: 0.8rem 1rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 0.15rem;
}
.stat-box .stat-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--color-text-secondary);
  text-transform: uppercase;
}
.stat-box .stat-val {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

.capacity-packing {
  border: 1px solid;
  border-radius: var(--radius);
  padding: 0.85rem;
  margin-bottom: 1rem;
}
.capacity-header-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}
.packing-track {
  height: 32px;
  background: #dcebea;
  border-radius: 4px;
  display: flex;
  overflow: hidden;
  gap: 2px;
}
.pack-block {
  height: 100%;
  background: #e27680;
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  white-space: nowrap;
  transition: width 0.3s ease;
}
.pack-block.empty {
  background: transparent;
  color: var(--color-text-secondary);
}

.interval-scale { margin-bottom: 0.75rem; }
.interval-scale-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
}
.interval-scale-track {
  height: 8px;
  background: #dcebea;
  border-radius: 4px;
  position: relative;
  overflow: hidden;
}
.interval-scale-fill {
  position: absolute;
  top: 0;
  bottom: 0;
  background: #e27680;
  border-radius: 4px;
}

/* ── Progress Bars ── */
.progress-bar-group {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}
.progress-item {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text);
}
.progress-track {
  height: 10px;
  background: #dcebea;
  border-radius: 5px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: #e27680;
  border-radius: 5px;
  transition: width 0.3s ease;
}

/* ── Textual Solution Output ── */

/* ── Textarea & Output Blocks ── */
textarea, .output {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 0.825rem;
  line-height: 1.5;
  border: 1px solid #d3e4e3;
  border-radius: 5px;
  outline: none;
  resize: vertical;
  background: #fff;
  color: var(--color-text);
  padding: 0.75rem 0.85rem;
  tab-size: 2;
  word-break: normal;
}
textarea:focus {
  border-color: #9ececc;
  background: #fff;
  box-shadow: 0 0 0 3px #9ececc30;
}

.output {
  min-height: 120px;
  max-height: 400px;
  overflow: auto;
  white-space: pre-wrap;
  word-break: break-all;
}
.output.error {
  color: #d90000;
  border-color: #e27680;
  background: #fff5f5;
}
.output.placeholder {
  color: var(--color-text-secondary);
  font-style: normal;
  border-style: dashed;
}

/* ── Solve Timing Bar ── */
.timing-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border: 0;
  background: transparent;
  color: #5c8987;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0;
  width: fit-content;
  margin-bottom: 0.85rem;
}

/* ── Metadata Footer ── */
.metadata-footer {
  font-size: 0.61rem;
  color: #899496;
  font-family: var(--font-mono);
  border-top: 1px solid var(--color-bg-secondary);
  padding-top: 0.5rem;
  letter-spacing: 0.02em;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  min-height: 40px;
  padding: 0.55rem 1.05rem;
  border: 1px solid var(--color-text);
  border-radius: 5px;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  background: var(--color-text);
  color: #fff;
}
.btn:hover { border-color: #b44a55; background: #b44a55; }
.btn:disabled { cursor: wait; opacity: 0.55; }
.btn.ghost {
  color: var(--color-text);
  border-color: #bad4d2;
  background: #fff;
}
.btn.ghost:hover { border-color: #9ececc; background: #e9f5f4; }

.btn-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-top: 0.85rem;
  margin-bottom: 1.25rem;
  align-items: center;
}

/* ── Form Controls ── */
label {
  font-size: 0.76rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  display: block;
  margin-bottom: 0.25rem;
}

select, input[type=text], input[type=number] {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  min-height: 40px;
  padding: 0.4rem 0.65rem;
  border: 1px solid #c9dddc;
  border-radius: 5px;
  background: #fff;
  color: var(--color-text);
  outline: none;
  transition: border-color 0.15s ease;
}
select:focus, input[type=text]:focus, input[type=number]:focus {
  border-color: var(--color-link);
  box-shadow: 0 0 0 3px var(--color-accent);
}
input[type=number] { width: 110px; }

.form-row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  align-items: flex-end;
  margin-bottom: 0.75rem;
}

/* ── Options Table ── */
.opts-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.825rem;
}
.opts-table th, .opts-table td {
  padding: 0.45rem 0.65rem;
  text-align: left;
  border-bottom: 1px solid var(--color-bg-secondary);
}
.opts-table th {
  font-weight: 600;
  color: var(--color-text-secondary);
  position: sticky;
  top: 0;
  background: #edf6f5;
}
.opts-table tr:hover td { background: #f1f8f7; }

.opts-filter { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: 0.75rem; }
.opts-filter input { flex: 1; }

.doc-link { font-weight: 500; }

/* ── IIS Empty State ── */
.iis-empty-state {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.5rem;
  align-items: center;
  padding: 1.25rem;
  border: 1px dashed #bad4d2;
  border-radius: 7px;
  background: #fff;
}
.iis-preview-lines { display: grid; gap: 0.45rem; }
.iis-preview-lines span { height: 7px; border-radius: 4px; background: #dcebea; }
.iis-preview-lines span:nth-child(2) { width: 78%; background: #e2768060; }
.iis-empty-state strong { display: block; margin-bottom: 0.25rem; font-size: 0.8rem; }
.iis-empty-state p { color: var(--color-text-secondary); font-size: 0.73rem; line-height: 1.55; }

/* ── Conflict Display ── */
.conflict-summary {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
  color: var(--color-text-secondary);
  font-size: 0.72rem;
}
.conflict-summary strong { color: #a6434c; }
.conflict-list { position: relative; display: grid; gap: 0.65rem; padding-left: 1rem; }
.conflict-list::before {
  content: "";
  position: absolute;
  top: 0.75rem;
  bottom: 0.75rem;
  left: 3px;
  width: 2px;
  background: #e27680;
}
.conflict-node {
  position: relative;
  display: grid;
  grid-template-columns: 52px 1fr auto;
  gap: 0.8rem;
  align-items: center;
  padding: 0.8rem 0.9rem;
  border: 1px solid #ebc5c9;
  border-radius: 6px;
  background: #fff;
}
.conflict-node::before {
  content: "";
  position: absolute;
  left: -1px;
  width: 8px;
  height: 8px;
  border: 2px solid #fff;
  border-radius: 50%;
  background: #d90000;
}
.conflict-node > span:first-child { color: #a6434c; font: 600 0.65rem/1 var(--font-mono); }
.conflict-node code { color: var(--color-text); font: 0.72rem/1.45 var(--font-mono); }
.conflict-node small { color: var(--color-text-secondary); font-size: 0.65rem; }
.iis-clear { padding: 1rem; border: 1px solid #9ececc; border-radius: 6px; background: #fff; color: #4e7775; font-size: 0.78rem; }

/* ── Responsive ── */
@media (max-width: 980px) {
  .container { grid-template-columns: 1fr; }
  .sparse-flow { grid-template-columns: 1fr; }
  .sparse-stage + .sparse-stage { border-left: 0; border-top: 1px solid #dcebea; }
  .sparse-stage + .sparse-stage::before { top: -0.7rem; left: 1.1rem; content: "\2193"; }
}

@media (max-width: 640px) {
  .top-nav {
    gap: 0.55rem;
  }
  .brand-name small { display: none; }
  .top-nav-right { width: min(57vw, 310px); }
  .top-nav-right a { font: 500 clamp(0.5rem, 2vw, 0.58rem)/1 var(--font-mono); }
  .hero {
    padding: 2.5rem 1rem 1.5rem;
  }
  .container {
    padding: 0 1rem 3rem;
  }
}

@media (max-width: 400px) {
  .brand-mark { width: 2rem; height: 2rem; }
  .brand-name { font-size: 0.82rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}