:root {
  --paper: #f4efe4;
  --paper-raised: #fffdf8;
  --ink: #1f2523;
  --ink-muted: #5e625d;
  --review-red: #9d2f23;
  --rule: #c7bdad;
  --pass: #3f6b42;
  --warn: #8a641f;
  --block: #9d2f23;
  --content-width: 1120px;
  --shadow-paper: 6px 6px 0 #ddd2bf;
  --serif: Georgia, "Times New Roman", "Noto Serif SC", "Songti SC", SimSun, serif;
  --sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
}

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

html {
  color-scheme: light;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 0;
  overflow-x: hidden;
  color: var(--ink);
  background:
    linear-gradient(rgb(31 37 35 / 3%) 1px, transparent 1px) 0 0 / 100% 32px,
    var(--paper);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--review-red);
  text-underline-offset: 0.2em;
  text-decoration-thickness: 0.09em;
}

button,
[role="button"],
.hero a {
  min-height: 44px;
  touch-action: manipulation;
}

button {
  padding: 0.65rem 1rem;
  border: 1px solid var(--ink);
  border-radius: 0;
  color: var(--ink);
  background: var(--paper-raised);
  box-shadow: 3px 3px 0 var(--rule);
  font: 700 0.94rem/1.25 var(--sans);
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: color 160ms ease, background-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

button:hover {
  color: var(--paper-raised);
  background: var(--ink);
  box-shadow: 1px 1px 0 var(--rule);
  transform: translate(2px, 2px);
}

button[aria-pressed="true"],
button.is-active,
.is-active {
  color: var(--paper-raised);
  background: var(--review-red);
  box-shadow: inset 0 0 0 2px var(--paper-raised), 3px 3px 0 var(--ink);
}

:focus-visible {
  outline: 3px solid var(--review-red);
  outline-offset: 3px;
}

::selection {
  color: var(--paper-raised);
  background: var(--review-red);
}

p {
  max-width: 70ch;
}

h1,
h2,
h3 {
  margin: 0 0 0.85rem;
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1.12;
  text-wrap: balance;
}

h1 {
  max-width: 14ch;
  font-size: clamp(2.5rem, 8vw, 5.9rem);
  letter-spacing: -0.045em;
}

h2 {
  font-size: clamp(1.85rem, 4vw, 3rem);
  letter-spacing: -0.025em;
}

h3 {
  font-size: clamp(1.35rem, 2.5vw, 1.85rem);
}

.skip-link {
  position: fixed;
  z-index: 20;
  top: 0.75rem;
  left: 0.75rem;
  min-height: 44px;
  padding: 0.65rem 1rem;
  color: var(--paper-raised);
  background: var(--ink);
  transform: translateY(-160%);
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header,
main,
footer {
  width: min(calc(100% - 2rem), var(--content-width));
  margin-inline: auto;
}

.site-header {
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  border-bottom: 2px solid var(--ink);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.site-header::after {
  content: "只读静态样本";
  padding: 0.18rem 0.5rem;
  border: 1px solid var(--review-red);
  color: var(--review-red);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
}

main {
  padding-block: clamp(1.5rem, 4vw, 4rem) 4rem;
}

main > section,
main > noscript > article {
  position: relative;
  margin-block: 0 clamp(4.5rem, 10vw, 8rem);
}

main > section:not(.hero) {
  padding-top: 1.5rem;
  border-top: 2px solid var(--ink);
}

main > section:not(.hero)::after {
  position: absolute;
  top: -1.15rem;
  right: 0;
  padding-inline: 0.4rem;
  color: var(--ink-muted);
  background: var(--paper);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.14em;
}

#experience::after { content: "01 / WORKBENCH"; }
#workflow::after { content: "02 / GATES"; }
#standards::after { content: "03 / STANDARDS"; }
#boundaries::after { content: "04 / LIMITS"; }
#case-study::after { content: "05 / REVISION"; }
#evidence::after { content: "06 / EVIDENCE"; }
#replicate::after { content: "07 / METHOD"; }

.hero {
  isolation: isolate;
  min-height: min(710px, calc(100vh - 120px));
  padding: clamp(2rem, 6vw, 5.5rem);
  border: 1px solid var(--ink);
  background:
    linear-gradient(90deg, transparent 0 64px, rgb(157 47 35 / 12%) 64px 65px, transparent 65px),
    var(--paper-raised);
  box-shadow: var(--shadow-paper);
}

.hero::after {
  content: "安全演示 / 无连接";
  position: absolute;
  z-index: -1;
  top: clamp(1rem, 3vw, 2rem);
  right: clamp(1rem, 3vw, 2rem);
  padding: 0.35rem 0.65rem;
  border: 2px solid var(--review-red);
  color: var(--review-red);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  transform: rotate(2deg);
}

.hero .eyebrow {
  margin: 0 0 clamp(2.5rem, 7vw, 6rem);
  color: var(--review-red);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.16em;
}

.hero > p:not(.eyebrow) {
  margin: 1.5rem 0 2rem;
  color: var(--ink-muted);
  font-size: clamp(1rem, 2vw, 1.2rem);
}

.hero a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin: 0.35rem 0.55rem 0.35rem 0;
  padding: 0.65rem 1rem;
  border: 1px solid var(--ink);
  color: var(--paper-raised);
  background: var(--ink);
  font-weight: 750;
  text-decoration: none;
  transition: color 160ms ease, background-color 160ms ease;
}

.hero a + a {
  color: var(--ink);
  background: transparent;
}

.hero a:hover {
  color: var(--paper-raised);
  background: var(--review-red);
}

/* Static experience workbench */
#experience {
  display: grid;
  grid-template-columns: minmax(230px, 0.72fr) minmax(0, 1.55fr);
  gap: 1rem clamp(1.25rem, 4vw, 3.5rem);
  align-items: start;
}

#experience > h2,
#experience > h2 + p {
  grid-column: 1 / -1;
}

#experience > h2 + p {
  margin-top: 0;
  color: var(--ink-muted);
}

#scenario-list {
  display: grid;
  grid-column: 1;
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

#scenario-list button {
  position: relative;
  width: 100%;
  min-height: 54px;
  padding-left: 2.35rem;
  text-align: left;
}

#scenario-list button::before {
  content: "○";
  position: absolute;
  left: 0.8rem;
  font-size: 1.05rem;
}

#scenario-list button[aria-pressed="true"]::before,
#scenario-list button.is-active::before {
  content: "●";
}

#scenario-list button:focus-visible {
  outline-color: var(--review-red);
}

.scenario-facts {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  gap: 0.25rem 0.75rem;
  margin: 1rem 0 0;
  padding-top: 0.85rem;
  border-top: 1px solid var(--rule);
  font-size: 0.88rem;
}

.scenario-facts dt {
  font-weight: 800;
}

.scenario-facts dd {
  margin: 0;
}

#experience > article {
  grid-column: 2;
  grid-row: 3 / span 7;
  min-width: 0;
  min-height: 460px;
  padding: clamp(1.1rem, 3vw, 2rem);
  border: 1px solid var(--ink);
  background: var(--paper-raised);
  box-shadow: var(--shadow-paper);
}

#experience > article h3 {
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--rule);
}

#demo-prompt {
  padding: 0.05rem 1rem;
  border-left: 4px solid var(--review-red);
  background: rgb(157 47 35 / 5%);
}

#demo-prompt p {
  margin-block: 0.65rem;
}

.demo-disclosure {
  color: var(--ink-muted);
  font-size: 0.86rem;
}

#demo-checks {
  display: grid;
  gap: 0.7rem;
  margin-block: 1.25rem;
  padding: 0;
  list-style: none;
}

#demo-checks li {
  position: relative;
  padding: 0.85rem 1rem;
  border: 1px solid var(--rule);
  background: var(--paper);
}

.status-label {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  margin-right: 0.55rem;
  font-weight: 800;
}

.status-pass,
[data-status="pass"] {
  border-left: 4px solid var(--pass) !important;
}

.status-label-pass {
  color: var(--pass);
}

.status-warn,
[data-status="warn"] {
  border-left: 4px dashed var(--warn) !important;
}

.status-label-warn {
  color: var(--warn);
}

.status-block,
[data-status="block"] {
  border-left: 4px double var(--block) !important;
}

.status-label-block {
  color: var(--block);
}

#demo-output:not(:empty) {
  margin-top: 1.3rem;
  padding: 0.75rem 1rem;
  border: 1px dashed var(--ink-muted);
}

#demo-verdict:not(:empty) {
  margin-top: 1rem;
  padding: 0.8rem 1rem;
  border: 2px solid var(--ink);
}

.verdict-pass,
[data-tone="pass"] { border-left: 6px solid var(--pass); }

.verdict-pass::before,
[data-tone="pass"]::before { content: "✓ 通过 / "; font-weight: 900; }

.verdict-revise,
[data-tone="revise"] { border-left: 6px dashed var(--warn); }

.verdict-revise::before,
[data-tone="revise"]::before { content: "△ 修订 / "; font-weight: 900; }

.verdict-hold,
[data-tone="hold"] { border-left: 6px double var(--block); }

.verdict-hold::before,
[data-tone="hold"]::before { content: "⛔ 暂缓 / "; font-weight: 900; }

#demo-verdict p {
  padding-left: 0.75rem;
}

#demo-verdict ul {
  padding-left: 1.35rem;
}

#play-demo,
#skip-demo,
#reset-demo {
  grid-column: 1;
}

#play-demo {
  color: var(--paper-raised);
  background: var(--ink);
}

#experience > .demo-disclosure,
#demo-status {
  grid-column: 1;
  margin-block: 0.25rem;
}

#demo-status {
  min-height: 1.7em;
  font-size: 0.86rem;
  font-weight: 700;
}

/* Seven editorial gates */
#workflow > ol {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 0;
  margin: 2.25rem 0 0;
  padding: 0;
  border-block: 1px solid var(--ink);
  counter-reset: gate;
  list-style: none;
}

#workflow li {
  position: relative;
  min-width: 0;
  padding: 3.1rem 0.85rem 1.15rem;
  border-right: 1px solid var(--rule);
  counter-increment: gate;
  font-size: 0.84rem;
  line-height: 1.55;
}

#workflow li:last-child {
  border-right: 0;
}

#workflow li::before {
  content: "0" counter(gate);
  position: absolute;
  top: 0.7rem;
  left: 0.85rem;
  color: var(--review-red);
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 700;
}

#workflow li::after {
  content: "";
  position: absolute;
  top: -5px;
  left: 0.85rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--review-red);
}

/* Three real grid items keep the standards stable at every font size. */
.standards-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 2rem 0;
  padding: 0;
  list-style: none;
}

.standard-card {
  display: flex;
  min-width: 0;
  min-height: 156px;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.5rem);
  padding: 1.2rem clamp(1rem, 3vw, 2rem);
  border: 1px solid var(--ink);
  color: var(--review-red);
  background: var(--paper-raised);
  box-shadow: var(--shadow-paper);
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1;
}

.standard-card strong {
  font-size: clamp(2rem, 4vw, 3.15rem);
}

.standard-card span {
  font-size: clamp(1.4rem, 3vw, 2.5rem);
}

#standards > p {
  padding-left: 1rem;
  border-left: 2px solid var(--rule);
}

/* Capability boundary cards */
#boundaries > ol {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 2rem;
  padding: 0;
  list-style: none;
}

.boundary-card {
  min-height: 230px;
  padding: 1.25rem;
  border: 1px solid var(--ink);
  background: var(--paper-raised);
  box-shadow: 4px 4px 0 var(--rule);
}

.boundary-category {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 0 0 1rem;
  font-weight: 900;
  letter-spacing: 0.05em;
}

.boundary-symbol {
  display: inline-grid;
  flex: 0 0 auto;
  width: 2.55rem;
  height: 2.55rem;
  place-items: center;
  border: 2px solid currentColor;
  font-size: 1.25rem;
  font-weight: 900;
}

.boundary-can .boundary-symbol { color: var(--pass); border-radius: 50%; }
.boundary-review .boundary-symbol { color: var(--warn); }
.boundary-never .boundary-symbol { color: var(--block); }

.boundary-card > p:last-child { margin: 0; }

/* Before/after editorial revision */
#case-study {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

#case-study > h2 {
  grid-column: 1 / -1;
}

#case-study > p {
  min-height: 190px;
  margin: 0;
  padding: 1.35rem;
  border: 1px solid var(--rule);
  background: var(--paper-raised);
}

#case-study > p:first-of-type {
  border-top: 5px double var(--block);
}

#case-study > p:last-of-type {
  border-top: 5px solid var(--pass);
  box-shadow: 4px 4px 0 var(--rule);
}

/* Evidence is a source-aware timeline, not a chat transcript. */
#evidence > ol {
  position: relative;
  display: grid;
  gap: 1rem;
  margin: 2rem 0;
  padding: 0 0 0 2.4rem;
  list-style: none;
}

#evidence > ol::before {
  content: "";
  position: absolute;
  top: 1rem;
  bottom: 1rem;
  left: 0.72rem;
  border-left: 2px solid var(--review-red);
}

#evidence li {
  position: relative;
  padding: 1rem 1.2rem;
  border: 1px solid var(--rule);
  background: var(--paper-raised);
  box-shadow: 3px 3px 0 #e3d8c7;
}

#evidence li::before {
  content: "";
  position: absolute;
  top: 1.25rem;
  left: -2.06rem;
  width: 0.76rem;
  height: 0.76rem;
  border: 2px solid var(--paper);
  border-radius: 50%;
  background: var(--review-red);
  box-shadow: 0 0 0 1px var(--review-red);
}

#evidence > p:first-of-type {
  padding: 1rem;
  border-left: 4px solid var(--ink);
  background: rgb(255 253 248 / 70%);
}

#evidence > p:last-of-type {
  color: var(--ink-muted);
  font-size: 0.88rem;
}

/* Four-layer replication stack */
#replicate > ol {
  display: grid;
  gap: 0.8rem;
  margin: 2rem 0;
  padding: 0;
  counter-reset: layer;
  list-style: none;
}

#replicate li {
  position: relative;
  width: calc(100% - (var(--layer, 0) * 3rem));
  margin-left: calc(var(--layer, 0) * 1.5rem);
  padding: 1.15rem 1.25rem 1.15rem 4.2rem;
  border: 1px solid var(--ink);
  background: var(--paper-raised);
  counter-increment: layer;
  box-shadow: 3px 3px 0 var(--rule);
}

#replicate li:nth-child(1) { --layer: 0; }
#replicate li:nth-child(2) { --layer: 1; }
#replicate li:nth-child(3) { --layer: 2; }
#replicate li:nth-child(4) { --layer: 3; }

#replicate li::before {
  content: "L" counter(layer);
  position: absolute;
  top: 50%;
  left: 1rem;
  color: var(--review-red);
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 700;
  transform: translateY(-50%);
}

#replicate > p {
  padding: 1rem;
  border: 1px dashed var(--review-red);
  color: var(--review-red);
  font-weight: 700;
}

noscript article {
  padding: 1.2rem;
  border: 2px solid var(--review-red);
  background: var(--paper-raised);
}

footer {
  padding-block: 1.5rem 2.5rem;
  border-top: 2px solid var(--ink);
  color: var(--ink-muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

@media (max-width: 900px) {
  #workflow > ol {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  #workflow li:nth-child(4) {
    border-right: 0;
  }

  #workflow li:nth-child(n + 5) {
    border-top: 1px solid var(--rule);
  }
}

@media (max-width: 720px) {
  .site-header,
  main,
  footer {
    width: min(calc(100% - 1.25rem), var(--content-width));
  }

  .site-header {
    min-height: 58px;
    font-size: 0.68rem;
    letter-spacing: 0.08em;
  }

  .site-header::after {
    content: "静态";
  }

  main {
    padding-top: 0.8rem;
  }

  .hero {
    min-height: 0;
    padding: 4.5rem 1.2rem 2rem;
    background: var(--paper-raised);
    box-shadow: 4px 4px 0 #ddd2bf;
  }

  .hero::after {
    left: 1.2rem;
    right: auto;
  }

  .hero .eyebrow {
    margin-bottom: 1.5rem;
  }

  .hero a {
    width: 100%;
    margin-right: 0;
  }

  #experience {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 0.8rem;
  }

  #experience > h2,
  #experience > h2 + p,
  #scenario-list,
  #experience > article,
  #play-demo,
  #skip-demo,
  #reset-demo,
  #experience > .demo-disclosure,
  #demo-status {
    grid-column: 1;
    grid-row: auto;
  }

  #experience > article {
    min-height: 390px;
    margin-block: 0.7rem;
    box-shadow: 4px 4px 0 #ddd2bf;
  }

  #workflow > ol {
    display: grid;
    grid-template-columns: 1fr;
    border-block: 0;
    border-left: 2px solid var(--ink);
  }

  #workflow li,
  #workflow li:nth-child(n + 5) {
    min-height: 92px;
    padding: 1rem 1rem 1rem 4rem;
    border-top: 0;
    border-right: 0;
    border-bottom: 1px solid var(--rule);
  }

  #workflow li::before {
    top: 50%;
    left: 1rem;
    transform: translateY(-50%);
  }

  #workflow li::after {
    top: 50%;
    left: -6px;
    transform: translateY(-50%);
  }

  .standards-grid {
    grid-template-columns: 1fr;
  }

  .standard-card {
    min-height: 96px;
  }

  #boundaries > ol,
  #case-study {
    grid-template-columns: 1fr;
  }

  .boundary-card {
    min-height: 190px;
  }

  #case-study > h2 {
    grid-column: 1;
  }

  #replicate li {
    width: 100%;
    margin-left: 0;
  }
}

@media (max-width: 380px) {
  h1 {
    font-size: 2.35rem;
  }

  .hero,
  #experience > article {
    padding-inline: 1rem;
  }

  #demo-checks li {
    padding-right: 0.75rem;
  }

  #replicate li {
    padding-left: 3.55rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}