/* Chapter layouts. Desktop first; tablet ≤ 900px; phone ≤ 520px. */
main { position: relative; z-index: 1; overflow-x: clip; }
.chapter { position: relative; padding-block: var(--section); }
.chapter-head { margin-bottom: clamp(40px, 5vw, 84px); }
.chapter-head .lead { margin-top: clamp(18px, 2vw, 28px); }
.chapter-head.is-center { text-align: center; }
.chapter-head.is-center .folio { justify-content: center; }
.chapter-head.is-center .lead { margin-inline: auto; }
.chapter-coda {
  margin-top: clamp(32px, 4vw, 56px); text-align: center;
  font: 500 clamp(17px, 1.4vw, 21px)/1.6 var(--serif); color: var(--text-2);
}
.chapter-coda::before { content: ""; display: block; width: 1px; height: 40px; margin: 0 auto 20px; background: linear-gradient(transparent, var(--hair-3)); }

/* Alternate bands of ink, joined without hard edges. */
.experience, .sample, .boundary {
  background: linear-gradient(180deg, var(--ink-1), var(--ink-2) 14%, var(--ink-2) 86%, var(--ink-1));
}

/* ==================================================================== § 00 hero */
.hero { padding: 0; isolation: isolate; } /* layout: css/hero-card.css (3.2) */
.hero-bg { position: absolute; inset: 0; z-index: -1; pointer-events: none; overflow: hidden; }
.hero-glow {
  position: absolute; left: 73%; top: 56%; width: min(1180px, 120vw); aspect-ratio: 1; margin: calc(min(1180px, 120vw) / -2) 0 0 calc(min(1180px, 120vw) / -2);
  border-radius: 50%; will-change: transform;
  background: radial-gradient(closest-side, rgba(36, 111, 241, 0.38), rgba(36, 111, 241, 0.13) 46%, rgba(36, 111, 241, 0.03) 66%, transparent 74%);
}
.hero-rings { position: absolute; left: 73%; top: 54%; width: min(900px, 96vw); margin: calc(min(900px, 96vw) / -2) 0 0 calc(min(900px, 96vw) / -2); will-change: transform; }
.hero-rings circle { stroke: rgba(156, 193, 255, 0.13); stroke-width: 1; vector-effect: non-scaling-stroke; }
.hero-rings .wire { stroke: rgba(112, 170, 255, 0.55); stroke-width: 1.2; vector-effect: non-scaling-stroke; stroke-dasharray: 1 1; stroke-dashoffset: 1; animation: wire-draw 2.6s var(--ease-out) 0.35s forwards; }
.hero-rings .wire:nth-of-type(2) { animation-delay: 0.55s; }
.hero-rings .wire:nth-of-type(3) { animation-delay: 0.75s; }
@keyframes wire-draw { to { stroke-dashoffset: 0; } }

.hero-lead { font-size: var(--fs-lead); line-height: 1.85; color: var(--text-2); max-width: 26.5em; }
.hero-lead strong { color: var(--text-1); font-weight: 600; background: linear-gradient(transparent 64%, rgba(36, 111, 241, 0.5) 64%, rgba(36, 111, 241, 0.5) 92%, transparent 92%); padding: 0 0.1em; }
.hero-signal {
  position: absolute; z-index: 3; display: flex; align-items: center; gap: 12px; padding: 9px 18px 9px 9px;
  border-radius: 999px; border: 1px solid var(--hair-2); background: rgba(7, 16, 32, 0.62);
  -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px);
  transition: border-color var(--t-base), background var(--t-base);
}
.hero-signal:hover { border-color: var(--hair-3); background: rgba(14, 30, 54, 0.8); }
.hero-signal b { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; border: 1px solid var(--hair-3); font: 500 11px/1 var(--mono); color: var(--blue-soft); transition: background var(--t-slow), color var(--t-slow), border-color var(--t-slow); }
.hero-signal strong { display: block; font-size: 14px; font-weight: 600; line-height: 1.35; }
.hero-signal small { display: block; font-size: 12px; line-height: 1.45; color: var(--text-3); }

.scroll-cue {
  position: absolute; left: max(var(--gutter), calc((100% - 1280px) / 2)); bottom: clamp(22px, 4vh, 40px);
  display: flex; align-items: center; gap: 14px; min-height: 44px; font-size: 12px; letter-spacing: 0.24em; color: var(--text-3);
  transition: color var(--t-base);
}
.scroll-cue:hover { color: var(--text-1); }
.scroll-cue-line { position: relative; width: 1px; height: 40px; background: var(--hair-2); overflow: hidden; }
.scroll-cue-line::after { content: ""; position: absolute; inset: 0; background: linear-gradient(transparent, var(--blue-soft)); animation: cue 2.6s var(--ease-in-out) infinite; }
@keyframes cue { 0% { transform: translateY(-100%); } 60%, 100% { transform: translateY(100%); } }

/* =============================================================== § 01 manifesto */
.manifesto h2 mark { position: relative; color: var(--blue-mist); white-space: nowrap; }
.manifesto h2 mark::after {
  content: ""; position: absolute; left: -0.04em; right: -0.04em; bottom: 0.02em; height: 0.11em; border-radius: 0.1em;
  background: var(--blue); transform-origin: left; transform: scaleX(0); transition: transform 1.2s var(--ease-out) 0.65s;
}
.manifesto h2.is-in mark::after, html:not(.js) .manifesto h2 mark::after, .motion-reduced .manifesto h2 mark::after { transform: scaleX(1); }
.ink-text { font: 500 clamp(23px, 2.15vw, 33px)/1.62 var(--serif); letter-spacing: -0.01em; color: var(--text-1); }
.ink-text span { opacity: clamp(0.2, calc((var(--ink, 1) - var(--i)) * 10 + 0.2), 1); }

/* ================================================================ § 02 work */
.work::before {
  content: ""; position: absolute; inset: 20% 0 0; z-index: -1; pointer-events: none;
  background: radial-gradient(60% 50% at 62% 55%, rgba(36, 111, 241, 0.1), transparent 70%);
}
.work-stage { display: grid; grid-template-columns: minmax(270px, 350px) minmax(0, 1fr); gap: clamp(18px, 2.6vw, 40px); align-items: stretch; }
.work-panel { display: flex; flex-direction: column; justify-content: space-between; gap: 22px; padding-block: 6px; }
.work-modes { display: grid; gap: 10px; }
.work-modes button {
  display: grid; grid-template-columns: 34px 1fr; column-gap: 8px; text-align: left;
  padding: 18px 20px 18px 16px; border-radius: var(--r-m); border: 1px solid var(--hair); background: rgba(255, 255, 255, 0.012);
  transition: border-color var(--t-base), background var(--t-base), box-shadow var(--t-base);
}
.work-modes button:hover { border-color: var(--hair-2); }
.work-modes b { grid-row: 1 / span 3; font: 500 12px/2.1 var(--mono); color: var(--text-4); transition: color var(--t-base); }
.mode-title { font: 500 clamp(18px, 1.5vw, 21px)/1.45 var(--serif); }
.mode-note { font-size: 13px; line-height: 1.6; color: var(--text-3); }
/* The output line always keeps its space and only fades: expanding it (3.0) changed the row
   height mid-transition, and the scroll-played beats (3.1) would shift everything below. */
.mode-output {
  display: block; opacity: 0.38; margin-top: 10px;
  font: 500 12px/1.6 var(--mono); letter-spacing: 0.02em; color: var(--blue-soft);
  transition: opacity 0.4s;
}
.work-modes button[aria-pressed="true"] { border-color: var(--hair-3); background: linear-gradient(150deg, rgba(36, 111, 241, 0.2), rgba(36, 111, 241, 0.03) 70%); box-shadow: inset 3px 0 0 var(--blue); }
.work-modes button[aria-pressed="true"] b { color: var(--blue-soft); }
.work-modes button[aria-pressed="true"] .mode-output { opacity: 1; }

/* ========================================================== § 03 experience */
.experience-head { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 30em); align-items: end; gap: 40px; }
.experience-head .lead { margin: 0; }

/* ============================================================= § 04 network */
.network::before {
  content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none; opacity: 0.6;
  background-image: radial-gradient(rgba(156, 193, 255, 0.16) 1px, transparent 1.2px); background-size: 28px 28px;
  -webkit-mask-image: radial-gradient(60% 50% at 50% 60%, #000, transparent); mask-image: radial-gradient(60% 50% at 50% 60%, #000, transparent);
}
.network-bar { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px 24px; margin-top: 18px; }
.network-steps { display: flex; flex-wrap: wrap; gap: 6px 0; font-size: 13px; color: var(--text-2); }
.network-steps li { display: flex; align-items: center; }
.network-steps li + li::before { content: ""; order: -2; width: 26px; height: 1px; margin: 0 12px; background: var(--hair-3); }
.network-steps li { counter-increment: step; }
.network-steps li::after { content: counter(step, decimal-leading-zero); order: -1; margin-right: 8px; font: 500 11px/1 var(--mono); color: var(--blue-soft); }
.network-steps { counter-reset: step; }
.network-foot { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px 40px; margin-top: clamp(30px, 3.4vw, 48px); padding-top: 28px; border-top: 1px solid var(--hair); }
.network-foot p { max-width: 40em; color: var(--text-2); }
.network-foot p small { display: block; margin-top: 6px; font-size: 12px; color: var(--text-3); }

/* ============================================================== § 05 sample: css/card-call.css (3.1) */

/* =============================================================== § 06 story */
.story-head { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 28em); align-items: end; gap: 40px; }
.story-head .lead { margin: 0; }
.growth-stage { display: grid; grid-template-columns: minmax(270px, 350px) minmax(0, 1fr); gap: clamp(18px, 2.6vw, 40px); align-items: stretch; }
.growth-panel { display: flex; flex-direction: column; gap: 22px; padding-block: 6px; }
.growth-tabs { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.growth-tabs button {
  display: grid; justify-items: start; gap: 2px; padding: 14px 12px 14px 14px; border-radius: var(--r-s); text-align: left;
  border: 1px solid var(--hair); font-size: 12px; color: var(--text-3); transition: border-color var(--t-base), background var(--t-base), color var(--t-base);
}
.growth-tabs button b { font: 500 11px/1 var(--mono); color: var(--text-4); margin-bottom: 6px; }
.growth-tabs button strong { font: 500 17px/1.4 var(--serif); color: var(--text-1); }
.growth-tabs button:hover { border-color: var(--hair-2); }
.growth-tabs button[aria-pressed="true"] { border-color: var(--blue); background: rgba(36, 111, 241, 0.14); color: var(--blue-mist); }
.growth-tabs button[aria-pressed="true"] b { color: var(--blue-soft); }
.growth-note { padding: 22px 0 0; border-top: 1px solid var(--hair-2); }
.growth-location { display: inline-block; font: 500 12px/1 var(--mono); letter-spacing: 0.06em; color: var(--blue-soft); }
.growth-note h3 { margin: 14px 0 10px; font: 500 clamp(22px, 2vw, 28px)/1.4 var(--serif); }
.growth-note p { color: var(--text-2); font-size: 15px; }
.growth-panel .scene-tools { margin-top: auto; }
.memory-strip {
  display: flex; align-items: center; justify-content: space-between; gap: 32px; margin-top: clamp(28px, 3.4vw, 48px);
  padding: 26px 30px; border-radius: var(--r-l); border: 1px solid var(--hair); background: linear-gradient(120deg, rgba(36, 111, 241, 0.1), rgba(36, 111, 241, 0) 60%);
}
.memory-copy { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 10px 28px; }
.memory-copy strong { font: 500 22px/1.4 var(--serif); }
.facets { display: flex; flex-wrap: wrap; gap: 8px; }
.facets li { padding: 5px 13px; border-radius: 999px; border: 1px solid var(--hair-2); font-size: 13px; color: var(--text-2); }
.memory-copy p { grid-column: 1 / -1; font-size: 14px; color: var(--text-3); }
.memory-strip .paper-dock { --w: 64px; }

/* ============================================================ § 07 boundary */
.boundary-grid { display: grid; grid-template-columns: minmax(0, 0.86fr) minmax(0, 1.14fr); gap: clamp(24px, 3.6vw, 56px); align-items: start; }
.boundary .clauses { position: sticky; top: calc(var(--header) + 40px); }

/* ================================================================ § 08 faq */
.faq-grid { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: clamp(40px, 7vw, 120px); align-items: start; }
.faq-aside { position: sticky; top: calc(var(--header) + 48px); display: grid; justify-items: start; gap: 0; }
.faq-aside .lead { margin: 20px 0 10px; }
.faq-aside .dock-note { margin-top: clamp(28px, 3vw, 44px); }
.dock-note.is-compact .paper-dock { --w: 58px; }

/* ============================================================ § 09 closing */
.closing { padding-bottom: clamp(90px, 10vw, 150px); overflow: clip; }
.closing::before {
  content: ""; position: absolute; left: 50%; bottom: -30%; width: min(1400px, 140vw); aspect-ratio: 2 / 1; translate: -50% 0; z-index: -1; pointer-events: none;
  background: radial-gradient(closest-side, rgba(36, 111, 241, 0.3), rgba(36, 111, 241, 0.06) 60%, transparent 75%);
}
.closure {
  display: grid; grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: clamp(32px, 5vw, 80px);
  max-width: 980px; margin: 0 auto clamp(80px, 10vw, 150px); padding: clamp(32px, 4vw, 56px);
  border-radius: var(--r-xl); border: 1px solid var(--hair); background: linear-gradient(150deg, rgba(156, 193, 255, 0.06), rgba(156, 193, 255, 0.01));
}
.paper-dock.is-large { --w: clamp(120px, 13vw, 168px); }
.closure-title { font-size: clamp(26px, 2.6vw, 40px); line-height: 1.4; }
.loop-map { display: flex; flex-wrap: wrap; gap: 8px; margin: 26px 0 22px; }
.loop-map a {
  display: inline-flex; align-items: center; gap: 8px; min-height: 40px; padding: 0 14px; border-radius: 999px;
  border: 1px solid var(--hair-2); font-size: 13px; color: var(--text-2); transition: border-color var(--t-base), color var(--t-base), background var(--t-base);
}
.loop-map a b { font: 500 11px/1 var(--mono); color: var(--text-4); }
.loop-map a:hover { color: var(--text-1); border-color: var(--hair-3); }
.loop-map a[aria-current="step"] { color: var(--paper-ink); background: var(--paper); border-color: var(--paper); }
.loop-map a[aria-current="step"] b { color: var(--blue); }
.return-link { display: inline-flex; align-items: center; gap: 10px; min-height: 44px; font-size: 15px; color: var(--blue-soft); }
.return-link:hover { color: var(--blue-mist); }
.return-link svg { transition: transform var(--t-base) var(--ease-out); }
.return-link:hover svg { transform: translateY(-3px); }
/* § 09 pricing and the trial dialog: css/trial.css (3.2) */
.cta-note { margin-top: 26px; font-size: 14px; color: var(--text-3); }

/* ================================================================ tablet */
@media (max-width: 1080px) {
  .signal-2 { right: -1%; }
}
@media (max-width: 900px) {
  .faq-grid, .boundary-grid, .experience-head, .story-head { grid-template-columns: 1fr; }
  .faq-aside, .boundary .clauses { position: static; }
  .experience-head, .story-head { gap: 0; }
  .experience-head .lead, .story-head .lead { margin-top: 20px; }
  .work-stage, .growth-stage { grid-template-columns: 1fr; gap: 14px; }
  .work-modes { grid-template-columns: repeat(3, 1fr); gap: 8px; }
  .work-modes button { grid-template-columns: 1fr; padding: 14px 14px 14px; }
  .work-modes b { grid-row: auto; line-height: 1.4; }
  .work-modes .mode-note { display: none; }
  .work-panel, .growth-panel { gap: 12px; padding: 0; }
  .growth-panel { display: grid; grid-template-columns: 1fr; }
  .boundary .clauses { margin-bottom: 28px; }
  .closure { grid-template-columns: 1fr; justify-items: center; text-align: center; }
  .loop-map { justify-content: center; }
}

/* ================================================================= phone */
@media (max-width: 520px) {
  .signal-1 { left: 0; top: 14%; }
  .signal-2 { right: 0; top: 46%; }
  .signal-3 { left: 0; bottom: 20%; }
  .scroll-cue { display: none; }
  .ink-text { font-size: 22px; }
  .work-modes .mode-title { font-size: 16px; }
  .work-modes button { padding: 12px 10px; }
  .work-modes .mode-output { display: none; }
  /* The pinned growth stage must fit one phone screen: compact tabs and note above the stage. */
  .growth-panel { gap: 10px; }
  .growth-tabs button { padding: 9px 10px 10px; }
  .growth-tabs button b { display: none; }
  .growth-tabs button strong { font-size: 15px; }
  .growth-note { padding-top: 12px; }
  .growth-note h3 { font-size: 19px; margin: 8px 0 4px; }
  .growth-note p { font-size: 13.5px; line-height: 1.7; }
  /* The state line keeps its own row: its text changes (居中后… / 动作演示中 / 已暂停) and must not re-wrap the toolbar. */
  .growth-panel .scene-state, .work-panel .scene-state { flex: 1 1 100%; margin: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .memory-strip { padding: 20px; gap: 18px; align-items: flex-start; }
  .memory-copy { grid-template-columns: 1fr; }
  .memory-strip .paper-dock { --w: 52px; }
  .closure { padding: 30px 20px; margin-bottom: 72px; }
  .dock-note { padding: 18px 18px 22px 16px; gap: 18px; }
  .dock-note .paper-dock { --w: 56px; }
}