.flow {
  display: grid;
  grid-template-columns: minmax(200px, 260px) minmax(0, 1fr);
  min-height: calc(100vh - 74px);
  align-items: start;
}

.rail {
  padding: 18px 18px 48px;
  border-right: 1px solid var(--rule);
  min-height: calc(100vh - 74px);
  position: sticky;
  top: 73px;
  max-height: calc(100vh - 73px);
  overflow: auto;
}

.rail h2 {
  margin: 0 0 6px;
  font-family: var(--serif);
  font-size: 18px;
}

.rail-lead {
  margin: 0 0 14px;
  font-size: 12px;
  color: var(--ink-soft);
  line-height: 1.5;
}

.rail-person {
  display: block;
  width: 100%;
  text-align: left;
  font-size: 13px;
  padding: 8px 9px;
  border: 1px solid var(--rule);
  background: var(--panel);
  margin-bottom: 12px;
  cursor: pointer;
}

.rail-person:hover {
  border-color: var(--ink);
}

.rail-person b {
  display: block;
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 2px;
}

.rail-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
  margin-bottom: 8px;
}

.rail-list {
  display: grid;
  gap: 6px;
}

.rail-item {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: stretch;
  border: 1px solid var(--rule);
  background: var(--panel);
}

.rail-item.is-on {
  border-color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--ink);
}

.rail-item > button[data-scheme] {
  text-align: left;
  border: 0;
  background: transparent;
  padding: 8px 9px;
  font-size: 12px;
  line-height: 1.4;
  width: 100%;
}

.rail-item small {
  display: block;
  color: var(--ink-faint);
  margin-top: 2px;
  font-size: 11px;
}

.rail-del {
  border: 0;
  border-left: 1px solid var(--rule);
  background: transparent;
  color: var(--ink-faint);
  padding: 0 10px;
  font-size: 16px;
  line-height: 1;
}

.rail-del:hover {
  color: var(--chop);
}

.flow-main {
  padding: 8px 28px 80px;
  max-width: 820px;
}

.flow-main .q h2 {
  font-size: 19px;
}

/* 首屏：一句话讲清产品，三张示例卡把「同一个人、三种递法」摆出来。 */
.hero {
  padding: 26px 0 24px;
  border-bottom: 1px solid var(--ink);
  margin-bottom: 2px;
}

.hero-title {
  margin: 10px 0 10px;
  font-family: var(--serif);
  font-size: clamp(26px, 3.4vw, 34px);
  line-height: 1.3;
  font-weight: 600;
  max-width: 22em;
}

.hero-sub {
  margin: 0 0 18px;
  color: var(--ink-soft);
  max-width: 34em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.btn.big {
  padding: 11px 22px;
  font-size: 15px;
  letter-spacing: 0.1em;
}

.hero-cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.hero-item {
  margin: 0;
  transition: transform 0.25s ease;
}

.hero-item:nth-child(2) {
  transform: translateY(-6px);
}

.hero-item:hover {
  transform: translateY(-4px);
}

.hero-item:nth-child(2):hover {
  transform: translateY(-10px);
}

.hero-item figcaption {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
  text-align: center;
}

.more {
  margin-top: 12px;
}

.more summary {
  cursor: pointer;
  font-size: 12px;
  color: var(--ink-soft);
  letter-spacing: 0.06em;
}

.folio-stage {
  margin-top: 18px;
}

.pick {
  margin-top: 12px;
  padding-top: 8px;
  scroll-margin-top: 148px;
}

.go-row {
  margin: 0;
  padding: 18px 0 10px;
  border-top: 1px solid var(--ink);
  display: grid;
  gap: 8px;
  justify-items: start;
}

.go-row .designer-note {
  justify-self: stretch;
  width: 100%;
  text-align: center;
}

.go-row .scene-read {
  font-family: var(--serif);
  font-size: 15px;
  line-height: 1.5;
  color: var(--ink);
}

.go-row .scene-read:empty {
  display: none;
}

.go-row .designer-note:empty {
  display: none;
}

.folio {
  display: grid;
  justify-items: center;
  position: sticky;
  top: 82px;
  z-index: 5;
  margin: 0;
  padding: 6px 0 10px;
  background: var(--paper);
  scroll-margin-top: 82px;
}

.folio:empty {
  display: none;
}

.folio-leaf {
  overflow: hidden;
  padding: 0.35em 0.6em;
  min-height: 2.2em;
}

.folio-title {
  margin: 0;
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 400;
  letter-spacing: 0.08em;
  line-height: 1.85;
  color: var(--ink);
  animation: folio-in 0.42s ease;
}

.folio.is-busy::after {
  content: "";
  display: block;
  width: 3.6em;
  height: 1px;
  margin: 0 auto;
  background: var(--ink);
  transform-origin: center;
  animation: folio-mark 2.2s ease-in-out infinite;
}

@keyframes folio-in {
  from {
    transform: translateY(0.55em);
    opacity: 0;
  }
  to {
    transform: none;
    opacity: 1;
  }
}

@keyframes folio-mark {
  0%,
  100% {
    transform: scaleX(0.28);
    opacity: 0.12;
  }
  50% {
    transform: scaleX(1);
    opacity: 0.48;
  }
}

@media (prefers-reduced-motion: reduce) {
  .folio-title {
    animation: none;
  }
  .folio.is-busy::after {
    animation: none;
    opacity: 0.28;
    transform: none;
  }
}

@media (max-width: 980px) {
  .flow {
    grid-template-columns: 1fr;
  }
  .rail {
    position: static;
    max-height: none;
    min-height: 0;
    border-right: 0;
    border-bottom: 1px solid var(--ink);
  }
}

@media (max-width: 640px) {
  .hero-cards {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .hero-item:nth-child(2) {
    transform: none;
  }
}