/* 首页专用样式 */

/* ---------- 首屏 ---------- */
.hero { padding-top: clamp(130px, 17vh, 180px); }
.hero-title { margin: 26px 0 0; max-width: 12.5em; }
.hero-title .line { display: block; overflow: hidden; padding-bottom: .08em; margin-bottom: -.08em; }
.hero-foot { margin-top: 36px; display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 28px 48px; }
.hero-foot .lead { max-width: 30em; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; }

/* 首屏逐行进入：从下方滑入 + 去模糊 */
.hero-in { display: inline-block; opacity: 0; transform: translateY(40%); filter: blur(8px); animation: heroIn 1.1s var(--ease-out) forwards; animation-delay: calc(var(--d, 0) * 90ms + 80ms); }
p.hero-in, div.hero-in { display: flex; transform: translateY(14px); }
p.hero-in.lead { display: block; }
@keyframes heroIn { to { opacity: 1; transform: none; filter: none; } }

/* ---------- 产品演示 ---------- */
.demo-wrap { margin-top: clamp(48px, 7vw, 84px); }
.demo-stage { perspective: 1800px; padding: 0 var(--gutter); }
.demo {
  max-width: 1080px; margin: 0 auto;
  transform-origin: 50% 0%;
  transform: rotateX(var(--rx, 14deg)) scale(var(--sc, .94)) translateY(var(--ty, 0px));
  opacity: 0; animation: demoIn 1.2s var(--ease-out) .45s forwards;
  will-change: transform;
}
@keyframes demoIn { to { opacity: 1; } }
.demo .app { display: grid; grid-template-columns: 228px 1fr; height: clamp(440px, 52vw, 560px); }
.app-side { background: var(--sidebar); border-right: 1px solid var(--line); padding: 14px 10px; display: flex; flex-direction: column; gap: 4px; font-size: 13.5px; }
.side-new { display: flex; align-items: center; gap: 8px; padding: 8px 10px; border-radius: 9px; font-weight: 560; }
.side-new .ico { width: 16px; height: 16px; color: var(--accent); }
.side-group { margin: 14px 10px 4px; font-size: 12px; color: var(--ink-3); }
.side-list { list-style: none; padding: 0; display: grid; gap: 1px; }
.side-list li { padding: 7px 10px; border-radius: 8px; color: var(--ink-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transition: background-color .3s ease, color .3s ease; }
.side-list li.on { background: color-mix(in srgb, var(--ink) 8%, transparent); color: var(--ink); }
.side-list li.dim { opacity: .55; }
.side-user { margin-top: auto; display: flex; align-items: center; gap: 9px; padding: 8px 10px; color: var(--ink-2); }
.side-user i { width: 24px; height: 24px; border-radius: 50%; background: linear-gradient(135deg, var(--accent), #E9B48F); }

.app-main { position: relative; display: flex; flex-direction: column; min-width: 0; background: var(--surface); }
.app-top { height: 48px; display: flex; align-items: center; gap: 10px; padding: 0 18px; font-size: 13.5px; }
.app-top .model { display: inline-flex; align-items: center; gap: 5px; font-weight: 580; padding: 5px 9px; border-radius: 8px; }
.app-top .effort { font-size: 12px; color: var(--ink-3); padding: 3px 9px; border-radius: 99px; border: 1px solid var(--line); }

.thread { flex: 1; overflow: hidden; padding: 8px clamp(18px, 5vw, 64px) 12px; display: flex; flex-direction: column; justify-content: flex-end; gap: 14px; font-size: 14.5px; line-height: 1.7;
  -webkit-mask-image: linear-gradient(to bottom, transparent 0, #000 40px); mask-image: linear-gradient(to bottom, transparent 0, #000 40px); }
.t-user { align-self: flex-end; max-width: 78%; padding: 10px 15px; border-radius: 18px; background: var(--bubble); animation: popIn .45s var(--ease-out) both; }
.t-file { align-self: flex-end; display: inline-flex; align-items: center; gap: 8px; padding: 7px 12px 7px 8px; border-radius: 11px; border: 1px solid var(--line); background: var(--surface-2); font-size: 12.5px; animation: popIn .45s var(--ease-out) both; }
.t-file i { width: 26px; height: 26px; border-radius: 7px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-style: normal; font-size: 10px; font-weight: 700; }
.t-ai { max-width: 92%; color: var(--ink); }
.t-ai .seg { animation: segIn .32s ease-out both; }
.t-ai b { font-weight: 620; }
.t-ai sup { color: var(--accent); font-size: 10px; font-weight: 700; margin: 0 1px; }
.t-tool { align-self: flex-start; display: inline-flex; align-items: center; gap: 8px; height: 30px; padding: 0 12px; border-radius: 99px; font-size: 12.5px; color: var(--ink-2); border: 1px solid var(--line); background: var(--surface-2); animation: popIn .4s var(--ease-out) both; }
.t-tool .spin { width: 12px; height: 12px; border-radius: 50%; border: 1.6px solid color-mix(in srgb, var(--accent) 30%, transparent); border-top-color: var(--accent); animation: spin .7s linear infinite; }
.t-tool.done .spin { animation: none; border-color: var(--ok); background: var(--ok); box-shadow: inset 0 0 0 2px var(--surface-2); }
.t-tool.shimmer span { background: linear-gradient(90deg, var(--ink-2) 30%, var(--ink-3) 50%, var(--ink-2) 70%) 0 0 / 200% 100%; -webkit-background-clip: text; background-clip: text; color: transparent; animation: shimmer 1.4s linear infinite; }
.t-sources { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.t-sources span { display: inline-flex; align-items: center; gap: 6px; font-size: 12px; padding: 4px 10px 4px 5px; border-radius: 8px; border: 1px solid var(--line); background: var(--surface-2); color: var(--ink-2); animation: popIn .4s var(--ease-out) both; }
.t-sources i { font-style: normal; width: 16px; height: 16px; display: grid; place-items: center; border-radius: 5px; background: var(--accent-soft); color: var(--accent); font-size: 10px; font-weight: 700; }
.t-card { margin-top: 10px; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: var(--surface-2); animation: popIn .5s var(--ease-out) both; }
.t-card-h { display: flex; justify-content: space-between; padding: 8px 12px; font-size: 12px; color: var(--ink-3); border-bottom: 1px solid var(--line); }
.t-card svg { width: 100%; height: 110px; }
.t-card .draw { stroke-dasharray: 600; stroke-dashoffset: 600; animation: draw 1.6s var(--ease-out) .1s forwards; }
.t-confirm { align-self: flex-start; width: min(100%, 380px); border: 1px solid var(--line-2); border-radius: 14px; background: var(--surface); box-shadow: var(--shadow); padding: 12px 14px; font-size: 13px; animation: popIn .45s var(--ease-out) both; }
.t-confirm .h { display: flex; align-items: center; gap: 8px; font-weight: 600; }
.t-confirm .h .ico { width: 16px; height: 16px; color: var(--accent); }
.t-confirm code { display: block; margin: 8px 0 10px; padding: 8px 10px; border-radius: 8px; font-size: 12px; white-space: pre-wrap; word-break: break-all; }
.t-confirm .a { display: flex; justify-content: flex-end; gap: 8px; }
.t-confirm .a span { padding: 5px 14px; border-radius: 8px; border: 1px solid var(--line-2); transition: transform .16s var(--ease-out), background-color .2s; }
.t-confirm .a .ok { background: var(--ink); color: var(--bg); border-color: transparent; }
.t-confirm .a .ok.press { transform: scale(.94); }
.t-confirm.decided .a { display: none; }
.t-confirm .res { display: none; color: var(--ok); font-weight: 560; }
.t-confirm.decided .res { display: block; }
.caret { display: inline-block; width: 7px; height: 15px; margin-left: 2px; vertical-align: -2px; border-radius: 2px; background: var(--accent); animation: blink 1s steps(2) infinite; }

.composer { margin: 0 clamp(14px, 4vw, 52px) 16px; border: 1px solid var(--line-2); border-radius: 20px; background: var(--surface); box-shadow: var(--shadow-sm); padding: 12px 12px 10px 16px; }
.composer-text { min-height: 24px; font-size: 14.5px; }
.composer-text .ph { color: var(--ink-3); }
.composer-row { display: flex; align-items: center; gap: 8px; margin-top: 8px; }
.c-btn { width: 30px; height: 30px; border-radius: 9px; border: 1px solid var(--line); display: grid; place-items: center; color: var(--ink-2); }
.c-btn .ico { width: 16px; height: 16px; }
.c-chip { display: inline-flex; align-items: center; gap: 6px; height: 30px; padding: 0 11px; border-radius: 99px; border: 1px solid var(--line); font-size: 12.5px; color: var(--ink-2); transition: color .3s ease, background-color .3s ease, border-color .3s ease; }
.c-chip .ico { width: 14px; height: 14px; }
.c-chip.on { color: var(--accent); background: var(--accent-soft); border-color: transparent; }
.composer-row .sp { flex: 1; }
.send { width: 32px; height: 32px; border-radius: 10px; display: grid; place-items: center; background: color-mix(in srgb, var(--ink) 12%, transparent); color: var(--surface); transition: background-color .25s ease, transform .16s var(--ease-out); }
.send.ready { background: var(--accent); }
.send.press { transform: scale(.88); }

.demo-tabs { max-width: 1080px; margin: 22px auto 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.demo-tabs button { position: relative; text-align: left; padding: 12px 4px 0; color: var(--ink-3); font-size: 14px; font-weight: 540; transition: color .25s ease; }
.demo-tabs button[aria-selected="true"] { color: var(--ink); }
@media (hover: hover) { .demo-tabs button:hover { color: var(--ink); } }
.demo-tabs .bar-p { display: block; height: 2px; margin-top: 10px; border-radius: 2px; background: var(--line-2); overflow: hidden; }
.demo-tabs .bar-p i { display: block; height: 100%; width: 100%; background: var(--accent); transform-origin: left; transform: scaleX(0); }
.demo-tabs button.done .bar-p i { transform: scaleX(1); background: color-mix(in srgb, var(--ink) 30%, transparent); }
.demo-note { max-width: 1080px; margin: 14px auto 0; }

@keyframes popIn { from { opacity: 0; transform: translateY(8px) scale(.98); } }
@keyframes segIn { from { opacity: 0; filter: blur(2px); } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes shimmer { to { background-position: -200% 0; } }
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes blink { 50% { opacity: 0; } }

/* ---------- 三端 ---------- */
.dev-grid { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.25fr); gap: clamp(32px, 6vw, 88px); align-items: start; }
.dev-steps { list-style: none; padding: 0; }
.dev-steps li { position: relative; padding: 30px 0 30px 0; border-top: 1px solid var(--line); min-height: 34vh; display: flex; flex-direction: column; justify-content: center; gap: 10px; opacity: .38; transition: opacity .5s var(--ease-out); cursor: pointer; }
.dev-steps li:last-child { border-bottom: 1px solid var(--line); }
.dev-steps li.on { opacity: 1; }
.dev-steps li::before { content: ""; position: absolute; left: 0; top: -1px; height: 1px; width: 100%; background: var(--accent); transform-origin: left; transform: scaleX(0); transition: transform .8s var(--ease-out); }
.dev-steps li.on::before { transform: scaleX(1); }
.dev-steps .num { font-size: 12.5px; color: var(--accent); }
.dev-steps .h3 { font-family: var(--font-serif); font-weight: 460; font-size: 30px; letter-spacing: -.015em; }
.dev-steps p { max-width: 30em; }

.dev-stage { position: sticky; top: 18vh; height: 64vh; min-height: 420px; max-height: 560px; }
.dev-frame { position: absolute; inset: 0; display: grid; place-items: center; opacity: 0; transform: translateY(24px) scale(.96); filter: blur(8px); transition: opacity .55s ease, transform .8s var(--ease-out), filter .6s ease; pointer-events: none; }
.dev-frame.on { opacity: 1; transform: none; filter: none; }
.dev-frame.leave-up { transform: translateY(-24px) scale(.98); }
.dev-frame .window { width: 100%; }
.mini { display: flex; height: 340px; font-size: 13px; }
.mini-side { width: 56px; border-right: 1px solid var(--line); background: var(--sidebar); padding: 16px 12px; display: flex; flex-direction: column; gap: 10px; }
.mini-side i { height: 8px; border-radius: 4px; background: color-mix(in srgb, var(--ink) 10%, transparent); }
.mini-side i.on { background: var(--accent); opacity: .7; }
.mini-main { flex: 1; padding: 18px 22px; display: flex; flex-direction: column; gap: 12px; min-width: 0; }
.mini-h { font-size: 19px; }
.m-msg { padding: 9px 13px; border-radius: 14px; max-width: 88%; line-height: 1.65; }
.m-msg.u { align-self: flex-end; background: var(--bubble); }
.m-msg.a { padding-left: 0; color: var(--ink); }
.m-msg.a b { font-weight: 620; }
.m-input { margin-top: auto; border: 1px solid var(--line-2); border-radius: 16px; padding: 10px 14px; color: var(--ink-3); }
.titlebar.win { background: var(--sidebar); padding: 0 0 0 14px; gap: 0; }
.win-title { font-size: 12.5px; font-weight: 560; }
.titlebar .sp { flex: 1; }
.win-ctl { width: 42px; height: 40px; display: grid; place-items: center; font-size: 11px; color: var(--ink-3); }
.mini-agent { width: 170px; border-left: 1px solid var(--line); background: var(--sidebar); padding: 16px; display: flex; flex-direction: column; gap: 2px; }
.m-confirm { border: 1px solid var(--line-2); border-radius: 12px; padding: 12px 14px; background: var(--surface); box-shadow: var(--shadow); }
.m-confirm-h { display: flex; align-items: center; gap: 8px; font-weight: 600; }
.m-confirm-h .ico { width: 16px; height: 16px; color: var(--accent); }
.m-confirm code { display: block; margin: 8px 0 10px; font-size: 12px; }
.m-confirm-a { display: flex; justify-content: flex-end; gap: 8px; }
.m-confirm-a span { padding: 4px 13px; border-radius: 8px; border: 1px solid var(--line-2); }
.m-confirm-a .ok { background: var(--ink); color: var(--bg); border-color: transparent; }
.phone { width: 270px; height: 540px; border-radius: 42px; background: var(--surface); border: 1px solid var(--line-2); box-shadow: var(--shadow-lg), 0 0 0 7px color-mix(in srgb, var(--ink) 88%, transparent); padding: 14px 14px 18px; display: flex; flex-direction: column; font-size: 13px; position: relative; }
.phone-notch { width: 84px; height: 22px; border-radius: 12px; background: color-mix(in srgb, var(--ink) 88%, transparent); margin: 0 auto 10px; }
.phone-top { display: flex; justify-content: space-between; align-items: center; padding: 4px 6px 12px; color: var(--ink-2); }
.phone-top .small { color: var(--ink); font-weight: 580; }
.phone-body { flex: 1; display: flex; flex-direction: column; justify-content: flex-end; gap: 12px; padding: 0 4px 12px; }
.phone-input { display: flex; align-items: center; justify-content: space-between; border: 1px solid var(--line-2); border-radius: 20px; padding: 8px 8px 8px 14px; color: var(--ink-3); }
.phone-input i { width: 26px; height: 26px; border-radius: 50%; background: var(--accent); }

/* ---------- 工具 ---------- */
.tool-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(28px, 5vw, 72px); align-items: start; }
.tool-list { list-style: none; padding: 0; border-top: 1px solid var(--line); }
.tool-list li { border-bottom: 1px solid var(--line); }
.tool-list button { width: 100%; text-align: left; display: grid; grid-template-columns: 40px 1fr; column-gap: 8px; padding: 18px 4px; align-items: baseline; }
.tool-list .name { font-size: clamp(22px, 2.4vw, 28px); letter-spacing: -.01em; transition: color .25s ease, transform .4s var(--ease-out); }
.tool-list .desc { grid-column: 2; color: var(--ink-2); font-size: 15px; display: grid; grid-template-rows: 0fr; opacity: 0; transition: grid-template-rows .45s var(--ease-out), opacity .3s ease, margin .45s var(--ease-out); overflow: hidden; }
.tool-list .desc > span { min-height: 0; overflow: hidden; }
.tool-list li.on .desc { grid-template-rows: 1fr; opacity: 1; margin-top: 6px; }
.tool-list li.on .name { color: var(--accent); }
@media (hover: hover) { .tool-list li:not(.on) button:hover .name { transform: translateX(6px); } }
.tool-preview { position: sticky; top: 120px; height: 360px; }
.tp { position: absolute; inset: 0; border-radius: var(--r-xl); padding: 28px; display: flex; flex-direction: column; justify-content: center; gap: 16px; font-size: 14.5px;
  opacity: 0; transform: translateY(14px) scale(.97); filter: blur(6px); transition: opacity .35s ease, transform .5s var(--ease-out), filter .4s ease; background: var(--glass-strong); }
.tp.on { opacity: 1; transform: none; filter: none; }
.tp sup { color: var(--accent); font-weight: 700; font-size: 10px; }
.tp-chip { align-self: flex-start; display: inline-flex; align-items: center; gap: 8px; height: 30px; padding: 0 12px; border-radius: 99px; font-size: 12.5px; color: var(--ink-2); border: 1px solid var(--line); background: var(--surface); }
.tp-chip .spin { width: 10px; height: 10px; border-radius: 50%; background: var(--ok); }
.tp-chip .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); }
.tp-sources { display: flex; flex-wrap: wrap; gap: 6px; }
.tp-sources span { display: inline-flex; align-items: center; gap: 6px; font-size: 12.5px; padding: 5px 10px 5px 6px; border-radius: 9px; border: 1px solid var(--line); background: var(--surface); color: var(--ink-2); }
.tp-sources i { font-style: normal; width: 17px; height: 17px; display: grid; place-items: center; border-radius: 5px; background: var(--accent-soft); color: var(--accent); font-size: 10px; font-weight: 700; }
.tp-steps { display: grid; gap: 10px; }
.tp-steps span { display: flex; align-items: center; gap: 10px; color: var(--ink-2); }
.tp-steps span::before { content: ""; width: 14px; height: 14px; border-radius: 50%; border: 1.6px solid var(--line-2); flex: none; }
.tp-steps .done::before { background: var(--ok); border-color: var(--ok); box-shadow: inset 0 0 0 2.5px var(--surface); }
.tp-steps .now { color: var(--ink); font-weight: 560; }
.tp-steps .now::before { border-color: var(--accent); border-top-color: transparent; animation: spin 1s linear infinite; }
.tp-doc { display: grid; gap: 8px; padding: 14px; border-radius: 12px; background: var(--surface); border: 1px solid var(--line); }
.tp-doc i { height: 8px; border-radius: 4px; background: color-mix(in srgb, var(--ink) 10%, transparent); }
.tp-term, .tp-code { margin: 0; font-size: 13px; }
.ok-t { color: var(--ok); }
.tp-files, .tp-tools, .tp-mem { display: flex; flex-wrap: wrap; gap: 6px; }
.tp-files span, .tp-tools span, .tp-mem span { font-size: 12.5px; padding: 5px 10px; border-radius: 9px; border: 1px solid var(--line); background: var(--surface); color: var(--ink-2); }
.tp-tools b { color: var(--accent); font-weight: 600; margin-left: 4px; }
.tp-skill { padding: 14px 16px; border-radius: 12px; background: var(--surface); border: 1px solid var(--line); }
.tp-skill .mono { font-size: 12px; color: var(--ink-3); }
.tp-skill p { margin-top: 6px; font-size: 13.5px; line-height: 1.8; }
.tp-art { border-radius: 14px; overflow: hidden; border: 1px solid var(--line); background: var(--surface); }
.tp-art-bar { display: flex; gap: 10px; align-items: center; padding: 9px 12px; font-size: 12.5px; border-bottom: 1px solid var(--line); }
.tp-art-bar .share { margin-left: auto; color: var(--accent); font-weight: 600; }
.tp-chart { width: 100%; height: 150px; }
.tp-task { padding: 14px 16px; border-radius: 12px; background: var(--surface); border: 1px solid var(--line); display: grid; gap: 6px; }
.tp-task .mono { font-size: 12px; color: var(--accent); }
.tp-task.dim { opacity: .55; }
.tp-proj { display: grid; gap: 2px; padding: 14px 16px; border-radius: 12px; background: var(--surface); border: 1px solid var(--line); }
.tp-proj .serif { font-size: 22px; }
.tools-more { margin-top: 36px; }

/* ---------- 档位阶梯 ---------- */
.stairs { display: grid; grid-template-columns: repeat(6, 1fr); gap: 10px; align-items: end; height: 380px; }
.step { position: relative; height: calc(30% + var(--h) * 11.6%); border-radius: 16px 16px 6px 6px; padding: 18px 16px; display: flex; flex-direction: column; gap: 2px; border: 1px solid var(--line); background: var(--glass); -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px); overflow: hidden;
  transition: transform .45s var(--ease-out), border-color .3s ease, background-color .3s ease, box-shadow .3s ease, opacity .9s var(--ease-out), filter .9s var(--ease-out); }
.step::after { content: ""; position: absolute; inset: auto 0 0 0; height: 100%; background: linear-gradient(to top, color-mix(in srgb, var(--accent) calc(var(--h) * 4%), transparent), transparent 80%); pointer-events: none; }
.step b { font-family: var(--font-serif); font-weight: 480; font-size: 26px; letter-spacing: -.01em; }
.step > span:last-child { color: var(--ink-2); font-size: 14px; position: relative; z-index: 1; }
.step[data-reveal] { transform: translateY(40px); }
.step[data-reveal].in { transform: none; }
@media (hover: hover) { .step:hover { transform: translateY(-6px); border-color: color-mix(in srgb, var(--accent) 45%, transparent); box-shadow: var(--shadow); } }
.step:active { transform: scale(.98); }

/* ---------- 可靠性 ---------- */
.facts { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.fact { padding: 28px 24px 8px 0; display: grid; gap: 10px; align-content: start; }
.fact + .fact { padding-left: 24px; border-left: 1px solid var(--line); }
.fact .mono { font-size: 14px; color: var(--accent); }
.fact p { color: var(--ink-2); font-size: 15px; }

/* ---------- 结尾 ---------- */
.final-card { border-radius: 32px; padding: clamp(40px, 7vw, 96px) clamp(24px, 6vw, 80px); text-align: center; display: grid; justify-items: center; gap: 22px; position: relative; overflow: hidden; }
.final-card::before { content: ""; position: absolute; inset: -40% 20% auto; height: 80%; background: radial-gradient(closest-side, var(--glow-a), transparent); filter: blur(30px); z-index: -1; }
.final-title { font-size: clamp(44px, 8vw, 96px); }
.final-card .hero-cta { justify-content: center; }

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .dev-grid { grid-template-columns: 1fr; }
  .dev-stage { position: relative; top: 0; order: -1; height: 400px; min-height: 0; }
  .dev-steps li { min-height: 0; padding: 22px 0; }
  .mini-agent { display: none; }
  .tool-grid { grid-template-columns: 1fr; }
  .tool-preview { position: relative; top: 0; order: -1; height: 300px; }
  .facts { grid-template-columns: 1fr 1fr; }
  .fact:nth-child(3) { padding-left: 0; border-left: 0; }
  .fact:nth-child(n+3) { border-top: 1px solid var(--line); }
}
@media (max-width: 760px) {
  .demo .app { grid-template-columns: 1fr; height: 470px; }
  .app-side { display: none; }
  .demo-tabs { grid-template-columns: repeat(2, 1fr); row-gap: 4px; }
  .stairs { grid-template-columns: 1fr; height: auto; gap: 8px; }
  .step { height: auto; flex-direction: row; align-items: baseline; gap: 12px; padding: 14px 16px; border-radius: 14px; }
  .step::after { background: linear-gradient(to right, color-mix(in srgb, var(--accent) calc(var(--h) * 4%), transparent), transparent 85%); }
  .step b { font-size: 22px; min-width: 72px; }
  .step[data-reveal] { transform: translateX(-20px); }
}
@media (max-width: 520px) {
  .hero-foot { margin-top: 26px; }
  .hero-cta { width: 100%; }
  .hero-cta .btn { flex: 1; padding: 0 12px; }
  .demo-stage { padding: 0 10px; }
  .demo .titlebar .url { min-width: 0; }
  .thread { padding: 6px 14px 10px; font-size: 13.5px; }
  .composer { margin: 0 10px 10px; }
  .dev-stage { height: 360px; }
  .mini { height: 300px; }
  .mini-side { display: none; }
  .phone { transform: scale(.66); transform-origin: center; }
  .tool-list .name { font-size: 21px; }
  .tool-preview { height: 280px; }
  .tp { padding: 20px; }
  .facts { grid-template-columns: 1fr; }
  .fact, .fact + .fact { padding: 22px 0 6px; border-left: 0; }
  .fact + .fact { border-top: 1px solid var(--line); }
  .final-card { border-radius: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  .hero-in, .demo { opacity: 1 !important; transform: none !important; filter: none !important; animation: none !important; }
  .dev-frame, .tp { transform: none !important; filter: none !important; }
}

/* 演示里的空对话问候 */
.greet { position: absolute; inset: 48px 0 120px; display: grid; place-content: center; justify-items: center; gap: 14px; pointer-events: none; animation: segIn .5s ease-out both; }
.greet p { font-size: clamp(24px, 3vw, 34px); color: var(--ink); letter-spacing: -.01em; }
.greet-mark { width: 34px; height: 34px; border-radius: 10px; background: var(--accent); -webkit-mask: radial-gradient(circle at 70% 40%, transparent 9px, #000 9.5px); mask: radial-gradient(circle at 70% 40%, transparent 9px, #000 9.5px); }