/* BidCore homepage — Lovart-style editorial layout with real product footage. */

/* ── hero ── */
.hero{text-align:center;padding:40px 24px 44px}
.hero .eyebrow{margin-bottom:18px}
.hero-title{max-width:1100px;margin:0 auto}
.hero-title .phrase{display:inline-block;white-space:nowrap}
/* every phrase ends in punctuation (投标有据， / 落笔有序。), so each line does: shift by half a punctuation
   width (1em - .02em letter-spacing) and the characters before it sit on the center line */
.hero-title>span{position:relative;left:.49em}
.hero .intro,.workflow-head .lead{text-wrap:balance;word-break:keep-all;overflow-wrap:anywhere}

.hero-title .ch{display:inline-block;will-change:transform,opacity,filter}
.motion .hero-title .ch{opacity:0;transform:translateY(.42em);filter:blur(8px);animation:ch-in 1s var(--ease) forwards;animation-delay:calc(160ms + var(--i) * 55ms)}
@keyframes ch-in{to{opacity:1;transform:none;filter:blur(0)}}
.intro{font-size:18px;line-height:1.85;color:var(--muted);max-width:760px;margin:22px auto 30px}
.br-m{display:none}
.cta{display:flex;justify-content:center;gap:12px;flex-wrap:wrap}
.motion .hero-in{opacity:0;transform:translateY(16px);animation:rise .9s var(--ease) forwards}
.motion .hero .eyebrow{animation-delay:60ms}.motion .intro{animation-delay:720ms}.motion .cta{animation-delay:840ms}
@keyframes rise{to{opacity:1;transform:none}}

/* ── painted stage with the product window ── */
.stage{position:relative;padding:48px max(24px,6%) 88px;background:#b3b9bf url("../assets/img/backdrop.webp") center/cover no-repeat;overflow:hidden}
.stage::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(20,30,50,.04),rgba(40,30,10,.06));pointer-events:none}
.window{position:relative;z-index:1;max-width:1280px;margin:0 auto;display:grid;grid-template-columns:300px 1fr;background:var(--surface);border-radius:22px;overflow:hidden;box-shadow:var(--shadow-lift),inset 0 0 0 1px rgba(255,255,255,.6)}
.chat{display:flex;flex-direction:column;gap:16px;padding:22px 20px 18px;border-right:1px solid var(--line);min-width:0}
.chat-head{display:flex;align-items:center;gap:9px;font-size:13px;font-weight:600;color:var(--ink)}
.chat-head span:first-of-type{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.chat-head .caret{color:var(--faint);font-weight:400;margin-left:-2px}
.bubble{background:#f3f2ef;border-radius:18px;padding:13px 15px;font-size:13px;line-height:1.75;color:var(--ink-2);transition:opacity .4s}
.steps{list-style:none;margin:2px 0 0;padding:0;display:flex;flex-direction:column;gap:11px}
.steps li{position:relative;display:flex;align-items:center;gap:10px;font-size:13px;color:var(--muted);transition:color .35s}
.steps li::before{content:"";flex:0 0 16px;height:16px;border-radius:50%;box-shadow:inset 0 0 0 1.5px rgba(23,23,19,.22);background:transparent center/10px no-repeat;transition:background-color .35s,box-shadow .35s}
.steps li.doing{color:var(--ink)}
.steps li.doing::before{box-shadow:inset 0 0 0 1.5px var(--ink);animation:spin-dash 1.1s linear infinite;background-image:none;border:0;-webkit-mask:conic-gradient(#000 0 70%,transparent 70%);mask:conic-gradient(#000 0 70%,transparent 70%)}
.steps li.done{color:var(--faint);text-decoration:line-through;text-decoration-color:rgba(23,23,19,.35)}
.steps li.done::before{background-color:var(--ink);box-shadow:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2.5 6.2l2.2 2.2L9.5 3.6' fill='none' stroke='white' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E")}
@keyframes spin-dash{to{transform:rotate(360deg)}}
.reply{font-size:12.5px;line-height:1.85;color:var(--muted);transition:opacity .4s}
.composer{margin-top:auto;border-radius:16px;box-shadow:inset 0 0 0 1px var(--line-2);padding:12px 12px 10px 14px;font-size:12.5px;color:var(--faint);display:flex;flex-direction:column;gap:14px}
.composer .row{display:flex;justify-content:space-between;align-items:center}
.composer .plus{color:var(--muted);font-size:15px}
.composer .send{width:24px;height:24px;border-radius:50%;background:#c9c8c2;color:#fff;display:grid;place-items:center;font-size:12px}
.screen{position:relative;padding:18px;background:#f6f6f4;min-width:0}
.screen video{width:100%;aspect-ratio:16/10;object-fit:cover;border-radius:12px;background:var(--paper);box-shadow:0 1px 0 var(--line)}
.screen video.swap{animation:swap .6s var(--ease)}
@keyframes swap{from{opacity:.2;transform:scale(.99)}to{opacity:1;transform:none}}
.screen-note{position:absolute;right:28px;bottom:26px;padding:4px 11px;border-radius:999px;background:rgba(255,255,255,.86);backdrop-filter:blur(8px);font-size:11px;color:var(--muted)}
.switcher{position:relative;z-index:2;display:flex;gap:4px;width:max-content;margin:-26px auto 0;padding:6px;border-radius:999px;background:rgba(255,255,255,.72);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);box-shadow:var(--shadow-float)}
.switcher button{display:inline-flex;align-items:center;gap:8px;border:0;background:transparent;border-radius:999px;padding:10px 18px;font-size:13.5px;color:var(--ink-2);transition:background .3s,color .3s,box-shadow .3s}
.switcher button:hover{color:var(--ink)}
.switcher button[aria-selected=true]{background:var(--surface);color:var(--ink);box-shadow:0 1px 2px rgba(23,23,19,.08),inset 0 0 0 1px var(--line)}
.ring{width:15px;height:15px;display:none;transform:rotate(-90deg)}
.switcher button[aria-selected=true] .ring{display:block}
.ring circle{fill:none;stroke:rgba(23,23,19,.14);stroke-width:2.2}
.ring .arc{stroke:var(--ink);stroke-linecap:round;stroke-dasharray:44;stroke-dashoffset:calc(44 - 44 * var(--p,0))}
.pause{position:absolute;left:50%;bottom:24px;z-index:2;transform:translateX(-50%);border:0;background:transparent;font-size:12px;color:rgba(23,23,19,.66);border-bottom:1px solid currentColor;padding:0 0 1px}
.principles{display:flex;justify-content:center;gap:88px;padding:30px 24px;color:var(--muted);font-size:13.5px;border-bottom:1px solid var(--line)}

/* ── slash-command list (Lovart style) ── */
.commands{max-width:1280px;margin:0 auto;padding:118px 48px 96px}
.commands-copy{text-align:center;margin-bottom:56px}
.commands-copy .eyebrow{margin-bottom:16px}
.commands-body{display:grid;grid-template-columns:minmax(260px,.8fr) 1.6fr;align-items:center;gap:56px}
.cmd-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}
.cmd-list button{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;border:0;background:transparent;border-radius:999px;padding:12px 18px;text-align:left;font-size:17px;letter-spacing:.01em;color:var(--faint);transition:color .35s,background .35s,box-shadow .35s,transform .45s var(--ease)}
.cmd-list button::after{content:"↑";width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:var(--ink);color:#fff;font-size:13px;opacity:0;transform:scale(.6) rotate(90deg);transition:opacity .3s,transform .45s var(--ease)}
.cmd-list button:hover{color:var(--ink-2)}
.cmd-list button[aria-current=true]{background:var(--surface);color:var(--ink);box-shadow:var(--shadow-float),inset 0 0 0 1px var(--line);transform:translateX(6px)}
.cmd-list button[aria-current=true]::after{opacity:1;transform:none}
.cmd-figure{margin:0;border-radius:24px;background:var(--paper-2);padding:22px 22px 18px;overflow:hidden}
.cmd-figure img{width:100%;height:auto;aspect-ratio:3/2;object-fit:cover;object-position:left top;border-radius:12px;box-shadow:0 14px 40px rgba(23,23,19,.12);transition:opacity .45s var(--ease),transform .7s var(--ease)}
.cmd-figure img.out{opacity:0;transform:translateY(10px) scale(.99)}
.cmd-figure figcaption{margin-top:16px;font-size:14px;color:var(--muted);line-height:1.8;min-height:3.6em}

/* ── film ── */
.film{padding:40px 24px 110px;text-align:center;background:linear-gradient(180deg,var(--paper),var(--paper-2))}
.film-copy .eyebrow{margin-bottom:16px}
.film-frame{position:relative;max-width:1160px;margin:48px auto 0;border-radius:24px;overflow:hidden;background:#e9e7e1;box-shadow:var(--shadow-lift)}
.film-frame video{width:100%;aspect-ratio:16/9;background:#f7f6f3;object-fit:cover}
.film-play{position:absolute;left:50%;top:50%;width:92px;height:92px;margin:-46px 0 0 -46px;border:0;border-radius:50%;background:rgba(23,23,19,.86);color:#fff;font-size:24px;padding-left:6px;box-shadow:0 12px 40px rgba(23,23,19,.3);transition:transform .35s var(--ease),background .3s}
.film-play:hover{transform:scale(1.06);background:var(--ink)}
.film-frame.playing .film-play{opacity:0;pointer-events:none}
.film-note{margin-top:18px;font-size:12.5px;color:var(--faint)}

/* ── four steps ── */
.workflow{max-width:1280px;margin:0 auto;padding:112px 48px}
.workflow-head{text-align:center}
.workflow-head .eyebrow{margin-bottom:16px}
.lead{font-size:16px;line-height:1.9;color:var(--muted);margin-top:22px}
.steps4{display:grid;grid-template-columns:repeat(4,1fr);gap:36px;margin-top:72px}
.steps4 article{border-top:1px solid var(--line-2);padding-top:22px}
.steps4 .num{display:block;font:italic 30px/1 var(--serif);color:var(--faint);margin-bottom:26px}
.steps4 p{margin-top:14px;color:var(--muted);font-size:14px;line-height:1.85}

/* ── detail cards ── */
.cards{max-width:1320px;margin:0 auto;padding:40px 48px 112px}
.cards-head{text-align:center;margin-bottom:64px}
.cards-head .eyebrow{margin-bottom:16px}
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.card h3{font-size:22px;margin-top:22px}
.card p{margin-top:8px;font-size:14px;line-height:1.8;color:var(--muted)}
.card-art{display:block;width:100%;border:0;padding:24px;border-radius:22px;background:var(--paper-2);overflow:hidden;cursor:zoom-in}
.card-art img{width:100%;height:auto;aspect-ratio:3/2;object-fit:cover;object-position:left top;border-radius:10px;box-shadow:0 10px 30px rgba(23,23,19,.12);transition:transform .8s var(--ease)}
@media (hover:hover){.card-art:hover img{transform:scale(1.035)}}

/* ── faq / closing ── */
.faq{max-width:1280px;margin:0 auto;padding:100px 48px;display:grid;grid-template-columns:1fr 1.3fr;gap:56px;border-top:1px solid var(--line)}
.faq .eyebrow{margin-bottom:16px}
.questions details{border-bottom:1px solid var(--line-2);padding:22px 0}
.questions details:first-child{padding-top:4px}
.questions summary{cursor:pointer;font-size:16px;list-style:none;display:flex;justify-content:space-between;gap:16px}
.questions summary::-webkit-details-marker{display:none}
.questions summary::after{content:"+";color:var(--faint);font-size:20px;line-height:1;transition:transform .3s var(--ease)}
.questions details[open] summary::after{transform:rotate(45deg)}
.questions p{color:var(--muted);font-size:14px;line-height:1.9;padding-top:14px}
.closing{text-align:center;padding:104px 24px 116px;background:var(--paper-2)}
.closing .eyebrow{margin-bottom:22px}
.closing h2{font-size:clamp(42px,5vw,72px)}
.closing .button{margin-top:36px}

/* ── responsive ── */
@media (max-width:1100px){
  .window{grid-template-columns:250px 1fr}
  .chat{padding:18px 16px}
  .reply{display:none}
  .commands-body{grid-template-columns:1fr 1.3fr;gap:32px}
  .card-grid{grid-template-columns:repeat(2,1fr)}
  .steps4{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:720px){
  .hero{padding:32px 20px 34px}
  .intro{font-size:15px;max-width:360px}
  .br-m{display:block}
  .stage{padding:22px 14px 80px}
  .window{grid-template-columns:1fr;border-radius:18px}
  .chat{border-right:0;border-bottom:1px solid var(--line);gap:10px;padding:14px}
  .steps{flex-direction:row;flex-wrap:wrap;gap:6px 12px}
  .steps li{font-size:11.5px;gap:6px}
  .steps li::before{flex-basis:13px;height:13px}
  .composer,.reply{display:none}
  .screen{padding:10px}
  .screen-note{right:16px;bottom:16px;font-size:10px}
  .switcher{max-width:calc(100% - 16px);overflow-x:auto;margin-top:-22px}
  .switcher button{padding:8px 12px;font-size:12.5px}
  .principles{gap:0;justify-content:space-around;font-size:11px;padding:22px 8px}
  .commands{padding:72px 20px}
  .commands-copy{margin-bottom:28px}
  .commands-body{grid-template-columns:1fr}
  .cmd-list{flex-direction:row;overflow-x:auto;gap:6px;padding-bottom:4px;scroll-snap-type:x mandatory}
  .cmd-list li{flex:0 0 auto;scroll-snap-align:center}
  .cmd-list button{font-size:14px;padding:9px 14px;white-space:nowrap}
  .cmd-list button::after{display:none}
  .cmd-list button[aria-current=true]{transform:none}
  .cmd-figure{padding:12px}
  .film{padding:24px 16px 72px}
  .film-frame{margin-top:28px;border-radius:18px}
  .film-frame.tall{max-width:400px}
  .film-frame.tall video{aspect-ratio:9/16}
  .film-play{width:72px;height:72px;margin:-36px 0 0 -36px;font-size:20px}
  .workflow,.cards,.faq{padding-left:20px;padding-right:20px}
  .workflow{padding-top:72px;padding-bottom:64px}
  .steps4{grid-template-columns:1fr;gap:26px;margin-top:40px}
  .cards{padding-top:24px;padding-bottom:72px}
  .cards-head{margin-bottom:36px}
  .card-grid{grid-template-columns:1fr;gap:34px}
  .card-art{padding:14px}
  .faq{grid-template-columns:1fr;gap:24px;padding-top:64px;padding-bottom:64px}
  .closing{padding:72px 20px 84px}
}