/* 抖音揭秘｜赛道档案馆：砂岩白、焦油黑、兔速橙；影像优先、工程档案、不对称叙事。 */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=Noto+Sans+SC:wght@400;500;600;700;800&family=Noto+Serif+SC:wght@600;700;900&display=swap');

:root{--ink:#171716;--ink-2:#2a2b29;--paper:#f4f1ea;--paper-2:#e8e2d7;--line:#cbc4b8;--muted:#77746e;--orange:#ff6a3d;--orange-2:#df4c26;--blue:#9fb4c2;--sage:#718277;--white:#fffdf8;--radius:18px;--shadow:0 18px 50px rgba(18,18,16,.12);--easing:cubic-bezier(.23,1,.32,1)}
*{box-sizing:border-box} html{scroll-behavior:smooth} body{margin:0;background:var(--paper);color:var(--ink);font-family:'Noto Sans SC',sans-serif;font-size:16px;line-height:1.72} a{color:inherit;text-decoration:none} img{display:block;max-width:100%;height:auto} button,input{font:inherit} button{cursor:pointer} ::selection{background:var(--orange);color:#fff}.screen-reader{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.site-wrap{overflow:hidden}.shell{width:min(1380px,calc(100% - 48px));margin-inline:auto}.eyebrow,.archive-code,.tag,.data-chip{font-family:'IBM Plex Mono',monospace;letter-spacing:.04em}.eyebrow{margin:0 0 10px;color:var(--orange-2);font-size:12px;font-weight:600;text-transform:uppercase}.archive-code{color:var(--muted);font-size:11px}.section-head{display:grid;grid-template-columns:1fr minmax(220px,420px);gap:34px;align-items:end;margin-bottom:34px}.section-head h2{font-family:'Noto Serif SC',serif;font-size:clamp(28px,4vw,50px);line-height:1.15;letter-spacing:-.06em;margin:0}.section-head h2:before{content:'';display:inline-block;width:28px;height:5px;background:var(--orange);vertical-align:middle;margin-right:14px}.section-head p{margin:0;color:#5e5b56;font-size:15px}.section-space{padding:104px 0}.button{display:inline-flex;gap:10px;align-items:center;justify-content:center;border:1px solid transparent;font-size:14px;font-weight:700;padding:14px 20px;transition:transform .18s var(--easing),background .18s var(--easing),color .18s var(--easing),border .18s var(--easing)}.button:active{transform:scale(.97)}.button-orange{background:var(--orange);color:#fff}.button-orange:hover{background:var(--orange-2)}.button-dark{background:var(--ink);color:#fff}.button-dark:hover{background:#333}.button-light{background:transparent;border-color:rgba(255,255,255,.44);color:#fff}.button-light:hover{background:#fff;color:var(--ink)}.arrow{font-family:Arial;font-size:19px;line-height:1}

/* Header */
.utility{background:var(--ink);color:#e9e4da;font-size:12px}.utility-inner{min-height:34px;display:flex;gap:18px;align-items:center;justify-content:space-between}.utility-note{display:flex;align-items:center;gap:8px}.live-dot{width:7px;height:7px;background:var(--orange);border-radius:99px}.utility-links{display:flex;gap:14px}.utility-links a:hover{color:var(--orange)}.masthead{background:rgba(244,241,234,.94);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20;backdrop-filter:blur(16px)}.masthead-inner{height:78px;display:flex;align-items:center;gap:28px}.brand{display:inline-flex;align-items:center;gap:10px;flex-shrink:0}.brand img{width:38px;height:38px;object-fit:contain}.brand-name{font-family:'Noto Serif SC',serif;font-weight:900;letter-spacing:-.1em;font-size:25px}.main-nav{display:flex;gap:4px;align-items:center;margin-right:auto}.main-nav a{padding:8px 11px;font-size:14px;font-weight:700;white-space:nowrap;border-bottom:2px solid transparent}.main-nav a:hover,.main-nav a.current{border-color:var(--orange);color:var(--orange-2)}.nav-actions{display:flex;align-items:center;gap:10px}.search-toggle,.menu-toggle{width:40px;height:40px;border:1px solid var(--line);background:transparent;display:inline-grid;place-items:center;color:var(--ink);font-size:16px}.search-bar{display:none;background:var(--paper-2);border-bottom:1px solid var(--line)}.search-bar.open{display:block}.search-inner{display:flex;gap:10px;align-items:center;padding:13px 0}.search-inner input{width:100%;border:0;background:var(--white);padding:12px 16px;outline:2px solid transparent;transition:outline .2s}.search-inner input:focus{outline-color:var(--orange)}.search-status{font-size:12px;color:var(--muted);min-width:160px}.menu-toggle{display:none}

/* Hero */
.hero{background:var(--ink);color:#fff;padding:34px 0 52px}.hero-grid{display:grid;grid-template-columns:minmax(0,.9fr) minmax(400px,1.2fr);gap:28px;align-items:stretch}.hero-copy{position:relative;min-height:500px;padding:34px 0 0 26px;display:flex;flex-direction:column;justify-content:flex-end}.hero-copy:before{content:'';position:absolute;left:0;top:2px;width:2px;height:100%;background:linear-gradient(transparent,var(--orange) 20%,var(--orange) 78%,transparent)}.hero h1{font-family:'Noto Serif SC',serif;font-size:clamp(43px,5.3vw,78px);line-height:1.06;letter-spacing:-.075em;margin:0 0 23px;max-width:620px}.hero h1 em{font-style:normal;color:var(--orange)}.hero-lede{font-size:17px;line-height:1.9;color:#d7d3cd;max-width:510px;margin:0 0 30px}.hero-actions{display:flex;flex-wrap:wrap;gap:12px}.hero-stamp{margin-top:auto;padding-top:38px;display:flex;gap:20px;align-items:center;color:#b9b5ae}.hero-stamp strong{font-family:'IBM Plex Mono',monospace;color:#fff;font-weight:500;font-size:12px}.hero-art{min-height:500px;position:relative;border-radius:var(--radius);overflow:hidden;background:#242321;isolation:isolate}.hero-art img{width:100%;height:100%;min-height:500px;object-fit:cover}.hero-art:after{content:'';position:absolute;inset:0;background:linear-gradient(90deg,rgba(12,12,12,.18),transparent 55%,rgba(10,10,10,.18))}.play-seal{position:absolute;z-index:2;left:28px;bottom:28px;width:74px;height:74px;border-radius:50%;border:1px solid rgba(255,255,255,.65);background:rgba(255,106,61,.9);color:#fff;display:grid;place-items:center;font-size:23px;transition:transform .22s var(--easing),background .22s}.hero-art:hover .play-seal{transform:translateX(6px) scale(1.04);background:var(--orange)}.hero-meta{position:absolute;z-index:2;right:22px;top:20px;background:rgba(18,18,17,.7);padding:10px 12px;backdrop-filter:blur(8px);font-family:'IBM Plex Mono',monospace;font-size:11px}.rail{display:flex;justify-content:space-between;gap:10px;border-top:1px solid rgba(255,255,255,.2);padding-top:15px;margin-top:25px}.rail span{font-family:'IBM Plex Mono',monospace;font-size:10px;color:#bbb6ad}.rail b{color:#fff;font-weight:500}

/* Common cards */
.film-strip{display:grid;grid-auto-flow:column;grid-auto-columns:minmax(280px,1fr);gap:18px;overflow:auto;padding-bottom:16px;scroll-snap-type:x mandatory}.film-strip::-webkit-scrollbar{height:5px}.film-strip::-webkit-scrollbar-thumb{background:var(--orange);border-radius:4px}.video-card{background:var(--white);scroll-snap-align:start;box-shadow:0 8px 20px rgba(30,29,27,.04);position:relative}.video-poster{display:block;position:relative;overflow:hidden;aspect-ratio:16/10;background:#343332}.video-poster img{width:100%;height:100%;object-fit:cover;transition:transform .35s var(--easing)}.video-poster:after{content:'';position:absolute;inset:0;background:linear-gradient(180deg,transparent 45%,rgba(0,0,0,.58))}.play-badge{position:absolute;z-index:1;display:grid;place-items:center;left:18px;bottom:16px;width:43px;height:43px;border-radius:50%;background:var(--orange);color:#fff;font-size:14px;transition:transform .22s var(--easing)}.duration{position:absolute;z-index:1;right:12px;bottom:10px;font:11px 'IBM Plex Mono',monospace;color:#fff;background:rgba(0,0,0,.62);padding:4px 6px}.video-card:hover .video-poster img{transform:scale(1.045)}.video-card:hover .play-badge{transform:translateX(5px)}.video-body{padding:17px 18px 18px}.video-body h3{font-size:17px;line-height:1.45;margin:7px 0 10px}.video-body p{font-size:13px;color:var(--muted);line-height:1.65;margin:0 0 12px}.video-data{display:flex;gap:12px;color:#68655f;font:11px 'IBM Plex Mono',monospace}.tag{font-size:10px;color:var(--orange-2);font-weight:600}.feature-grid{display:grid;grid-template-columns:1.35fr .65fr;gap:22px}.feature-panel{padding:30px;background:var(--ink);color:#fff;min-height:342px;display:flex;flex-direction:column;justify-content:flex-end;position:relative;overflow:hidden}.feature-panel:before{content:'KUN\A KUN\A RABBIT';white-space:pre;position:absolute;right:16px;top:18px;color:rgba(255,255,255,.075);font:900 43px/1 'Noto Serif SC',serif;text-align:right;letter-spacing:-.12em}.feature-panel h3{position:relative;font-family:'Noto Serif SC',serif;font-size:34px;line-height:1.2;letter-spacing:-.05em;margin:0 0 12px}.feature-panel p{position:relative;max-width:500px;color:#c7c2ba;margin:0 0 22px}.feature-stack{display:grid;gap:22px}.feature-mini{padding:20px;background:var(--paper-2);min-height:160px;display:flex;flex-direction:column;justify-content:space-between}.feature-mini h3{margin:0;font-size:19px;line-height:1.4}.feature-mini p{margin:8px 0 0;font-size:13px;color:#65615a}.feature-mini .arrow-link{align-self:flex-end}.arrow-link{color:var(--orange-2);font-weight:700;font-size:13px}.orange-line{display:block;width:30px;height:3px;background:var(--orange);margin-bottom:13px}

/* Columns, data blocks */
.archive-layout{display:grid;grid-template-columns:190px 1fr;gap:42px;border-top:1px solid var(--line);padding-top:24px}.index-rail{font:11px 'IBM Plex Mono',monospace;color:var(--muted)}.index-rail b{display:block;color:var(--ink);margin-bottom:11px}.index-rail a{display:block;padding:7px 0;border-bottom:1px solid var(--line)}.index-rail a:hover{color:var(--orange-2)}.copy-block{max-width:830px}.copy-block h3{font-family:'Noto Serif SC',serif;font-size:30px;line-height:1.25;letter-spacing:-.05em;margin:0 0 16px}.copy-block p{color:#5b5852;margin:0 0 18px}.ai-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border:1px solid var(--line);margin-top:32px}.ai-item{background:var(--paper);padding:24px;min-height:200px}.ai-number{font:600 13px 'IBM Plex Mono',monospace;color:var(--orange-2)}.ai-item h4{font-size:18px;line-height:1.4;margin:20px 0 10px}.ai-item p{font-size:13px;line-height:1.7;color:#67645e;margin:0}.community{background:var(--paper-2)}.community-grid{display:grid;grid-template-columns:1fr 1.1fr;gap:48px}.topic-list{border-top:1px solid var(--ink)}.topic{display:grid;grid-template-columns:44px 1fr auto;gap:14px;align-items:center;border-bottom:1px solid var(--line);padding:15px 0}.topic-no{font:12px 'IBM Plex Mono',monospace;color:var(--orange-2)}.topic h3{font-size:16px;margin:0}.topic p{font-size:12px;color:var(--muted);margin:3px 0 0}.topic-count{font:11px 'IBM Plex Mono',monospace;color:var(--muted)}.quote-note{padding:32px;background:var(--ink);color:#fff;position:relative}.quote-note:before{content:'“';font:900 90px/1 Georgia,serif;color:var(--orange);position:absolute;top:16px;right:26px}.quote-note h3{font-family:'Noto Serif SC',serif;font-size:28px;line-height:1.35;letter-spacing:-.05em;margin:0 0 14px;max-width:420px}.quote-note p{color:#c9c4bb;font-size:14px;max-width:440px;margin:0}.quote-note .archive-code{display:block;margin-top:30px;color:#aaa49b}

/* experts, process, faq */
.experts-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.expert{border-top:3px solid var(--ink);padding-top:15px}.expert:nth-child(2){border-color:var(--orange)}.expert:nth-child(3){border-color:var(--blue)}.expert:nth-child(4){border-color:var(--sage)}.expert-role{font:11px 'IBM Plex Mono',monospace;color:var(--orange-2)}.expert h3{font-size:20px;margin:10px 0 5px}.expert p{font-size:13px;line-height:1.65;color:#68645e;margin:0 0 13px}.expert-links{display:flex;gap:13px;font-size:12px;font-weight:700}.expert-links a{border-bottom:1px solid var(--orange)}.process{background:var(--ink);color:#fff}.process .section-head p{color:#c8c2b9}.process-grid{display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid rgba(255,255,255,.25)}.process-item{padding:25px 24px 25px 0;margin-right:22px;border-right:1px solid rgba(255,255,255,.2)}.process-item:last-child{border:0;margin-right:0}.process-num{font:600 13px 'IBM Plex Mono',monospace;color:var(--orange)}.process-item h3{font-size:19px;margin:46px 0 11px}.process-item p{font-size:13px;line-height:1.7;color:#c5c0b8;margin:0}.faq-wrap{display:grid;grid-template-columns:.7fr 1.3fr;gap:70px}.faq-copy h2{font-family:'Noto Serif SC',serif;font-size:42px;line-height:1.2;letter-spacing:-.07em;margin:0 0 16px}.faq-copy p{font-size:14px;color:var(--muted);margin:0}.faq-list{border-top:1px solid var(--ink)}.faq-item{border-bottom:1px solid var(--line)}.faq-question{width:100%;border:0;background:transparent;display:flex;align-items:center;justify-content:space-between;text-align:left;padding:20px 0;gap:20px;font-weight:700;font-size:16px}.faq-question span:last-child{color:var(--orange);font-size:23px;font-weight:400}.faq-answer{display:none;padding:0 34px 18px 0;color:#625f59;font-size:14px;line-height:1.8}.faq-item.open .faq-answer{display:block}.faq-item.open .faq-question span:last-child{transform:rotate(45deg)}

/* contact and footer */
.contact-band{background:var(--orange);color:#fff}.contact-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:50px;align-items:center}.contact-grid h2{font-family:'Noto Serif SC',serif;font-size:clamp(35px,4vw,58px);line-height:1.14;letter-spacing:-.07em;margin:0 0 14px}.contact-grid p{max-width:560px;margin:0;color:#fff2ed}.contact-ways{border-left:1px solid rgba(255,255,255,.55);padding-left:32px;display:grid;gap:13px}.contact-way{display:flex;justify-content:space-between;gap:14px;font:13px 'IBM Plex Mono',monospace}.contact-way span{color:#ffe1d4}.footer{background:#10100f;color:#ebe7de;padding:66px 0 24px}.footer-top{display:grid;grid-template-columns:1.1fr .7fr .7fr .9fr;gap:28px;padding-bottom:42px;border-bottom:1px solid rgba(255,255,255,.18)}.footer .brand-name{color:#fff}.footer-brand p{max-width:290px;color:#bdb8ae;font-size:13px;margin:16px 0}.footer h3{font:600 12px 'IBM Plex Mono',monospace;color:#fff;margin:0 0 13px}.footer-list{display:grid;gap:8px;font-size:13px;color:#c1bdb5}.footer-list a:hover{color:var(--orange)}.qr-row{display:flex;gap:12px}.qr{width:83px}.qr-square{width:83px;height:83px;background:repeating-linear-gradient(45deg,#fff 0 4px,#111 4px 8px),repeating-linear-gradient(-45deg,transparent 0 7px,rgba(255,106,61,.95) 7px 10px);border:4px solid #fff}.qr p{font:10px 'IBM Plex Mono',monospace;color:#bdb8ae;line-height:1.35;margin:7px 0 0}.footer-bottom{display:flex;align-items:center;justify-content:space-between;gap:20px;padding-top:22px;color:#aaa69e;font:11px 'IBM Plex Mono',monospace}.share-row{display:flex;gap:8px;align-items:center}.share-row button{border:1px solid rgba(255,255,255,.28);background:transparent;color:#e5e0d7;padding:5px 8px;font:10px 'IBM Plex Mono',monospace}.share-row button:hover{border-color:var(--orange);color:var(--orange)}

/* Inner pages */
.page-hero{background:var(--ink);color:#fff;padding:64px 0 58px}.breadcrumb{display:flex;gap:8px;color:#bbb5ac;font:11px 'IBM Plex Mono',monospace;margin-bottom:28px}.breadcrumb a:hover{color:var(--orange)}.page-hero-grid{display:grid;grid-template-columns:1fr .8fr;gap:40px;align-items:end}.page-hero h1{font-family:'Noto Serif SC',serif;font-size:clamp(40px,5vw,68px);line-height:1.1;letter-spacing:-.075em;margin:0}.page-hero p{margin:15px 0 0;color:#cec9c0;max-width:570px}.page-hero .page-archive{font:12px 'IBM Plex Mono',monospace;color:var(--orange);align-self:start;text-align:right}.list-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.page-intro{max-width:720px;font-size:17px;color:#56534e;margin:0 0 40px}.tool-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;background:var(--line);border:1px solid var(--line)}.tool-card{background:var(--white);padding:30px;min-height:210px}.tool-card strong{font:600 12px 'IBM Plex Mono',monospace;color:var(--orange-2)}.tool-card h2{font-family:'Noto Serif SC',serif;letter-spacing:-.05em;font-size:27px;line-height:1.25;margin:35px 0 9px}.tool-card p{color:#65615c;font-size:14px;margin:0}.notice{border-left:4px solid var(--orange);padding:18px 20px;background:#fff7f2;color:#5d4036;font-size:14px;margin-top:28px}

@media(max-width:1040px){.main-nav{gap:0}.main-nav a{padding-inline:8px}.hero-grid{grid-template-columns:1fr 1fr}.hero-copy,.hero-art,.hero-art img{min-height:450px}.experts-grid{grid-template-columns:repeat(2,1fr);row-gap:30px}.footer-top{grid-template-columns:1.2fr 1fr 1fr}.footer-top>div:last-child{grid-column:1/-1}.ai-grid{grid-template-columns:1fr 1fr}.process-grid{grid-template-columns:1fr 1fr}.process-item:nth-child(2){border:0}.process-item:nth-child(3),.process-item:nth-child(4){border-top:1px solid rgba(255,255,255,.2)}}
@media(max-width:760px){.shell{width:min(100% - 32px,1380px)}.utility-links{display:none}.masthead-inner{height:66px;gap:12px}.brand img{width:33px;height:33px}.brand-name{font-size:23px}.main-nav{display:none}.nav-actions .button{display:none}.menu-toggle{display:grid}.search-status{display:none}.hero{padding-top:18px}.hero-grid,.feature-grid,.community-grid,.contact-grid,.page-hero-grid{grid-template-columns:1fr}.hero-copy{min-height:330px;padding:28px 0 0 20px}.hero h1{font-size:46px}.hero-lede{font-size:15px}.hero-art,.hero-art img{min-height:305px}.hero-stamp{padding-top:20px}.section-space{padding:68px 0}.section-head{grid-template-columns:1fr;gap:13px;margin-bottom:25px}.section-head h2{font-size:34px}.film-strip{grid-auto-columns:84%}.archive-layout{grid-template-columns:1fr;gap:23px}.index-rail{display:flex;gap:13px;overflow:auto}.index-rail b{margin:6px 0}.index-rail a{white-space:nowrap;padding:6px 0}.ai-grid,.list-grid{grid-template-columns:1fr}.experts-grid{grid-template-columns:1fr}.faq-wrap{grid-template-columns:1fr;gap:28px}.faq-copy h2{font-size:34px}.footer-top{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}.footer-bottom{flex-direction:column;align-items:flex-start}.page-hero{padding:45px 0}.page-hero .page-archive{text-align:left;margin-top:20px}.tool-grid{grid-template-columns:1fr}.contact-ways{border-left:0;border-top:1px solid rgba(255,255,255,.55);padding:20px 0 0}.topic{grid-template-columns:35px 1fr}.topic-count{display:none}.rail{flex-wrap:wrap}.feature-panel{min-height:275px}.qr-row{gap:9px}}
@media(prefers-reduced-motion:no-preference){.reveal{animation:reveal .55s var(--easing) both}.reveal:nth-child(2){animation-delay:.05s}.reveal:nth-child(3){animation-delay:.1s}@keyframes reveal{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}}