/* roulang page: index */
:root{--teal:#1f6f64;--teal-deep:#164e48;--teal-ink:#0f3b36;--teal-soft:#e7f3f0;--orange:#e07a2f;--orange-deep:#c4621c;--ink:#1c2421;--muted:#5d675f;--line:#d9d2c5;--paper:#f7f3ea;--paper-2:#eef6f3;--white:#fffcf7;--dark:#14221f;--card:#fffdf8;--danger:#b42318;--radius:10px;--radius-xs:6px;--shadow:0 8px 24px rgba(28,36,33,.06);--shadow-sm:0 4px 12px rgba(28,36,33,.05);--container:1240px;--fs-h1:44px;--fs-h2:28px;--fs-h3:20px;--z-header:40;--z-drawer:50;--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
*,*:before,*:after{box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{margin:0;padding:0}
body{font-family:"Noto Sans SC","PingFang SC","Microsoft YaHei","Source Han Sans SC",sans-serif;font-size:16px;font-weight:400;line-height:1.75;color:var(--ink);background:var(--paper);min-width:320px}
img{max-width:100%;height:auto;display:block}
a{color:var(--teal);text-decoration:none}
a:hover{color:var(--teal-deep)}
button,input,select,textarea{font-family:inherit;font-size:inherit}
button{cursor:pointer;border:0;background:none}
h1,h2,h3,p{margin:0}
ul{margin:0;padding:0;list-style:none}
.container{width:min(var(--container),calc(100% - 32px));margin:0 auto}
.num{font-variant-numeric:tabular-nums;font-family:var(--mono)}
.skip{position:absolute;left:-999px;top:8px}
.skip:focus{left:8px;z-index:100;background:#fff;padding:8px 12px;border-radius:6px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 18px;border-radius:var(--radius-xs);font-weight:700;line-height:1.2;transition:background .2s,color .2s,border-color .2s,transform .15s,box-shadow .2s}
.btn:focus-visible,.nav-links a:focus-visible,.link:focus-visible,input:focus-visible,select:focus-visible,.faq-q:focus-visible,.dot:focus-visible,.hero-nav:focus-visible{outline:3px solid rgba(31,111,100,.45);outline-offset:2px}
.btn-primary{background:var(--teal);color:#fff}
.btn-primary:hover{background:var(--teal-deep);color:#fff}
.btn-primary:active{background:var(--teal-ink);transform:translateY(1px)}
.btn-ghost{background:transparent;color:#fff;border:1px solid rgba(255,255,255,.55)}
.btn-ghost:hover{background:rgba(255,255,255,.12);color:#fff}
.btn-line{background:transparent;color:var(--teal-deep);border:1px solid var(--teal)}
.btn-line:hover{background:var(--teal-soft);color:var(--teal-ink)}
.btn-line:active{transform:translateY(1px)}
.btn-sm{min-height:36px;padding:6px 12px;font-size:13px}
.btn-block{width:100%}
.link{position:relative;color:var(--teal-deep);font-weight:700}
.link:after{content:"";position:absolute;left:0;bottom:-2px;width:100%;height:2px;background:var(--orange);transform:scaleX(0);transform-origin:left;transition:transform .2s}
.link:hover:after{transform:scaleX(1)}
.badge{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;font-size:12px;font-weight:700;letter-spacing:.04em;background:var(--teal-soft);color:var(--teal-deep)}
.badge-orange{background:#f8e6d4;color:var(--orange-deep)}
.badge-dark{background:rgba(255,255,255,.14);color:#fff}
.qmark{width:28px;height:28px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;background:var(--orange);color:#fff;font-size:12px;font-weight:800;flex:none}
.site-header{position:relative;z-index:var(--z-header)}
.toolbar{background:#edf3f1;color:var(--muted);font-size:13px;border-bottom:1px solid var(--line)}
.toolbar-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:38px}
.toolbar-left,.toolbar-right{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.toolbar a{color:var(--ink)}
.toolbar a:hover{color:var(--teal)}
.trust{color:var(--teal-deep);font-weight:500}
.nav-main{background:rgba(255,252,247,.96);border-bottom:1px solid var(--line);backdrop-filter:blur(10px)}
.nav-main.is-sticky{position:sticky;top:0;box-shadow:var(--shadow-sm)}
.nav-inner{display:flex;align-items:center;gap:20px;min-height:72px}
.logo{display:flex;align-items:center;gap:10px;color:var(--ink);flex:none}
.logo:hover{color:var(--ink)}
.logo-mark{width:36px;height:36px;border-radius:8px;background:var(--teal);color:#fff;display:grid;place-items:center;position:relative;overflow:hidden}
.logo-mark span{font-weight:800;font-size:14px;position:relative;z-index:1}
.logo-mark:before{content:"";position:absolute;right:0;bottom:0;width:18px;height:14px;background:#fff;border-radius:4px 0 0 0;opacity:.18}
.logo-text{display:flex;flex-direction:column;line-height:1.15}
.logo-text b{font-size:16px;font-weight:800}
.logo-text small{font-size:11px;color:var(--muted);font-weight:500}
.nav-links{display:flex;align-items:center;gap:4px;margin-left:auto}
.nav-links a{position:relative;padding:10px 10px;color:var(--ink);font-weight:500;font-size:15px}
.nav-links a:hover{color:var(--teal-deep)}
.nav-links a.is-active{color:var(--teal-deep);font-weight:700}
.nav-links a.is-active:after{content:"";position:absolute;left:10px;right:10px;bottom:4px;height:2px;background:var(--teal);border-radius:2px}
.nav-cta{margin-left:8px}
.hamburger{display:none;width:44px;height:44px;border-radius:8px;border:1px solid var(--line);align-items:center;justify-content:center;flex-direction:column;gap:5px}
.hamburger i{display:block;width:18px;height:2px;background:var(--ink)}
.drawer{display:none;position:fixed;inset:0;z-index:var(--z-drawer)}
.drawer.open{display:block}
.drawer-mask{position:absolute;inset:0;background:rgba(20,34,31,.45)}
.drawer-panel{position:absolute;top:0;right:0;width:min(320px,86vw);height:100%;background:var(--white);padding:24px 20px;box-shadow:-12px 0 32px rgba(0,0,0,.12);display:flex;flex-direction:column;gap:8px}
.drawer-panel a{padding:12px 8px;border-bottom:1px solid var(--line);color:var(--ink);font-weight:600}
.hero{position:relative;overflow:hidden;background:var(--dark)}
.hero-track{position:relative;min-height:640px}
.slide{position:absolute;inset:0;opacity:0;pointer-events:none;transition:opacity .55s ease}
.slide.is-on{opacity:1;pointer-events:auto;z-index:1}
.slide-bg{position:absolute;inset:0}
.slide-bg img{width:100%;height:100%;object-fit:cover}
.slide-bg:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(15,35,32,.88) 0%,rgba(15,35,32,.62) 46%,rgba(15,35,32,.28) 100%)}
.slide-copy{position:relative;z-index:2;padding:92px 0 108px;color:#fff;width:min(var(--container),calc(100% - 32px));margin:0 auto}
.hero h1,.hero .display{font-size:var(--fs-h1);font-weight:800;line-height:1.22;max-width:16ch;margin-bottom:18px}
.hero .lead{max-width:38em;font-size:16px;line-height:1.8;color:rgba(255,255,255,.9);margin-bottom:22px}
.hero-pills{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px}
.burst{position:absolute;right:8%;top:18%;z-index:3;width:108px;height:108px;border-radius:50%;background:var(--orange);color:#fff;display:grid;place-items:center;text-align:center;transform:rotate(8deg);box-shadow:0 10px 24px rgba(224,122,47,.35)}
.burst b{font-size:18px;line-height:1.2}
.burst small{display:block;font-size:12px;opacity:.9}
.hero-nav,.dots{z-index:3}
.hero-nav{position:absolute;top:50%;transform:translateY(-50%);width:44px;height:44px;border-radius:50%;background:rgba(255,252,247,.16);color:#fff;border:1px solid rgba(255,255,255,.25);display:grid;place-items:center}
.hero-nav:hover{background:rgba(255,252,247,.28)}
.hero-prev{left:16px}
.hero-next{right:16px}
.dots{position:absolute;left:50%;bottom:22px;transform:translateX(-50%);display:flex;gap:8px}
.dot{width:10px;height:10px;border-radius:50%;background:rgba(255,255,255,.35);border:1px solid rgba(255,255,255,.5)}
.dot.is-on{background:var(--orange);border-color:var(--orange)}
.pause-hint{position:absolute;right:24px;bottom:22px;color:rgba(255,255,255,.75);font-size:12px;z-index:3}
.section{padding:88px 0;position:relative}
.section-alt{background:var(--paper-2)}
.section-paper{background:var(--paper)}
.section h2{font-size:var(--fs-h2);font-weight:800;line-height:1.3;margin-bottom:14px}
.section .sec-lead{max-width:46em;color:var(--muted);margin-bottom:32px}
.kicker{color:var(--orange-deep);font-weight:700;font-size:13px;letter-spacing:.08em;margin-bottom:8px}
.intro-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:48px;align-items:center}
.intro-photo{position:relative}
.intro-photo img{width:100%;border-radius:12px;border:1px solid var(--line);box-shadow:var(--shadow);min-height:320px;object-fit:cover}
.paper-note{position:absolute;left:-18px;bottom:-18px;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:14px 16px;box-shadow:var(--shadow-sm);max-width:240px}
.facts{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:22px}
.fact{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:14px}
.fact b{display:block;font-size:22px;font-weight:800}
.fact span{color:var(--muted);font-size:13px}
.func-wrap{display:grid;grid-template-columns:240px 1fr;gap:28px;align-items:start}
.func-index{position:sticky;top:92px;display:flex;flex-direction:column;gap:8px}
.func-tab{text-align:left;padding:14px 16px;border:1px solid var(--line);background:var(--card);border-radius:8px;font-weight:700;color:var(--ink)}
.func-tab.is-on,.func-tab:hover{border-color:var(--teal);background:var(--teal-soft);color:var(--teal-ink)}
.func-panel{display:none;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:28px;min-height:280px}
.func-panel.is-on{display:grid;grid-template-columns:1.1fr .9fr;gap:24px;align-items:center}
.func-panel h3{font-size:var(--fs-h3);font-weight:800;margin-bottom:10px}
.func-list li{padding:8px 0 8px 28px;position:relative;color:var(--muted)}
.func-list li:before{content:attr(data-n);position:absolute;left:0;top:8px;width:20px;height:20px;border-radius:50%;background:var(--orange);color:#fff;font-size:11px;font-weight:800;display:grid;place-items:center}
.func-panel img{width:100%;height:240px;object-fit:cover;border-radius:10px;border:1px solid var(--line)}
.grid-6{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.cap-card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:22px;box-shadow:var(--shadow-sm);transition:transform .2s,border-color .2s,box-shadow .2s}
.cap-card:hover{transform:translateY(-3px);border-color:var(--teal);box-shadow:var(--shadow)}
.cap-ico{width:42px;height:42px;border-radius:8px;background:var(--teal-soft);color:var(--teal-deep);display:grid;place-items:center;font-weight:800;margin-bottom:12px}
.cap-card h3{font-size:18px;font-weight:800;margin-bottom:8px}
.cap-card p{color:var(--muted);margin-bottom:12px}
.mini-metric{font-size:13px;color:var(--teal-deep);font-weight:700}
.scene-board{display:grid;grid-template-columns:1.4fr 1fr 1fr;grid-template-rows:auto auto;gap:16px}
.scene{position:relative;overflow:hidden;border-radius:12px;min-height:220px;padding:24px;color:#fff;display:flex;flex-direction:column;justify-content:flex-end}
.scene:nth-child(1){grid-row:1 / span 2;min-height:460px}
.scene img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.scene:after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(20,34,31,.15),rgba(20,34,31,.82))}
.scene-body{position:relative;z-index:1}
.scene h3{font-size:22px;font-weight:800;margin:8px 0}
.scene p{color:rgba(255,255,255,.88);margin-bottom:10px}
.scene .link{color:#fff}
.prod-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.prod-card{background:var(--card);border:1px solid var(--line);border-radius:12px;overflow:hidden;display:flex;flex-direction:column;transition:transform .2s,border-color .2s}
.prod-card:hover{transform:translateY(-3px);border-color:var(--teal)}
.prod-card img{width:100%;height:190px;object-fit:cover}
.prod-body{padding:20px;display:flex;flex-direction:column;gap:10px;flex:1}
.prod-body h3{font-size:20px;font-weight:800}
.prod-body ul{color:var(--muted)}
.prod-body li{padding:4px 0 4px 16px;position:relative}
.prod-body li:before{content:"";position:absolute;left:0;top:13px;width:7px;height:7px;border-radius:50%;background:var(--teal)}
.demo{display:grid;grid-template-columns:.9fr 1.1fr;gap:28px;align-items:center}
.demo-stage{position:relative;border-radius:16px;overflow:hidden;min-height:420px;border:1px solid var(--line);background:#1b2e2a}
.demo-stage .frame-bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.35}
.screen{position:relative;z-index:1;margin:36px 28px;background:var(--white);border-radius:10px;overflow:hidden;border:1px solid var(--line);min-height:320px}
.screen img{width:100%;height:320px;object-fit:cover}
.steps{display:flex;flex-direction:column;gap:14px}
.step{display:grid;grid-template-columns:48px 1fr;gap:12px;padding:16px;border:1px solid var(--line);border-radius:10px;background:var(--card);cursor:pointer}
.step.is-on{border-color:var(--teal);background:var(--teal-soft)}
.step b{display:block;font-size:18px}
.step span{color:var(--muted)}
.dark{background:var(--dark);color:#e9f1ee;padding:88px 0}
.dark h2{color:#fff}
.dark-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:36px;align-items:start}
.dark .big{font-size:34px;font-weight:800;line-height:1.35;max-width:16em;margin-bottom:16px}
.method{display:grid;gap:12px}
.method li{display:flex;gap:12px;padding:14px;border:1px solid rgba(255,255,255,.12);border-radius:10px;background:rgba(255,255,255,.04)}
.method b{color:#fff}
.data-pills{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.data-pills div{padding:18px;border-radius:10px;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.1)}
.data-pills b{display:block;font-size:28px;color:#fff}
.case{display:grid;grid-template-columns:140px 1fr;gap:24px;padding:24px 0;border-bottom:1px dashed var(--line)}
.case:last-child{border-bottom:0}
.case-year{font-weight:800;color:var(--teal-deep)}
.case h3{font-size:20px;margin-bottom:6px}
.case p{color:var(--muted)}
.result{margin-top:8px;color:var(--teal-ink);font-weight:700}
.price-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.price-card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:24px;display:flex;flex-direction:column;gap:12px}
.price-card.featured{border-color:var(--teal);transform:translateY(-8px);box-shadow:var(--shadow);position:relative}
.price-card.featured:before{content:"教研常用";position:absolute;top:12px;right:12px;background:var(--orange);color:#fff;font-size:12px;font-weight:800;padding:4px 8px;border-radius:999px}
.price{font-size:36px;font-weight:800;letter-spacing:-.03em}
.price small{font-size:14px;color:var(--muted);font-weight:500}
.price-card ul{color:var(--muted);flex:1}
.price-card li{padding:6px 0 6px 18px;position:relative}
.price-card li:before{content:"✓";position:absolute;left:0;color:var(--teal);font-weight:800}
.compare-wrap{overflow:auto;margin-top:28px;border:1px solid var(--line);border-radius:10px;background:var(--card)}
.compare{width:100%;border-collapse:collapse;min-width:640px}
.compare th,.compare td{padding:12px 14px;border-bottom:1px solid var(--line);text-align:left}
.compare th{background:var(--teal-soft);font-weight:800}
.compare td:nth-child(3){background:#f4faf8;font-weight:700}
.stories{display:grid;grid-template-columns:1.4fr 1fr;gap:16px}
.story{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:24px}
.story h3{font-size:20px;margin:8px 0 10px}
.story p{color:var(--muted)}
.who{font-size:13px;color:var(--teal-deep);font-weight:700}
.stats{display:grid;grid-template-columns:repeat(5,1fr);gap:12px;background:var(--teal-ink);color:#fff;border-radius:12px;padding:28px 18px}
.stat{text-align:center}
.stat b{display:block;font-size:32px;font-weight:800}
.stat span{color:rgba(255,255,255,.75);font-size:13px}
.wall{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.review{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:16px;box-shadow:var(--shadow-sm)}
.stars{color:var(--orange);letter-spacing:1px;font-size:13px;margin-bottom:6px}
.review p{font-size:14px}
.meta{margin-top:10px;font-size:12px;color:var(--muted)}
.voice{display:grid;grid-template-columns:.9fr 1.1fr;gap:28px;align-items:center}
.logo-wall{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.brand-chip{border:1px dashed var(--line);border-radius:8px;padding:16px 10px;text-align:center;background:var(--card);font-weight:700;color:var(--teal-ink)}
.quote{background:var(--card);border-left:4px solid var(--orange);padding:24px;border-radius:0 12px 12px 0}
.quote p{font-size:18px;line-height:1.8}
.compare-before{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:16px}
.compare-before div{padding:14px;border-radius:8px;border:1px solid var(--line)}
.compare-before .after{background:var(--teal-soft);border-color:var(--teal)}
.news-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.news-card{background:var(--card);border:1px solid var(--line);border-radius:12px;overflow:hidden;display:flex;flex-direction:column}
.news-card img{height:150px;width:100%;object-fit:cover}
.news-card .body{padding:16px}
.news-card time{font-size:12px;color:var(--muted)}
.news-card h3{font-size:17px;margin:6px 0 8px}
.topics{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.topic{display:grid;grid-template-columns:140px 1fr;gap:16px;background:var(--card);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.topic img{width:140px;height:100%;object-fit:cover}
.topic .body{padding:16px 16px 16px 0}
.topic li{padding:4px 0;color:var(--muted)}
.faq-list{display:grid;gap:10px}
.faq-item{border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--card)}
.faq-q{width:100%;text-align:left;padding:16px 18px;display:flex;align-items:center;gap:12px;font-weight:700;background:var(--card);color:var(--ink)}
.faq-q[aria-expanded="true"]{background:var(--teal-soft)}
.faq-a{display:none;padding:0 18px 16px;background:var(--teal-soft)}
.faq-item.open .faq-a{display:block}
.faq-a p{padding-top:4px}
.cta{background:linear-gradient(180deg,#12332e,#0f2925);color:#e7f3f0;padding:88px 0}
.cta-grid{display:grid;grid-template-columns:.9fr 1.1fr;gap:36px}
.form{background:var(--white);color:var(--ink);border-radius:12px;padding:24px}
.form-row{margin-bottom:14px}
label{display:block;font-weight:700;margin-bottom:6px}
input,select{width:100%;min-height:44px;border:1px solid var(--line);border-radius:8px;padding:10px 12px;background:#fffdf8;color:var(--ink)}
input:focus,select:focus{border-color:var(--teal)}
.field.error input,.field.error select{border-color:var(--danger)}
.err{display:none;color:var(--danger);font-size:13px;margin-top:4px}
.field.error .err{display:block}
.privacy{font-size:13px;color:var(--muted);margin:8px 0 14px}
.form-ok{display:none;padding:16px;border-radius:8px;background:var(--teal-soft);color:var(--teal-ink);font-weight:700;margin-bottom:12px}
.form-ok.show{display:block}
.site-footer{background:#101c1a;color:#c9d6d1;padding:56px 0 24px}
.foot-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr 1fr;gap:24px}
.site-footer h3{color:#fff;font-size:16px;margin-bottom:12px}
.site-footer a{color:#c9d6d1}
.site-footer a:hover{color:#fff}
.foot-copy{margin-top:28px;padding-top:18px;border-top:1px solid rgba(255,255,255,.08);font-size:13px;display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}
@media (max-width:1280px){:root{--fs-h1:40px}}
@media (max-width:1024px){:root{--fs-h1:36px;--fs-h2:26px}.section,.dark,.cta{padding:72px 0}.intro-grid,.func-wrap,.func-panel.is-on,.demo,.dark-grid,.stories,.voice,.cta-grid{grid-template-columns:1fr}.func-index{position:static;display:grid;grid-template-columns:repeat(4,1fr)}.scene-board{grid-template-columns:1fr 1fr}.scene:nth-child(1){grid-row:auto;min-height:280px}.grid-6{grid-template-columns:repeat(2,1fr)}.wall{grid-template-columns:repeat(2,1fr)}.news-grid{grid-template-columns:repeat(2,1fr)}.stats{grid-template-columns:repeat(3,1fr);gap:18px}.foot-grid{grid-template-columns:1fr 1fr}.nav-links{display:none}.hamburger{display:flex}.nav-cta{display:none}.burst{right:16px;top:12px;width:88px;height:88px}.hero-track{min-height:560px}}
@media (max-width:768px){:root{--fs-h1:30px;--fs-h2:24px;--fs-h3:18px}.toolbar-inner{flex-direction:column;align-items:flex-start;padding:8px 0}.section,.dark,.cta{padding:56px 0}.prod-3,.price-grid,.topics,.compare-before{grid-template-columns:1fr}.price-card.featured{transform:none}.func-index{grid-template-columns:1fr 1fr}.case{grid-template-columns:1fr}.stats{grid-template-columns:1fr 1fr}.hero-track{min-height:620px}.slide-copy{padding:72px 0 96px}.hero h1,.hero .display{max-width:none}.burst{display:none}.topic{grid-template-columns:1fr}.topic img{width:100%;height:160px}}
@media (max-width:520px){:root{--fs-h1:28px}.grid-6,.wall,.news-grid,.scene-board,.func-index{grid-template-columns:1fr}.stats{grid-template-columns:1fr}.hero-actions,.toolbar-right{width:100%}.hero-actions .btn{flex:1}.foot-grid,.foot-copy{grid-template-columns:1fr}.hero-nav{display:none}}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important;animation:none!important}}
@media print{.toolbar,.hamburger,.hero-nav,.dots,.burst,.cta,.drawer{display:none!important}}