/* 方案 B · 星图研学。页面样式限定在独立根节点内。 */
.sc-study-b{--sb-blue:#1761f5;--sb-ink:#112c54;--sb-muted:#617fa1;--sb-line:#d5e5f9;--sb-paper:#f6faff;--sb-serif:'Source Han Serif SC','Noto Serif SC','Songti SC','SimSun',serif;--sb-sans:'Microsoft YaHei','PingFang SC',sans-serif;max-width:1404px;margin:auto;padding:22px 42px 24px;color:var(--sb-ink);font:14px/1.65 var(--sb-sans);min-width:0}
.sc-study-b *{box-sizing:border-box}.sc-study-b button,.sc-study-b a{font:inherit}.sc-study-b button{cursor:pointer;color:inherit}.sc-study-b a{text-decoration:none;color:inherit}.sc-study-b button:focus-visible,.sc-study-b a:focus-visible{outline:3px solid #78b3ff;outline-offset:5px}.sc-study-b button:disabled{cursor:default}
.sc-study-b .sb-worlds{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;position:relative;isolation:isolate}
.sc-study-b .sb-world{min-height:254px;height:clamp(254px,32vh,310px);border:1px solid #c7ddf7;border-radius:15px;background:#f6fbff;position:relative;overflow:hidden;isolation:isolate;transition:border-color .3s,box-shadow .3s}
.sc-study-b .sb-world:before{content:'';position:absolute;inset:0;z-index:-1;background:linear-gradient(110deg,#ffffffdc,#ffffff40 58%,transparent)}
.sc-study-b .sb-world:after{content:'';position:absolute;width:80%;height:100%;left:-95%;top:0;transform:skewX(-22deg);background:linear-gradient(90deg,transparent,#ffffff5c,transparent);pointer-events:none;transition:left .85s}
.sc-study-b .sb-world:hover{border-color:#7fb6f6;box-shadow:0 9px 30px #4087c914}.sc-study-b .sb-world:hover:after{left:120%}
.sc-study-b .sb-art{position:absolute;right:0;top:0;bottom:0;width:77%;z-index:-2;background-image:url('assets/ai-study-worlds.png');background-size:200% 200%;background-repeat:no-repeat;mask-image:linear-gradient(90deg,transparent,#000 18%);transition:filter .4s,transform .8s;scale:1.025;animation:sb-space-drift 16s ease-in-out infinite}
.sc-study-b .sb-world:hover .sb-art{filter:saturate(1.13) brightness(1.02);transform:scale(1.025)}
.sc-study-b .sb-read .sb-art{background-position:0 0}.sc-study-b .sb-write .sb-art{background-position:100% 0;animation-delay:-4s}.sc-study-b .sb-exam .sb-art{background-position:0 100%;animation-delay:-8s}.sc-study-b .sb-voice .sb-art{background-position:100% 100%;animation-delay:-12s}
.sc-study-b .sb-world-content{position:relative;width:56%;height:100%;padding:29px 0 25px 30px;display:flex;flex-direction:column;align-items:flex-start;z-index:1}
.sc-study-b .sb-world-type{display:flex;align-items:center;gap:7px;color:#658bb5;font-size:11px;margin-bottom:9px;white-space:nowrap}
.sc-study-b .sb-world-type svg{width:15px;height:15px;stroke-width:1.3;fill:none;stroke:currentColor;stroke-linecap:round;stroke-linejoin:round;flex:none}
.sc-study-b .sb-world h2{font:500 30px/1.4 var(--sb-serif);letter-spacing:3px;margin:0 0 10px;color:var(--sb-ink)}
.sc-study-b .sb-world-description{font-size:12px;line-height:1.8;color:#55769a;margin:0;max-width:260px}
.sc-study-b .sb-world-tags{font-size:11px;display:flex;gap:8px;align-items:center;flex-wrap:wrap;color:#728eae;margin-top:12px}
.sc-study-b .sb-world-tags span+span:before{content:'';display:inline-block;width:2px;height:2px;border-radius:50%;vertical-align:middle;margin-right:8px;background:#9bb6d4}
.sc-study-b .sb-enter{margin-top:auto;display:inline-flex;align-items:center;justify-content:space-between;gap:24px;background:#ffffffed;color:#2f72c1;border:1px solid #bdd8f7;padding:8px 16px;border-radius:22px;font-size:12px;line-height:1.6;min-height:38px;box-shadow:0 3px 10px #2b72c206}
.sc-study-b .sb-enter:hover{background:#eaf4ff;border-color:#83b6f2}.sc-study-b .sb-enter svg,.sc-study-b .sb-ask svg{width:16px;height:16px;stroke:currentColor;fill:none;stroke-width:1.5;flex:none}
.sc-study-b .sb-world:focus-within{border-color:#7fb6f6}.sc-study-b .sb-world-corner{position:absolute;right:14px;top:14px;width:11px;height:11px;border-top:1px solid #9bc8f0;border-right:1px solid #9bc8f0}
.sc-study-b .sb-world-bottom{position:absolute;right:16px;bottom:13px;display:flex;gap:4px;align-items:center}.sc-study-b .sb-world-bottom i{height:2px;width:12px;background:#9cc8ed77}.sc-study-b .sb-world-bottom i:nth-child(2){width:4px;background:#8fbae4}.sc-study-b .sb-world-bottom i:nth-child(3){width:4px;background:#b9dbf5}
.sc-study-b .sb-network{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;z-index:2}.sc-study-b .sb-network-line{stroke:#76b6f080;stroke-width:1;fill:none;vector-effect:non-scaling-stroke}.sc-study-b .sb-network-signal{stroke:#479deb;stroke-width:2;stroke-linecap:round;stroke-dasharray:9 100;fill:none;vector-effect:non-scaling-stroke;animation:sb-light-flow 9s linear infinite}
.sc-study-b .sb-hub{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:65px;height:65px;border:1px solid #9acbf2;border-radius:50%;background:radial-gradient(circle at 40% 30%,#fff,#f4faff 70%);box-shadow:0 0 0 7px #f5faffde,0 3px 20px #4f95c82e;z-index:4;padding:0;display:grid;place-items:center;animation:sb-hub-glow 7s ease-in-out infinite}
.sc-study-b .sb-hub img{width:59px;height:59px;object-fit:contain;scale:-1 1}.sc-study-b .sb-hub>span{position:absolute;bottom:-7px;padding:0 8px;border-radius:10px;background:#367fdb;color:white;font-size:9px;line-height:18px;box-shadow:0 2px 6px #3268ac18}.sc-study-b .sb-hub:hover{border-color:#438feb}
.sc-study-b .sb-dialog{position:fixed;inset:0;max-width:600px;width:calc(100% - 32px);max-height:calc(100dvh - 40px);margin:auto;border:1px solid #bfd9f6;background:#fcfeff;color:var(--sb-ink);border-radius:18px;padding:31px;box-shadow:0 24px 100px #183b6830;overflow:auto;font:14px/1.7 var(--sb-sans)}
.sc-study-b .sb-dialog::backdrop{background:#2247673a;backdrop-filter:blur(5px)}
.sc-study-b .sb-dialog-close{position:absolute;right:12px;top:12px;width:36px;height:36px;display:grid;place-items:center;border:0;background:transparent;border-radius:8px;color:#6c8caf;padding:9px}.sc-study-b .sb-dialog-close:hover{background:#edf5ff}.sc-study-b .sb-dialog-close svg{height:18px;width:18px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round}
.sc-study-b .sb-dialog h2{font:500 28px/1.5 var(--sb-serif);letter-spacing:2px;margin:0 35px 15px 0;color:var(--sb-ink)}
.sc-study-b .sb-dialog-description{font-size:13px;color:#597a9e;line-height:1.95;margin:0}.sc-study-b .sb-branches{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin:23px 0 17px}.sc-study-b .sb-branches>button{min-height:72px;padding:14px 9px;border:1px solid #d7e6f8;background:#f1f7ff;border-radius:10px;color:#3c6ba5;font-size:12px;line-height:1.8}.sc-study-b .sb-branches>button:hover,.sc-study-b .sb-branches>button[aria-pressed=true]{border-color:#92bff5;background:#eaf4ff}
.sc-study-b .sb-branch-status{min-height:45px;font-size:12px;line-height:1.95;color:#6d88a8;margin:0 0 20px;overflow-wrap:anywhere}.sc-study-b .sb-module-links{display:flex;flex-wrap:wrap;gap:10px}.sc-study-b .sb-module-links>a{font-size:12px;line-height:1.8;color:#386fac;padding:8px 12px;border:1px solid #d5e5f8;border-radius:8px;background:#f6faff}.sc-study-b .sb-module-links>a:hover{background:#eaf4ff}.sc-study-b .sb-ask{display:inline-flex;align-items:center;gap:12px;border:0;background:transparent;color:#3676bd;padding:9px 0;margin-top:15px;font-size:12px;min-height:38px}
@keyframes sb-space-drift{0%,100%{translate:0 2px}50%{translate:-3px -2px}}@keyframes sb-light-flow{0%{stroke-dashoffset:109;opacity:.15}25%,75%{opacity:.8}100%{stroke-dashoffset:-109;opacity:.15}}@keyframes sb-hub-glow{0%,100%{box-shadow:0 0 0 7px #f5faffde,0 3px 20px #4f95c82e}50%{box-shadow:0 0 0 8px #e8f4ffba,0 0 27px #42a0ee4a}}
@media(min-width:1700px){.sc-study-b{max-width:1484px}.sc-study-b .sb-world-content{padding:34px}.sc-study-b .sb-world h2{font-size:34px}.sc-study-b .sb-world-description{font-size:13px}.sc-study-b .sb-world-tags{margin-top:15px}}
@media(max-width:1150px){.sc-study-b{padding-left:30px;padding-right:30px}.sc-study-b .sb-world-content{padding-left:24px;width:62%}.sc-study-b .sb-world h2{font-size:28px}.sc-study-b .sb-world-tags{font-size:10px;gap:6px}.sc-study-b .sb-world-tags span+span:before{margin-right:6px}.sc-study-b .sb-worlds{gap:22px}.sc-study-b .sb-art{width:82%}}
@media(max-width:850px){.sc-study-b{padding-left:24px;padding-right:24px}.sc-study-b .sb-world-content{padding:23px 0 20px 20px;width:78%}.sc-study-b .sb-world h2{font-size:26px;letter-spacing:2px}.sc-study-b .sb-world-description{font-size:11px;max-width:205px}.sc-study-b .sb-world-tags{max-width:190px}.sc-study-b .sb-art{opacity:.75;width:100%}.sc-study-b .sb-world:before{background:linear-gradient(90deg,#ffffffdf,#ffffff55 66%,transparent)}.sc-study-b .sb-world{height:242px;min-height:242px}.sc-study-b .sb-enter{font-size:11px;padding:7px 12px}.sc-study-b .sb-hub{width:57px;height:57px}.sc-study-b .sb-hub img{width:51px;height:51px}}
@media(max-height:800px) and (min-width:851px){.sc-study-b .sb-world{height:225px;min-height:225px}.sc-study-b .sb-world-content{padding-top:22px;padding-bottom:18px}.sc-study-b .sb-world h2{font-size:28px}.sc-study-b .sb-world-description{font-size:11px}.sc-study-b .sb-world-tags{margin-top:7px}}
@media(min-width:651px) and (max-width:900px) and (max-height:800px){.sc-study-b .sb-world{height:218px;min-height:218px}.sc-study-b .sb-world-content{padding-top:17px;padding-bottom:14px}.sc-study-b .sb-world h2{font-size:24px;margin-bottom:5px}.sc-study-b .sb-world-type{font-size:9px;margin-bottom:5px}.sc-study-b .sb-world-description{font-size:11px}.sc-study-b .sb-world-tags{margin-top:7px;font-size:9px}.sc-study-b .sb-enter{font-size:11px;padding:6px 11px}.sc-study-b .sb-hub{width:52px;height:52px}.sc-study-b .sb-hub img{width:47px;height:47px}}
@media(max-width:650px){.sc-study-b{padding:16px 18px 24px}.sc-study-b .sb-worlds{grid-template-columns:1fr;gap:16px}.sc-study-b .sb-world{height:256px;min-height:0}.sc-study-b .sb-world-content{width:76%;padding:25px 0 23px 25px}.sc-study-b .sb-world h2{font-size:29px}.sc-study-b .sb-world-description{font-size:12px;max-width:215px}.sc-study-b .sb-world-tags{font-size:10px;max-width:225px}.sc-study-b .sb-world-type{font-size:10px}.sc-study-b .sb-art{width:90%;opacity:1}.sc-study-b .sb-world:before{background:linear-gradient(100deg,#ffffffdf,#ffffff55 61%,transparent)}.sc-study-b .sb-network{display:none}.sc-study-b .sb-hub{left:auto;top:auto;right:10px;bottom:12px;transform:none;width:50px;height:50px}.sc-study-b .sb-hub img{width:47px;height:47px}.sc-study-b .sb-hub>span{font-size:8px;line-height:16px}.sc-study-b .sb-enter{min-height:40px;font-size:12px}.sc-study-b .sb-dialog{padding:27px 22px;border-radius:15px}.sc-study-b .sb-branches{grid-template-columns:1fr;gap:9px}.sc-study-b .sb-branches>button{min-height:46px;padding:11px 15px;text-align:left}.sc-study-b .sb-dialog h2{font-size:26px}.sc-study-b .sb-module-links{flex-direction:column}.sc-study-b .sb-module-links>a{min-height:42px;display:flex;align-items:center}}
@media(prefers-reduced-motion:reduce){.sc-study-b *,.sc-study-b *:before,.sc-study-b *:after{animation:none!important;transition:none!important}.sc-study-b .sb-art{translate:none;scale:1}.sc-study-b .sb-network-signal{display:none}}
/* 文星自主研习对话：冰蓝光学界面，复用真实提问服务。 */
.sc-study-b [hidden]{display:none!important}
.sc-study-b .sb-chat{position:fixed;right:26px;bottom:26px;z-index:84;width:430px;max-width:calc(100vw - 32px);height:min(680px,calc(100dvh - 130px));display:flex;flex-direction:column;overflow:hidden;border:1px solid #bddafb;border-radius:22px;background:#fafdfff5;backdrop-filter:blur(22px);box-shadow:0 22px 80px #22578f29,0 0 0 5px #ffffff70;isolation:isolate;color:#254b78}
.sc-study-b .sb-chat:before{content:'';position:absolute;inset:0;border-radius:inherit;pointer-events:none;z-index:-1;background:radial-gradient(ellipse at 0 0,#e6f8ff90,transparent 60%)}
.sc-study-b .sb-chat-header{display:flex;align-items:center;gap:13px;position:relative;min-height:126px;padding:22px 24px 21px 20px;flex:none;background:linear-gradient(120deg,#e3f4ffed,#f8fcffff 64%,#e7f3ffff);border-bottom:1px solid #d0e6fb;overflow:hidden}
.sc-study-b .sb-chat-header:after{content:'';position:absolute;right:27px;bottom:0;width:67px;height:2px;background:linear-gradient(90deg,#61c7f1,#407bf0);box-shadow:0 0 12px #42aaf870}
.sc-study-b .sb-chat-header-grid{position:absolute;inset:0;opacity:.35;pointer-events:none;background-image:linear-gradient(#b4d6f333 1px,transparent 1px),linear-gradient(90deg,#b4d6f333 1px,transparent 1px);background-size:22px 22px;mask-image:linear-gradient(90deg,#000,transparent 70%)}
.sc-study-b .sb-chat-portrait{position:relative;display:grid;place-items:center;width:83px;height:83px;flex:none;border:1px solid #a8d6f5;border-radius:50%;background:radial-gradient(circle,#f8fdff,#e0f3ff77);box-shadow:0 0 0 6px #ffffff8a,inset 0 0 18px #9bd8ff32}
.sc-study-b .sb-chat-portrait>img{width:88px;height:88px;object-fit:contain;scale:-1 1;position:relative;z-index:1;filter:drop-shadow(0 3px 7px #3c8ac92b)}
.sc-study-b .sb-chat-portrait>i{position:absolute;inset:-8px -1px;border-top:1px solid #70bced;border-bottom:1px solid #70bced;border-radius:50%;transform:rotate(-28deg)}
.sc-study-b .sb-chat-identity{position:relative;min-width:0;flex:1;padding-right:6px}
.sc-study-b .sb-chat-identity>p{font-size:10px;line-height:1.8;color:#6189b2;letter-spacing:.8px;margin:0 0 4px}
.sc-study-b .sb-chat-identity h2{font:500 30px/1.4 var(--sb-serif);letter-spacing:4px;color:#173f74;margin:0}
.sc-study-b .sb-chat-identity h2>span{display:block;font:11px/1.8 var(--sb-sans);letter-spacing:.7px;color:#7495b8;margin-top:3px}
.sc-study-b .sb-chat-close{position:absolute;right:10px;top:10px;display:grid;place-items:center;width:34px;height:34px;padding:8px;border:0;border-radius:10px;background:#ffffff6b;color:#7b9ab8}
.sc-study-b .sb-chat-close:hover{background:#dfefff;color:#2c72bd}
.sc-study-b .sb-chat-close svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round}
.sc-study-b .sb-chat-scroll{min-height:0;flex:1;overflow-y:auto;overscroll-behavior:contain;padding:24px 23px 17px;scrollbar-width:thin;scrollbar-color:#c7dff7 transparent}
.sc-study-b .sb-chat-welcome{position:relative;margin:0 0 23px;padding:0 0 0 15px;border-left:2px solid #b3d4f7}
.sc-study-b .sb-chat-welcome h3{font:500 24px/1.5 var(--sb-serif);letter-spacing:1px;margin:0 0 9px;color:#2d5887}
.sc-study-b .sb-chat-welcome p{font-size:13px;line-height:1.95;color:#6682a0;margin:0}
.sc-study-b .sb-chat-orbit{position:absolute;right:9px;top:8px;width:48px;height:18px;border:1px solid #b5d9f466;border-radius:50%;transform:rotate(-29deg)}
.sc-study-b .sb-chat-prompts{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:0 0 7px}
.sc-study-b .sb-chat-prompts>button{display:flex;align-items:flex-start;justify-content:space-between;gap:8px;text-align:left;font-size:12px;line-height:1.85;color:#507aa6;min-height:66px;padding:12px 11px 11px 13px;border:1px solid #d9e8f8;border-radius:10px;background:linear-gradient(135deg,#ffffff,#f0f7ff);box-shadow:0 3px 10px #7ba3ce05}
.sc-study-b .sb-chat-prompts>button:hover{border-color:#9ec8f2;background:#edf6ff;color:#2f6cad}
.sc-study-b .sb-chat-prompts svg{width:13px;height:13px;flex:none;fill:none;stroke:currentColor;stroke-width:1.5;margin-top:5px}
.sc-study-b .sb-chat-message{margin:0 0 19px}
.sc-study-b .sb-chat-message>span{display:block;font-size:10px;line-height:1.8;color:#88a1bc;margin-bottom:6px;letter-spacing:1px}
.sc-study-b .sb-chat-message>p{white-space:pre-wrap;overflow-wrap:anywhere;font-size:13px;line-height:1.95;color:#3e6289;padding:12px 14px;border:1px solid #dae8f8;border-radius:0 13px 13px 13px;background:#f0f7fe;margin:0}
.sc-study-b .sb-chat-message-user{padding-left:24px}.sc-study-b .sb-chat-message-user>span{text-align:right}
.sc-study-b .sb-chat-message-user>p{background:#e9f2ff;border-color:#d1e3fb;border-radius:13px 0 13px 13px;color:#34649d}
.sc-study-b .sb-chat-status{font-size:12px;line-height:1.9;color:#6b88a6;padding:11px 12px;border:1px solid #e0ebf8;border-radius:9px;background:#f3f8ff;margin:13px 0 0;overflow-wrap:anywhere}
.sc-study-b .sb-chat-thinking:before{content:'';display:inline-block;width:5px;height:5px;border-radius:50%;background:#6caceb;box-shadow:0 0 0 4px #dfefff;margin-right:11px;vertical-align:2px;animation:sb-chat-pulse 1.4s ease-in-out infinite}
.sc-study-b .sb-chat-login{font-size:12px;line-height:1.7;color:#2f73c5;border:1px solid #bad7f7;background:#eaf4ff;border-radius:8px;padding:9px 13px;margin-top:11px;min-height:38px}
.sc-study-b .sb-chat-form{padding:15px 20px 14px;border-top:1px solid #dceafa;background:#f8fcffff;flex:none;position:relative}
.sc-study-b .sb-chat-form>label{display:block;font-size:11px;line-height:1.8;color:#6b8fb4;letter-spacing:1px;margin-bottom:8px}
.sc-study-b .sb-chat-input{display:flex;align-items:stretch;gap:8px}
.sc-study-b .sb-chat-input>textarea{font:13px/1.8 var(--sb-sans);min-height:67px;max-height:125px;resize:vertical;width:100%;min-width:0;border:1px solid #c1dafa;border-radius:11px;background:#fff;padding:11px 12px;color:#355b86;box-shadow:inset 0 1px 6px #638bb307}
.sc-study-b .sb-chat-input>textarea::placeholder{color:#9aaec4}.sc-study-b .sb-chat-input>textarea:focus-visible{outline:2px solid #94bfff;outline-offset:2px}
.sc-study-b .sb-chat-send{flex:none;width:43px;border:1px solid #2e76ed;border-radius:11px;background:linear-gradient(155deg,#3e9af7,#1761e9);color:#fff;padding:0;display:grid;place-items:center;box-shadow:0 4px 11px #326fda1c}
.sc-study-b .sb-chat-send:hover{background:linear-gradient(155deg,#2788ed,#0b50d4)}.sc-study-b .sb-chat-send:disabled{opacity:.45;cursor:wait}
.sc-study-b .sb-chat-send svg{width:19px;height:19px;fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}
.sc-study-b .sb-chat-form>small{display:block;font-size:9px;line-height:1.8;color:#94a9be;margin-top:8px}
@keyframes sb-chat-pulse{0%,100%{opacity:.4}50%{opacity:1}}
@media(max-width:720px){.sc-study-b .sb-chat{left:12px;right:12px;bottom:79px;width:auto;max-width:none;height:min(660px,calc(100dvh - 160px));border-radius:18px;box-shadow:0 15px 60px #22578f32,0 0 0 3px #ffffff70}.sc-study-b .sb-chat-header{min-height:111px;padding:17px 17px 17px 16px;gap:12px}.sc-study-b .sb-chat-portrait{width:68px;height:68px}.sc-study-b .sb-chat-portrait>img{width:75px;height:75px}.sc-study-b .sb-chat-identity>p{font-size:9px;letter-spacing:.4px}.sc-study-b .sb-chat-identity h2{font-size:27px}.sc-study-b .sb-chat-identity h2>span{font-size:10px;letter-spacing:0}.sc-study-b .sb-chat-close{width:38px;height:38px;right:5px;top:5px;padding:11px;background:transparent}.sc-study-b .sb-chat-scroll{padding:20px 18px 16px}.sc-study-b .sb-chat-welcome h3{font-size:23px}.sc-study-b .sb-chat-welcome p{font-size:12px}.sc-study-b .sb-chat-prompts{gap:8px}.sc-study-b .sb-chat-prompts>button{font-size:11px;min-height:64px;padding:11px}.sc-study-b .sb-chat-message>p{font-size:13px}.sc-study-b .sb-chat-form{padding:12px 15px}.sc-study-b .sb-chat-input>textarea{font-size:16px;min-height:70px;padding:10px}.sc-study-b .sb-chat-send{width:42px}.sc-study-b .sb-chat-form>small{font-size:9px}}
@media(max-width:380px){.sc-study-b .sb-chat-identity>p{font-size:8px}.sc-study-b .sb-chat-identity h2>span{font-size:9px}.sc-study-b .sb-chat-header{gap:9px}}
@media(prefers-reduced-motion:reduce){.sc-study-b .sb-chat-thinking:before{animation:none}}