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.course-hero{padding:35px;min-height:230px;display:flex;align-items:center;background:linear-gradient(135deg,#3a37638c,#18243a9e)}.course-hero h1{font-size:clamp(30px,4vw,52px)}.course-layout{display:grid;grid-template-columns:minmax(250px,.9fr) minmax(0,1.2fr);gap:16px;margin-top:18px}.course-panel{padding:25px}.course-panel textarea{min-height:230px}.course-chat{display:flex;flex-direction:column;min-height:520px;padding:0;overflow:hidden}.course-messages{padding:25px;flex:1;overflow:auto;max-height:520px}.message{max-width:90%;padding:14px 16px;border-radius:17px;margin-bottom:12px;background:#ffffff0e;line-height:1.6;font-size:13px;white-space:pre-wrap;overflow-wrap:anywhere}.message.user{margin-left:auto;background:linear-gradient(130deg,#788cdf59,#9979cc42)}.message.assistant{border:1px solid #ffffff16}.message.error{border-color:#ff83986b;color:#ffb9c8}.course-compose{padding:15px;border-top:1px solid var(--line);display:flex;gap:9px;align-items:end}.course-compose textarea{min-height:60px;margin:0;flex:1}.course-compose .btn{flex:none}.notice{padding:13px 16px;border-radius:14px;border:1px solid #e9be7b42;background:#ac78481e;color:#f2c994;font-size:12px;line-height:1.6}.notice.ok{border-color:#83dfb546;background:#79dca81b;color:#aeecca}.notice p{margin:0}
.chat-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:16px;height:calc(100dvh - 120px);min-height:560px}.chat-sidebar{padding:15px;display:flex;flex-direction:column;gap:12px;overflow:hidden}.chat-sidebar .btn{width:100%}.chat-sidebar input{width:100%;border:1px solid var(--line);background:#0d1224;color:white;border-radius:11px;padding:10px;font-size:12px}.chat-list{overflow:auto;min-height:0}.chat-item{width:100%;text-align:left;border:0;border-radius:12px;padding:12px 10px;background:transparent;color:#adb5ce;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:12px}.chat-item:hover,.chat-item.active{background:#ffffff16;color:#fff}.chat-main{display:flex;flex-direction:column;min-height:0;overflow:hidden}.chat-heading{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid var(--line);gap:8px}.chat-heading strong{font-size:14px}.chat-heading .actions{display:flex;gap:6px}.chat-stream{flex:1;overflow:auto;padding:30px clamp(16px,5%,65px)}.chat-stream .message{max-width:75%}.empty-state{min-height:300px;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center;color:#aeb5ca}.empty-state .halo{width:74px;height:74px;border-radius:24px;display:grid;place-items:center;font-size:35px;margin-bottom:20px;background:linear-gradient(130deg,#8797ee5e,#ca92d858);box-shadow:0 18px 50px #7380dd2b}.composer{padding:16px 20px;border-top:1px solid var(--line)}.composer-box{display:flex;align-items:end;gap:9px;padding:8px;border:1px solid #ffffff28;border-radius:19px;background:#0c1123bd}.composer textarea{border:0;background:transparent;box-shadow:none!important;min-height:46px;max-height:160px;margin:0;padding:10px}.composer .round-icon{flex:none;width:39px;height:39px;margin:3px}.composer .btn{margin:3px}.composer-foot{font-size:10px;color:#7f88a4;margin-top:7px;text-align:center}.message-actions{display:flex;gap:6px;margin:-5px 0 15px}.message-actions button{border:0;background:transparent;color:#8f9abc;font-size:11px;padding:4px 8px}.message-actions button:hover{color:#fff}
.voice-hero{max-width:770px;margin:30px auto;text-align:center;padding:44px 30px}.voice-orb{width:182px;height:182px;margin:0 auto 30px;border-radius:50%;background:radial-gradient(circle at 37% 30%,#e9eaff,#a3a8ee 30%,#6a6ac4 60%,#27295e 82%);box-shadow:inset -18px -22px 32px #1f235e66,inset 8px 8px 24px #ffffffa8,0 0 0 17px #a3a9ec0c,0 25px 80px #7881e658;position:relative;transition:transform .5s,box-shadow .5s}.voice-orb.active{animation:breathe 3s ease-in-out infinite}.voice-orb::after{content:'';position:absolute;inset:-24px;border-radius:50%;border:1px solid #bac5ff40}@keyframes breathe{50%{transform:scale(1.06);box-shadow:inset -18px -22px 32px #1f235e66,inset 8px 8px 24px #ffffffa8,0 0 0 25px #a3a9ec12,0 25px 100px #7881e68a}}.voice-status{margin:22px 0;color:#c9d2ed;font-size:13px}.voice-actions{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}.voice-note{max-width:580px;margin:25px auto 0;text-align:left}.voice-subtitle{color:#b9c1d8}.photo-layout{display:grid;grid-template-columns:1fr 1fr;gap:17px}.photo-card{padding:27px}.photo-drop{border:1px dashed #a2ace568;border-radius:19px;background:#ffffff09;min-height:280px;display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;padding:20px;gap:14px;position:relative;overflow:hidden}.photo-drop img{max-width:100%;max-height:300px;border-radius:12px}.photo-drop input{position:absolute;inset:0;opacity:0;cursor:pointer}.photo-confirm textarea{min-height:250px}.photo-confirm .btn{margin-top:10px}.history-grid,.settings-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.stat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.stat{padding:18px;border-radius:15px;background:#ffffff0b;border:1px solid #ffffff13}.stat strong{display:block;font-size:25px}.stat small{color:#a5aec6;font-size:11px}.history-list{margin:0;padding:0;list-style:none}.history-list li{padding:13px 0;border-bottom:1px solid var(--line);font-size:12px;color:#cdd1e3}.history-list li:last-child{border:0}.settings-card{padding:25px}.settings-card h3{margin-bottom:18px}.field{display:flex;flex-direction:column;gap:6px;margin-bottom:13px}.field label{color:#aeb6cc;font-size:12px;font-weight:700}.field input,.field select{width:100%;border:1px solid #ffffff25;background:#0c1122;color:#fff;border-radius:12px;padding:11px 12px;outline:0}.status-row{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:12px 0;border-bottom:1px solid var(--line);font-size:12px}.status-row:last-child{border:0}.settings-card .btn{margin-top:7px}.auth{min-height:100dvh;display:grid;place-items:center;padding:24px}.auth-panel{width:min(100%,450px);padding:40px;background:linear-gradient(145deg,#222947cc,#151a2fd9)}.auth-panel .brand{padding:0 0 40px}.auth-panel h1{font-size:38px}.auth-panel p{font-size:13px;color:#b7bed2}.auth-panel .field{margin:26px 0 17px}.auth-panel .btn{width:100%}.auth-panel .lang-wrap{position:absolute;top:24px;right:24px}.auth-panel{position:relative}.auth-panel .notice{margin-top:13px}.toast{position:fixed;right:20px;bottom:20px;max-width:min(380px,calc(100vw - 30px));padding:13px 17px;border-radius:14px;background:#252b44ed;border:1px solid #ffffff30;box-shadow:0 15px 42px #0008;color:#f8f9ff;font-size:12px;line-height:1.5;backdrop-filter:blur(18px);opacity:0;transform:translateY(12px);pointer-events:none;transition:.35s;z-index:200}.toast.show{opacity:1;transform:none}.spinner{width:17px;height:17px;border:2px solid #ffffff5c;border-top-color:#fff;border-radius:50%;animation:spin .7s linear infinite;display:inline-block}@keyframes spin{to{transform:rotate(360deg)}}.loading-shine{background:linear-gradient(105deg,#ffffff09 20%,#ffffff26 40%,#ffffff09 60%);background-size:220% 100%;animation:shimmer 2s ease-in-out infinite}@keyframes shimmer{to{background-position-x:-220%}}
@media(max-width:1150px){.shell{grid-template-columns:78px minmax(0,1fr)}.sidebar{padding-inline:8px}.brand{justify-content:center;padding-inline:0}.brand strong,.brand small,.nav-item span:not(.nav-icon),.nav-label,.sidebar-bottom{display:none}.nav-item{justify-content:center;padding:12px}.nav-icon{font-size:19px}.content{padding-inline:24px}.math-layout{grid-template-columns:minmax(0,1.2fr) minmax(270px,.8fr)}}
@media(max-width:850px){.content{padding:21px 22px 90px}.math-layout{grid-template-columns:1fr 1fr}.formula-options{grid-template-columns:1fr}.course-layout{grid-template-columns:1fr}.course-panel textarea{min-height:150px}.course-chat{min-height:400px}.chat-layout{grid-template-columns:180px 1fr}.grid-3{gap:10px}.subject-card{padding:18px;min-height:170px}.hero{min-height:260px}}
@media(max-width:650px){.shell{display:block}.sidebar{position:fixed;inset:auto 10px max(8px,env(safe-area-inset-bottom)) 10px;height:66px;border:1px solid #ffffff2b;border-radius:22px;padding:5px 6px;background:#191f36e8;box-shadow:0 15px 45px #0009;backdrop-filter:blur(27px);z-index:70}.sidebar .brand,.sidebar-bottom,.nav-label,.sidebar .secondary-nav{display:none}.sidebar .nav{display:grid;grid-template-columns:repeat(5,1fr);height:100%;gap:2px}.sidebar .nav-item{flex-direction:column;gap:2px;border-radius:16px;padding:6px 1px;font-size:10px;min-height:54px}.sidebar .nav-item span:not(.nav-icon){display:block;text-align:center;line-height:1.15;max-width:65px;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}.nav-icon{height:24px}.nav-glider{height:54px;right:auto;width:calc((100% - 8px)/5);border-radius:16px;transition:transform .5s cubic-bezier(.2,1.1,.2,1)}.content{padding:16px 16px calc(95px + env(safe-area-inset-bottom))}.topbar{margin-bottom:24px}.topbar-left{font-size:11px}.topbar .round-icon{width:38px;height:38px}.hero{min-height:310px;padding:29px 24px;align-items:flex-start}.hero::after{width:260px;height:260px;right:-110px;top:80px}.hero h1{font-size:38px;max-width:330px}.hero p{font-size:13px;max-width:290px}.hero-actions{margin-top:22px}.section-head{margin:30px 0 15px}.grid-3{grid-template-columns:1fr}.grid-2{grid-template-columns:1fr 1fr}.subject-card{min-height:125px}.subject-icon{margin-bottom:10px;width:37px;height:37px}.tool-card{min-height:130px;padding:17px}.tool-card .subject-icon{margin-bottom:8px}.continue-card{align-items:flex-start;flex-direction:column}.math-header{align-items:start;flex-direction:column}.math-layout,.photo-layout,.history-grid,.settings-grid{grid-template-columns:1fr}.formula-options{grid-template-columns:1fr 1fr}.formula-option{min-height:92px;padding:12px}.math-side{order:2}.problem-card{padding:25px;min-height:150px}.problem-card .math-expression{font-size:34px}.chat-layout{height:calc(100dvh - 167px);min-height:440px;display:flex;flex-direction:column}.chat-sidebar{display:flex;flex-direction:row;align-items:center;min-height:58px;padding:10px;overflow:visible}.chat-sidebar .btn{width:auto;flex:none}.chat-sidebar input{max-width:130px}.chat-list{display:flex;overflow-x:auto;overflow-y:hidden;gap:2px;flex:1}.chat-item{width:auto;max-width:100px;flex:none}.chat-main{flex:1}.chat-heading{padding:10px 12px}.chat-stream{padding:17px}.chat-stream .message{max-width:90%}.composer{padding:9px}.course-hero{min-height:170px;padding:25px}.course-chat{min-height:410px}.course-compose{padding:10px}.stat-grid{grid-template-columns:repeat(3,1fr)}.stat{padding:13px}.stat strong{font-size:19px}.voice-hero{padding:35px 19px;margin:15px 0}.voice-orb{width:150px;height:150px}.auth-panel{padding:31px 23px}.lang-menu{width:165px}}
@media(max-width:375px){.content{padding-inline:12px}.hero{padding:26px 19px}.hero h1{font-size:34px}.grid-2{gap:9px}.formula-options{gap:7px}.formula-option strong{font-size:11px}.formula-option small{font-size:10px}.nav-item span:not(.nav-icon){font-size:9px}.mode-picker button{padding:8px}.auth-panel .lang-wrap{top:13px;right:13px}.auth-panel .brand{padding-bottom:52px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important;scroll-behavior:auto!important}.orb{filter:blur(65px)}}
.nav-short{display:none}
@media(max-width:650px){.sidebar .nav-item span.nav-full{display:none!important}.sidebar .nav-item span.nav-short{display:block;max-width:none;overflow:visible;text-overflow:clip;white-space:nowrap}}