:root{
    --ink:#102033;
    --muted:#667085;
    --line:#dfe8f2;
    --paper:#ffffff;
    --soft:#f3f8fb;
    --blue:#1769aa;
    --deep:#0b3558;
    --green:#2f9e75;
    --cyan:#1aa6b7;
    --gold:#d8a642;
    --danger:#c62828;
    --shadow:0 18px 45px rgba(21,67,104,.12);
}
*{box-sizing:border-box}
[hidden]{display:none!important}
html{min-height:100%}
body{
    margin:0;
    font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",Arial,sans-serif;
    background:linear-gradient(180deg,#eef7fb 0%,#f8fbfd 46%,#f4f7fb 100%);
    color:var(--ink);
}
a{color:inherit;text-decoration:none}
button,input,select{font-family:inherit}
.school-home{min-height:100vh}
.school-hero{
    position:relative;
    min-height:620px;
    overflow:hidden;
    padding:24px clamp(18px,4vw,56px) 70px;
    color:#fff;
    background:
        radial-gradient(circle at 76% 20%,rgba(255,255,255,.24),transparent 26%),
        linear-gradient(135deg,#0a3557 0%,#1477a5 46%,#33a678 100%);
}
.school-hero.compact{min-height:430px}
.school-hero:before{
    content:"";
    position:absolute;
    inset:auto -12% -38% -12%;
    height:330px;
    background:#f7fbfd;
    border-radius:50% 50% 0 0;
}
.school-hero:after{
    content:"";
    position:absolute;
    right:6%;
    top:122px;
    width:360px;
    height:360px;
    background:
        linear-gradient(45deg,transparent 42%,rgba(255,255,255,.18) 42% 44%,transparent 44%),
        linear-gradient(-45deg,transparent 48%,rgba(255,255,255,.15) 48% 50%,transparent 50%);
    border-radius:50%;
    opacity:.7;
}
.school-nav{
    position:relative;
    z-index:2;
    display:flex;
    justify-content:space-between;
    align-items:center;
    max-width:1180px;
    margin:0 auto;
    padding:14px 0;
}
.school-name{font-size:20px;font-weight:800;letter-spacing:.5px}
.school-en{font-size:13px;color:rgba(255,255,255,.78);margin-top:4px}
.nav-admin{
    border:1px solid rgba(255,255,255,.45);
    border-radius:999px;
    padding:10px 18px;
    color:#fff;
    background:rgba(255,255,255,.12);
}
.hero-content{
    position:relative;
    z-index:2;
    max-width:1180px;
    margin:76px auto 0;
    display:grid;
    grid-template-columns:minmax(0,1.05fr) 390px;
    gap:54px;
    align-items:center;
}
.hero-content.one-col{grid-template-columns:1fr;margin-top:64px}
.hero-kicker{
    display:inline-flex;
    align-items:center;
    gap:8px;
    padding:8px 14px;
    border-radius:999px;
    background:rgba(255,255,255,.14);
    border:1px solid rgba(255,255,255,.28);
    color:#e9fbf4;
    font-weight:700;
}
.hero-copy h1{
    margin:22px 0 18px;
    font-size:clamp(38px,5vw,64px);
    line-height:1.08;
    letter-spacing:0;
}
.hero-copy p{
    max-width:700px;
    margin:0;
    font-size:19px;
    line-height:1.9;
    color:rgba(255,255,255,.9);
}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-top:32px}
.orchid-panel{
    min-height:390px;
    border:1px solid rgba(255,255,255,.32);
    border-radius:8px;
    background:linear-gradient(160deg,rgba(255,255,255,.24),rgba(255,255,255,.08));
    box-shadow:0 24px 70px rgba(4,31,55,.22);
    position:relative;
    overflow:hidden;
    backdrop-filter:blur(14px);
}
.orchid-mark{
    position:absolute;
    left:50%;
    top:48%;
    transform:translate(-50%,-50%);
    width:150px;
    height:150px;
    border-radius:50%;
    display:flex;
    align-items:center;
    justify-content:center;
    color:#0d6b61;
    background:linear-gradient(135deg,#fff,#e3fbef);
    font-size:72px;
    font-weight:900;
    box-shadow:0 20px 50px rgba(0,0,0,.16);
}
.orbital{position:absolute;border:1px solid rgba(255,255,255,.46);border-radius:50%}
.orbital.one{width:270px;height:120px;left:58px;top:122px;transform:rotate(-25deg)}
.orbital.two{width:270px;height:120px;left:58px;top:122px;transform:rotate(25deg)}
.hero-stat{
    position:absolute;
    left:24px;
    right:24px;
    bottom:24px;
    display:flex;
    justify-content:space-between;
    align-items:center;
    background:rgba(255,255,255,.88);
    color:var(--deep);
    border-radius:8px;
    padding:16px 18px;
}
.hero-stat strong{font-size:28px;color:var(--green)}
.hero-stat span{color:#4b6375}
.home-section{
    position:relative;
    z-index:3;
    max-width:1180px;
    margin:-54px auto 54px;
    padding:0 clamp(18px,4vw,0px);
}
.library-section{margin-top:-70px}
.room-entry{margin-top:28px}
.section-title{
    display:flex;
    align-items:end;
    justify-content:space-between;
    margin-bottom:18px;
}
.section-title span{color:var(--green);font-weight:800}
.section-title h2{margin:4px 0 0;font-size:30px}
.home-grid{
    display:grid;
    grid-template-columns:1.25fr .85fr .85fr;
    gap:18px;
}
.folder-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.folder-card{
    background:rgba(255,255,255,.97);
    border:1px solid var(--line);
    border-radius:8px;
    box-shadow:var(--shadow);
    padding:22px;
}
.folder-head{display:flex;align-items:center;gap:14px;margin-bottom:16px}
.folder-icon{
    width:52px;
    height:52px;
    border-radius:8px;
    display:flex;
    align-items:center;
    justify-content:center;
    background:#e9f8f0;
    color:var(--green);
    font-weight:900;
}
.folder-head h3{margin:0 0 4px;font-size:22px}
.folder-head span{color:var(--muted)}
.file-list{display:flex;flex-direction:column;gap:10px}
.front-file{
    display:flex;
    justify-content:space-between;
    gap:14px;
    align-items:center;
    border:1px solid #e4edf5;
    border-radius:8px;
    padding:13px 14px;
    background:#f9fcfe;
}
.front-file:hover{border-color:#a9d7c2;background:#f3fbf7}
.front-file strong{display:block;margin-bottom:5px}
.front-file span{display:block;color:var(--muted);font-size:14px}
.front-file em{
    font-style:normal;
    color:var(--green);
    font-weight:800;
    white-space:nowrap;
}
.empty-library{
    background:#fff;
    border:1px solid var(--line);
    border-radius:8px;
    padding:28px;
    box-shadow:var(--shadow);
    color:var(--muted);
}
.join-panel{display:grid;grid-template-columns:1fr auto;gap:12px;align-items:center}
.upload-row{display:flex;gap:10px;align-items:center;margin-top:14px;flex-wrap:wrap}
.folder-admin-list{display:grid;gap:10px;margin-top:16px}
.folder-admin-item{display:flex;align-items:center;justify-content:space-between;gap:12px;border:1px solid #e2edf5;background:#f8fcff;border-radius:8px;padding:12px 14px}
.folder-admin-item span{font-weight:800;color:var(--deep)}
.service-card,.glass,.card,.admin-card{
    background:rgba(255,255,255,.96);
    border:1px solid var(--line);
    border-radius:8px;
    box-shadow:var(--shadow);
    padding:24px;
    color:var(--ink);
}
.service-card{min-height:270px}
.service-card.feature{background:linear-gradient(180deg,#fff,#f5fbff)}
.card-icon{
    width:48px;
    height:48px;
    border-radius:8px;
    display:flex;
    align-items:center;
    justify-content:center;
    background:#e9f4ff;
    color:var(--blue);
    font-weight:900;
    margin-bottom:16px;
}
.card-icon.green{background:#e9f8f0;color:var(--green)}
.card-icon.cyan{background:#e8f8fb;color:var(--cyan)}
.service-card h3,.glass h2,.card h2{margin:0 0 12px;font-size:23px}
.service-card p,.muted{color:var(--muted);line-height:1.75}
.join-row{display:grid;grid-template-columns:1fr auto;gap:10px;margin-top:8px}
.btn{
    border:0;
    border-radius:8px;
    background:var(--blue);
    color:#fff;
    padding:12px 18px;
    font-size:16px;
    font-weight:700;
    cursor:pointer;
    display:inline-flex;
    align-items:center;
    justify-content:center;
    gap:8px;
    min-height:46px;
}
.btn:hover{filter:brightness(.95)}
.btn.primary{background:linear-gradient(135deg,var(--blue),var(--green))}
.btn.secondary{background:#eaf3f8;color:var(--deep);border:1px solid #cfe0eb}
.btn.ghost{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.36)}
.btn.ghost-dark{background:#f1f7fb;color:var(--deep);border:1px solid #d8e6ef}
.btn.danger{background:var(--danger)}
.btn.ok{background:var(--green)}
.btn.block{width:100%;margin-top:14px}
.input,select{
    width:100%;
    border:1px solid #cfdce8;
    border-radius:8px;
    padding:12px 14px;
    min-height:46px;
    font-size:16px;
    background:#fff;
    color:var(--ink);
}
.input:focus,select:focus{outline:2px solid rgba(47,158,117,.18);border-color:var(--green)}
label{display:block;margin:12px 0 7px;font-weight:700;color:#23415a}
.row{display:flex;gap:10px;align-items:center}
.msg{padding:12px 14px;border-radius:8px;margin:12px 0}
.msg.err{background:#fee2e2;color:#991b1b}
.msg.ok{background:#dcfce7;color:#166534}
.app-toast{position:fixed;left:50%;bottom:28px;z-index:1000;transform:translate(-50%,18px);max-width:min(90vw,560px);padding:12px 18px;border-radius:999px;background:rgba(8,34,52,.94);color:#fff;font-weight:800;box-shadow:0 14px 38px rgba(0,0,0,.22);opacity:0;pointer-events:none;transition:.2s}
.app-toast.show{opacity:1;transform:translate(-50%,0)}
.topbar{
    min-height:68px;
    background:linear-gradient(135deg,var(--deep),#166b90);
    color:#fff;
    display:flex;
    align-items:center;
    justify-content:space-between;
    padding:0 clamp(16px,4vw,32px);
    box-shadow:0 10px 28px rgba(12,49,79,.14);
}
.container{max-width:1120px;margin:24px auto;padding:0 16px}
.chat-wrap{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:18px}
.chat-card{min-width:0}
.chat-head{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;margin-bottom:14px}
.chat-head h2{margin:0 0 4px}
.chat-box{height:58vh;overflow:auto;background:#fff;border:1px solid var(--line);border-radius:8px;padding:16px}
.bubble{
    max-width:min(78%,760px);
    min-width:180px;
    margin:10px 0;
    padding:12px 14px;
    border-radius:8px;
    background:#eef7ff;
    border:1px solid #d9ebfb;
    overflow-wrap:anywhere;
    word-break:break-word;
}
.bubble.mine{margin-left:auto;background:#eaf8ef;border-color:#cdebd8}
.bubble-meta{display:flex;align-items:center;gap:8px;margin-bottom:7px;color:#486177;font-size:13px}
.bubble-meta b{max-width:160px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:var(--deep)}
.bubble-meta span{white-space:nowrap}
.copy-msg{
    margin-left:auto;
    border:1px solid #cbddea;
    background:#fff;
    color:#28506b;
    border-radius:6px;
    padding:4px 8px;
    font-size:12px;
    line-height:1;
    cursor:pointer;
}
.copy-msg:hover{border-color:var(--green);color:var(--green)}
.message-text{margin:0;white-space:normal;line-height:1.65}
.chat-code{
    margin:8px 0;
    padding:12px;
    max-width:100%;
    overflow:auto;
    white-space:pre;
    background:#0b2239;
    color:#e9f8ff;
    border-radius:8px;
    font-family:Consolas,"SFMono-Regular","Liberation Mono",Menlo,monospace;
    font-size:14px;
    line-height:1.55;
}
.chat-code code{font-family:inherit}
.code-lang{
    display:block;
    margin:0 0 8px;
    color:#9bd6ff;
    font-size:12px;
    font-family:inherit;
}
.file-card{background:#fff;border:1px solid #cfe2ff;border-left:4px solid var(--green);border-radius:8px;padding:12px;margin-top:8px;max-width:100%}
.file-card strong{display:block;margin:8px 0 4px;overflow-wrap:anywhere}
.file-card .muted{margin:0 0 10px}
.chat-image{
    display:block;
    width:min(100%,420px);
    max-height:360px;
    object-fit:contain;
    border-radius:8px;
    background:#f3f7fb;
    border:1px solid #dfe8f2;
}
.chat-input-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:10px;align-items:end;margin-top:12px}
.chat-textarea{resize:vertical;min-height:52px;max-height:150px;line-height:1.5}
.chat-send-actions{display:flex;gap:10px;align-items:center}
.compact-btn{min-height:38px;padding:8px 12px;font-size:14px}
.progress{height:10px;background:#e5eaf0;border-radius:10px;overflow:hidden;margin-top:10px}
.progress span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--blue),var(--green))}
.room-page{padding-bottom:36px}
.room-join{max-width:520px;margin:32px auto;display:grid;gap:12px}
.room-sidebar{display:flex;flex-direction:column;gap:10px;height:max-content}
.room-sidebar .btn{width:100%}
.room-expiry{font-size:13px;line-height:1.65;margin:8px 0 0}
.new-messages{display:block;margin:-48px auto 14px;position:relative;z-index:2;border:0;border-radius:999px;background:var(--blue);color:#fff;padding:9px 16px;font-weight:800;cursor:pointer}
.new-messages[hidden]{display:none}
.upload-dropzone{margin-top:12px;border:1px dashed #9cc9d9;border-radius:12px;background:#f5fbfd;padding:12px;display:flex;align-items:center;gap:12px;flex-wrap:wrap;transition:.2s}
.file-input-visually-hidden{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip:rect(0,0,0,0)!important;white-space:nowrap!important;border:0!important;opacity:0!important}
.upload-dropzone{position:relative;overflow:hidden}
.upload-dropzone:after{content:"";position:absolute;left:0;bottom:0;height:3px;width:var(--upload-progress,0%);background:linear-gradient(90deg,var(--blue),var(--green));transition:width .15s}
.upload-dropzone.dragging{border-color:var(--green);background:#ebfaf3;box-shadow:0 0 0 4px rgba(32,170,130,.1)}
.upload-queue{display:grid;gap:8px;margin-top:10px}
.upload-queue[hidden]{display:none}
.upload-item{display:grid;grid-template-columns:minmax(0,1fr) minmax(90px,180px) 48px auto;gap:10px;align-items:center;border:1px solid #dbe8f0;background:#fff;border-radius:9px;padding:10px 12px}
.upload-item[data-state="done"]{border-color:#b9e3ca;background:#f1fbf5}
.upload-item[data-state="error"]{border-color:#f1c3c3;background:#fff7f7}
.upload-item-details{min-width:0;display:grid;gap:4px}
.upload-item-details strong{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.upload-status{font-size:12px;color:var(--muted)}
.upload-item progress{width:100%;accent-color:var(--green)}
.upload-percent{font-size:12px;color:var(--muted);text-align:right}
.upload-item-actions{display:flex;gap:6px}
.file-card-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:12px}
.file-card-heading strong{margin:0;min-width:0}
.file-meta{margin:5px 0 9px;color:var(--muted);font-size:12px;overflow-wrap:anywhere}
.file-image-preview{display:block;width:min(100%,520px);max-height:420px;object-fit:contain;border:1px solid #dfe8f2;border-radius:8px;background:#f3f7fb}
.file-media-preview{display:block;width:min(100%,560px);max-height:420px;margin-top:8px}
.file-preview-link{display:inline-block;color:var(--blue);font-weight:800;margin-top:5px}
.source-preview{margin-top:8px}
.source-preview summary{cursor:pointer;color:var(--blue);font-weight:800}
.file-source-preview{max-height:360px;margin:8px 0 0;font-size:13px;white-space:pre;overflow:auto}
.admin-layout{display:grid;grid-template-columns:250px 1fr;min-height:100vh}
.admin-side{
    background:linear-gradient(180deg,#0b2f50,#08253f);
    color:#fff;
    padding:26px 20px;
}
.admin-brand{
    font-size:22px;
    font-weight:900;
    margin-bottom:24px;
    padding-bottom:18px;
    border-bottom:1px solid rgba(255,255,255,.16);
}
.admin-side a{
    display:block;
    padding:13px 14px;
    border-radius:8px;
    color:#dff2fb;
    font-weight:700;
    margin-bottom:6px;
}
.admin-side a:hover{background:rgba(255,255,255,.1)}
.admin-side form{margin:0}
.admin-side form button{display:block;width:100%;padding:13px 14px;border:0;border-radius:8px;background:transparent;color:#dff2fb;font:inherit;font-weight:700;text-align:left;cursor:pointer}
.admin-side form button:hover{background:rgba(255,255,255,.1)}
.admin-main{padding:26px;background:#f4f8fb}
.admin-main h1{margin-top:0}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.admin-card strong{font-size:32px;display:block;color:var(--green);margin-top:8px}
.table{width:100%;border-collapse:collapse;background:#fff;border-radius:8px;overflow:hidden;box-shadow:var(--shadow)}
.table th,.table td{padding:13px;border-bottom:1px solid #e5edf4;text-align:left;vertical-align:middle}
.table th{background:#edf6fa;color:#28465d}
.actions{display:flex;gap:8px;flex-wrap:wrap}
.login{
    min-height:100vh;
    display:flex;
    align-items:center;
    justify-content:center;
    padding:24px;
    background:
        radial-gradient(circle at 22% 18%,rgba(58,174,128,.25),transparent 28%),
        linear-gradient(135deg,#0b3558,#1482ad 58%,#42a978);
}
.login .card{width:min(440px,92vw)}
pre{
    white-space:pre-wrap;
    background:#0b2239;
    color:#e9f8ff;
    border-radius:8px;
    padding:16px;
    overflow:auto;
}
@media(max-width:920px){
    .hero-content,.home-grid,.folder-grid,.chat-wrap,.admin-layout{grid-template-columns:1fr}
    .orchid-panel{display:none}
    .school-hero{min-height:auto}
    .home-section{margin-top:-32px}
    .stats{grid-template-columns:1fr 1fr}
}
@media(max-width:640px){
    .school-nav{align-items:flex-start;gap:14px;flex-direction:column}
    .hero-actions,.row{flex-direction:column;align-items:stretch}
    .join-row{grid-template-columns:1fr}
    .join-panel{grid-template-columns:1fr}
    .section-title{display:block}
    .stats{grid-template-columns:1fr}
    .table{font-size:14px}
    .table th,.table td{padding:10px}
    .chat-head{display:block}
    .chat-head .compact-btn{margin-top:10px}
    .chat-box{height:56vh;padding:12px}
    .bubble{max-width:100%;min-width:0}
    .bubble-meta{flex-wrap:wrap}
    .copy-msg{margin-left:0}
    .chat-input-row{grid-template-columns:1fr}
    .chat-send-actions{display:grid;grid-template-columns:1fr 1fr}
    .chat-image{width:100%;max-height:300px}
    .upload-item{grid-template-columns:minmax(0,1fr) 48px auto}
    .upload-item progress{grid-column:1/-1;grid-row:2}
}