/* 我们的作业本 · 样式
   布局：吸顶顶栏；首页 = 问候、「Ta 新传的」、课程卡片、右侧最近动态；课程页 = 彩色横幅 + 两栏（Ta 那边在前、我这边在后），按教学周分组 */
:root{
  --bg:#FFF8F0; --surface:#FFFFFF; --surface-2:#FBF0E3; --line:#F0E1CF;
  --ink:#4A3B33; --ink-2:#7A6A60; --ink-3:#AE9D90;
  --btn:#4A3B33; --btn-ink:#FFF8F0;
  --me:#7AA5D8; --me-soft:#E4EEFA; --me-ink:#35679F;
  --ta:#EC8CA7; --ta-soft:#FDE6ED; --ta-ink:#B0466A;
  --hot-soft:#FDE5DE; --hot-ink:#B03F2B;
  --leaf:#7DB89A;
  --apricot:#FDE4BB; --apricot-ink:#875D1E;
  --mint:#D2EBE3; --mint-ink:#386D5E;
  --lavender:#E7DDF6; --lavender-ink:#67539A;
  --mist:#D7E7F7; --mist-ink:#3E6894;
  --peach:#FCDCCD; --peach-ink:#975037;
  --sakura:#FADDE6; --sakura-ink:#9B4961;
  --pdf:#E0736A; --word:#5B8DD6; --ppt:#E39A4F; --file:#AE9D90; --file-on:#FFFFFF;
  --paper:#FFFFFF; --paper-ink:#2E2A27;
  --overlay:rgba(74,52,38,.42);
  --lb-bg:rgba(30,22,18,.94); --lb-ink:#F7EEE5;
  --shadow:0 1px 2px rgba(120,82,50,.06),0 8px 24px -10px rgba(120,82,50,.18);
  --shadow-lift:0 2px 6px rgba(120,82,50,.08),0 18px 40px -12px rgba(120,82,50,.28);
  --shadow-modal:0 30px 80px -24px rgba(60,36,20,.45);
  --font-display:"ZCOOL KuaiLe","Nunito","PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Nunito","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",system-ui,sans-serif;
  --font-doc:"Songti SC","STSong","SimSun","Noto Serif SC",serif;
  --r-lg:24px; --r-md:18px; --r-sm:12px;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#1D1815; --surface:#29221E; --surface-2:#332A25; --line:#40352E;
    --ink:#F4E9DE; --ink-2:#BBA899; --ink-3:#8A7A70;
    --btn:#F4E9DE; --btn-ink:#29221E;
    --me:#8DB6E8; --me-soft:#273444; --me-ink:#B5D1F3;
    --ta:#F2A0B7; --ta-soft:#422B35; --ta-ink:#F7BCCD;
    --hot-soft:#46291F; --hot-ink:#F8AE9C;
    --leaf:#8FCBAA;
    --apricot:#43361F; --apricot-ink:#F1CD8C;
    --mint:#213B35; --mint-ink:#9ED5C4;
    --lavender:#352C4B; --lavender-ink:#CBBBEE;
    --mist:#243649; --mist-ink:#A9C8EA;
    --peach:#45291F; --peach-ink:#F2B49C;
    --sakura:#432731; --sakura-ink:#F2AFC2;
    --pdf:#EE8F86; --word:#86AEEA; --ppt:#F0B47A; --file:#8A7A70; --file-on:#1D1815;
    --paper:#EDE6DC; --paper-ink:#2A2420;
    --overlay:rgba(0,0,0,.55);
    --shadow:0 1px 2px rgba(0,0,0,.25),0 8px 24px -10px rgba(0,0,0,.55);
    --shadow-lift:0 2px 6px rgba(0,0,0,.3),0 18px 40px -12px rgba(0,0,0,.65);
    --shadow-modal:0 30px 80px -24px rgba(0,0,0,.7);
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#1D1815; --surface:#29221E; --surface-2:#332A25; --line:#40352E;
  --ink:#F4E9DE; --ink-2:#BBA899; --ink-3:#8A7A70;
  --btn:#F4E9DE; --btn-ink:#29221E;
  --me:#8DB6E8; --me-soft:#273444; --me-ink:#B5D1F3;
  --ta:#F2A0B7; --ta-soft:#422B35; --ta-ink:#F7BCCD;
  --hot-soft:#46291F; --hot-ink:#F8AE9C;
  --leaf:#8FCBAA;
  --apricot:#43361F; --apricot-ink:#F1CD8C;
  --mint:#213B35; --mint-ink:#9ED5C4;
  --lavender:#352C4B; --lavender-ink:#CBBBEE;
  --mist:#243649; --mist-ink:#A9C8EA;
  --peach:#45291F; --peach-ink:#F2B49C;
  --sakura:#432731; --sakura-ink:#F2AFC2;
  --pdf:#EE8F86; --word:#86AEEA; --ppt:#F0B47A; --file:#8A7A70; --file-on:#1D1815;
  --paper:#EDE6DC; --paper-ink:#2A2420;
  --overlay:rgba(0,0,0,.55);
  --shadow:0 1px 2px rgba(0,0,0,.25),0 8px 24px -10px rgba(0,0,0,.55);
  --shadow-lift:0 2px 6px rgba(0,0,0,.3),0 18px 40px -12px rgba(0,0,0,.65);
  --shadow-modal:0 30px 80px -24px rgba(0,0,0,.7);
  color-scheme:dark;
}

*{box-sizing:border-box}
body{background:var(--bg);color:var(--ink);font-family:var(--font-body);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}
body::before{content:"";position:fixed;inset:0 0 auto;height:env(safe-area-inset-top,0px);z-index:30;background:var(--bg)}
body.locked{overflow:hidden}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer;text-align:inherit}
:focus-visible{outline:3px solid var(--me);outline-offset:2px}
h1,h2,h3,h4{text-wrap:balance}
.i{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;flex:none}
.i-sm{width:14px;height:14px;stroke-width:2.4}
.heart{width:14px;height:14px;fill:var(--ta);flex:none}
.muted{color:var(--ink-2);font-size:13.5px;margin:0}
.nw{white-space:nowrap}
[tabindex="-1"]:focus{outline:none}

.wrap{width:100%;max-width:1180px;margin-inline:auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
@media (min-width:900px){.wrap{padding-left:max(32px,env(safe-area-inset-left,0px));padding-right:max(32px,env(safe-area-inset-right,0px))}}

/* top bar */
.topbar{position:sticky;top:env(safe-area-inset-top,0px);z-index:20;background:var(--bg);background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid transparent;transition:border-color .2s}
.topbar.scrolled{border-bottom-color:var(--line)}
.topbar-in{display:flex;align-items:center;justify-content:space-between;gap:12px;padding-block:14px}
.brand{display:flex;align-items:center;gap:10px;border-radius:14px}
.brand-mark{width:36px;height:36px;flex:none}
.brand-name{font-family:var(--font-display);font-size:24px;letter-spacing:.03em;line-height:1}
.topbar-right{display:flex;align-items:center;gap:10px}
.pair{display:flex;align-items:center;gap:4px;padding:4px;border-radius:999px;background:var(--surface);box-shadow:var(--shadow)}
.av{width:32px;height:32px;border-radius:50%;display:grid;place-items:center;font-weight:800;font-size:13px;flex:none;line-height:1}
.av-me{background:var(--me-soft);color:var(--me-ink)}
.av-ta{background:var(--ta-soft);color:var(--ta-ink)}
.av-sm{width:28px;height:28px;font-size:11.5px}
.av-lg{width:40px;height:40px;font-size:14px}
.icon-btn{width:40px;height:40px;border-radius:50%;display:grid;place-items:center;background:var(--surface);box-shadow:var(--shadow);color:var(--ink-2);flex:none}
.icon-btn:hover{color:var(--ink)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:7px;height:42px;padding:0 18px;border-radius:999px;font-weight:800;font-size:15px;white-space:nowrap;transition:transform .15s ease,box-shadow .15s ease,background .15s}
.btn-primary{background:var(--btn);color:var(--btn-ink);box-shadow:var(--shadow)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:var(--shadow-lift)}
.btn-ghost{color:var(--ink-2)}
.btn-ghost:hover{background:var(--surface-2);color:var(--ink)}
.btn-soft{background:var(--surface-2);color:var(--ink);height:38px;font-size:14px}
.btn-soft:hover{background:var(--line)}
.btn-danger{color:var(--hot-ink);white-space:normal;text-align:left;line-height:1.3}
.btn-danger:hover,.btn-danger.armed{background:var(--hot-soft);color:var(--hot-ink)}
@media (max-width:540px){.pair{display:none}.btn-label{display:none}.topbar-right .btn{width:42px;padding:0}.brand-name{font-size:21px}}

kbd{font-family:inherit;font-size:12px;font-weight:700;padding:1px 6px;border-radius:6px;background:var(--surface);border:1px solid var(--line);color:var(--ink)}

main.wrap{padding-block:6px 80px}
.view{animation:rise .35s ease}
.still .view,.still .course-card{animation:none}
@keyframes rise{from{transform:translateY(8px)}to{transform:none}}
@keyframes fade{from{opacity:0}to{opacity:1}}
@keyframes pop{from{opacity:0;transform:translateY(14px) scale(.98)}to{opacity:1;transform:none}}
@keyframes pulse{0%{box-shadow:0 0 0 0 color-mix(in srgb,var(--ta) 70%,transparent)}70%{box-shadow:0 0 0 7px transparent}100%{box-shadow:0 0 0 0 transparent}}
@keyframes flash{0%,100%{box-shadow:var(--shadow)}20%,65%{box-shadow:0 0 0 3px var(--ta),0 0 0 9px var(--ta-soft),var(--shadow)}}

/* home */
.home{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:32px;align-items:start}
@media (max-width:980px){.home{grid-template-columns:minmax(0,1fr)}}
.home-main{min-width:0}
.hello{padding-block:22px 4px}
.eyebrow{margin:0;font-size:13px;font-weight:800;letter-spacing:.06em;color:var(--ink-2);font-variant-numeric:tabular-nums}
.hello-title{font-family:var(--font-display);font-weight:400;font-size:clamp(34px,4.2vw,46px);line-height:1.15;margin:6px 0 8px;letter-spacing:.02em}
.hello-sub{margin:0;display:flex;align-items:center;gap:10px;font-size:16px;color:var(--ink-2)}
.hello-sub b{color:var(--ta-ink);font-size:18px}
.dot{width:8px;height:8px;border-radius:50%;display:inline-block;flex:none}
.dot.me{background:var(--me)}
.dot.ta{background:var(--ta)}
.dot.pulse{animation:pulse 1.8s ease-out infinite}

.fresh{margin-top:24px;padding:16px;border-radius:var(--r-lg);background:var(--ta-soft)}
.fresh-head{display:flex;align-items:center;gap:10px;padding:0 4px}
.fresh-head h2{margin:0;font-size:16px;font-weight:800;color:var(--ta-ink)}
.fresh-head .av-ta{background:var(--surface)}
.fresh-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:10px;margin-top:12px}
.fresh-item{display:flex;align-items:center;gap:12px;padding:10px;border-radius:18px;background:var(--surface);transition:transform .15s ease,box-shadow .15s ease;min-width:0}
.fresh-item:hover{transform:translateY(-2px);box-shadow:var(--shadow-lift)}
.fresh-thumb{width:54px;height:54px;border-radius:14px;overflow:hidden;flex:none;background:var(--c);display:grid;place-items:center;font-size:24px}
.fresh-thumb img{width:100%;height:100%;object-fit:cover;object-position:50% 20%;display:block}
.fresh-text{display:flex;flex-direction:column;min-width:0}
.fresh-title{font-weight:800;font-size:14px;line-height:1.4}
.fresh-meta{font-size:12.5px;color:var(--ink-2)}

.sec-head{display:flex;align-items:baseline;gap:10px;margin:30px 0 14px;padding:0 2px}
.sec-head h2{margin:0;font-size:18px;font-weight:800}
.course-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
@media (max-width:700px){.course-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}}
.course-card{position:relative;display:flex;flex-direction:column;gap:10px;padding:18px;border-radius:var(--r-lg);background:var(--c);min-height:184px;transition:transform .2s ease,box-shadow .2s ease;animation:rise .45s cubic-bezier(.2,.8,.2,1) backwards;animation-delay:calc(var(--i,0) * 45ms);min-width:0}
.course-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lift)}
.cc-top{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:flex-start;gap:8px}
.cc-emoji{width:50px;height:50px;border-radius:17px;display:grid;place-items:center;font-size:26px;background:var(--surface);box-shadow:var(--shadow);flex:none}
.cc-new{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;background:var(--surface);color:var(--ta-ink);font-size:12px;font-weight:800;white-space:nowrap}
@media (max-width:400px){.cc-emoji{width:42px;height:42px;font-size:22px;border-radius:14px}.cc-new{padding:3px 8px}}
.cc-name{display:block;font-size:19px;font-weight:800;line-height:1.3;margin-top:4px;overflow-wrap:anywhere}
.cc-teachers{display:flex;flex-wrap:wrap;gap:2px 14px;font-size:13px;font-weight:700;color:var(--ci)}
.cc-teachers span{display:inline-flex;align-items:baseline;gap:6px;min-width:0;overflow-wrap:anywhere}
.cc-foot{margin-top:auto;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:6px 8px;font-size:13px;font-weight:700;color:var(--ci)}
.cc-time{display:inline-flex;align-items:center;gap:5px;font-weight:700}
.course-card.add{background:transparent;border:2px dashed var(--line);color:var(--ink-2);align-items:center;justify-content:center;gap:8px;font-weight:800;box-shadow:none}
.course-card.add:hover{border-color:var(--ink-3);color:var(--ink);box-shadow:none}
.add-plus{width:48px;height:48px;border-radius:50%;display:grid;place-items:center;background:var(--surface-2)}

.home-side{display:flex;flex-direction:column;gap:20px;padding-top:24px;min-width:0}
.panel{background:var(--surface);border-radius:var(--r-lg);padding:18px;box-shadow:var(--shadow)}
.panel h3{margin:0 0 10px;padding:0 6px;font-size:16px;font-weight:800}
.feed-sum{margin:0 0 6px;padding:10px 12px;border-radius:14px;background:var(--surface-2);font-size:13.5px;color:var(--ink-2)}
.feed{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:2px}
.feed-item{display:grid;grid-template-columns:28px minmax(0,1fr);gap:10px;padding:8px 6px}
.feed-item p{margin:0;font-size:13.5px;line-height:1.55}
.feed-item time{font-size:12px;color:var(--ink-2)}
.link{font-weight:700;color:var(--ink);text-decoration:underline;text-decoration-color:var(--line);text-decoration-thickness:2px;text-underline-offset:3px;display:inline}
.link:hover{text-decoration-color:var(--ta)}
.side-empty{margin:0;padding:6px;font-size:13.5px;color:var(--ink-2)}
.who{font-weight:800}
.who.me{color:var(--me-ink)}
.who.ta{color:var(--ta-ink)}

/* course page */
.back{display:inline-flex;align-items:center;gap:4px;color:var(--ink-2);font-weight:800;padding:8px 14px 8px 8px;border-radius:999px;margin:10px 0 10px -8px}
.back:hover{background:var(--surface-2);color:var(--ink)}
.banner{position:relative;overflow:hidden;display:flex;align-items:center;flex-wrap:wrap;gap:16px 22px;padding:26px 28px;border-radius:30px;background:var(--c)}
.banner-deco{position:absolute;right:-18px;bottom:-56px;font-size:190px;line-height:1;opacity:.16;transform:rotate(-14deg);pointer-events:none;user-select:none}
.banner-emoji{position:relative;width:74px;height:74px;border-radius:24px;background:var(--surface);display:grid;place-items:center;font-size:38px;box-shadow:var(--shadow);flex:none}
.banner-text{position:relative;flex:1 1 260px;min-width:0}
.banner h1{font-family:var(--font-display);font-weight:400;font-size:clamp(30px,3.6vw,40px);line-height:1.2;margin:0;letter-spacing:.02em;overflow-wrap:anywhere}
.banner p{margin:6px 0 0;display:flex;flex-wrap:wrap;gap:4px 18px;color:var(--ci);font-weight:800;font-size:14px}
.banner p span{display:inline-flex;align-items:baseline;gap:7px;min-width:0;overflow-wrap:anywhere}
.banner-actions{position:relative;display:flex;align-items:center;gap:10px}
.cols{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px;margin-top:28px;align-items:start}
@media (max-width:780px){.cols{grid-template-columns:minmax(0,1fr);gap:36px}}
.col{min-width:0}
.col-head{display:flex;align-items:center;gap:12px;padding:0 4px 14px}
.col-head h2{margin:0;font-size:17px;font-weight:800;line-height:1.3}
.col-head p{margin:0;font-size:13px;color:var(--ink-2)}
.col-body{display:flex;flex-direction:column;gap:24px}
.week{display:flex;flex-direction:column;gap:14px}
.week-label{margin:0;padding:0 6px;display:flex;align-items:center;gap:12px;font-size:12.5px;font-weight:800;letter-spacing:.04em;color:var(--ink-2);font-variant-numeric:tabular-nums}
.week-label::after{content:"";flex:1;height:1px;background:var(--line)}
.hw{background:var(--surface);border-radius:22px;padding:18px 18px 14px;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:10px;min-width:0;scroll-margin:90px}
.hw.flash{animation:flash 1.8s ease}
.hw-head{display:flex;align-items:flex-start;gap:10px}
.hw-title{flex:1;min-width:0;margin:0;font-size:16.5px;font-weight:800;line-height:1.45}
.new-badge{flex:none;margin-top:2px;display:inline-flex;align-items:center;gap:6px;padding:2px 10px;border-radius:999px;background:var(--ta-soft);color:var(--ta-ink);font-size:12px;font-weight:800}
.hw-note{margin:0;font-size:14px;line-height:1.7;color:var(--ink-2);white-space:pre-line}
.hw-files{display:flex;flex-direction:column;gap:8px;margin-top:2px}
.thumbs{display:grid;gap:8px}
.thumbs.n1{grid-template-columns:minmax(0,1fr)}
.thumbs.n2{grid-template-columns:repeat(2,minmax(0,1fr))}
.thumbs.n3{grid-template-columns:repeat(3,minmax(0,1fr))}
.thumb{position:relative;display:block;aspect-ratio:4/3;max-width:100%;border-radius:14px;overflow:hidden;background:var(--surface-2)}
.thumbs.n1 .thumb{aspect-ratio:2/1}
.thumb img{width:100%;height:100%;object-fit:cover;object-position:50% 20%;display:block;transition:transform .35s ease}
.thumb:hover img{transform:scale(1.04)}
.thumb .more{position:absolute;inset:0;display:grid;place-items:center;background:var(--overlay);color:var(--lb-ink);font-weight:800;font-size:18px}
.file-chip{width:100%;display:flex;align-items:center;gap:12px;padding:10px 14px 10px 10px;border-radius:14px;background:var(--surface-2);transition:background .15s}
.file-chip:hover{background:color-mix(in srgb,var(--surface-2) 55%,var(--line))}
.file-ico{width:34px;height:40px;flex:none;display:grid;place-items:end center;padding-bottom:6px;border-radius:6px;font-size:10px;font-weight:800;letter-spacing:.04em;color:var(--file-on);background:var(--file);clip-path:polygon(0 0,68% 0,100% 24%,100% 100%,0 100%)}
.file-ico.pdf{background:var(--pdf)}
.file-ico.word{background:var(--word)}
.file-ico.ppt{background:var(--ppt)}
.file-meta{display:flex;flex-direction:column;min-width:0;text-align:left}
.file-name{font-weight:700;font-size:14px;line-height:1.4;overflow-wrap:anywhere}
.file-size{font-size:12px;color:var(--ink-2)}
.file-chip .go{margin-left:auto;font-size:13px;font-weight:800;color:var(--ink-2);white-space:nowrap}
.hw-foot{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:4px 10px;margin-top:2px;padding-top:10px;border-top:1px dashed var(--line);font-size:12.5px;color:var(--ink-2)}
.method{display:inline-flex;align-items:center;gap:6px;font-weight:700;color:var(--ink-2)}
.method::before{content:"";width:6px;height:6px;border-radius:2px;background:var(--ci,var(--ink-3))}
details.older summary{list-style:none;display:inline-flex;align-items:center;gap:6px;padding:7px 14px 7px 10px;border-radius:999px;font-size:13.5px;font-weight:800;color:var(--ink-2);cursor:pointer}
details.older summary::-webkit-details-marker{display:none}
details.older summary:hover{background:var(--surface-2);color:var(--ink)}
details.older summary .i{transition:transform .2s}
details.older[open] summary .i{transform:rotate(90deg)}
details.older .col-body{margin-top:14px}
.empty{display:flex;flex-direction:column;align-items:center;gap:6px;text-align:center;padding:28px 20px;border:2px dashed var(--line);border-radius:22px;color:var(--ink-2);font-size:14px}
.empty b{font-size:15.5px;color:var(--ink)}
.empty .btn{margin-top:8px}

/* modal */
.modal-root{position:fixed;inset:0;z-index:50;display:flex;align-items:center;justify-content:center;padding-block:max(24px,env(safe-area-inset-top,0px)) max(24px,env(safe-area-inset-bottom,0px));padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
.backdrop{position:absolute;inset:0;background:var(--overlay);backdrop-filter:blur(4px);-webkit-backdrop-filter:blur(4px);animation:fade .2s ease}
.sheet{position:relative;width:min(620px,100%);max-height:100%;overflow:auto;overscroll-behavior:contain;background:var(--bg);border-radius:30px;padding:26px 28px;box-shadow:var(--shadow-modal);animation:pop .28s cubic-bezier(.2,.9,.3,1.15)}
.sheet.wide{width:min(780px,100%)}
.sheet-head{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:20px}
.sheet-head h2{margin:0;font-family:var(--font-display);font-weight:400;font-size:28px;letter-spacing:.02em;line-height:1.2}
.close-btn{width:38px;height:38px;border-radius:50%;display:grid;place-items:center;color:var(--ink-2);flex:none}
.close-btn:hover{background:var(--surface-2);color:var(--ink)}
.form{display:flex;flex-direction:column;gap:20px}
.field{display:flex;flex-direction:column;gap:8px;min-width:0}
.label{font-size:14px;font-weight:800;color:var(--ink)}
.label small{font-size:12.5px;font-weight:600;color:var(--ink-2);margin-left:6px}
.input,.textarea{width:100%;min-width:0;border:1.5px solid var(--line);background:var(--surface);color:var(--ink);border-radius:14px;padding:10px 14px;font:inherit;font-size:15px;transition:border-color .15s,box-shadow .15s}
.input::placeholder,.textarea::placeholder{color:var(--ink-2)}
.input:focus,.textarea:focus{outline:none;border-color:var(--ta);box-shadow:0 0 0 4px var(--ta-soft)}
.textarea{min-height:84px;resize:vertical;line-height:1.6}
.row2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
@media (max-width:480px){.row2{grid-template-columns:minmax(0,1fr)}}
.pills{display:flex;flex-wrap:wrap;gap:8px}
.pill{display:inline-flex;align-items:center;gap:6px;min-height:36px;padding:6px 14px;line-height:1.35;text-align:left;max-width:100%;border-radius:999px;background:var(--surface);border:1.5px solid var(--line);font-weight:700;font-size:14px;color:var(--ink-2);transition:border-color .15s,background .15s,color .15s}
.pill:hover{border-color:var(--ink-3);color:var(--ink)}
.pill[aria-pressed="true"]{border-color:var(--ink);background:var(--surface-2);color:var(--ink)}
.course-pill[aria-pressed="true"]{background:var(--c);border-color:var(--ci)}
.dropzone{display:flex;flex-direction:column;align-items:center;gap:6px;padding:24px 20px;text-align:center;border:2px dashed var(--line);border-radius:22px;background:var(--surface);cursor:pointer;transition:border-color .15s,background .15s}
.dropzone:hover,.dropzone.over{border-color:var(--ta);background:var(--ta-soft)}
.dz-ico{width:64px;height:64px;margin-bottom:2px}
.dz-title{font-weight:800;font-size:15.5px}
.dz-sub{font-size:13px;color:var(--ink-2)}
.picked{display:grid;grid-template-columns:repeat(auto-fill,minmax(100px,1fr));gap:10px}
.picked-item{position:relative;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;min-height:100px;padding:10px;border-radius:14px;background:var(--surface);border:1px solid var(--line);text-align:center;font-size:12px;color:var(--ink-2);overflow:hidden;min-width:0}
.picked-item.img{aspect-ratio:1;max-width:100%;padding:0}
.picked-item img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.picked-item .pn{overflow-wrap:anywhere;line-height:1.35}
.rm{position:absolute;top:6px;right:6px;z-index:1;width:26px;height:26px;border-radius:50%;display:grid;place-items:center;background:var(--surface);color:var(--ink);box-shadow:var(--shadow)}
.rm .i{width:14px;height:14px}
.err{font-size:13px;font-weight:700;color:var(--hot-ink)}
.sheet-foot{display:flex;justify-content:flex-end;align-items:center;flex-wrap:wrap;gap:10px;margin-top:24px}
.sheet-foot .btn-danger{margin-right:auto}
.emoji-grid{display:grid;grid-template-columns:repeat(6,minmax(0,44px));gap:min(8px,1.8vw)}
.del-note{margin:16px 0 0}
.del-note:empty{margin:0}
@media (max-width:340px){.sheet-foot .btn-danger{flex-basis:100%}}
.emoji-pick{width:100%;aspect-ratio:1;border-radius:14px;display:grid;place-items:center;font-size:22px;background:var(--surface);border:1.5px solid var(--line)}
.emoji-pick[aria-pressed="true"]{border-color:var(--ink);background:var(--surface-2)}
.swatch{width:40px;height:40px;border-radius:50%;background:var(--c);box-shadow:inset 0 0 0 1.5px var(--line)}
.swatch[aria-pressed="true"]{box-shadow:0 0 0 3px var(--bg),0 0 0 5.5px var(--ci)}
.doc-head{display:flex;align-items:center;gap:12px;min-width:0}
.doc-name{font-family:var(--font-body)!important;font-size:17px!important;font-weight:800!important;letter-spacing:0!important;overflow-wrap:anywhere}
.doc-pages{display:flex;flex-direction:column;gap:16px;max-height:62vh;overflow:auto;padding:16px;border-radius:20px;background:var(--surface-2)}
.doc-paper{background:var(--paper);color:var(--paper-ink);border-radius:6px;padding:40px 46px;box-shadow:var(--shadow);font-family:var(--font-doc);font-size:15px;line-height:2}
.doc-paper h4{margin:0 0 16px;text-align:center;font-family:var(--font-body);font-size:18px;font-weight:800}
.doc-paper p{margin:0;white-space:pre-wrap}
.doc-tip{margin:14px 0 0;font-size:13px;color:var(--ink-2)}
@media (max-width:560px){
  .modal-root{align-items:flex-end;padding-block:0;padding-left:0;padding-right:0}
  .sheet,.sheet.wide{width:100%;max-height:92%;border-radius:28px 28px 0 0;padding-top:22px;padding-bottom:max(22px,env(safe-area-inset-bottom,0px));padding-left:max(20px,env(safe-area-inset-left,0px));padding-right:max(20px,env(safe-area-inset-right,0px))}
  .doc-paper{padding:24px 20px;font-size:14px}
  .doc-pages{padding:10px}
  body.locked .toast{bottom:auto;top:calc(16px + env(safe-area-inset-top,0px))}
}

/* lightbox */
.lightbox{position:fixed;inset:0;z-index:60;display:flex;flex-direction:column;background:var(--lb-bg);color:var(--lb-ink);animation:fade .2s ease}
.lb-top{display:flex;align-items:center;justify-content:space-between;gap:12px;padding-top:max(14px,env(safe-area-inset-top,0px));padding-bottom:10px;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
.lb-cap{display:flex;flex-direction:column;min-width:0}
.lb-cap b{font-size:16px;line-height:1.4}
.lb-cap span{font-size:13px;opacity:.72}
.lb-btn{width:44px;height:44px;border-radius:50%;display:grid;place-items:center;flex:none;color:var(--lb-ink);background:rgba(255,255,255,.1)}
.lb-btn:hover{background:rgba(255,255,255,.2)}
.lb-stage{position:relative;flex:1;min-height:0;display:flex;align-items:center;justify-content:center;padding:8px 80px max(28px,env(safe-area-inset-bottom,0px))}
.lb-stage img{max-width:100%;max-height:calc(100vh - 140px);object-fit:contain;border-radius:10px;box-shadow:0 24px 70px rgba(0,0,0,.5)}
.lb-nav{position:absolute;top:50%;transform:translateY(-50%)}
.lb-prev{left:max(18px,env(safe-area-inset-left,0px))}
.lb-next{right:max(18px,env(safe-area-inset-right,0px))}
@media (max-width:600px){
  .lb-stage{padding-left:12px;padding-right:12px;padding-bottom:max(84px,env(safe-area-inset-bottom,0px))}
  .lb-stage img{max-height:calc(100vh - 200px)}
  .lb-nav{top:auto;bottom:max(20px,env(safe-area-inset-bottom,0px));transform:none}
}

/* drop overlay + toast */
.drop-overlay{position:fixed;inset:0;z-index:70;display:grid;place-items:center;background:color-mix(in srgb,var(--ta-soft) 82%,transparent);pointer-events:none;animation:fade .15s ease}
.drop-card{display:flex;flex-direction:column;align-items:center;gap:6px;padding:40px 56px;border:3px dashed var(--ta);border-radius:34px;background:var(--bg);font-family:var(--font-display);font-size:30px;color:var(--ta-ink);text-align:center;margin-inline:16px}
.drop-card small{font-family:var(--font-body);font-size:14px;font-weight:700;color:var(--ink-2)}
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));z-index:80;width:max-content;max-width:calc(100% - 32px);overflow-wrap:anywhere;transform:translate(-50%,20px);opacity:0;pointer-events:none;padding:12px 22px;border-radius:999px;background:var(--btn);color:var(--btn-ink);font-weight:800;font-size:14.5px;box-shadow:var(--shadow-lift);transition:opacity .25s ease,transform .25s ease}
.toast.show{opacity:1;transform:translate(-50%,0)}

@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* ---------- 正式版新增 ---------- */
:root{color-scheme:light;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px)}
body{margin:0}
img{max-width:100%}
[hidden]{display:none!important}

/* 加载 / 连接状态 */
.boot{min-height:60vh;display:grid;place-items:center;color:var(--ink-2);font-size:15px}
.boot-dot{display:inline-block;width:10px;height:10px;border-radius:50%;background:var(--ta);margin-right:10px;animation:pulse 1.4s ease-out infinite}
.net{position:fixed;left:50%;top:calc(12px + env(safe-area-inset-top,0px));transform:translateX(-50%);z-index:85;width:max-content;max-width:calc(100% - 32px);padding:8px 16px;border-radius:999px;background:var(--hot-soft);color:var(--hot-ink);font-size:13.5px;font-weight:800;box-shadow:var(--shadow)}

/* 登录 */
.login{min-height:calc(100vh - 40px);display:grid;place-items:center;padding-block:32px}
.login-card{width:min(400px,100%);background:var(--surface);border-radius:30px;padding:34px 30px 28px;box-shadow:var(--shadow-lift);display:flex;flex-direction:column;gap:18px}
.login-brand{display:flex;flex-direction:column;align-items:center;gap:10px;text-align:center;margin-bottom:4px}
.login-brand .brand-mark{width:56px;height:56px}
.login-brand h1{margin:0;font-family:var(--font-display);font-weight:400;font-size:32px;letter-spacing:.03em}
.login-brand p{margin:0;color:var(--ink-2);font-size:14px}
.login .btn-primary{width:100%;height:46px;margin-top:4px}
.login .btn-primary[disabled]{opacity:.6;cursor:progress}

/* 自己的作业：编辑 / 删除 */
.hw-foot-right{display:inline-flex;align-items:center;gap:4px}
.hw-act{display:inline-flex;align-items:center;gap:4px;height:28px;padding:0 9px;border-radius:999px;font-size:12.5px;font-weight:800;color:var(--ink-2)}
.hw-act:hover{background:var(--surface-2);color:var(--ink)}
.hw-act .i{width:14px;height:14px}
.hw-act.danger.armed{background:var(--hot-soft);color:var(--hot-ink)}

/* 上传进度 */
.progress{height:8px;border-radius:999px;background:var(--surface-2);overflow:hidden}
.progress span{display:block;height:100%;width:0;background:var(--ta);border-radius:inherit;transition:width .2s ease}
.progress-text{margin:6px 0 0;font-size:13px;font-weight:700;color:var(--ink-2)}
.btn-primary[disabled]{opacity:.6;cursor:progress;transform:none}
.picked-item.existing{border-style:dashed}

/* 文件预览 */
.doc-frame{width:100%;height:min(70vh,820px);border:0;border-radius:16px;background:var(--surface-2)}
.doc-actions{display:flex;justify-content:flex-end;flex-wrap:wrap;gap:10px;margin-top:14px}
.btn-link{text-decoration:none}

/* 账号 / 设置 */
.pair{cursor:pointer}
.pair:hover{box-shadow:var(--shadow-lift)}
.acct{display:flex;flex-direction:column;gap:10px}
.acct-row{display:flex;align-items:center;gap:12px;padding:12px 14px;border-radius:16px;background:var(--surface)}
.acct-row b{font-size:15px}
.acct-row span{font-size:13px;color:var(--ink-2)}
.eyebrow .link{font-size:12.5px;font-weight:800;letter-spacing:0;color:var(--ink-2)}
body:not(.authed) .topbar{display:none}
.lb-cap{flex:1}
.lb-top .lb-btn{text-decoration:none}
/* 手机上顶栏放不下两个头像，只留「我」，点它进账号设置 */
@media (max-width:540px){.pair{display:flex;padding:3px}.pair .heart,.pair .av-ta{display:none}}