:root{
  --bg:#f3f3f0;--panel:#fff;--text:#161616;--muted:#77766f;--line:#e5e4de;
  --soft:#ecece7;--ink:#111;--danger:#9a3737;--good:#355c43;--warn:#8a6425;--radius:18px;
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif}button,input,textarea,select{font:inherit}button{cursor:pointer}.hidden{display:none!important}a{color:inherit}
.app{min-height:100vh;display:grid;grid-template-columns:224px minmax(0,1fr)}
.sidebar{position:sticky;top:0;height:100vh;border-right:1px solid var(--line);background:#fafaf8;padding:26px 16px 20px;display:flex;flex-direction:column;z-index:5}
.brand{display:flex;align-items:center;gap:11px;padding:0 8px 24px}.brand-mark{width:35px;height:35px;background:#171717;color:#fff;border-radius:10px;display:grid;place-items:center;font-size:11px;font-weight:800;letter-spacing:.08em}.brand strong{display:block;font-size:14px}.brand small{display:block;font-size:10px;color:var(--muted);margin-top:3px;letter-spacing:.04em}
.nav{display:flex;flex-direction:column;gap:5px}.nav-item{border:0;background:transparent;text-align:left;border-radius:10px;padding:11px 12px;color:#595953}.nav-item:hover,.nav-item.active{background:#eaeae5;color:#111}.nav-item.active{font-weight:700}.sidebar-foot{margin-top:auto;padding:12px 9px 0;border-top:1px solid var(--line);font-size:10px;color:#99988f;line-height:1.6}
.main{min-width:0;padding:32px 42px 78px;max-width:1440px;width:100%;margin:0 auto}.topbar{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:26px}.eyebrow{font-size:10px;letter-spacing:.15em;font-weight:800;color:#898880}.topbar h1{margin:6px 0 0;font-size:30px;letter-spacing:-.035em;line-height:1.15}.top-actions{display:flex;gap:8px;align-items:center}
.primary,.ghost,.danger,.text-btn,.rating{border:0;border-radius:10px;padding:10px 14px}.primary{background:#151515;color:#fff}.primary:hover{background:#2b2b2b}.ghost{background:var(--soft);color:#34342f}.ghost:hover{background:#deded8}.danger{background:#f5e8e8;color:var(--danger)}.text-btn{background:transparent;color:var(--muted);padding:7px}.text-btn:hover{color:#111}.small-btn{padding:7px 10px;font-size:12px}
.hero{background:#171717;color:#fff;border-radius:24px;padding:30px;display:grid;grid-template-columns:minmax(0,1.25fr) minmax(330px,.75fr);gap:28px;box-shadow:0 16px 45px rgba(0,0,0,.07)}.hero h2{font-size:38px;line-height:1.08;letter-spacing:-.045em;margin:8px 0 9px}.hero p{color:#bababa;margin:0;max-width:650px;line-height:1.65}.hero-actions{display:flex;gap:8px;margin-top:22px}.hero .primary{background:#fff;color:#111}.due-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:9px}.due-box{background:rgba(255,255,255,.075);border:1px solid rgba(255,255,255,.09);border-radius:15px;padding:17px}.due-box strong{font-size:26px;letter-spacing:-.04em;display:block}.due-box span{font-size:11px;color:#bcbcbc;margin-top:3px;display:block}
.section{margin-top:27px}.section-head{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:11px}.section-head h3,.section h3{margin:0;font-size:16px}.section-note{font-size:11px;color:var(--muted)}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:17px}.card.clickable{cursor:pointer;transition:transform .12s ease,border-color .12s ease}.card.clickable:hover{transform:translateY(-1px);border-color:#cfcec6}.card h4{margin:0 0 7px;font-size:15px}.metric{font-size:29px;font-weight:780;letter-spacing:-.045em}.mini{font-size:10px;letter-spacing:.09em;color:var(--muted);font-weight:750}.muted{color:var(--muted)}.small{font-size:12px}.strong{font-weight:700}.empty{padding:32px 18px;text-align:center;color:var(--muted);background:#fff;border:1px dashed #d9d8d0;border-radius:16px}
.row-list{display:flex;flex-direction:column;gap:8px}.row{display:flex;justify-content:space-between;align-items:center;gap:14px;background:#fff;border:1px solid var(--line);border-radius:14px;padding:13px 15px}.row-main{min-width:0;flex:1}.row-title{font-size:14px;font-weight:680;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.row-sub{font-size:11px;color:var(--muted);margin-top:4px;line-height:1.45}.row-actions{display:flex;align-items:center;gap:7px;flex-shrink:0}.tag{display:inline-flex;align-items:center;border-radius:999px;background:#ededE8;padding:5px 8px;color:#62625c;font-size:10px}.tag.good{background:#e7efe9;color:var(--good)}.tag.warn{background:#f3eddf;color:var(--warn)}.tag.danger{background:#f5e7e7;color:var(--danger)}
.paper-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:11px}.paper-card{position:relative;min-height:142px;display:flex;flex-direction:column;justify-content:space-between}.paper-year{font-size:28px;font-weight:780;letter-spacing:-.04em}.paper-meta{font-size:11px;color:var(--muted);line-height:1.55}.paper-badges{display:flex;gap:5px;flex-wrap:wrap;margin-top:10px}.paper-card .corner{position:absolute;right:14px;top:14px;font-size:10px;color:#aaa}
.paper-head{display:flex;align-items:center;justify-content:space-between;gap:16px;background:#fff;border:1px solid var(--line);border-radius:19px;padding:18px 20px}.paper-head h2{margin:0;font-size:25px;letter-spacing:-.03em}.paper-head p{margin:4px 0 0;color:var(--muted);font-size:11px}.unit-section-title{display:flex;gap:8px;align-items:center;margin:24px 0 10px}.unit-section-title h3{font-size:15px;margin:0}.unit-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}.unit-card{min-height:138px;display:flex;flex-direction:column;justify-content:space-between}.unit-card.reading{border-color:#d6d5ce}.unit-card.reading h4{font-size:17px}.unit-top{display:flex;justify-content:space-between;gap:8px}.unit-stats{display:flex;gap:8px;flex-wrap:wrap;margin-top:11px;font-size:10px;color:var(--muted)}
.workspace-shell{display:grid;grid-template-columns:minmax(480px,1.35fr) minmax(390px,.9fr);gap:13px;align-items:start}.source-pane,.review-pane{background:#fff;border:1px solid var(--line);border-radius:18px;overflow:hidden}.source-toolbar{min-height:52px;padding:10px 13px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:8px}.source-title{font-size:12px;font-weight:700}.source-sub{font-size:10px;color:var(--muted);margin-top:2px}.pdf-frame{width:100%;height:calc(100vh - 166px);min-height:610px;border:0;background:#ececec}.review-pane{position:sticky;top:20px;max-height:calc(100vh - 40px);display:flex;flex-direction:column}.review-head{padding:17px 18px 13px;border-bottom:1px solid var(--line)}.review-head h2{margin:4px 0 4px;font-size:21px;letter-spacing:-.025em}.review-head .meta-line{display:flex;flex-wrap:wrap;gap:6px;align-items:center}.tabs{display:flex;gap:4px;overflow:auto;padding:8px;border-bottom:1px solid var(--line);background:#fafaf8}.tab{white-space:nowrap;border:0;background:transparent;padding:8px 10px;border-radius:8px;color:#66665f;font-size:11px}.tab.active{background:#eaeae5;color:#111;font-weight:700}.tab-content{padding:14px;overflow:auto}.review-callout{border:1px solid #e3e2da;background:#f8f8f5;border-radius:13px;padding:12px 13px;font-size:11px;color:#66665f;line-height:1.6;margin-bottom:12px}.review-callout strong{color:#222}.question-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:6px;margin-bottom:13px}.q-chip{border:1px solid var(--line);background:#fff;border-radius:9px;padding:9px 4px;text-align:center;font-size:11px}.q-chip:hover{background:#f2f2ee}.q-chip.saved{border-color:#b8b7ae}.q-chip.wrong{background:#f8eeee;border-color:#ead0d0;color:#873737}.q-chip.correct{background:#eef4ef;border-color:#d7e4da;color:#345842}.q-chip.note{box-shadow:inset 0 -2px #96958c}.q-detail{border:1px solid var(--line);border-radius:13px;padding:13px;margin-top:8px}.q-detail-top{display:flex;align-items:center;justify-content:space-between;gap:8px}.q-detail p{font-size:11px;line-height:1.55;margin:8px 0 0;color:#5f5f58}.answer-flow{font-size:12px;margin-top:7px}.answer-flow b{font-size:13px}.answer-pill{display:inline-grid;place-items:center;min-width:24px;height:24px;border-radius:7px;background:#ededE8;font-weight:800}.answer-pill.correct{background:#e5eee7;color:#31543e}.answer-pill.wrong{background:#f4e4e4;color:#873737}
.form{display:grid;gap:11px}.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.field label{display:block;font-size:10px;color:var(--muted);margin-bottom:5px}.field input,.field textarea,.field select,.search{width:100%;border:1px solid var(--line);background:#fff;border-radius:9px;padding:10px 11px;outline:0;color:#171717}.field textarea{min-height:76px;resize:vertical;line-height:1.5}.field input:focus,.field textarea:focus,.field select:focus,.search:focus{border-color:#aaa9a0}.span-2{grid-column:span 2}.form-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:2px}.form-sep{height:1px;background:var(--line);margin:4px 0}
.item-stack{display:flex;flex-direction:column;gap:8px}.note-card{border:1px solid var(--line);border-radius:13px;padding:12px;background:#fff}.note-card h4{margin:0;font-size:14px}.note-card p{margin:7px 0 0;font-size:11px;color:#62625b;line-height:1.55}.note-card .note-top{display:flex;justify-content:space-between;gap:8px}.note-card .context{font-style:italic;color:#77766f}.mastery-dots{display:flex;gap:3px;margin-top:9px}.dot{width:6px;height:6px;border-radius:50%;background:#d7d6cf}.dot.on{background:#222}
.session-form{background:#f7f7f4;border:1px solid var(--line);border-radius:13px;padding:13px}.session-history{margin-top:12px}.session-row{padding:10px 0;border-bottom:1px solid var(--line)}.session-row:last-child{border-bottom:0}.session-score{display:inline-grid;place-items:center;width:25px;height:25px;border-radius:8px;background:#ecece7;font-weight:800;font-size:11px}.session-row p{font-size:11px;color:#5f5f58;margin:5px 0;line-height:1.5}
.filter-row{display:flex;gap:8px;margin-bottom:13px}.filter-row .search{max-width:360px}.history-year{margin-top:22px}.history-year-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:9px}.history-year h3{font-size:19px;margin:0}.history-unit{margin-bottom:12px}.history-unit-title{font-size:11px;font-weight:800;color:#686860;margin:0 0 7px}.history-question{background:#fff;border:1px solid var(--line);border-radius:13px;padding:13px;margin-bottom:7px}.history-question-top{display:flex;justify-content:space-between;gap:9px}.history-question p{margin:7px 0 0;font-size:11px;color:#62625b;line-height:1.55}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.bar-row{display:grid;grid-template-columns:135px minmax(100px,1fr) 35px;align-items:center;gap:9px;margin:10px 0;font-size:11px}.bar{height:8px;background:#ecece7;border-radius:999px;overflow:hidden}.bar span{height:100%;display:block;background:#252525;border-radius:999px}.year-table{width:100%;border-collapse:collapse}.year-table th,.year-table td{padding:10px;border-bottom:1px solid var(--line);text-align:left;font-size:11px}.year-table th{color:var(--muted);font-size:10px}.year-table tr:last-child td{border-bottom:0}
.modal{position:fixed;inset:0;background:rgba(0,0,0,.42);display:grid;place-items:center;padding:18px;z-index:30}.modal-card{width:min(690px,100%);max-height:90vh;overflow:auto;background:#fafafa;border-radius:20px;padding:20px;box-shadow:0 28px 80px rgba(0,0,0,.27)}.modal-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:15px}.modal-head h3{margin:0;font-size:18px}.modal-head p{margin:4px 0 0;font-size:10px;color:var(--muted)}.review-prompt{font-size:22px;line-height:1.48;letter-spacing:-.015em;margin:17px 0}.answer-box{background:#fff;border:1px solid var(--line);border-radius:13px;padding:14px;margin:10px 0;font-size:12px;line-height:1.6}.rating-row{display:grid;grid-template-columns:repeat(6,1fr);gap:6px;margin-top:14px}.rating{background:#eaeae5;padding:10px 3px;font-weight:750}.rating span{display:block;font-size:9px;color:var(--muted);font-weight:500;margin-top:2px}.rating:hover{background:#dcdcd5}
.login{min-height:100vh;display:grid;place-items:center;padding:20px}.login-card{width:min(390px,100%);background:#fff;border:1px solid var(--line);border-radius:21px;padding:27px}.login-card h1{font-size:28px;letter-spacing:-.035em;margin:8px 0}.login-card p{font-size:12px;color:var(--muted);line-height:1.55}.login-card input{width:100%;padding:11px;border:1px solid var(--line);border-radius:9px;margin:8px 0}.login-card .primary{width:100%}.error-text{font-size:11px;color:var(--danger);margin-top:8px}
.toast{position:fixed;right:18px;bottom:18px;background:#151515;color:#fff;border-radius:10px;padding:10px 13px;font-size:11px;z-index:50;box-shadow:0 10px 35px rgba(0,0,0,.18)}
@media(max-width:1150px){.paper-grid{grid-template-columns:repeat(3,1fr)}.unit-grid{grid-template-columns:repeat(3,1fr)}.workspace-shell{grid-template-columns:1fr}.review-pane{position:relative;top:0;max-height:none}.pdf-frame{height:680px;min-height:0}}
@media(max-width:880px){.app{grid-template-columns:1fr}.sidebar{position:fixed;left:0;right:0;top:auto;bottom:0;height:auto;padding:7px 7px max(7px,env(safe-area-inset-bottom));border-right:0;border-top:1px solid var(--line);background:rgba(250,250,248,.96);backdrop-filter:blur(18px)}.brand,.sidebar-foot{display:none}.nav{display:grid;grid-template-columns:repeat(6,1fr);gap:2px}.nav-item{text-align:center;padding:9px 2px;font-size:10px}.main{padding:25px 17px 88px}.hero{grid-template-columns:1fr}.paper-grid{grid-template-columns:repeat(2,1fr)}.unit-grid{grid-template-columns:repeat(2,1fr)}.stats-grid,.grid{grid-template-columns:repeat(2,1fr)}.pdf-frame{height:620px}.workspace-shell{display:block}.review-pane{margin-top:10px}}
@media(max-width:580px){.topbar{align-items:flex-start}.topbar h1{font-size:26px}.hero{padding:22px}.hero h2{font-size:32px}.due-grid{grid-template-columns:repeat(2,1fr)}.paper-grid,.unit-grid{grid-template-columns:1fr 1fr}.paper-card{min-height:126px}.paper-year{font-size:24px}.stats-grid,.grid{grid-template-columns:1fr 1fr}.form-grid{grid-template-columns:1fr}.span-2{grid-column:auto}.pdf-frame{height:520px}.source-toolbar{align-items:flex-start}.question-grid{grid-template-columns:repeat(5,1fr)}.rating-row{grid-template-columns:repeat(3,1fr)}.bar-row{grid-template-columns:92px 1fr 30px}.row{align-items:flex-start}.row-actions{flex-direction:column}.paper-head{align-items:flex-start}.paper-head .row-actions{flex-direction:row}.modal{padding:9px}.modal-card{padding:16px;border-radius:17px}}