:root{
  --bg:#f5f4fc;
  --bg-hi:#ede9fb;
  --bg2:#ffffff;
  --card:#ffffff;
  --card2:#f3f1fc;
  --line:#e5e1f3;
  --txt:#2c2a45;
  --txt-soft:#4c4968;
  --muted:#7d7aa3;
  --accent:#7c5cff;
  --accent2:#ff5c8a;
  --accent-soft:rgba(124,92,255,.12);
  --accent-line:rgba(124,92,255,.4);
  --glass:rgba(124,92,255,.07);
  --glass2:rgba(124,92,255,.12);
  --ok:#17a861;
  --danger:#ff5470;
  --warn:#f08a26;
  --info:#2f8dff;
  --shadow:0 6px 22px rgba(96,76,190,.10);
}
html.dark{
  --bg:#16141f;
  --bg-hi:#251f36;
  --bg2:#1d1a29;
  --card:#221e30;
  --card2:#2b2642;
  --line:#393350;
  --txt:#f0effb;
  --txt-soft:#cdc8e8;
  --muted:#a29ec7;
  --accent:#9d84ff;
  --accent2:#ff7aa7;
  --accent-soft:rgba(157,132,255,.16);
  --accent-line:rgba(157,132,255,.45);
  --glass:rgba(255,255,255,.07);
  --glass2:rgba(255,255,255,.12);
  --shadow:0 6px 22px rgba(0,0,0,.3);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:'Segoe UI',system-ui,-apple-system,sans-serif;
  background:
    radial-gradient(1000px 620px at 88% -12%,var(--bg-hi) 0%,transparent 55%),
    radial-gradient(900px 520px at -12% 8%,#ffe7f0 0%,transparent 50%),
    radial-gradient(700px 500px at 50% 110%,#e7ebff 0%,transparent 55%),
    var(--bg);
  background-attachment:fixed;
  color:var(--txt);
  min-height:100vh;
  font-size:15px;
  line-height:1.5;
  transition:background-color .3s,color .3s;
}
html.dark body{background:
  radial-gradient(1000px 620px at 88% -12%,var(--bg-hi) 0%,transparent 55%),
  radial-gradient(700px 500px at 50% 110%,rgba(124,92,255,.10) 0%,transparent 55%),
  var(--bg)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
h1{font-size:26px;margin:0 0 4px;letter-spacing:.3px}
h3{font-size:16px;margin:0}
p{margin:0}
input,select,button{font-family:inherit;font-size:inherit;color:inherit}
.muted{color:var(--muted)}
.green{color:var(--ok)!important}
.boot{text-align:center;padding:80px;color:var(--muted)}
#app{display:flex;min-height:100vh}

/* ---------- SIDEBAR ---------- */
.sidebar{
  width:250px;
  flex:0 0 250px;
  background:linear-gradient(170deg,var(--card),var(--bg2));
  border-right:1px solid var(--line);
  position:sticky;
  top:0;
  height:100vh;
  display:flex;
  flex-direction:column;
  padding:18px 14px;
  z-index:20;
}
.brand{display:flex;align-items:center;gap:8px;font-size:19px;padding:6px 8px 14px}
.brand b{letter-spacing:.5px;background:linear-gradient(135deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.brand .brand-ic{width:34px;height:34px;flex:0 0 34px;border-radius:10px;background:linear-gradient(135deg,var(--accent),var(--accent2));display:flex;align-items:center;justify-content:center;font-size:18px;box-shadow:var(--shadow)}
.nav{display:flex;flex-direction:column;gap:4px;flex:1}
.nav-item{
  display:flex;align-items:center;gap:10px;
  padding:11px 12px;border-radius:12px;
  color:var(--txt);font-weight:500;
  transition:background .15s;
}
.nav-item span{font-size:14px}
.nav-item:hover{background:var(--glass);text-decoration:none}
.nav-item.active{background:linear-gradient(135deg,var(--accent-soft),rgba(255,92,138,.12));box-shadow:inset 0 0 0 1px var(--accent-line)}
.userbox{margin-top:14px;padding:12px;background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}
.u-name{font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.u-login{color:var(--muted);font-size:13px;margin:2px 0 10px}
.nav-toggle{display:none;position:fixed;top:12px;right:12px;z-index:40;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:8px 12px;cursor:pointer;box-shadow:var(--shadow)}

/* ---------- CHROME (language + theme) ---------- */
.chrome{display:flex;flex-direction:column;gap:8px;margin-bottom:14px}
.auth-chrome{position:fixed;top:14px;right:14px;z-index:60;display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}
.lang-row{display:flex;gap:6px;flex-wrap:wrap}
.flag-btn{
  display:flex;align-items:center;gap:7px;
  border:1px solid var(--line);background:var(--card);
  color:var(--txt);border-radius:10px;padding:5px 10px;cursor:pointer;
  font-size:12.5px;font-weight:600;transition:.15s;box-shadow:var(--shadow);
}
.flag-btn:hover{transform:translateY(-1px);border-color:var(--accent)}
.flag-btn.active{border-color:var(--accent);background:var(--accent-soft);box-shadow:inset 0 0 0 1px var(--accent)}
.flag{width:22px;height:15px;border-radius:3px;display:inline-block;overflow:hidden;box-shadow:0 0 0 1px rgba(0,0,0,.2);flex:0 0 auto}
.flag svg{display:block;width:100%;height:100%}
.theme-toggle{
  display:flex;align-items:center;gap:7px;justify-content:center;
  border:1px solid var(--line);background:var(--card);
  color:var(--txt);border-radius:10px;padding:8px 12px;cursor:pointer;
  font-size:13px;font-weight:600;transition:.15s;box-shadow:var(--shadow);
}
.theme-toggle:hover{border-color:var(--accent);transform:translateY(-1px)}
.auth-chrome .theme-toggle{width:auto}
.auth-chrome .flag-btn{padding:6px 10px}

/* ---------- MAIN ---------- */
.main{flex:1;min-width:0;padding:26px 30px 60px;max-width:1150px;margin:0 auto;width:100%}
.page{animation:fade .25s ease}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.page-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-bottom:22px;flex-wrap:wrap}
.page-head p{font-size:14px}

/* ---------- GRIDS ---------- */
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
@media(max-width:1000px){.grid4{grid-template-columns:1fr 1fr}.grid3{grid-template-columns:1fr}}
@media(max-width:800px){.grid2{grid-template-columns:1fr}}

/* ---------- CARDS ---------- */
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:16px;
  padding:18px;
  margin-bottom:16px;
  box-shadow:var(--shadow);
}
.card-h{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}
.card-h h3{background:linear-gradient(135deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.stat{display:flex;gap:14px;align-items:center;padding:16px}
.stat-ic{width:46px;height:46px;flex:0 0 46px;border-radius:14px;background:linear-gradient(135deg,var(--accent),var(--accent2));display:flex;align-items:center;justify-content:center;font-size:22px;box-shadow:var(--shadow)}
.stat-num{font-size:23px;font-weight:700}
.stat-label{color:var(--muted);font-size:13px;font-weight:600;text-transform:uppercase;letter-spacing:.4px}
.stat-sub{font-size:12px;color:var(--muted);opacity:.85}

/* ---------- BUTTONS ---------- */
.btn{
  border:1px solid var(--line);
  background:var(--card2);
  color:var(--txt);
  padding:10px 16px;
  border-radius:12px;
  cursor:pointer;
  font-weight:600;
  transition:.15s;
  display:inline-flex;align-items:center;gap:6px;
  white-space:nowrap;
}
.btn:hover{transform:translateY(-1px);filter:brightness(1.05)}
.btn.primary{background:linear-gradient(135deg,var(--accent),var(--accent2));border-color:transparent;color:#fff;box-shadow:0 6px 18px rgba(124,92,255,.35)}
.btn.primary:hover{box-shadow:0 8px 22px rgba(124,92,255,.45)}
.btn.danger{background:rgba(255,84,112,.12);border-color:rgba(255,84,112,.5);color:var(--danger)}
.btn.ghost{background:transparent;box-shadow:none}
.btn.sm{padding:6px 11px;font-size:13px;border-radius:10px}
.btn.block{width:100%;justify-content:center}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}

/* ---------- FORMS ---------- */
.field{margin-bottom:14px}
.field label{display:block;font-size:13px;color:var(--muted);margin-bottom:6px;font-weight:600}
.field input,.field select,input.input,select.input{
  width:100%;
  background:var(--bg2);
  border:1px solid var(--line);
  border-radius:12px;
  padding:11px 13px;
  outline:none;
  transition:.15s;
  color:var(--txt);
  box-shadow:0 1px 2px rgba(96,76,190,.05);
}
.field input:focus,.field select:focus,input.input:focus,select.input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
.field.sm{display:inline-flex;align-items:center;gap:10px;margin:0}
.field.sm label{margin:0}
.field.sm select{width:auto}
.input.sm{width:auto;padding:9px 12px}

/* ---------- AUTH ---------- */
.auth-wrap{flex:1;display:flex;align-items:center;justify-content:center;padding:20px}
.auth-box{width:100%;max-width:420px}
.auth-card{position:relative;overflow:hidden;background:var(--card);border:1px solid var(--line);border-radius:22px;padding:32px;box-shadow:0 20px 60px rgba(96,76,190,.18)}
.auth-card::before{content:'';position:absolute;top:0;left:0;right:0;height:6px;background:linear-gradient(90deg,var(--accent),var(--accent2),#ffb35c,var(--info))}
html.dark .auth-card{box-shadow:0 20px 60px rgba(0,0,0,.5)}
.auth-logo{width:64px;height:64px;border-radius:20px;background:linear-gradient(135deg,var(--accent),var(--accent2));display:flex;align-items:center;justify-content:center;font-size:32px;margin:0 auto 16px;box-shadow:0 10px 24px rgba(124,92,255,.4)}
.auth-card h1{text-align:center;background:linear-gradient(135deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.auth-sub{text-align:center;color:var(--muted);font-size:14px;margin-bottom:22px}
.auth-err{color:var(--danger);font-size:13px;min-height:18px;margin:4px 0 12px;text-align:center}
.auth-alt{text-align:center;margin-top:16px;font-size:14px;color:var(--muted)}
.auth-alt a{font-weight:600}
.auth-note{margin-top:18px;font-size:12px;color:var(--muted);opacity:.85;text-align:center;border-top:1px dashed var(--line);padding-top:14px}

/* ---------- TAGS / BADGES ---------- */
.tag{display:inline-block;padding:3px 10px;border-radius:999px;font-size:12px;font-weight:600;background:var(--glass);margin-right:6px}
.tag-ghost{background:transparent;border:1px solid var(--line);color:var(--muted)}
.tag-math{background:rgba(124,92,255,.14);color:#6a4bff}
.tag-physics{background:rgba(47,141,255,.12);color:#2f8dff}
.tag-sat-math{background:rgba(240,138,38,.14);color:#e0871b}
.tag-add{background:var(--accent-soft);color:var(--accent)}
.tag-other{background:var(--glass);color:var(--muted)}
.tag-sat_math{background:rgba(240,138,38,.14);color:#e0871b}
html.dark .tag-math{color:#b39dff}
html.dark .tag-physics{color:#7db8ff}
html.dark .tag-sat-math,html.dark .tag-sat_math{color:#ffc24b}
html.dark .tag-add{color:var(--accent)}
.badge{
  display:inline-block;padding:4px 10px;border-radius:999px;font-size:13px;font-weight:700;
  background:var(--glass);white-space:nowrap;
}
.st-new{color:var(--info);background:rgba(47,141,255,.12)}
.st-in_progress{color:var(--warn);background:rgba(240,138,38,.12)}
.st-done{color:var(--ok);background:rgba(23,168,97,.12)}
.st-login{color:var(--ok);background:rgba(23,168,97,.12)}
.st-logout{color:var(--danger);background:rgba(255,84,112,.12)}
.st-register{color:var(--accent);background:var(--accent-soft)}

/* ---------- ROWS ---------- */
.row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:12px 4px;border-bottom:1px solid var(--line);opacity:.9;transition:opacity .15s}
.row:hover{opacity:1}
.row:last-child{border-bottom:none}
.row-name{display:flex;flex-direction:column;gap:2px;min-width:0}
.row-name b{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.row-name small{color:var(--muted);font-size:12px}
.empty{color:var(--muted);text-align:center;padding:22px;font-size:14px}
.empty.green{color:var(--ok)}

/* ---------- TASKS ---------- */
.filter-row{display:flex;gap:10px;margin-bottom:16px;flex-wrap:wrap}
.task-item{display:flex;justify-content:space-between;align-items:center;gap:14px;flex-wrap:wrap;margin-bottom:12px}
.task-left{flex:1;min-width:220px}
.task-title{font-weight:600;margin:6px 0 2px}
.task-meta{font-size:13px}
.task-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap}

/* ---------- EXAMS ---------- */
.exam-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:900px){.exam-grid{grid-template-columns:1fr}}
.exam-card{display:flex;gap:14px;align-items:flex-start}
.exam-ic{width:54px;height:54px;flex:0 0 54px;border-radius:16px;background:linear-gradient(135deg,var(--accent-soft),rgba(255,92,138,.14));border:1px solid var(--line);display:flex;align-items:center;justify-content:center;font-size:26px}
.exam-info{flex:1;min-width:0}
.exam-name{font-weight:700;font-size:16px}
.exam-desc{font-size:13px;margin:4px 0 8px}
.exam-meta{font-size:12px;line-height:1.8}
.accent-banner{display:flex;justify-content:space-between;align-items:center;gap:14px;flex-wrap:wrap;border-color:var(--accent-line);background:linear-gradient(90deg,var(--accent-soft),rgba(255,92,138,.08))}
.big{font-size:17px}

.progress{height:8px;background:var(--bg2);border-radius:99px;overflow:hidden;margin-bottom:18px;border:1px solid var(--line)}
.progress-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:99px;transition:width .3s;display:block}
.exam-page .card{margin-bottom:0}
.exam-head{display:flex;justify-content:space-between;align-items:center;gap:14px;margin-bottom:16px;flex-wrap:wrap}
.exam-title{font-size:21px;font-weight:700}
.exam-clock{font-size:22px;font-weight:700;color:var(--warn);background:var(--card);border:1px solid var(--line);padding:8px 16px;border-radius:12px;font-variant-numeric:tabular-nums;box-shadow:var(--shadow)}
.exam-body{padding:26px}
.exam-nav{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-top:18px;flex-wrap:wrap}
.qdots{display:flex;gap:6px;flex-wrap:wrap}
.qdot{width:32px;height:32px;border-radius:10px;border:1px solid var(--line);background:var(--bg2);cursor:pointer;font-weight:600;transition:.15s}
.qdot:hover{border-color:var(--accent)}
.qdot.done{background:var(--accent-soft);border-color:var(--accent)}
.qdot.cur{background:linear-gradient(135deg,var(--accent),var(--accent2));border-color:transparent;color:#fff;box-shadow:0 4px 12px rgba(124,92,255,.35)}
.q-meta{margin-bottom:14px}
.q-text{font-size:17px;margin:14px 0 18px;line-height:1.55}
.opts{display:flex;flex-direction:column;gap:10px}
.opt{
  display:flex;align-items:flex-start;gap:12px;
  padding:13px 15px;border-radius:12px;border:1px solid var(--line);
  background:var(--bg2);cursor:pointer;transition:.15s;user-select:none;
}
.opt:hover{border-color:var(--accent)}
.opt.sel{border-color:var(--accent);background:var(--accent-soft);box-shadow:inset 0 0 0 1px var(--accent)}
.opt.good{border-color:var(--ok);background:rgba(23,168,97,.12)}
.opt.bad{border-color:var(--danger);background:rgba(255,84,112,.12)}
.opt input{display:none}
.opt-letter{width:26px;height:26px;flex:0 0 26px;border-radius:50%;background:var(--card);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:700}
.opt.sel .opt-letter{border-color:var(--accent);color:var(--accent)}
.opt-text{flex:1}

/* ---------- RESULT ---------- */
.result-hero{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap;margin-top:18px}
.rh-name{font-size:20px;font-weight:700;background:linear-gradient(135deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.rh-right{text-align:right}
.rh-grade{font-size:44px;font-weight:800;line-height:1}
.rh-percent{font-size:24px;font-weight:700}
.r-row{display:flex;gap:14px;padding:14px 2px;border-bottom:1px solid var(--line);opacity:.9}
.r-row:last-child{border-bottom:none}
.r-res{width:30px;height:30px;flex:0 0 30px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:800}
.r-res.ok{background:rgba(23,168,97,.16);color:var(--ok)}
.r-res.bad{background:rgba(255,84,112,.16);color:var(--danger)}
.r-body{flex:1;min-width:0}
.r-q{font-weight:600;margin-bottom:4px}
.r-ans{font-size:14px}
.r-ans.ok{color:var(--ok)}
.r-ans.bad{color:var(--danger)}
.r-cor{font-size:14px;color:var(--ok);margin-top:2px}
.r-expl{margin-top:8px}
.r-expl summary{cursor:pointer;color:var(--accent);font-weight:600}
.r-expl div{background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:12px;margin-top:8px;font-size:14px;line-height:1.6;color:var(--txt-soft)}

/* ---------- ANALYZER ---------- */
.bar-row{display:flex;align-items:center;gap:10px;margin:9px 0}
.bar-label{min-width:120px;text-align:right;flex-shrink:0;display:flex;justify-content:flex-end;font-size:13px}
.tag.bar-label{padding-top:4px;padding-bottom:4px}
.bar-track{flex:1;height:14px;background:var(--bg2);border-radius:8px;overflow:hidden;border:1px solid var(--line)}
.bar-fill{height:100%;border-radius:8px;background:linear-gradient(90deg,var(--accent),var(--accent2));transition:width .4s}
.bar-fill.warn{background:linear-gradient(90deg,var(--danger),var(--warn))}
.bar-val{width:70px;font-size:12px;color:var(--muted);flex-shrink:0}

/* ---------- PRACTICE ---------- */
.tabs{display:flex;gap:8px;margin:0 0 16px;flex-wrap:wrap}
.tab{padding:10px 18px;border-radius:12px;background:var(--card);border:1px solid var(--line);color:var(--txt);font-weight:600;cursor:pointer;box-shadow:var(--shadow)}
.tab.active{background:linear-gradient(135deg,var(--accent),var(--accent2));border-color:transparent;color:#fff;box-shadow:0 6px 16px rgba(124,92,255,.3)}
.tab:hover{text-decoration:none}
.solve-top{display:flex;align-items:flex-end;justify-content:space-between;gap:14px;margin-bottom:18px;flex-wrap:wrap}
.ps-actions{display:flex;gap:10px;margin-top:16px}
.ps-result{font-weight:700;padding:12px 14px;border-radius:12px;margin-top:14px;font-size:15px}
.ps-result.ok{background:rgba(23,168,97,.14);color:var(--ok)}
.ps-result.bad{background:rgba(255,84,112,.14);color:var(--danger)}
.ps-result.warn{background:rgba(240,138,38,.14);color:var(--warn)}
.ps-expl{background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:14px;margin-top:12px;line-height:1.65;font-size:14px;color:var(--txt-soft)}
.info-card{font-size:14px;color:var(--muted)}

.err-item{margin-bottom:12px;border-radius:14px}
.err-item summary{display:flex;align-items:center;gap:12px;cursor:pointer;font-weight:500}
.err-q{flex:1;min-width:0}
.err-a{color:var(--ok);margin:12px 14px 0;font-size:14px}
.err-expl{background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:12px;margin:10px 14px 14px;font-size:14px;line-height:1.6;color:var(--txt-soft)}
details summary::-webkit-details-marker{display:none}
details summary::before{content:'▸';margin-right:6px;color:var(--accent)}
details[open] summary::before{content:'▾'}

/* ---------- ACTIVITY ---------- */
.week-chart{display:flex;align-items:flex-end;gap:10px;height:170px;padding-top:20px}
.week-col{flex:1;display:flex;flex-direction:column;align-items:center;gap:6px;height:100%;justify-content:flex-end}
.week-val{font-size:12px;height:18px}
.week-bar{width:100%;max-width:44px;height:120px;display:flex;align-items:flex-end;background:var(--bg2);border-radius:10px;overflow:hidden;border:1px solid var(--line)}
.week-fill{width:100%;background:linear-gradient(180deg,var(--accent),var(--accent2));border-radius:10px;min-height:4px;transition:height .4s}
.week-label{font-size:12px;color:var(--muted)}
.week-label.on{color:var(--txt);font-weight:700}

/* ---------- MODAL ---------- */
.sh-modal{position:fixed;inset:0;background:rgba(30,26,56,.5);backdrop-filter:blur(4px);display:flex;align-items:center;justify-content:center;padding:20px;z-index:100;animation:fade .18s ease}
.sh-modal-card{width:100%;max-width:440px;background:var(--card);border:1px solid var(--line);border-radius:20px;padding:24px;box-shadow:0 24px 70px rgba(60,40,120,.35)}
.sh-modal-card h3{margin:0 0 16px}
.modal-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:6px}
.field input.err{border-color:var(--danger)}

/* ---------- MEDIA ---------- */
@media(max-width:900px){
  .sidebar{position:fixed;transform:translateX(-100%);transition:.25s;box-shadow:0 0 50px rgba(30,26,56,.4)}
  body.nav-open .sidebar{transform:none}
  .nav-toggle{display:block}
  .main{padding:64px 16px 50px}
}
@media(max-width:640px){
  .auth-chrome{top:10px;right:10px}
  .flag-btn .flag-name{display:none}
}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-thumb{background:var(--line);border-radius:99px}
::-webkit-scrollbar-track{background:transparent}