:root {
  --side-bg: linear-gradient(180deg,#0f172a,#1e293b);
  --side-text: #94a3b8;
  --side-active: #f8fafc;
  --brand: #6366f1;
  --brand-dark: #4f46e5;
  --brand-soft: #eef2ff;
  --ok: #22c55e;
  --danger: #ef4444;
  --warn: #f59e0b;
  --text: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #f1f5f9;
  --panel: #fff;
  --shadow: 0 1px 3px rgba(0,0,0,.06),0 1px 2px rgba(0,0,0,.04);
  --shadow-lg: 0 4px 6px rgba(0,0,0,.07),0 10px 15px rgba(0,0,0,.1);
  --radius: 12px;
  --radius-sm: 8px;
  --font: 'Segoe UI','Microsoft YaHei',system-ui,sans-serif;
}
*,:after,:before{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}

/* Layout */
.layout{display:flex;min-height:100vh}
.main{flex:1;min-width:0;display:flex;flex-direction:column}

/* Sidebar */
.sidebar{
  position:sticky;top:0;width:260px;height:100vh;
  padding:20px 16px;
  background:radial-gradient(circle at 24% 0%,rgba(99,102,241,.3),transparent 34%),
             linear-gradient(180deg,#0f172a,#1e293b);
  color:var(--side-text);flex-shrink:0;
  box-shadow:4px 0 20px rgba(15,23,42,.12)
}
.logo{display:flex;gap:12px;align-items:center;padding:4px 8px 16px;border-bottom:1px solid rgba(255,255,255,.08);margin-bottom:8px}
.logo-icon{
  display:grid;width:44px;height:44px;place-items:center;border-radius:14px;
  background:linear-gradient(135deg,#fff,#e0e7ff);color:#0f172a;font-weight:900;
  box-shadow:0 8px 20px rgba(99,102,241,.25)
}
.logo strong{font-size:16px;color:var(--side-active)}
.logo span{display:block;margin-top:2px;font-size:12px;color:var(--side-text)}

/* Navigation */
.nav{display:grid;gap:2px;margin-top:8px}
.nav a{
  display:flex;align-items:center;gap:10px;
  padding:11px 14px;border-radius:10px;
  color:var(--side-text);text-decoration:none;
  font-weight:600;transition:all .15s;position:relative
}
.nav a:hover{background:rgba(255,255,255,.08);color:var(--side-active)}
.nav a.active{
  background:var(--brand);color:#fff;
  box-shadow:0 8px 20px rgba(99,102,241,.3)
}
.nav a.active::before{content:'';position:absolute;left:6px;top:50%;width:3px;height:18px;border-radius:99px;background:rgba(255,255,255,.6);transform:translateY(-50%)}

/* Sidebar footer */
.sidebar-footer{margin-top:auto;padding:14px;border:1px solid rgba(255,255,255,.1);border-radius:14px;background:rgba(255,255,255,.06);font-size:13px;line-height:1.6}
.sidebar-footer b{color:var(--side-active)}
.sidebar-footer p{margin:6px 0 0;color:var(--side-text)}

/* Topbar */
.topbar{
  display:flex;align-items:center;justify-content:space-between;
  margin:16px 20px 0;padding:16px 20px;
  border:1px solid var(--line);border-radius:var(--radius);
  background:rgba(255,255,255,.8);backdrop-filter:blur(12px);
  box-shadow:var(--shadow)
}
.topbar h1{margin:0;font-size:22px;letter-spacing:-.02em}
.topbar p{margin:3px 0 0;font-size:14px;color:var(--muted)}
.user-actions{display:flex;gap:10px;align-items:center}
.user-chip{padding:8px 14px;border-radius:999px;background:var(--brand-soft);color:var(--brand);font-weight:700;font-size:14px}

/* Page content */
.page{padding:20px;flex:1}
.page.active{animation:pageIn .25s ease both}
@keyframes pageIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

/* Cards & Panels */
.panel{
  margin-bottom:16px;padding:20px;border:1px solid var(--line);
  border-radius:var(--radius);background:var(--panel);box-shadow:var(--shadow)
}
.panel:hover{box-shadow:0 8px 24px rgba(15,23,42,.07)}
.panel h3{margin:0 0 14px;font-size:17px}
.inner-panel{margin:0 0 16px;padding:16px;background:#fbfdff}
.inner-panel h4{margin:0 0 10px}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-bottom:16px}
.grid-2.compact{margin-top:12px}

/* Stats */
.stat-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:16px}
.stat{
  padding:16px 18px;border:1px solid var(--line);border-radius:var(--radius);
  background:var(--panel);box-shadow:var(--shadow);
  transition:transform .15s,box-shadow .15s
}
.stat:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.stat span{color:var(--muted);font-size:13px}
.stat strong{display:block;margin-top:8px;font-size:28px;letter-spacing:-.03em;color:var(--text)}
.stat em{margin-left:4px;color:var(--muted);font-size:13px;font-style:normal}

/* Cards grid (problems, recommendations) */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:12px}
.data-card{
  padding:16px;border:1px solid var(--line);border-radius:var(--radius);
  background:var(--panel);box-shadow:var(--shadow);
  transition:transform .15s,box-shadow .15s;cursor:pointer
}
.data-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.data-card b,.data-card span{display:block}
.data-card span{margin:6px 0 0;color:var(--muted);font-size:13px}

/* Buttons */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:6px;
  min-height:38px;padding:0 16px;
  border:1px solid var(--line);border-radius:var(--radius-sm);
  background:#fff;color:var(--text);font-weight:700;font-size:14px;
  cursor:pointer;transition:all .15s;position:relative;overflow:hidden;
  white-space:nowrap;user-select:none
}
.btn:hover:not(:disabled){transform:translateY(-1px)}
.btn:active:not(:disabled){transform:scale(.97)}
.btn:disabled{opacity:.6;cursor:not-allowed}
.btn.primary{
  border-color:var(--brand);background:var(--brand);color:#fff;
  box-shadow:0 4px 12px rgba(99,102,241,.25)
}
.btn.primary:hover:not(:disabled){box-shadow:0 6px 16px rgba(99,102,241,.35)}
.btn.danger{border-color:var(--danger);background:var(--danger);color:#fff}
.btn.ghost{background:transparent;border-color:transparent}
.btn.sm{min-height:32px;padding:0 12px;font-size:13px}
.btn.is-loading{pointer-events:none;opacity:.8}
.btn.is-loading .btn-text{visibility:hidden}
.btn .btn-spinner{display:none;position:absolute;width:16px;height:16px;border:2px solid rgba(255,255,255,.3);border-top-color:#fff;border-radius:50%;animation:btnSpin .6s linear infinite}
.btn.is-loading .btn-spinner{display:block}
@keyframes btnSpin{to{transform:rotate(360deg)}}

/* Forms */
.form{display:grid;gap:10px}
.form-group{display:grid;gap:4px}
.form label,.form-group label{font-size:13px;font-weight:700;color:var(--muted)}
input,select,textarea{
  min-height:40px;padding:0 12px;border:1.5px solid var(--line);
  border-radius:var(--radius-sm);background:#fcfdff;color:var(--text);
  font:inherit;transition:border-color .15s,box-shadow .15s,background .15s;
  outline:0
}
input:focus,select:focus,textarea:focus{border-color:var(--brand);background:#fff;box-shadow:0 0 0 4px rgba(99,102,241,.12)}
textarea{padding:10px 12px;min-height:120px}
select{cursor:pointer}

/* Filters */
.filters,.filter{display:flex;gap:10px;flex-wrap:wrap;align-items:end;margin-bottom:16px}
.filter-group{display:grid;gap:4px}
.filter-group label{font-size:13px;font-weight:700;color:var(--muted)}
.filter-group input,.filter-group select{min-width:200px}

/* Tables */
.table-wrap{overflow-x:auto}
table{
  width:100%;border-collapse:separate;border-spacing:0;
  border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:var(--panel)
}
th,td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);white-space:nowrap;font-size:14px}
th{background:#f8fafc;color:var(--muted);font-weight:700;font-size:13px}
tbody tr:last-child td{border-bottom:0}
tbody tr:hover td{background:var(--brand-soft)}
.table-wrap table{box-shadow:var(--shadow)}

/* Badges & Tags */
.badge,.tag{
  display:inline-block;padding:3px 9px;border-radius:999px;
  font-size:12px;font-weight:800;white-space:nowrap
}
.badge{background:var(--brand-soft);color:var(--brand)}
.badge.ac{background:#e8f7f1;color:var(--ok)}
.badge.wa,.badge.re,.badge.ce{background:#fef2f2;color:var(--danger)}
.badge.pending,.badge.tle{background:#fffbeb;color:#b45309}
.tag{margin:2px;color:var(--muted);background:#f1f5f9}

/* Hero (dashboard) */
.hero{
  position:relative;overflow:hidden;
  display:grid;grid-template-columns:1.4fr 360px;gap:24px;align-items:center;
  padding:36px;margin-bottom:20px;border-radius:20px;
  background:radial-gradient(circle at 16% 12%,rgba(99,102,241,.5),transparent 28%),
             radial-gradient(circle at 88% 82%,rgba(34,197,94,.25),transparent 24%),
             linear-gradient(135deg,#0f172a,#1e293b);
  color:#fff;box-shadow:0 20px 60px rgba(15,23,42,.18)
}
.hero::after{
  content:'';position:absolute;inset:0;
  background-image:linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),
                   linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px);
  background-size:40px 40px;pointer-events:none
}
.hero>*{position:relative;z-index:1}
.hero h2{margin:0;font-size:clamp(26px,3vw,38px);letter-spacing:-.04em}
.hero p{color:rgba(255,255,255,.7);line-height:1.7;font-size:15px}
.hero-actions{display:flex;gap:10px;flex-wrap:wrap}
.dashboard-hero{margin-bottom:16px}
.real-list{display:grid;gap:10px}
.real-list div{padding:14px 16px;border:1px solid rgba(255,255,255,.12);border-radius:var(--radius);background:rgba(255,255,255,.1)}
.real-list span{display:block;margin-top:4px;color:rgba(255,255,255,.6);font-size:13px}

/* Charts */
.chart{height:300px}

/* Modal */
.modal{
  position:fixed;inset:0;z-index:50;
  display:grid;place-items:center;
  background:rgba(15,23,42,.5);backdrop-filter:blur(4px)
}
.modal-card{
  position:relative;display:grid;grid-template-columns:300px 1fr;
  width:min(760px,calc(100vw - 32px));
  overflow:hidden;border-radius:20px;background:var(--panel);
  box-shadow:0 20px 60px rgba(15,23,42,.3)
}
.auth-side{padding:28px;background:linear-gradient(135deg,#0f172a,#1e293b);color:#fff}
.auth-side p{color:rgba(255,255,255,.6);line-height:1.7}
.auth-forms{padding:24px}
.close{position:absolute;right:14px;top:12px;border:0;background:transparent;font-size:26px;cursor:pointer;color:var(--muted)}
.close:hover{color:var(--text)}

/* Tabs */
.tabs{display:flex;gap:8px;margin-bottom:16px}
.tabs button{
  flex:1;padding:10px;border:1px solid var(--line);border-radius:var(--radius-sm);
  background:#fff;font-weight:700;font-size:14px;cursor:pointer;transition:all .15s
}
.tabs button.active{border-color:var(--brand);background:var(--brand-soft);color:var(--brand)}
.tabs button:hover:not(.active){background:#f8fafc}

/* Toast */
.toast{
  position:fixed;right:20px;bottom:20px;z-index:80;
  padding:12px 18px;border-radius:var(--radius-sm);
  background:#1e293b;color:#fff;font-weight:700;font-size:14px;
  box-shadow:0 10px 30px rgba(15,23,42,.2);
  border:1px solid rgba(255,255,255,.1);
  animation:toastIn .2s ease
}
.toast.success{background:var(--ok)}
.toast.error{background:var(--danger)}
.toast.info{background:#1e293b}
@keyframes toastIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}

/* Utilities */
.hidden{display:none!important}
.muted{color:var(--muted)}
.empty{
  padding:32px;border:1px dashed var(--line);border-radius:var(--radius);
  background:#f8fafc;color:var(--muted);text-align:center;
  display:flex;flex-direction:column;align-items:center;gap:6px
}
.empty .empty-icon{font-size:28px;opacity:.4}
.break{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;padding:10px 14px;border-radius:var(--radius-sm);background:#f8fafc}
.mt-16{margin-top:16px}
.link-btn{color:var(--brand);cursor:pointer;background:0 0;border:0;font-weight:600}
.link-btn:hover{text-decoration:underline}

/* Account page */
.account-layout{display:grid;grid-template-columns:1fr 340px;gap:16px;margin-bottom:16px}
.account-main .form{position:relative}
.credential-fieldset{
  overflow:hidden;transition:max-height .3s,opacity .25s;max-height:400px;opacity:1
}
.credential-fieldset.collapsed{max-height:0;opacity:0;pointer-events:none}
.credential-fieldset>*{transition:opacity .2s,transform .25s}
.credential-fieldset.collapsed>*{opacity:0;transform:translateY(-6px)}
.cookie-hint{font-size:13px;color:var(--muted);line-height:1.6;margin-top:6px;padding:10px 12px;background:#f8fafc;border-radius:var(--radius-sm);border:1px solid var(--line)}
.cookie-hint code{padding:2px 5px;border-radius:4px;background:var(--brand-soft);color:var(--brand)}
.notice{padding:12px 14px;border-radius:var(--radius-sm);background:#fffbeb;color:#92400e;line-height:1.6;overflow:hidden;transition:all .3s;max-height:120px;opacity:1}
.notice.collapsed{max-height:0;opacity:0;padding:0;margin:0;pointer-events:none}
.account-help{background:linear-gradient(180deg,#fff,#f8fafc);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.account-help h3{font-size:15px;margin-bottom:12px}
.help-list{margin:0;padding-left:20px;color:var(--muted);line-height:2;font-size:14px}
.help-list code{padding:2px 5px;border-radius:4px;background:var(--brand-soft);color:var(--brand)}

/* Problem rows (new flat layout) */
.problem-tab-pane{animation:fadeIn .2s ease}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.prob-row{
  display:flex;align-items:center;gap:12px;
  padding:12px 16px;border-bottom:1px solid var(--line);
  text-decoration:none;color:inherit;transition:background .12s
}
.prob-row:last-child{border-bottom:0}
.prob-row:hover{background:#f8fafc}
.prob-oj{width:44px;font-weight:800;font-size:11px;color:var(--muted);text-align:center}
.prob-id{width:72px;font-family:monospace;font-size:13px;color:var(--muted)}
.prob-title{flex:1;font-weight:600;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.prob-tags{display:flex;gap:4px;flex:0 0 auto;max-width:200px;overflow:hidden}
.prob-tags .tag-sm{font-size:11px;padding:1px 6px;border-radius:4px;background:var(--brand-soft);color:var(--brand);white-space:nowrap}
.prob-diff{width:52px;text-align:right}

/* Problem card wide */
.problem-card-wide{
  display:grid;grid-template-columns:1fr 300px;gap:0;
  margin-bottom:16px;border:1px solid var(--line);border-radius:var(--radius);
  background:var(--panel);box-shadow:var(--shadow);overflow:hidden;
  transition:box-shadow .25s
}
.problem-card-wide:hover{box-shadow:var(--shadow-lg)}
.problem-body{padding:20px 22px;border-right:1px solid var(--line)}
.problem-header{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:12px}
.problem-header h3{margin:0;font-size:18px;flex:1}
.problem-meta-tags{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:12px}
.problem-statement{color:var(--text);line-height:1.7;font-size:15px;padding:16px 0}
.problem-statement .section-title{margin:20px 0 8px;font-weight:700;font-size:16px}
.problem-statement .title{font-size:22px;font-weight:800;margin-bottom:12px}
.problem-statement .input-specification,.problem-statement .output-specification,.problem-statement .note{margin-top:16px}
.problem-statement .sample-test{margin:12px 0;border:1px solid var(--line);border-radius:10px;overflow:hidden}
.problem-statement .sample-test .input,.problem-statement .sample-test .output{padding:10px 14px}
.problem-statement .sample-test .input-title,.problem-statement .sample-test .output-title{font-weight:700;font-size:13px;margin-bottom:4px;color:var(--muted)}
.problem-statement .sample-test pre{margin:0;white-space:pre-wrap;word-break:break-word;font-family:'Cascadia Code','Fira Code','Consolas',monospace;font-size:13px;background:var(--bg);padding:10px;border-radius:6px}
.problem-statement .sample-test .output pre{background:#f1f5f9}
.problem-statement div[style*="font-family"]{margin-bottom:8px}
.problem-content{border:1px solid var(--line);border-radius:14px;padding:20px;background:var(--bg);overflow-x:auto}
.problem-statement::-webkit-scrollbar{width:4px}
.problem-statement::-webkit-scrollbar-thumb{background:var(--line);border-radius:99px}
.problem-translation{margin-top:10px;padding:12px 14px;border-radius:var(--radius-sm);background:#f0f7ff;border-left:3px solid var(--brand);color:var(--text);line-height:1.7;font-size:14px;white-space:pre-wrap;display:none}
.problem-translation.visible{display:block;animation:translateIn .25s ease}
@keyframes translateIn{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}
.problem-sidebar{padding:20px;background:#fafcff;display:flex;flex-direction:column;gap:12px}
.problem-sidebar .btn{width:100%;min-height:40px;justify-content:center}
.translate-btn{display:inline-flex;align-items:center;gap:6px;padding:5px 12px;border:1px solid var(--brand);border-radius:999px;background:transparent;color:var(--brand);font-size:13px;font-weight:700;cursor:pointer;transition:all .15s}
.translate-btn:hover{background:var(--brand);color:#fff}
.translate-btn.is-active{background:var(--brand);color:#fff}
.translate-pending{color:var(--muted);font-style:italic;font-size:14px}

/* Problem sets */
.sets-page{display:grid;gap:16px}
.set-hero{
  display:flex;justify-content:space-between;align-items:center;gap:18px;
  padding:26px 28px;border:1px solid rgba(99,102,241,.18);border-radius:20px;
  background:radial-gradient(circle at 10% 0%,rgba(99,102,241,.2),transparent 32%),
             linear-gradient(135deg,#fff,#f8fafc);
  box-shadow:var(--shadow)
}
.set-kicker{display:block;margin-bottom:5px;color:var(--brand);font-size:12px;font-weight:900;letter-spacing:.08em;text-transform:uppercase}
.set-hero h2{margin:0;font-size:28px;letter-spacing:-.04em}
.set-hero p{margin:8px 0 0;color:var(--muted);line-height:1.7}
.set-panel{margin-bottom:0}
.set-panel .break h3{margin:0 0 4px}
.set-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:14px}
.set-loading{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.set-card{
  width:100%;padding:18px;border:1px solid var(--line);border-radius:18px;
  background:linear-gradient(180deg,#fff,#fbfdff);box-shadow:var(--shadow);
  color:var(--text);text-align:left;cursor:pointer;transition:transform .16s,box-shadow .16s,border-color .16s
}
.set-card:hover{transform:translateY(-3px);border-color:rgba(99,102,241,.35);box-shadow:var(--shadow-lg)}
.set-card-top{display:flex;align-items:center;gap:12px}
.set-card-top b{display:block;font-size:16px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.set-card-top span:not(.set-card-icon){display:block;margin-top:3px;color:var(--muted);font-size:13px}
.set-card-icon{
  display:grid;place-items:center;width:46px;height:46px;border-radius:15px;
  background:linear-gradient(135deg,var(--brand),#8b5cf6);color:#fff;font-weight:900;
  box-shadow:0 10px 24px rgba(99,102,241,.24)
}
.set-card-meta,.set-card-foot{display:flex;align-items:center;justify-content:space-between;gap:10px}
.set-card-meta{margin-top:18px;color:var(--muted);font-size:13px}
.set-card-meta strong{color:var(--text);font-size:14px}
.set-progress{height:8px;margin-top:10px;overflow:hidden;border-radius:999px;background:#e2e8f0}
.set-progress i{display:block;height:100%;border-radius:999px;background:linear-gradient(90deg,var(--ok),#84cc16)}
.set-card-foot{margin-top:10px;color:var(--muted);font-size:12px;font-weight:700}
.set-card-foot span:last-child{color:var(--brand)}
.set-empty{grid-column:1/-1}
.set-detail-panel{animation:pageIn .22s ease both}
.set-detail-head{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:14px;padding-bottom:14px;border-bottom:1px solid var(--line)}
.set-detail-head h3{margin:0;font-size:20px}
.set-problem-list{display:grid;gap:10px}
.set-problem-row{
  display:flex;align-items:center;gap:12px;padding:13px 14px;
  border:1px solid var(--line);border-radius:14px;background:#fff;box-shadow:var(--shadow);
  transition:border-color .15s,transform .15s,box-shadow .15s
}
.set-problem-row:hover{transform:translateY(-1px);border-color:rgba(99,102,241,.28);box-shadow:var(--shadow-lg)}
.set-problem-index{display:grid;place-items:center;flex:0 0 34px;width:34px;height:34px;border-radius:11px;background:#f1f5f9;color:var(--muted);font-weight:900;font-size:13px}
.set-problem-main{flex:1;min-width:0}
.set-problem-title{display:flex;align-items:center;gap:8px;min-width:0}
.set-problem-title b{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.set-problem-meta{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:6px;color:var(--muted);font-size:13px}
.set-problem-meta code{padding:2px 7px;border-radius:7px;background:#f1f5f9;color:#334155;font-family:'Cascadia Code','Consolas',monospace;font-size:12px}
.badge.ok{background:#e8f7f1;color:var(--ok)}
.btn.small{min-height:32px;padding:0 12px;font-size:13px}

/* Dashboard extras */
.mini-list{display:grid;gap:10px}
.mini-item{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:12px 14px;border:1px solid var(--line);border-radius:14px;background:#fff;color:inherit;text-decoration:none;box-shadow:var(--shadow)}
.mini-item:hover{transform:translateY(-1px);box-shadow:var(--shadow-lg);text-decoration:none}
.mini-item b{display:block;font-size:14px}
.mini-item span{display:block;margin-top:4px;color:var(--muted);font-size:12px;line-height:1.4}
.mini-item>div{min-width:0;flex:1}
.mini-item .set-progress{margin-top:8px}
.mini-item strong{color:var(--brand);font-size:14px}
.cf-cache-mini{padding:14px;border:1px solid rgba(99,102,241,.22);border-radius:14px;background:linear-gradient(135deg,#eef2ff,#fff);box-shadow:var(--shadow)}
.cf-cache-mini b{display:block;font-size:14px}
.cf-cache-mini span{display:block;margin-top:5px;color:var(--muted);font-size:12px;line-height:1.5}
.cf-cache-mini a{display:inline-block;margin-top:8px;font-weight:800;font-size:13px}
.chart-metrics{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}
.chart-metrics span{display:inline-flex;align-items:center;gap:5px;padding:6px 9px;border-radius:999px;background:#f8fafc;color:var(--muted);font-size:12px;font-weight:700}
.chart-metrics b{color:var(--text);font-weight:900}

/* Codeforces contest analysis */
.cf-contest-panel .break h3{margin:0 0 4px}
.cf-contest-summary{display:grid;grid-template-columns:repeat(6,1fr);gap:12px;margin-bottom:16px}
.cf-contest-summary .stat{margin:0}
.cf-phase-note{grid-column:1/-1;padding:12px 14px;border-radius:14px;background:#f8fafc;border:1px solid var(--line);color:var(--muted);font-size:13px;line-height:1.6}
.cf-phase-note span{display:block;margin-top:3px;color:#334155;font-weight:700}
.cf-best-card,.cf-rating-card,.cf-rating-trend{
  padding:16px 18px;border:1px solid rgba(99,102,241,.22);border-radius:var(--radius);
  background:linear-gradient(135deg,#eef2ff,#fff);box-shadow:var(--shadow)
}
.cf-rating-card{grid-column:span 2;background:linear-gradient(135deg,#ecfeff,#fff)}
.cf-rating-trend{background:linear-gradient(135deg,#fff7ed,#fff)}
.cf-best-card span,.cf-rating-card span,.cf-rating-trend span{color:var(--muted);font-size:13px;font-weight:700}
.cf-best-card b,.cf-rating-card b,.cf-rating-trend b{display:block;margin-top:8px;font-size:22px;letter-spacing:-.03em}
.cf-rating-trend b.is-up,.cf-head-score em.is-up{color:#16a34a}
.cf-rating-trend b.is-down,.cf-head-score em.is-down{color:#dc2626}
.cf-best-card p,.cf-rating-card p,.cf-rating-trend p{margin:6px 0 0;color:var(--muted);font-size:13px;line-height:1.5}
.cf-rating-card em{display:block;margin-top:8px;color:#0f766e;font-size:12px;font-style:normal;line-height:1.5}
.cf-index-grid{display:grid;gap:10px}
.cf-index-card{
  display:grid;grid-template-columns:1fr auto;gap:8px 12px;align-items:center;
  padding:12px 14px;border:1px solid var(--line);border-radius:14px;background:#fff;box-shadow:var(--shadow)
}
.cf-index-card b{font-size:18px}
.cf-index-card span{display:block;margin-top:2px;color:var(--muted);font-size:13px}
.cf-index-card strong{color:var(--brand)}
.cf-index-card .set-progress{grid-column:1/-1;margin-top:0}
.cf-contest-list{display:grid;gap:10px;max-height:560px;overflow:auto;padding-right:4px}
.cf-contest-card{padding:14px;border:1px solid var(--line);border-radius:15px;background:#fff;box-shadow:var(--shadow)}
.cf-contest-head{display:flex;justify-content:space-between;gap:12px;align-items:flex-start}
.cf-contest-head b{display:block;font-size:16px}
.cf-contest-head span{display:block;margin-top:3px;color:var(--muted);font-size:12px}
.cf-head-score{display:grid;gap:6px;justify-items:end}
.cf-contest-head strong{padding:5px 10px;border-radius:999px;background:var(--brand-soft);color:var(--brand);font-size:13px}
.cf-head-score em{font-size:18px;font-style:normal;font-weight:900;letter-spacing:-.03em}
.cf-problem-dots{display:flex;gap:6px;flex-wrap:wrap;margin:12px 0}
.cf-phase-bars{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:10px;color:var(--muted);font-size:12px;font-weight:800}
.cf-phase-bars span{padding:7px 9px;border-radius:10px;background:#f8fafc}
.cf-problem-dot{display:grid;place-items:center;min-width:28px;height:28px;padding:0 8px;border-radius:999px;background:#f1f5f9;color:var(--muted);font-size:12px;font-weight:900}
.cf-problem-dot.is-live{background:#dcfce7;color:#15803d}
.cf-problem-dot.is-upsolve{background:#dbeafe;color:#1d4ed8}
.cf-contest-meta{display:grid;gap:4px;color:var(--muted);font-size:12px;line-height:1.5}

/* Loading */
.loading-overlay{display:flex;align-items:center;justify-content:center;gap:10px;padding:40px;color:var(--muted)}
.loading-spinner{width:22px;height:22px;border:3px solid var(--line);border-top-color:var(--brand);border-radius:50%;animation:btnSpin .6s linear infinite}

/* Skeleton */
.skeleton{background:linear-gradient(90deg,#e2e8f0 25%,#f1f5f9 50%,#e2e8f0 75%);background-size:200% 100%;animation:skeletonGlide 1.4s ease infinite;border-radius:6px;height:1em;margin-bottom:6px}
@keyframes skeletonGlide{0%{background-position:200% 0}100%{background-position:-200% 0}}
.skeleton-card{padding:18px;border-radius:var(--radius);background:var(--panel);border:1px solid var(--line);box-shadow:var(--shadow)}
.skeleton-card .skeleton{width:100%}
.skeleton-card .skeleton:nth-child(1){width:55%;height:20px}
.skeleton-card .skeleton:nth-child(2){width:88%;height:13px;margin-top:10px}
.skeleton-card .skeleton:nth-child(3){width:40%;height:13px}

/* Page entrance */
.page.active{animation:pageIn .25s ease both}

/* Responsive */
@media(max-width:980px){
  .layout{flex-direction:column}
  .sidebar{position:relative;width:auto;height:auto;padding:14px}
  .nav{grid-template-columns:repeat(2,1fr)}
  .topbar{flex-direction:column;align-items:flex-start;gap:10px;margin:12px 12px 0}
  .hero,.grid-2,.modal-card,.account-layout{grid-template-columns:1fr}
  .stat-grid{grid-template-columns:repeat(2,1fr)}
  .cards{grid-template-columns:1fr}
  .hero{padding:24px}
  .page{padding:12px}
  .auth-side{display:none}
  .filters .filter-group input,.filters .filter-group select{min-width:100%}
  .prob-tags{display:none}
  .set-hero{flex-direction:column;align-items:flex-start;padding:22px}
  .set-loading{grid-template-columns:1fr}
  .set-detail-head{flex-direction:column;align-items:flex-start}
  .set-problem-row{align-items:flex-start;flex-wrap:wrap}
  .set-problem-row .btn{width:100%}
  .cf-contest-summary{grid-template-columns:1fr}
  .cf-rating-card{grid-column:auto}
  .cf-contest-list{max-height:none}
}