:root{--ink:#172033;--muted:#718096;--line:#e8ebf2;--bg:#f7f8fc;--white:#fff;--purple:#6656e8;--purple-dark:#5143c9;--green:#20a478;--red:#df5d68;--yellow:#e9a23b;--shadow:0 15px 40px rgba(35,35,70,.08)}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:'DM Sans',Arial,sans-serif;font-size:14px}h1,h2,h3,h4{font-family:'Space Grotesk',sans-serif;margin:0 0 10px;letter-spacing:-.025em}h1{font-size:30px}h2{font-size:22px}h3{font-size:17px}p{color:var(--muted);line-height:1.65}.app-layout{display:flex;min-height:100vh}.sidebar{width:245px;background:#fff;border-right:1px solid var(--line);padding:25px 16px;display:flex;flex-direction:column;flex-shrink:0}.brand{display:flex;align-items:center;gap:11px;color:var(--ink);font:700 18px 'Space Grotesk';text-decoration:none;padding:0 12px 30px}.brand small{display:block;font:400 10px 'DM Sans';color:#9ba3b4;letter-spacing:.05em;text-transform:uppercase;margin-top:3px}.brand-mark{display:inline-flex;align-items:center;justify-content:center;width:35px;height:35px;border-radius:11px;background:linear-gradient(135deg,#796aff,#5344d2);color:#fff;font-size:25px;box-shadow:0 6px 12px #6656e833}.sidebar-user{display:flex;align-items:center;gap:10px;margin:0 5px 25px;padding:12px;background:#f8f8fe;border-radius:12px}.avatar{display:flex;align-items:center;justify-content:center;flex:none;width:32px;height:32px;border-radius:10px;background:#ddd9ff;color:var(--purple-dark);font-weight:700}.sidebar-user strong{display:block;font-size:12px;white-space:nowrap;max-width:140px;overflow:hidden;text-overflow:ellipsis}.sidebar-user small{font-size:11px;color:var(--muted)}nav{display:grid;gap:5px}.nav-link{display:flex;align-items:center;gap:13px;color:#737d91;text-decoration:none;border-radius:10px;padding:12px 13px;font-weight:600;transition:.2s}.nav-link span{width:18px;text-align:center;font-size:17px}.nav-link:hover,.nav-link.active{background:#efedff;color:var(--purple-dark)}.logout{margin-top:auto}.main-content{flex:1;min-width:0}.topbar{height:70px;background:#fff;border-bottom:1px solid var(--line);display:flex;justify-content:flex-end;align-items:center;padding:0 40px;color:#8991a1;font-size:12px;gap:9px}.mobile-brand{display:none}.status-dot{width:7px;height:7px;background:#2dc48a;border-radius:100%}.topbar-divider{height:17px;border-left:1px solid var(--line);margin:0 8px}.page-content{max-width:1260px;margin:auto;padding:38px 42px}.page-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;margin-bottom:28px}.eyebrow{font-size:11px;color:var(--purple);font-weight:700;text-transform:uppercase;letter-spacing:.1em;margin-bottom:8px}.page-heading p{margin:0}.button{border:0;border-radius:9px;background:var(--purple);color:white;text-decoration:none;padding:11px 17px;font:600 13px 'DM Sans';cursor:pointer;display:inline-flex;gap:8px;align-items:center;justify-content:center}.button:hover{background:var(--purple-dark)}.button.secondary{background:#eeecff;color:var(--purple-dark)}.button.light{background:#f3f4f8;color:#606a7c}.button.danger{background:#fff0f1;color:#cf4c58}.button.small{padding:8px 11px;font-size:12px}.button.full{width:100%}.cards{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-bottom:25px}.stat-card,.panel,.exam-card{background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}.stat-card{padding:19px}.stat-card .label{color:var(--muted);font-size:12px}.stat-card .number{font:700 27px 'Space Grotesk';margin:7px 0 3px}.stat-card .detail{font-size:11px;color:var(--green)}.grid-2{display:grid;grid-template-columns:1.45fr 1fr;gap:20px}.panel{padding:22px;margin-bottom:20px}.panel-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:18px}.panel-heading h2,.panel-heading h3{margin:0}.muted{color:var(--muted)}.table-wrap{overflow:auto}.data-table{width:100%;border-collapse:collapse}.data-table th{text-align:left;color:#9aa1b1;font-size:10px;text-transform:uppercase;letter-spacing:.08em;padding:11px 10px;border-bottom:1px solid var(--line);white-space:nowrap}.data-table td{padding:14px 10px;border-bottom:1px solid #f0f1f5;vertical-align:middle}.data-table tr:last-child td{border:0}.badge{display:inline-flex;border-radius:99px;padding:5px 9px;font-size:11px;font-weight:700}.badge.green{background:#e6f8f1;color:#16815e}.badge.gray{background:#f0f1f5;color:#777f8e}.badge.orange{background:#fff4df;color:#b27720}.badge.red{background:#ffeaec;color:#c64a56}.exam-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.exam-card{padding:20px;display:flex;flex-direction:column;min-height:190px}.exam-card .card-icon{width:39px;height:39px;border-radius:12px;background:#efedff;color:var(--purple);display:flex;align-items:center;justify-content:center;font-size:20px;margin-bottom:15px}.exam-card h3{margin-bottom:8px}.exam-card p{font-size:12px;margin:0 0 17px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.exam-meta{display:flex;gap:14px;color:#9ba2b0;font-size:11px;margin-top:auto}.exam-card .card-action{margin-top:15px}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.form-group{margin-bottom:17px}.form-group.full{grid-column:1/-1}.form-label{display:block;font-weight:700;font-size:12px;margin-bottom:7px}.input,.textarea,.select{width:100%;border:1px solid #dfe3ed;border-radius:8px;background:#fff;padding:11px 12px;font:inherit;color:var(--ink);outline:none;transition:.2s}.textarea{resize:vertical;min-height:110px}.input:focus,.textarea:focus,.select:focus{border-color:var(--purple);box-shadow:0 0 0 3px #6656e814}.help{font-size:11px;color:#9299a8;margin-top:5px}.form-actions{display:flex;justify-content:flex-end;gap:9px;border-top:1px solid var(--line);padding-top:18px;margin-top:5px}.alert{padding:13px 17px;border-radius:9px;margin-bottom:18px;display:flex;gap:10px;align-items:center;font-size:13px}.alert-success{background:#e7f8f1;color:#197b5b}.alert-error{background:#ffebed;color:#bf4854}.alert-info{background:#eeecff;color:#5546c8}.login-page{min-height:100vh;display:grid;grid-template-columns:1.1fr 1fr;background:#fff}.login-side{padding:65px 10%;background:linear-gradient(145deg,#211b53,#584ad6);color:#fff;position:relative;overflow:hidden}.login-side:after{content:'';position:absolute;width:430px;height:430px;border:1px solid #ffffff29;border-radius:50%;right:-180px;bottom:-150px;box-shadow:0 0 0 40px #ffffff08,0 0 0 80px #ffffff05}.login-side h1{font-size:45px;max-width:460px;margin-top:100px}.login-side p{color:#d6d2ff;max-width:390px}.feature-list{list-style:none;padding:0;margin-top:42px;display:grid;gap:14px}.feature-list li{display:flex;gap:10px;align-items:center;color:#dedbff}.feature-list b{color:#8ef0c8;font-size:18px}.login-form-side{display:flex;align-items:center;justify-content:center;padding:30px}.login-box{width:100%;max-width:380px}.login-box .brand{padding:0;margin-bottom:45px}.login-box h2{font-size:27px}.login-box > p{font-size:13px;margin-bottom:28px}.password-wrap{position:relative}.password-wrap .input{padding-right:45px}.show-password{position:absolute;right:11px;top:11px;border:0;background:none;color:#9aa1b1;cursor:pointer}.editor-layout{display:grid;grid-template-columns:1fr 1.15fr;gap:20px;align-items:start}.question-box{background:#fff;border:1px solid var(--line);border-radius:14px;padding:24px;box-shadow:var(--shadow);position:sticky;top:20px}.question-box .question-text{font-size:15px;line-height:1.7;white-space:pre-wrap}.code-box{background:#1f2432;border-radius:13px;overflow:hidden;box-shadow:var(--shadow)}.code-toolbar{height:48px;display:flex;align-items:center;justify-content:space-between;padding:0 14px;color:#abb4c8;font-size:11px}.code-dots{display:flex;gap:5px}.code-dots i{width:8px;height:8px;border-radius:50%;background:#ef6b73}.code-dots i:nth-child(2){background:#f4bd4e}.code-dots i:nth-child(3){background:#54cf89}.code-editor{width:100%;min-height:390px;border:0;resize:vertical;padding:17px 19px;background:#292e3e;color:#e6e9f4;outline:none;font:13px/1.65 'SFMono-Regular',Consolas,monospace}.test-result{margin-top:15px;background:#fff;border:1px solid var(--line);border-radius:13px;padding:18px}.result-row{display:flex;justify-content:space-between;gap:15px;border-bottom:1px solid #f0f1f5;padding:10px 0;font-size:12px}.result-row:last-child{border:0}.result-pass{color:var(--green);font-weight:700}.result-fail{color:var(--red);font-weight:700}.score-big{font:700 44px 'Space Grotesk';color:var(--purple)}.progress{height:7px;background:#edeef4;border-radius:10px;overflow:hidden}.progress span{display:block;height:100%;background:linear-gradient(90deg,var(--purple),#9c82ff);border-radius:10px}.empty{text-align:center;padding:35px 20px;color:var(--muted)}.empty strong{display:block;color:var(--ink);margin-bottom:5px}.error-page{min-height:100vh;display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;padding:25px}.error-page .brand-mark{margin-bottom:15px}.error-page h1{margin-bottom:5px}.error-page p{max-width:400px}.import-note{background:#f5f3ff;border-left:3px solid var(--purple);padding:14px 16px;font-size:12px;color:#605b9c;line-height:1.6}.question-editor{border:1px solid var(--line);border-radius:12px;padding:18px;margin-bottom:15px;background:#fcfcfe}.case-row{display:grid;grid-template-columns:1fr 1fr;gap:10px}.mobile-only{display:none}@media(max-width:1000px){.sidebar{width:210px}.page-content{padding:28px}.cards{grid-template-columns:repeat(2,1fr)}.exam-grid{grid-template-columns:repeat(2,1fr)}.editor-layout{grid-template-columns:1fr}.question-box{position:static}}@media(max-width:700px){.sidebar{display:none}.topbar{height:58px;padding:0 18px;justify-content:space-between}.mobile-brand{display:flex;align-items:center;gap:7px;font-weight:700;font-family:'Space Grotesk'}.mobile-brand .brand-mark{width:28px;height:28px;font-size:19px}.topbar-right{font-size:0}.topbar-right .status-dot{display:inline-block}.topbar-right span:last-child,.topbar-divider{display:none}.page-content{padding:22px 16px}.page-heading{display:block;margin-bottom:20px}.page-heading .button{margin-top:15px}.cards,.exam-grid,.grid-2,.form-grid{grid-template-columns:1fr}.login-page{display:block}.login-side{padding:28px 25px 35px}.login-side h1{font-size:31px;margin-top:45px}.feature-list{display:none}.login-form-side{padding:40px 25px}.login-box .brand{margin-bottom:30px}.case-row{grid-template-columns:1fr}.code-editor{min-height:300px}.data-table{min-width:620px}}
.sample-input{margin:0;padding:10px 12px;background:#f8f8fe;border-radius:10px;color:var(--ink);font:12px/1.6 'SFMono-Regular',Consolas,monospace;white-space:pre-wrap;word-break:break-word}
.stdin-panel{border-top:1px solid #394054;padding:12px 14px 14px}
.stdin-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:6px}
.stdin-label{color:#c8cde0;font:600 12px 'Space Grotesk',sans-serif}
.stdin-hint{color:#8a91aa;font-size:11px;line-height:1.5}
.stdin-input{display:block;width:100%;min-height:52px;resize:vertical;border:1px solid #3d4459;border-radius:10px;background:#232838;color:#e6e9f4;padding:9px 12px;outline:none;font:12px/1.6 'SFMono-Regular',Consolas,monospace}
.stdin-input::placeholder{color:#78809a}
.stdin-input:focus{border-color:#796aff;box-shadow:0 0 0 3px rgba(121,106,255,.18)}