:root {
  --bg: #0f0f13;
  --bg2: #16161d;
  --bg3: #1e1e28;
  --border: rgba(255,255,255,0.08);
  --border2: rgba(255,255,255,0.14);
  --text: #e8e8f0;
  --text2: #9898b0;
  --text3: #5a5a72;
  --accent: #7c6af7;
  --accent2: #a594f9;
  --accent-bg: rgba(124,106,247,0.12);
  --success: #34d399;
  --success-bg: rgba(52,211,153,0.1);
  --warning: #fbbf24;
  --warning-bg: rgba(251,191,36,0.1);
  --danger: #f87171;
  --danger-bg: rgba(248,113,113,0.1);
  --radius: 10px;
  --radius-lg: 16px;
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px;-webkit-font-smoothing:antialiased}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;background:var(--bg);color:var(--text);line-height:1.6;min-height:100vh}
a{color:var(--accent2);text-decoration:none}
a:hover{text-decoration:underline}
button{cursor:pointer;font-family:inherit}
input,select,textarea{font-family:inherit}
pre,code{font-family:'JetBrains Mono','Fira Code',monospace}

/* Layout */
.app{display:flex;min-height:100vh}
.sidebar{width:260px;flex-shrink:0;background:var(--bg2);border-right:0.5px solid var(--border);display:flex;flex-direction:column;position:fixed;height:100vh;overflow-y:auto;z-index:100}
.main{margin-left:260px;flex:1;min-height:100vh}
.page{padding:2rem;max-width:960px}

/* Sidebar */
.sidebar-logo{padding:1.25rem 1.25rem 1rem;border-bottom:0.5px solid var(--border)}
.logo-mark{display:flex;align-items:center;gap:10px}
.logo-icon{width:32px;height:32px;background:var(--accent);border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:16px;color:#fff;font-weight:700}
.logo-text{font-size:15px;font-weight:600;color:var(--text)}
.logo-sub{font-size:11px;color:var(--text3);margin-top:1px}

.sidebar-nav{padding:0.75rem 0;flex:1}
.nav-section{font-size:10px;font-weight:600;text-transform:uppercase;letter-spacing:0.1em;color:var(--text3);padding:0.75rem 1.25rem 0.35rem}
.nav-item{display:flex;align-items:center;gap:10px;padding:0.5rem 1.25rem;font-size:14px;color:var(--text2);transition:all 0.15s;border-left:2px solid transparent;cursor:pointer;text-decoration:none}
.nav-item:hover{color:var(--text);background:var(--bg3);text-decoration:none}
.nav-item.active{color:var(--accent2);background:var(--accent-bg);border-left-color:var(--accent)}
.nav-item .icon{font-size:16px;width:18px;text-align:center}
.nav-badge{margin-left:auto;background:var(--accent);color:#fff;font-size:10px;font-weight:600;padding:1px 6px;border-radius:20px}

.sidebar-user{padding:1rem 1.25rem;border-top:0.5px solid var(--border)}
.user-card{display:flex;align-items:center;gap:10px}
.user-avatar{width:34px;height:34px;border-radius:50%;background:var(--bg3);border:0.5px solid var(--border2);display:flex;align-items:center;justify-content:center;font-size:16px}
.user-name{font-size:13px;font-weight:500;color:var(--text)}
.user-role{font-size:11px;color:var(--text3)}
.logout-btn{margin-left:auto;font-size:12px;color:var(--text3);background:none;border:none;padding:4px 8px;border-radius:6px;transition:all 0.15s}
.logout-btn:hover{color:var(--danger);background:var(--danger-bg)}

/* Cards */
.card{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);padding:1.5rem}
.card-sm{padding:1rem 1.25rem}

/* Stats grid */
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:1.5rem}
.stat-box{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius);padding:1rem 1.25rem}
.stat-label{font-size:12px;color:var(--text3);margin-bottom:4px}
.stat-value{font-size:22px;font-weight:600;color:var(--text)}
.stat-sub{font-size:12px;color:var(--text2);margin-top:2px}

/* Module cards */
.modules-grid{display:flex;flex-direction:column;gap:10px}
.module-card{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);overflow:hidden;transition:border-color 0.15s}
.module-card:hover{border-color:var(--border2)}
.module-header{display:flex;align-items:center;gap:14px;padding:1rem 1.25rem;cursor:pointer}
.mod-num{width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:600;flex-shrink:0}
.mod-info{flex:1;min-width:0}
.mod-title{font-size:15px;font-weight:500;color:var(--text);line-height:1.3}
.mod-meta{font-size:12px;color:var(--text3);margin-top:2px}
.mod-right{display:flex;align-items:center;gap:8px;flex-shrink:0}
.diff-pill{font-size:11px;padding:3px 9px;border-radius:20px;font-weight:500}
.diff-beginner{background:#1a3320;color:#34d399}
.diff-intermediate{background:#332510;color:#fbbf24}
.diff-advanced{background:#331515;color:#f87171}
.prog-bar-wrap{width:80px;height:4px;background:var(--bg3);border-radius:2px;overflow:hidden}
.prog-bar-fill{height:100%;background:var(--accent);border-radius:2px;transition:width 0.3s}
.chevron{color:var(--text3);transition:transform 0.2s;font-size:14px}
.chevron.open{transform:rotate(180deg)}

.module-body{border-top:0.5px solid var(--border);padding:1rem 1.25rem}
.lesson-list{list-style:none}
.lesson-row{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:8px;transition:background 0.15s;cursor:pointer}
.lesson-row:hover{background:var(--bg3)}
.lesson-row.done .lesson-title{color:var(--text2)}
.check-circle{width:20px;height:20px;border-radius:50%;border:1.5px solid var(--border2);display:flex;align-items:center;justify-content:center;font-size:11px;flex-shrink:0;transition:all 0.2s}
.check-circle.done{background:var(--success-bg);border-color:var(--success);color:var(--success)}
.lesson-title{font-size:13px;color:var(--text);flex:1}
.lesson-type-tag{font-size:10px;color:var(--text3);background:var(--bg3);padding:2px 7px;border-radius:20px}
.take-test-btn{display:flex;align-items:center;gap:8px;margin-top:12px;padding:9px 16px;background:var(--accent-bg);color:var(--accent2);border:0.5px solid var(--accent);border-radius:8px;font-size:13px;font-weight:500;text-decoration:none;transition:all 0.15s;width:fit-content}
.take-test-btn:hover{background:var(--accent);color:#fff;text-decoration:none}
.take-test-btn.passed{background:var(--success-bg);color:var(--success);border-color:var(--success)}
.take-test-btn.passed:hover{background:var(--success-bg)}

/* Buttons */
.btn{display:inline-flex;align-items:center;gap:8px;padding:9px 18px;border-radius:8px;font-size:14px;font-weight:500;border:none;transition:all 0.15s;cursor:pointer;text-decoration:none}
.btn:hover{text-decoration:none}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:#6b59e8;color:#fff}
.btn-ghost{background:transparent;color:var(--text2);border:0.5px solid var(--border2)}
.btn-ghost:hover{background:var(--bg3);color:var(--text)}
.btn-success{background:var(--success-bg);color:var(--success);border:0.5px solid var(--success)}
.btn-danger{background:var(--danger-bg);color:var(--danger);border:0.5px solid var(--danger)}
.btn-sm{padding:6px 12px;font-size:13px}
.btn-lg{padding:12px 24px;font-size:16px}

/* Quiz */
.quiz-wrap{max-width:680px}
.quiz-progress{display:flex;gap:6px;margin-bottom:1.5rem;flex-wrap:wrap}
.quiz-dot{width:28px;height:6px;border-radius:3px;background:var(--bg3)}
.quiz-dot.answered{background:var(--accent)}
.quiz-dot.current{background:var(--accent2);animation:pulse 1s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:0.5}}

.question-card{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);padding:1.5rem;margin-bottom:1rem}
.q-num{font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:0.08em;color:var(--text3);margin-bottom:8px}
.q-text{font-size:17px;font-weight:500;color:var(--text);line-height:1.5;margin-bottom:1.25rem}
.options-list{display:flex;flex-direction:column;gap:8px}
.option-btn{display:flex;align-items:center;gap:12px;padding:12px 14px;border:0.5px solid var(--border2);border-radius:10px;background:var(--bg3);color:var(--text);font-size:14px;text-align:left;transition:all 0.15s;cursor:pointer;width:100%}
.option-btn:hover:not(:disabled){border-color:var(--accent);background:var(--accent-bg)}
.option-btn.selected{border-color:var(--accent);background:var(--accent-bg);color:var(--accent2)}
.option-btn.correct{border-color:var(--success);background:var(--success-bg);color:var(--success)}
.option-btn.wrong{border-color:var(--danger);background:var(--danger-bg);color:var(--danger)}
.opt-letter{width:26px;height:26px;border-radius:6px;background:var(--bg);display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:600;flex-shrink:0}
.explanation-box{background:var(--bg3);border-left:3px solid var(--accent);border-radius:0 8px 8px 0;padding:10px 14px;margin-top:10px;font-size:13px;color:var(--text2);line-height:1.5}

.quiz-nav{display:flex;align-items:center;justify-content:space-between;margin-top:1rem}
.q-counter{font-size:13px;color:var(--text3)}

/* Results */
.result-card{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);padding:2rem;text-align:center;max-width:500px;margin:0 auto}
.score-ring{width:120px;height:120px;margin:0 auto 1.25rem;position:relative}
.score-ring svg{transform:rotate(-90deg)}
.score-big{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.score-pct{font-size:28px;font-weight:700;color:var(--text)}
.score-label{font-size:11px;color:var(--text3)}
.result-title{font-size:20px;font-weight:600;margin-bottom:6px}
.result-sub{font-size:14px;color:var(--text2);margin-bottom:1.5rem}
.cert-box{background:var(--accent-bg);border:0.5px solid var(--accent);border-radius:10px;padding:12px 16px;margin-bottom:1.5rem;display:flex;align-items:center;gap:10px;text-align:left}
.cert-box .cert-icon{font-size:24px}
.cert-code{font-size:11px;color:var(--accent2);font-family:monospace;margin-top:2px}

/* Lesson viewer */
.lesson-viewer{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);overflow:hidden}
.lesson-topbar{display:flex;align-items:center;justify-content:space-between;padding:1rem 1.5rem;border-bottom:0.5px solid var(--border)}
.lesson-content{padding:2rem;max-width:720px}
.lesson-content h2{font-size:20px;font-weight:600;margin:1.5rem 0 0.75rem;color:var(--text)}
.lesson-content h3{font-size:16px;font-weight:500;margin:1.25rem 0 0.5rem;color:var(--text2)}
.lesson-content p{font-size:15px;color:var(--text2);line-height:1.75;margin-bottom:1rem}
.lesson-content ul{padding-left:1.25rem;margin-bottom:1rem}
.lesson-content li{font-size:14px;color:var(--text2);margin-bottom:6px;line-height:1.6}
.lesson-content pre{background:var(--bg);border:0.5px solid var(--border2);border-radius:10px;padding:1.25rem;overflow-x:auto;margin-bottom:1rem}
.lesson-content code{font-size:13px;color:#c084fc;font-family:'JetBrains Mono','Fira Code',monospace;line-height:1.6}
.lesson-content pre code{color:#e2e8f0}
.lesson-footer{border-top:0.5px solid var(--border);padding:1rem 1.5rem;display:flex;align-items:center;justify-content:space-between}

/* Auth pages */
.auth-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:2rem;background:var(--bg)}
.auth-card{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);padding:2rem;width:100%;max-width:400px}
.auth-logo{text-align:center;margin-bottom:1.75rem}
.auth-title{font-size:20px;font-weight:600;color:var(--text);margin-bottom:4px}
.auth-sub{font-size:14px;color:var(--text3)}
.form-group{margin-bottom:1rem}
.form-label{display:block;font-size:13px;font-weight:500;color:var(--text2);margin-bottom:6px}
.form-input{width:100%;padding:10px 12px;background:var(--bg3);border:0.5px solid var(--border2);border-radius:8px;color:var(--text);font-size:14px;transition:border-color 0.15s;outline:none}
.form-input:focus{border-color:var(--accent)}
.form-input::placeholder{color:var(--text3)}
.form-error{background:var(--danger-bg);border:0.5px solid var(--danger);color:var(--danger);padding:10px 12px;border-radius:8px;font-size:13px;margin-bottom:1rem}
.form-success{background:var(--success-bg);border:0.5px solid var(--success);color:var(--success);padding:10px 12px;border-radius:8px;font-size:13px;margin-bottom:1rem}

/* Page headers */
.page-header{margin-bottom:1.5rem}
.page-title{font-size:22px;font-weight:600;color:var(--text)}
.page-sub{font-size:14px;color:var(--text3);margin-top:4px}
.breadcrumb{font-size:12px;color:var(--text3);margin-bottom:0.5rem}
.breadcrumb a{color:var(--text3)}
.breadcrumb a:hover{color:var(--text2)}

/* Badges */
.badge{display:inline-flex;align-items:center;gap:4px;padding:3px 8px;border-radius:20px;font-size:11px;font-weight:500}
.badge-purple{background:var(--accent-bg);color:var(--accent2)}
.badge-green{background:var(--success-bg);color:var(--success)}
.badge-amber{background:var(--warning-bg);color:var(--warning)}
.badge-red{background:var(--danger-bg);color:var(--danger)}

/* Admin table */
.data-table{width:100%;border-collapse:collapse}
.data-table th{font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:0.07em;color:var(--text3);padding:8px 12px;border-bottom:0.5px solid var(--border);text-align:left}
.data-table td{padding:10px 12px;border-bottom:0.5px solid var(--border);font-size:14px;color:var(--text2)}
.data-table tr:hover td{background:var(--bg3)}

/* Responsive */
@media(max-width:768px){
  .sidebar{width:100%;height:auto;position:relative}
  .main{margin-left:0}
  .stats-grid{grid-template-columns:repeat(2,1fr)}
  .page{padding:1rem}
}

/* Scrollbar */
::-webkit-scrollbar{width:6px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border2);border-radius:3px}

/* Tests */
.tests-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px;margin-top:0.5rem}
.test-card{background:var(--bg2);border:0.5px solid var(--border);border-radius:var(--radius-lg);padding:1.25rem;display:flex;flex-direction:column;gap:1rem;transition:border-color 0.15s}
.test-card:hover{border-color:var(--border2)}
.test-card.test-passed{border-color:rgba(52,211,153,0.3)}
.test-card-top{display:flex;gap:14px;align-items:flex-start}
.test-num{width:36px;height:36px;border-radius:10px;background:var(--accent-bg);color:var(--accent2);border:0.5px solid var(--accent);display:flex;align-items:center;justify-content:center;font-size:14px;font-weight:700;flex-shrink:0}
.test-passed .test-num{background:var(--success-bg);color:var(--success);border-color:var(--success)}
.test-card-info{flex:1;min-width:0}
.test-card-title{font-size:15px;font-weight:600;color:var(--text);line-height:1.3;margin-bottom:4px}
.test-card-desc{font-size:12px;color:var(--text3);line-height:1.5}
.test-card-footer{display:flex;align-items:center;justify-content:space-between;gap:8px;flex-wrap:wrap;padding-top:0.75rem;border-top:0.5px solid var(--border)}
.test-meta-row{display:flex;gap:6px;flex-wrap:wrap}