:root{--color-primary: #175DDC;--color-primary-dark: #0f45a8;--color-primary-light:#63A2FD;--color-bg: #F3F6F9;--color-surface: #FFFFFF;--color-text: #282A31;--color-text-heading: #020F66;--color-text-muted: #6B7280;--color-success: #57C86B;--color-warning: #F59E0B;--color-error: #E5544A;--radius-sm: 6px;--radius-md: 12px;--radius-lg: 20px;--shadow-card: 0 2px 12px rgba(23, 93, 220, .08);--shadow-btn: 0 2px 8px rgba(23, 93, 220, .25);--font-base: system-ui, "Segoe UI", Roboto, "SF Pro Text", sans-serif}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-base);background:var(--color-bg);color:var(--color-text);font-size:16px;line-height:1.6;min-height:100vh}.app-container{max-width:860px;margin:0 auto;padding:0 20px 60px}.navbar{background:var(--color-surface);border-bottom:2px solid var(--color-primary);padding:14px 20px;display:flex;align-items:center;gap:14px;margin-bottom:32px;position:sticky;top:0;z-index:100;box-shadow:0 2px 8px #0000000f}.navbar-logo{width:32px;height:32px;background:var(--color-primary);border-radius:8px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:900;font-size:18px}.navbar-title{font-size:18px;font-weight:700;color:var(--color-text-heading)}.navbar-home-btn{margin-left:auto;background:none;border:none;color:var(--color-primary);font-size:14px;font-weight:600;cursor:pointer;padding:6px 12px;border-radius:var(--radius-sm);transition:background .15s}.navbar-home-btn:hover{background:#eef3fc}.card{background:var(--color-surface);border-radius:var(--radius-md);box-shadow:var(--shadow-card);padding:24px;margin-bottom:20px}.btn-primary{display:inline-flex;align-items:center;gap:8px;background:var(--color-primary);color:#fff;border:none;border-radius:var(--radius-sm);padding:12px 24px;font-size:15px;font-weight:600;cursor:pointer;box-shadow:var(--shadow-btn);transition:background .15s,transform .1s;text-decoration:none}.btn-primary:hover{background:var(--color-primary-dark)}.btn-primary:active{transform:scale(.98)}.btn-secondary{display:inline-flex;align-items:center;gap:8px;background:transparent;color:var(--color-primary);border:2px solid var(--color-primary);border-radius:var(--radius-sm);padding:10px 22px;font-size:15px;font-weight:600;cursor:pointer;transition:background .15s;text-decoration:none}.btn-secondary:hover{background:#eef3fc}.alert{display:flex;gap:12px;align-items:flex-start;border-radius:var(--radius-sm);padding:14px 16px;font-size:14px;margin-bottom:16px}.alert-icon{font-size:20px;flex-shrink:0}.alert-success{background:#edfbf0;border-left:4px solid var(--color-success)}.alert-warning{background:#fffbeb;border-left:4px solid var(--color-warning)}.alert-error{background:#fef2f1;border-left:4px solid var(--color-error)}.alert-info{background:#eef5ff;border-left:4px solid var(--color-primary-light)}.step-list{list-style:none;display:flex;flex-direction:column;gap:16px}.step-item{display:flex;gap:16px;align-items:flex-start;background:var(--color-surface);border-radius:var(--radius-md);padding:18px;box-shadow:var(--shadow-card)}.step-number{width:36px;height:36px;min-width:36px;border-radius:50%;background:var(--color-primary);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:16px}.step-content h4{font-size:16px;color:var(--color-text-heading);margin-bottom:4px}.step-content p{font-size:14px;color:var(--color-text)}.step-content a{color:var(--color-primary);font-weight:600}.module-header{text-align:center;margin-bottom:32px}.module-header .module-icon{font-size:48px;display:block;margin-bottom:12px}.module-header h1{font-size:26px;color:var(--color-text-heading);margin-bottom:8px}.module-header p{font-size:16px;color:var(--color-text-muted);max-width:520px;margin:0 auto}.module-footer{display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;align-items:center;margin-top:36px;padding-top:24px;border-top:1px solid #E5EAF2}.menu-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:28px}@media (max-width: 600px){.menu-grid{grid-template-columns:1fr}}.menu-card{background:var(--color-surface);border-radius:var(--radius-md);box-shadow:var(--shadow-card);padding:28px 22px;cursor:pointer;transition:transform .15s,box-shadow .15s;border:2px solid transparent;text-align:left}.menu-card:hover{transform:translateY(-3px);box-shadow:0 6px 20px #175ddc24;border-color:var(--color-primary)}.menu-card .card-icon{font-size:36px;margin-bottom:12px;display:block}.menu-card h2{font-size:17px;color:var(--color-text-heading);margin-bottom:6px}.menu-card p{font-size:13px;color:var(--color-text-muted);line-height:1.5}.menu-card .card-tag{display:inline-block;margin-top:10px;font-size:11px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--color-primary);background:#eef3fc;padding:3px 8px;border-radius:4px}.platform-choice{display:flex;gap:16px;margin:24px 0;flex-wrap:wrap}.platform-btn{flex:1;min-width:160px;padding:20px;border:2px solid #D1D9E8;border-radius:var(--radius-md);background:var(--color-surface);cursor:pointer;text-align:center;transition:border-color .15s,background .15s;font-size:16px;font-weight:600;color:var(--color-text)}.platform-btn:hover,.platform-btn.active{border-color:var(--color-primary);background:#eef3fc;color:var(--color-primary)}.platform-btn .platform-icon{font-size:32px;display:block;margin-bottom:8px}.diagram-container{position:relative;background:#f8fafd;border:1.5px solid #D1D9E8;border-radius:var(--radius-lg);padding:32px;min-height:260px;display:flex;align-items:center;justify-content:center;margin:24px 0;overflow:hidden}.diagram-center{position:relative;z-index:2;background:var(--color-primary);color:#fff;border-radius:50%;width:110px;height:110px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;font-weight:700;font-size:13px;box-shadow:0 4px 16px #175ddc4d;cursor:default}.diagram-center .diagram-center-icon{font-size:28px;margin-bottom:4px}.diagram-nodes{position:absolute;top:0;right:0;bottom:0;left:0;display:flex;align-items:center;justify-content:center}.diagram-node{position:absolute;width:84px;height:84px;border-radius:50%;background:var(--color-surface);border:2px solid var(--color-primary);display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:11px;font-weight:600;color:var(--color-text-heading);cursor:pointer;transition:background .15s,transform .15s;box-shadow:var(--shadow-card);text-align:center}.diagram-node:hover,.diagram-node.active{background:#eef3fc;transform:scale(1.08)}.diagram-node .node-icon{font-size:24px;margin-bottom:2px}.diagram-node:nth-child(1){top:18px;left:50%;transform:translate(-50%)}.diagram-node:nth-child(2){bottom:18px;left:50%;transform:translate(-50%)}.diagram-node:nth-child(3){left:24px;top:50%;transform:translateY(-50%)}.diagram-node:nth-child(4){right:24px;top:50%;transform:translateY(-50%)}.diagram-node:nth-child(1):hover,.diagram-node:nth-child(1).active{transform:translate(-50%) scale(1.08)}.diagram-node:nth-child(2):hover,.diagram-node:nth-child(2).active{transform:translate(-50%) scale(1.08)}.diagram-node:nth-child(3):hover,.diagram-node:nth-child(3).active{transform:translateY(-50%) scale(1.08)}.diagram-node:nth-child(4):hover,.diagram-node:nth-child(4).active{transform:translateY(-50%) scale(1.08)}.diagram-info{background:var(--color-surface);border-left:4px solid var(--color-primary);border-radius:var(--radius-sm);padding:14px 16px;font-size:14px;color:var(--color-text);margin-top:12px;min-height:56px;transition:all .2s}.before-after{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:20px 0}@media (max-width: 540px){.before-after{grid-template-columns:1fr}}.before-card,.after-card{border-radius:var(--radius-md);padding:20px}.before-card{background:#fef2f1;border:1.5px solid #FECACA}.after-card{background:#edfbf0;border:1.5px solid #A7F3D0}.before-card h3{color:var(--color-error);margin-bottom:10px;font-size:15px}.after-card h3{color:#166534;margin-bottom:10px;font-size:15px}.before-card ul,.after-card ul{padding-left:18px;font-size:14px}.before-card li,.after-card li{margin-bottom:5px}.quiz-card{background:#f8fafd;border:1.5px solid #D1D9E8;border-radius:var(--radius-md);padding:24px;margin-top:24px}.quiz-card h3{font-size:17px;color:var(--color-text-heading);margin-bottom:16px}.quiz-question{margin-bottom:24px}.quiz-question p{font-size:15px;font-weight:600;margin-bottom:10px}.quiz-options{display:flex;flex-direction:column;gap:8px}.quiz-option{background:var(--color-surface);border:2px solid #D1D9E8;border-radius:var(--radius-sm);padding:10px 16px;cursor:pointer;font-size:14px;transition:border-color .15s,background .15s;text-align:left}.quiz-option:hover{border-color:var(--color-primary);background:#eef3fc}.quiz-option.correct{border-color:var(--color-success);background:#edfbf0;color:#166534}.quiz-option.wrong{border-color:var(--color-error);background:#fef2f1;color:#7f1d1d}.quiz-result{margin-top:16px;padding:12px 16px;border-radius:var(--radius-sm);font-size:15px;font-weight:600;text-align:center}.quiz-result.success{background:#edfbf0;color:#166534}.quiz-result.retry{background:#fffbeb;color:#92400e}.quiz-question-card{display:flex;flex-direction:column;gap:0}.quiz-progress{font-size:12px;font-weight:600;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.05em;margin-bottom:10px}.quiz-question-text{font-size:15px;font-weight:600;color:var(--color-text-heading);margin-bottom:14px;line-height:1.5}.quiz-option.selected{border-color:var(--color-primary);background:#eef3fc;color:var(--color-primary);font-weight:600}.quiz-option:disabled{cursor:default}.quiz-option:disabled:hover{border-color:inherit;background:inherit}.quiz-option.correct:disabled:hover{border-color:var(--color-success);background:#edfbf0}.quiz-option.wrong:disabled:hover{border-color:var(--color-error);background:#fef2f1}.quiz-feedback{display:flex;align-items:flex-start;gap:10px;margin-top:14px;padding:12px 16px;border-radius:var(--radius-sm);font-size:14px;line-height:1.5}.quiz-feedback.feedback-correct{background:#edfbf0;color:#166534;border:1.5px solid var(--color-success)}.quiz-feedback.feedback-wrong{background:#fef2f1;color:#7f1d1d;border:1.5px solid var(--color-error)}.feedback-icon{font-size:18px;flex-shrink:0;margin-top:1px}.timeline{display:flex;flex-direction:column;gap:0;position:relative;margin:20px 0}.timeline:before{content:"";position:absolute;left:22px;top:0;bottom:0;width:2px;background:#d1d9e8}.timeline-item{display:flex;gap:16px;align-items:flex-start;position:relative;padding-bottom:20px}.timeline-dot{width:44px;height:44px;min-width:44px;border-radius:50%;background:var(--color-primary);color:#fff;display:flex;align-items:center;justify-content:center;font-size:20px;z-index:1;box-shadow:0 2px 8px #175ddc33}.timeline-body{padding-top:8px}.timeline-body h4{font-size:15px;color:var(--color-text-heading);margin-bottom:4px}.timeline-body p{font-size:13px;color:var(--color-text-muted)}@media (max-width: 480px){.module-header h1{font-size:21px}.card{padding:18px}.module-footer{flex-direction:column}}