:root{--primary:#173f74;--primary2:#0f2f58;--accent:#f5b942;--bg:#f5f8fc;--surface:#fff;--text:#14213a;--muted:#60708a;--border:#dbe4ef;--success:#166534;--danger:#991b1b;--radius:18px;--shadow:0 14px 40px rgba(20,33,58,.08)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;background:var(--bg);color:var(--text);line-height:1.6}a{color:var(--primary)}button,input,textarea{font:inherit}.container{width:min(1140px,calc(100% - 36px));margin:auto}.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.96);border-bottom:1px solid var(--border);backdrop-filter:blur(12px)}.nav{height:72px;display:flex;align-items:center;gap:24px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:900;color:var(--primary);font-size:1.05rem}.brand-mark{display:grid;place-items:center;width:36px;height:36px;border-radius:11px;background:var(--primary);color:#fff}.nav-links{margin-left:auto;display:flex;align-items:center;gap:20px}.nav-links>a{text-decoration:none;font-weight:650}.mobile-menu{display:none;margin-left:auto;border:0;background:none;font-size:1.4rem}.inline-form{margin:0}.link-button{border:0;background:none;color:var(--primary);font-weight:650;cursor:pointer}.button{display:inline-flex;justify-content:center;align-items:center;border:0;border-radius:11px;background:var(--primary);color:#fff;text-decoration:none;padding:13px 20px;font-weight:800;cursor:pointer}.button:hover{background:var(--primary2)}.button.secondary{background:#e8eff8;color:var(--primary)}.button.ghost{background:#fff;color:var(--primary);border:1px solid var(--border)}.button.small{padding:9px 14px}.button.full{width:100%}.hero{padding:82px 0;background:linear-gradient(135deg,#f5f8fc 0%,#edf4ff 100%)}.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:64px;align-items:center}.eyebrow{display:inline-block;color:var(--primary);font-size:.78rem;font-weight:900;letter-spacing:.12em}.hero h1{font-size:clamp(2.5rem,5vw,4.6rem);line-height:1.04;margin:14px 0 22px;letter-spacing:-.04em}.lead{font-size:1.15rem;color:var(--muted);max-width:690px}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}.trust-row{display:flex;gap:22px;flex-wrap:wrap;margin-top:28px;color:var(--muted);font-weight:650}.hero-panel{background:linear-gradient(160deg,var(--primary),#2b67a9);padding:26px;border-radius:28px;box-shadow:var(--shadow);transform:rotate(1deg)}.lesson-preview{background:#fff;border-radius:21px;padding:28px;transform:rotate(-1deg)}.lesson-preview h2{font-size:1.7rem;margin:18px 0 8px}.preview-footer{display:flex;justify-content:space-between;margin-top:16px;color:var(--muted)}.pill{display:inline-flex;padding:5px 10px;border-radius:999px;background:#eaf2fc;color:var(--primary);font-size:.78rem;font-weight:800}.section{padding:70px 0}.section.compact{padding-top:35px}.section-heading{max-width:760px;margin-bottom:28px}.section-heading h1,.section-heading h2{font-size:clamp(2rem,4vw,3.1rem);line-height:1.12;margin:8px 0}.section-heading p,.muted{color:var(--muted)}.grid{display:grid;gap:20px}.grid.three{grid-template-columns:repeat(3,1fr)}.grid.four{grid-template-columns:repeat(4,1fr)}.feature,.metric-card,.course-card,.side-card,.skill-card,.profile-card,.notice-card,.empty{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px}.feature .icon{width:42px;height:42px;display:grid;place-items:center;border-radius:12px;background:var(--primary);color:#fff;font-weight:900}.feature h3{font-size:1.3rem}.auth-shell{min-height:calc(100vh - 150px);display:grid;place-items:center;padding:55px 0}.auth-card{width:min(520px,100%);background:#fff;border:1px solid var(--border);border-radius:24px;padding:34px;box-shadow:var(--shadow)}.auth-card.wide{width:min(760px,100%)}.auth-card h1{font-size:2rem;margin:8px 0}.form-stack{display:grid;gap:17px;margin-top:26px}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:25px}.full-span{grid-column:1/-1}label{display:grid;gap:7px;font-weight:750}input,textarea{width:100%;border:1px solid var(--border);border-radius:10px;padding:12px 13px;background:#fff;color:var(--text)}input:focus,textarea:focus{outline:3px solid rgba(23,63,116,.15);border-color:var(--primary)}.auth-note{text-align:center;color:var(--muted);margin-top:20px}.flash{margin-top:14px;border-radius:10px;padding:12px 15px;background:#edf6ff;border:1px solid #cae2fa}.flash.error{background:#fff1f2;border-color:#fecdd3;color:var(--danger)}.flash.success{background:#f0fdf4;border-color:#bbf7d0;color:var(--success)}.dashboard-hero{background:linear-gradient(120deg,var(--primary),#326eaf);color:#fff;padding:48px 0}.welcome-row{display:flex;justify-content:space-between;align-items:center;gap:20px}.welcome-row h1{font-size:2.5rem;margin:5px 0}.welcome-row .eyebrow{color:#cde2ff}.metrics strong{display:block;font-size:2.2rem;margin:5px 0}.progress{height:9px;border-radius:999px;background:#e3eaf3;overflow:hidden;margin-top:12px}.progress span{display:block;height:100%;background:linear-gradient(90deg,var(--primary),#4b8dcc);border-radius:inherit}.dashboard-grid{display:grid;grid-template-columns:1fr 310px;gap:24px;margin-top:30px}.course-card{display:flex;justify-content:space-between;align-items:center;gap:20px}.side-card{height:max-content}.skill-card{display:flex;flex-direction:column}.skill-top{display:flex;justify-content:space-between;color:var(--muted)}.skill-card h2{font-size:1.35rem}.skill-card p{color:var(--muted);flex:1}.skill-outcome{display:grid;gap:3px;padding:13px;background:#f5f8fc;border-radius:10px;margin:12px 0 18px}.profile-card{max-width:800px}.notice-card{margin-top:25px}.center-card{min-height:70vh;display:grid;place-items:center}footer{padding:42px 0;border-top:1px solid var(--border);background:#fff}.footer-grid{display:flex;justify-content:space-between;gap:20px;color:var(--muted)}
@media(max-width:850px){.hero-grid,.dashboard-grid{grid-template-columns:1fr}.grid.three,.grid.four{grid-template-columns:1fr 1fr}.hero-panel{max-width:600px}.nav-links{display:none;position:absolute;top:72px;left:0;right:0;background:#fff;padding:18px;box-shadow:var(--shadow);flex-direction:column;align-items:stretch}.nav-links.open{display:flex}.mobile-menu{display:block}.welcome-row{align-items:flex-start;flex-direction:column}}
@media(max-width:560px){.grid.three,.grid.four,.form-grid{grid-template-columns:1fr}.full-span{grid-column:auto}.hero{padding:55px 0}.hero h1{font-size:2.6rem}.auth-card{padding:24px}.footer-grid,.course-card{flex-direction:column;align-items:flex-start}}
\n.activity-hero{padding:54px 0;background:linear-gradient(135deg,#edf4ff,#f8fbff);border-bottom:1px solid var(--border)}.activity-heading{display:grid;grid-template-columns:1fr 330px;gap:42px;align-items:end}.activity-heading h1{font-size:clamp(2.3rem,5vw,4rem);line-height:1.05;margin:12px 0}.activity-heading p{font-size:1.08rem;color:var(--muted)}.back-link{display:block;margin-bottom:24px;text-decoration:none;font-weight:750}.activity-meta-card,.content-card,.start-card,.completion-card{background:#fff;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:25px}.activity-meta-card{display:grid;gap:16px}.activity-meta-card div{display:grid}.activity-meta-card span{color:var(--muted);font-size:.85rem}.activity-layout{display:grid;grid-template-columns:1fr 330px;gap:26px}.learning-checklist{display:grid;gap:11px;background:#f4f8fd;border-radius:14px;padding:20px;margin:24px 0}.prompt-preview{border-left:4px solid var(--accent);padding:16px 18px;background:#fffbef;border-radius:0 12px 12px 0}.start-card{height:max-content;position:sticky;top:95px}.privacy-note{font-size:.82rem;color:var(--muted);margin-top:18px}.completion-badge{display:inline-flex;background:#eaf8ef;color:var(--success);padding:7px 11px;border-radius:999px;font-weight:850}.success-button{background:var(--success)}.chat-page{padding:34px 0;background:#eef3f9;min-height:72vh}.chat-layout{display:grid;grid-template-columns:310px 1fr;gap:22px}.chat-sidebar{background:#fff;border:1px solid var(--border);border-radius:var(--radius);padding:24px;height:max-content;position:sticky;top:90px}.chat-guidance{padding:15px;background:#fff8e7;border:1px solid #f4dda0;border-radius:12px;margin:20px 0}.chat-panel{background:#fff;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden;display:flex;flex-direction:column;min-height:650px}.chat-header{display:flex;justify-content:space-between;align-items:center;padding:17px 20px;border-bottom:1px solid var(--border)}.chat-header div{display:grid}.chat-header span{font-size:.82rem;color:var(--muted)}.online-dot{color:var(--success)!important;font-weight:800}.messages{padding:22px;display:flex;flex-direction:column;gap:18px;overflow-y:auto;max-height:560px;min-height:460px}.message{display:flex;gap:10px;align-items:flex-start}.message.user{flex-direction:row-reverse}.avatar{flex:0 0 38px;width:38px;height:38px;border-radius:12px;background:var(--primary);color:#fff;display:grid;place-items:center;font-size:.75rem;font-weight:900}.message.user .avatar{background:#dfe8f5;color:var(--primary)}.bubble{max-width:min(720px,82%);background:#f1f5fa;border-radius:5px 16px 16px 16px;padding:13px 16px}.message.user .bubble{background:var(--primary);color:#fff;border-radius:16px 5px 16px 16px}.chat-form{display:grid;grid-template-columns:1fr auto;gap:12px;padding:16px;border-top:1px solid var(--border);background:#fafcff}.chat-form textarea{resize:none}.chat-error{margin:0 16px 16px;padding:10px 13px;background:#fff1f2;color:var(--danger);border:1px solid #fecdd3;border-radius:10px}.completion-card{display:grid;grid-template-columns:.75fr 1.25fr;gap:35px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:900px){.activity-heading,.activity-layout,.chat-layout,.completion-card{grid-template-columns:1fr}.start-card,.chat-sidebar{position:static}.chat-panel{min-height:560px}}@media(max-width:560px){.messages{padding:14px}.bubble{max-width:88%}.chat-form{grid-template-columns:1fr}}\n\n.activity-hero{padding:54px 0;background:linear-gradient(135deg,#edf4ff,#f8fbff);border-bottom:1px solid var(--border)}.activity-heading{display:grid;grid-template-columns:1fr 330px;gap:42px;align-items:end}.activity-heading h1{font-size:clamp(2.3rem,5vw,4rem);line-height:1.05;margin:12px 0}.activity-heading p{font-size:1.08rem;color:var(--muted)}.back-link{display:block;margin-bottom:24px;text-decoration:none;font-weight:750}.activity-meta-card,.content-card,.start-card,.completion-card{background:#fff;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:25px}.activity-meta-card{display:grid;gap:16px}.activity-meta-card div{display:grid}.activity-meta-card span{color:var(--muted);font-size:.85rem}.activity-layout{display:grid;grid-template-columns:1fr 330px;gap:26px}.learning-checklist{display:grid;gap:11px;background:#f4f8fd;border-radius:14px;padding:20px;margin:24px 0}.prompt-preview{border-left:4px solid var(--accent);padding:16px 18px;background:#fffbef;border-radius:0 12px 12px 0}.start-card{height:max-content;position:sticky;top:95px}.privacy-note{font-size:.82rem;color:var(--muted);margin-top:18px}.completion-badge{display:inline-flex;background:#eaf8ef;color:var(--success);padding:7px 11px;border-radius:999px;font-weight:850}.success-button{background:var(--success)}.chat-page{padding:34px 0;background:#eef3f9;min-height:72vh}.chat-layout{display:grid;grid-template-columns:310px 1fr;gap:22px}.chat-sidebar{background:#fff;border:1px solid var(--border);border-radius:var(--radius);padding:24px;height:max-content;position:sticky;top:90px}.chat-guidance{padding:15px;background:#fff8e7;border:1px solid #f4dda0;border-radius:12px;margin:20px 0}.chat-panel{background:#fff;border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden;display:flex;flex-direction:column;min-height:650px}.chat-header{display:flex;justify-content:space-between;align-items:center;padding:17px 20px;border-bottom:1px solid var(--border)}.chat-header div{display:grid}.chat-header span{font-size:.82rem;color:var(--muted)}.online-dot{color:var(--success)!important;font-weight:800}.messages{padding:22px;display:flex;flex-direction:column;gap:18px;overflow-y:auto;max-height:560px;min-height:460px}.message{display:flex;gap:10px;align-items:flex-start}.message.user{flex-direction:row-reverse}.avatar{flex:0 0 38px;width:38px;height:38px;border-radius:12px;background:var(--primary);color:#fff;display:grid;place-items:center;font-size:.75rem;font-weight:900}.message.user .avatar{background:#dfe8f5;color:var(--primary)}.bubble{max-width:min(720px,82%);background:#f1f5fa;border-radius:5px 16px 16px 16px;padding:13px 16px}.message.user .bubble{background:var(--primary);color:#fff;border-radius:16px 5px 16px 16px}.chat-form{display:grid;grid-template-columns:1fr auto;gap:12px;padding:16px;border-top:1px solid var(--border);background:#fafcff}.chat-form textarea{resize:none}.chat-error{margin:0 16px 16px;padding:10px 13px;background:#fff1f2;color:var(--danger);border:1px solid #fecdd3;border-radius:10px}.completion-card{display:grid;grid-template-columns:.75fr 1.25fr;gap:35px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:900px){.activity-heading,.activity-layout,.chat-layout,.completion-card{grid-template-columns:1fr}.start-card,.chat-sidebar{position:static}.chat-panel{min-height:560px}}@media(max-width:560px){.messages{padding:14px}.bubble{max-width:88%}.chat-form{grid-template-columns:1fr}}\n
.activity-choice-stack{display:grid;gap:12px;margin-top:18px}.external-layout{display:grid;grid-template-columns:1fr 330px;gap:26px}.copy-panel{display:grid;gap:14px}.copy-panel textarea{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.55;background:#f7f9fc;resize:vertical}.copy-status{color:var(--success);font-weight:700;min-height:24px}.external-step{margin-top:36px}.tool-links{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.tool-link{display:flex;justify-content:center;align-items:center;padding:13px;border:1px solid var(--border);border-radius:11px;text-decoration:none;font-weight:800;background:#fff}.tool-link:hover{background:#edf4ff}.return-reminder{margin-top:28px;padding:18px;background:#fff8e7;border:1px solid #f4dda0;border-radius:12px}.return-reminder code{display:block;overflow-wrap:anywhere;margin:9px 0;background:#fff;padding:10px;border-radius:8px}.external-completion{align-items:start}.checkbox-label{display:flex;grid-template-columns:auto 1fr;align-items:flex-start;gap:10px;font-weight:600}.checkbox-label input{width:auto;margin-top:6px}select{width:100%;border:1px solid var(--border);border-radius:10px;padding:12px 13px;background:#fff;color:var(--text);font:inherit}@media(max-width:900px){.external-layout{grid-template-columns:1fr}}@media(max-width:560px){.tool-links{grid-template-columns:1fr}}

.simple-steps{display:grid;gap:16px;margin:26px 0}.simple-steps>div{display:grid;grid-template-columns:44px 1fr;gap:14px;align-items:start}.simple-steps>div>span,.step-number{width:42px;height:42px;border-radius:13px;background:var(--primary);color:#fff;display:grid;place-items:center;font-weight:900}.simple-steps strong{font-size:1.05rem}.simple-steps p{margin:3px 0;color:var(--muted)}.copy-activity-hero{padding:52px 0;background:linear-gradient(135deg,#edf4ff,#f9fbff);border-bottom:1px solid var(--border)}.copy-activity-hero h1{font-size:clamp(2.3rem,5vw,4rem);line-height:1.05;margin:10px 0}.copy-workflow{display:grid;grid-template-columns:1fr 360px;gap:24px}.copy-main-card,.tool-card,.confirmation-card{background:#fff;border:1px solid var(--border);border-radius:22px;box-shadow:var(--shadow);padding:27px}.step-heading{display:grid;grid-template-columns:48px 1fr;gap:16px;align-items:start}.step-heading h2{margin:2px 0 5px}.step-heading p{margin:0;color:var(--muted)}.compact-heading{grid-template-columns:42px 1fr}.prompt-copy-box{display:grid;gap:14px;margin-top:24px}.prompt-copy-box textarea{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.55;background:#f7f9fc;border:1px solid #ccd9e7;border-radius:15px;padding:18px;resize:vertical}.copy-button{justify-self:start}.copy-status{min-height:24px;color:var(--success);font-weight:750}.tool-list{display:grid;gap:10px;margin:24px 0}.tool-list a{display:grid;gap:1px;text-decoration:none;border:1px solid var(--border);border-radius:12px;padding:13px 15px;background:#f9fbfd}.tool-list a:hover{background:#eef5ff;border-color:#b9cde5}.tool-list span{font-size:.82rem;color:var(--muted)}.start-confirm-form{display:grid;gap:14px;padding-top:18px;border-top:1px solid var(--border)}.confirmation-section{padding:25px 0 70px;background:#edf3f9}.confirmation-card{max-width:900px;margin:auto}.simple-confirmation-form{display:grid;gap:18px;margin-top:26px}.simple-confirmation-form small{color:var(--muted);font-weight:500}.confirmation-checkbox{padding:14px;background:#f7f9fc;border:1px solid var(--border);border-radius:12px}.confirm-button{justify-self:start}.soft-notice{margin-top:24px;padding:16px;background:#fff8e7;border:1px solid #f4dda0;border-radius:12px}.completed-confirmation{text-align:center}.completed-confirmation .completion-badge{margin-bottom:13px}
@media(max-width:900px){.copy-workflow{grid-template-columns:1fr}}
@media(max-width:560px){.step-heading{grid-template-columns:1fr}.copy-button,.confirm-button{width:100%}}