:root{--bg: #fbf7ef;--card: #ffffff;--ink: #2b2a26;--muted: #8a857a;--line: #ece5d6;--green: #2f9e5e;--green-dk: #247a49;--coral: #e2725b;--gold: #e7a93c;--locked: #cfc8b8;--shadow: 0 2px 0 var(--line), 0 8px 24px rgba(60, 50, 30, .06);font-family:Avenir Next,Segoe UI,system-ui,-apple-system,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink)}a{color:inherit;text-decoration:none}.app{min-height:100vh}.topbar{display:flex;align-items:center;gap:24px;padding:14px 24px;background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}.brand{font-weight:800;font-size:20px;letter-spacing:-.02em}.brand-mark{margin-right:4px}.nav{display:flex;gap:6px;margin-left:8px}.nav a{padding:8px 14px;border-radius:999px;font-weight:600;color:var(--muted)}.nav a.active{color:var(--green-dk);background:#eaf6ee}.topbar-right{margin-left:auto;display:flex;align-items:center;gap:16px}.level-switch{display:flex;align-items:center;gap:6px}.level-switch select{padding:5px 8px;border-radius:8px;border:1px solid var(--line);background:var(--card);font-weight:700;color:var(--green-dk);cursor:pointer}.link-btn{background:none;border:none;color:var(--muted);cursor:pointer;font-weight:600}.content{max-width:720px;margin:0 auto;padding:28px 20px 80px}h1{font-size:26px;letter-spacing:-.02em;margin:4px 0 18px}h2{font-size:18px;margin:0 0 12px}.muted{color:var(--muted)}.card{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:20px}.unit{margin-bottom:26px}.unit-head{display:flex;align-items:center;gap:12px;margin-bottom:12px}.unit-icon{width:44px;height:44px;border-radius:14px;display:grid;place-items:center;font-size:22px;background:#eaf6ee}.unit-title{font-weight:800;font-size:17px}.badge{font-size:12px;font-weight:700;padding:3px 10px;border-radius:999px}.badge.available{background:#eaf6ee;color:var(--green-dk)}.badge.complete{background:#fbeede;color:#b6781b}.badge.locked{background:#f1ede2;color:var(--muted)}.lesson-node{display:flex;align-items:center;gap:14px;width:100%;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:14px 16px;margin-bottom:10px;cursor:pointer;text-align:left;box-shadow:var(--shadow);font:inherit;color:inherit}.lesson-node:hover{transform:translateY(-1px)}.lesson-node.locked{opacity:.55;cursor:not-allowed;box-shadow:none}.node-dot{width:34px;height:34px;border-radius:50%;display:grid;place-items:center;color:#fff;font-weight:800}.node-dot.available{background:var(--green)}.node-dot.complete{background:var(--gold)}.node-dot.locked{background:var(--locked)}.node-title{font-weight:700}.node-sub{font-size:13px;color:var(--muted)}.vocab-word{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;align-items:center}.gender-mark{font-size:.6em;font-weight:700;color:var(--muted);vertical-align:middle}.chip{-webkit-appearance:none;-moz-appearance:none;appearance:none;cursor:pointer;font:inherit;font-weight:600;font-size:13px;padding:6px 12px;border-radius:999px;border:1px solid var(--line);background:var(--card);color:var(--muted)}.chip:hover{color:var(--ink)}.chip.active{background:#eaf6ee;color:var(--green-dk);border-color:var(--green)}.chip:focus-visible{outline:2px solid var(--line);outline-offset:2px}.btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:none;cursor:pointer;font:inherit;font-weight:800;padding:13px 18px;border-radius:14px;background:var(--green);color:#fff;box-shadow:0 4px 0 var(--green-dk);transition:transform .04s}.btn:active{transform:translateY(2px);box-shadow:0 2px 0 var(--green-dk)}.btn:disabled{background:var(--locked);box-shadow:none;cursor:default}.btn.secondary{background:#fff;color:var(--ink);border:1px solid var(--line);box-shadow:var(--shadow)}.btn.wide{width:100%}.btn-row{display:flex;gap:10px;flex-wrap:wrap}.exercise .prompt{font-size:18px;font-weight:700;margin-bottom:16px}.options{display:grid;gap:10px}.option{text-align:left;padding:14px 16px;border-radius:14px;border:2px solid var(--line);background:#fff;cursor:pointer;font:inherit;font-weight:600}.option.selected,.option.correct{border-color:var(--green);background:#eaf6ee}.option.wrong{border-color:var(--coral);background:#fdede9}.tiles{display:flex;flex-wrap:wrap;gap:8px}.tile{padding:10px 14px;border-radius:12px;border:2px solid var(--line);background:#fff;cursor:pointer;font:inherit;font-weight:700}.build-line{min-height:52px;border-bottom:2px dashed var(--line);margin-bottom:16px;display:flex;gap:8px;flex-wrap:wrap;align-items:center;padding-bottom:8px}.text-input{width:100%;padding:13px 14px;border-radius:12px;border:2px solid var(--line);font:inherit;background:#fff}.feedback{margin-top:16px;padding:14px 16px;border-radius:12px;font-weight:700}.feedback.ok{background:#eaf6ee;color:var(--green-dk)}.feedback.no{background:#fdede9;color:#b23c28}.progress-bar{height:10px;background:var(--line);border-radius:999px;overflow:hidden;margin-bottom:22px}.progress-bar>div{height:100%;background:var(--green);transition:width .25s}.row{display:flex;align-items:center;gap:14px;padding:14px 16px;border-bottom:1px solid var(--line)}.row:last-child{border-bottom:none}.rank{width:26px;font-weight:800;color:var(--muted)}.avatar{width:38px;height:38px;border-radius:50%;background:#eaf6ee;display:grid;place-items:center;font-weight:800;color:var(--green-dk)}.grow{flex:1}.stat{font-weight:800}.stat small{color:var(--muted);font-weight:600}.center{text-align:center}.stack{display:grid;gap:14px}.pill{display:inline-flex;gap:6px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:999px;padding:6px 12px;font-weight:700}.auth-wrap{min-height:100vh;display:grid;place-items:center;padding:20px}.auth-card{width:100%;max-width:380px}.auth-card h1{text-align:center}.field{display:grid;gap:6px;margin-bottom:14px}.field label{font-size:13px;font-weight:700;color:var(--muted)}.error{color:#b23c28;font-weight:700;margin:4px 0 12px}.switch{text-align:center;margin-top:14px;color:var(--muted)}.switch button{background:none;border:none;color:var(--green-dk);font-weight:800;cursor:pointer}