@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@400;500&family=DM+Sans:wght@400;500;600;700&display=swap');
:root{--bg:#101b19;--surface:#192722;--edge:#375044;--gold:#e0bd79;--cream:#f5edda;--muted:#a7b4a4;--green:#a8e88a}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:radial-gradient(circle at 50% 0,#253b32 0,#101b19 480px);color:var(--cream);font-family:'DM Sans',system-ui,sans-serif;-webkit-font-smoothing:antialiased}.shell{max-width:780px;margin:auto;padding:0 22px}.topbar{height:82px;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid #486052}.brand{display:flex;align-items:center;gap:10px;color:var(--cream);text-decoration:none;font-size:15px;font-weight:700;letter-spacing:.16em}.brand-mark{display:grid;place-items:center;width:32px;height:32px;border:1px solid var(--gold);border-radius:8px;color:var(--gold);font:700 18px 'DM Mono',monospace;letter-spacing:-.16em;padding-right:3px}.brand-light{font-weight:400;color:var(--gold)}.nav-link{color:var(--gold);text-decoration:none;font:500 11px 'DM Mono',monospace;letter-spacing:.04em}.nav-link span{font-size:16px}.intro{padding:58px 0 35px}.eyebrow,.mini-label{font:500 10px 'DM Mono',monospace;letter-spacing:.16em;color:var(--gold)}h1,h2,p{margin-top:0}h1{font-size:clamp(44px,9vw,75px);letter-spacing:-.065em;line-height:1.02;margin:16px 0 20px;font-weight:600}h1 em{font-weight:400;color:var(--gold);font-style:normal}.lede{max-width:510px;color:#bcc9ba;font-size:16px;line-height:1.6}.device{position:relative;overflow:hidden;background:linear-gradient(145deg,#1e352b,#14251f 65%);border:1px solid #6b7955;border-radius:22px;padding:22px;box-shadow:0 28px 50px #07100d66,inset 0 0 0 5px #101c1766}.device:before{content:'';position:absolute;inset:0;pointer-events:none;opacity:.13;background:repeating-linear-gradient(90deg,transparent 0 76px,#92b289 77px 78px,transparent 79px 154px)}.device>*{position:relative}.device-head,.device-foot,.key-caption,.key-guide,.display-label{display:flex;justify-content:space-between;gap:12px;font:500 10px 'DM Mono',monospace;letter-spacing:.11em;color:var(--gold)}.device-head .muted,.serial{color:#8ca98d}.device-rule{height:1px;background:#758466;margin:17px 0}.status-row{display:flex;align-items:center;gap:9px;font:500 10px 'DM Mono',monospace;letter-spacing:.1em;color:#b6c9aa}.led{width:10px;height:10px;border-radius:50%;background:#577c52;box-shadow:0 0 0 3px #223e2b}.led.on{background:var(--green);box-shadow:0 0 13px 5px #a8e88a77}.sound{margin-left:auto;background:none;border:1px solid #678166;border-radius:5px;color:var(--gold);font:500 9px 'DM Mono',monospace;padding:8px 9px;cursor:pointer}.display{background:#0c1713;border:1px solid #547157;border-radius:12px;margin:22px 0;padding:17px;min-height:138px;box-shadow:inset 0 2px 14px #0008}.display-label{color:#809986}.signal{font:500 31px 'DM Mono',monospace;color:var(--green);letter-spacing:.2em;min-height:48px;margin-top:12px;overflow-wrap:anywhere}.decoded{display:flex;align-items:baseline;gap:15px;border-top:1px solid #324c39;padding-top:10px}.decoded>span:first-child{font-size:28px;font-weight:700;color:var(--cream)}.decoded-hint{font:10px 'DM Mono',monospace;color:#8da08d}.key-area{text-align:center;padding:4px 0}.key-caption{color:#9aac96}.telegraph-key{display:block;touch-action:none;user-select:none;-webkit-user-select:none;width:164px;height:164px;margin:20px auto 18px;border:8px solid #a68c59;border-radius:50%;background:linear-gradient(145deg,#e9c984,#ad8d54);box-shadow:0 8px 0 #74623e,0 14px 18px #0007,inset 0 2px 6px #fff8;cursor:pointer;color:#1d2e24}.telegraph-key:active,.telegraph-key.pressed{transform:translateY(6px);box-shadow:0 2px 0 #74623e,0 6px 10px #0007}.key-inner{display:flex;flex-direction:column;align-items:center;justify-content:center;width:100%;height:100%;border:1px solid #5f573b;border-radius:50%;font:700 10px 'DM Mono',monospace;letter-spacing:.1em}.key-symbol{font-size:40px;letter-spacing:-.2em;padding-right:8px;line-height:1.1}.key-guide{justify-content:center;gap:24px;color:#a6b8a6;letter-spacing:0}.key-guide b{color:var(--gold);font-weight:500}.device-foot{border-top:1px solid #687b62;margin-top:26px;padding-top:18px;color:#9eb399;font-size:9px}.panel{background:#192820;border:1px solid #425a47;border-radius:18px;padding:25px;margin-top:26px}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:10px}.section-heading .eyebrow{margin:0 0 8px}h2{font-size:30px;letter-spacing:-.045em;margin:0;font-weight:600}.small-button{border:1px solid #7c8b65;border-radius:7px;color:var(--gold);background:transparent;padding:10px;font:500 10px 'DM Mono',monospace;white-space:nowrap;cursor:pointer}.panel-copy{color:#aebfae;font-size:14px;margin:13px 0 21px}.challenge-code{text-align:center;font:500 52px 'DM Mono',monospace;letter-spacing:.17em;color:var(--gold);padding:12px 0 20px}.answer-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.answer-grid button,.code-grid button,.nato-grid button{cursor:pointer;color:var(--cream);background:#23372b;border:1px solid #567051;border-radius:9px}.answer-grid button{min-height:55px;font:600 22px 'DM Sans',sans-serif}.answer-grid button.correct{background:#456c42;border-color:var(--green)}.answer-grid button.wrong{background:#67423b;border-color:#c5826b}.feedback{min-height:20px;color:var(--muted);font-size:13px;margin:14px 0 0}.code-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.code-grid button{text-align:left;padding:12px 10px;min-height:65px}.code-grid strong,.code-grid span{display:block}.code-grid strong{font-size:17px}.code-grid span{font:12px 'DM Mono',monospace;color:var(--gold);margin-top:3px}.code-grid button.active{border-color:var(--green);background:#345b37}.next-card{display:flex;align-items:end;justify-content:space-between;gap:20px;border:1px solid #686c4e;border-radius:18px;background:linear-gradient(125deg,#354636,#263a2e);padding:28px;margin:26px 0 42px}.next-card h2{margin:8px 0}.next-card p:not(.eyebrow){font-size:14px;color:#c9d3bd;margin:8px 0 0}.next-link{white-space:nowrap;background:var(--gold);color:#19271e;text-decoration:none;border-radius:8px;padding:13px 15px;font:700 10px 'DM Mono',monospace}.next-link span{font-size:15px}footer{border-top:1px solid #3d5548;padding:22px 0 35px;color:#829986;font:10px 'DM Mono',monospace;letter-spacing:.1em}footer span{color:var(--gold);padding:0 8px}.nato-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:9px}.nato-grid button{text-align:left;display:flex;align-items:center;gap:13px;min-height:69px;padding:11px 14px}.nato-grid button:active,.nato-grid button.active{border-color:var(--green);background:#345b37}.nato-letter{color:var(--gold);font:500 28px 'DM Mono',monospace;width:28px}.nato-word{font-size:16px;font-weight:600}.note{font-size:12px;color:#a8b8a7;margin:19px 0 0}.note strong{color:var(--gold)}button:focus-visible,a:focus-visible{outline:3px solid var(--green);outline-offset:3px}@media(max-width:580px){.shell{padding:0 16px}.topbar{height:68px}.intro{padding:43px 0 24px}.device{padding:16px;border-radius:17px}.device-head,.device-foot{font-size:8px}.key-guide{font-size:8px;gap:11px}.panel{padding:18px}.code-grid{grid-template-columns:repeat(3,1fr)}.next-card{display:block}.next-link{display:inline-block;margin-top:20px}.nato-grid{gap:7px}.nato-grid button{gap:8px;padding:9px}.nato-word{font-size:14px}}@media(max-width:370px){.nato-grid{grid-template-columns:1fr}.nav-link{font-size:9px}.brand{font-size:12px}.code-grid{grid-template-columns:repeat(2,1fr)}}