/* Deutsch Interactive — visual design ported verbatim from the fahrplan-a1
   prototype (palette, header, module cards, drill card) with additions for
   this app's own surfaces: the language toggle, the bilingual sub-line,
   and the per-lesson tutor chat panel. Google Fonts via <link> in
   index.html is the only permitted external resource — everything else
   here is self-contained. */

:root{
  --board:#16202B; --board2:#1E2B39; --line:#31465C;
  --paper:#EDEEF0; --ink:#12171D; --ink2:#5A6875;
  --amber:#F5C518; --green:#3F8F68; --red:#C6362F; --blue:#4A7FB5;
  --disp:'Barlow Condensed',sans-serif;
  --body:'IBM Plex Sans',sans-serif;
  --mono:'IBM Plex Mono',monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{background:var(--paper);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.55;padding-bottom:80px}
.wrap{max-width:860px;margin:0 auto;padding:0 18px}

/* ---------- board header ---------- */
.board{background:var(--board);color:var(--paper);border-bottom:3px solid var(--amber)}
.board .wrap{padding-top:16px;padding-bottom:16px}
.brow{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;flex-wrap:wrap}
.blogo{font-family:var(--disp);font-weight:700;font-size:30px;letter-spacing:.06em;text-transform:uppercase;line-height:1}
.blogo span{color:var(--amber)}
.bsub{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:#8FA5B8;margin-top:5px}
.bactions{display:flex;align-items:flex-end;gap:16px}
.langtoggle{background:var(--board2);border:1px solid var(--line);color:var(--paper);font-family:var(--mono);font-size:11px;letter-spacing:.08em;padding:6px 10px;border-radius:3px;cursor:pointer;align-self:flex-start}
.langtoggle:hover{background:var(--amber);color:var(--board);border-color:var(--amber)}
.cd{text-align:right}
.cdnum{font-family:var(--mono);font-weight:600;font-size:30px;color:var(--amber);line-height:1}
.cdlab{font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:#8FA5B8;margin-top:4px}
.cd input{background:var(--board2);border:1px solid var(--line);color:#8FA5B8;font-family:var(--mono);font-size:10px;padding:2px 4px;border-radius:3px;margin-top:5px}

/* progress rail */
.rail{height:6px;background:var(--board2);display:flex;gap:2px;margin-top:14px;border-radius:3px;overflow:hidden}
.rail i{flex:1;background:#2A3B4D;transition:background .3s}
.rail i.done{background:var(--green)}
.rail i.part{background:var(--amber)}
.stats{display:flex;gap:22px;margin-top:10px;font-family:var(--mono);font-size:11px;color:#8FA5B8;letter-spacing:.06em;flex-wrap:wrap}
.stats b{color:var(--paper);font-weight:600}

/* ---------- nav ---------- */
nav{background:var(--board2);position:sticky;top:0;z-index:50;border-bottom:1px solid var(--line)}
nav .wrap{display:flex;gap:2px;overflow-x:auto;padding-top:0;padding-bottom:0;scrollbar-width:none}
nav .wrap::-webkit-scrollbar{display:none}
nav button{background:none;border:0;color:#8FA5B8;font-family:var(--disp);font-weight:600;font-size:16px;letter-spacing:.05em;text-transform:uppercase;padding:11px 14px;cursor:pointer;white-space:nowrap;border-bottom:3px solid transparent}
nav button:hover{color:var(--paper)}
nav button.on{color:var(--board);background:var(--amber);border-bottom-color:var(--amber)}

/* ---------- bilingual sub-line ---------- */
.de-sub{font-size:.85em;color:var(--ink2);font-weight:400;margin-top:2px}
.q .de-sub, .mt .de-sub{margin-top:3px}

/* ---------- module list ---------- */
.sect{font-family:var(--mono);font-size:10px;letter-spacing:.18em;text-transform:uppercase;color:var(--ink2);margin:30px 0 10px;display:flex;align-items:center;gap:10px}
.sect:after{content:'';flex:1;height:1px;background:#CFD4DA}
.mods{display:flex;flex-direction:column;gap:7px}
.mod{background:#fff;border:1px solid #DCE0E5;border-left:4px solid #C3C9D0;border-radius:4px;padding:13px 15px;cursor:pointer;display:flex;align-items:center;gap:14px;transition:.15s;text-align:left;width:100%;font:inherit;color:inherit}
.mod:hover{border-color:var(--blue);border-left-color:var(--blue);transform:translateX(2px)}
.mod.done{border-left-color:var(--green);background:#F5FAF7}
.mod.part{border-left-color:var(--amber)}
.mtime{font-family:var(--mono);font-size:12px;font-weight:600;color:var(--ink2);min-width:34px}
.mmain{flex:1;min-width:0}
.mt{font-family:var(--disp);font-weight:600;font-size:20px;letter-spacing:.02em;line-height:1.1}
.md{font-size:12.5px;color:var(--ink2);margin-top:2px}
.mlek{font-family:var(--mono);font-size:10px;font-weight:600;letter-spacing:.06em;background:#E7EAEE;color:var(--ink2);padding:3px 6px;border-radius:3px;white-space:nowrap}
.mscore{font-family:var(--mono);font-size:12px;font-weight:600;min-width:44px;text-align:right}
.mscore.g{color:var(--green)} .mscore.a{color:#B08800} .mscore.r{color:var(--red)}

/* ---------- lesson view ---------- */
.lhead{background:var(--board);color:var(--paper);padding:16px 0;margin-bottom:22px}
.lhead .wrap{display:flex;align-items:center;gap:14px}
.back{background:var(--board2);border:1px solid var(--line);color:var(--paper);font-family:var(--mono);font-size:11px;padding:7px 11px;border-radius:3px;cursor:pointer;letter-spacing:.06em}
.back:hover{background:var(--amber);color:var(--board);border-color:var(--amber)}
.lh1{font-family:var(--disp);font-weight:700;font-size:27px;letter-spacing:.03em;text-transform:uppercase;line-height:1}
.lh2{font-family:var(--mono);font-size:10.5px;letter-spacing:.13em;color:#8FA5B8;text-transform:uppercase;margin-top:3px}

.teach{background:#fff;border:1px solid #DCE0E5;border-radius:5px;padding:20px 22px;margin-bottom:16px}
.teach h3{font-family:var(--disp);font-weight:700;font-size:22px;letter-spacing:.02em;margin:22px 0 9px;color:var(--board)}
.teach h3:first-child{margin-top:0}
.teach p{margin:9px 0}
.teach ul{margin:9px 0 9px 20px}
.teach li{margin:4px 0}
.de{font-weight:600;color:var(--board)}
.en{color:var(--ink2);font-style:italic}
.warn{background:#FFF6E0;border-left:3px solid var(--amber);padding:11px 14px;margin:13px 0;border-radius:0 4px 4px 0;font-size:14.5px}
.warn b{color:#8A6A00}
.key{background:#EAF2F9;border-left:3px solid var(--blue);padding:11px 14px;margin:13px 0;border-radius:0 4px 4px 0;font-size:14.5px}
table{border-collapse:collapse;width:100%;margin:13px 0;font-size:14.5px}
th,td{border:1px solid #DCE0E5;padding:7px 10px;text-align:left}
th{background:#F1F3F5;font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:var(--ink2)}
td.m{font-family:var(--mono);font-size:13.5px}
.tbl-sm td,.tbl-sm th{padding:5px 8px;font-size:13.5px}

/* ---------- drill ---------- */
.drill{background:var(--board);border-radius:5px;padding:22px;color:var(--paper)}
.dtop{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px;font-family:var(--mono);font-size:11px;letter-spacing:.1em;color:#8FA5B8;text-transform:uppercase}
.dbar{height:4px;background:var(--board2);border-radius:2px;overflow:hidden;margin-bottom:20px}
.dbar i{display:block;height:100%;background:var(--amber);transition:width .3s}
.qtag{font-family:var(--mono);font-size:10px;letter-spacing:.12em;color:var(--amber);text-transform:uppercase;margin-bottom:7px}
.q{font-family:var(--body);font-size:19px;font-weight:500;line-height:1.4;margin-bottom:16px}
.q code{font-family:var(--mono);background:var(--board2);padding:1px 6px;border-radius:3px;color:var(--amber)}
.opts{display:flex;flex-direction:column;gap:8px}
.opt{background:var(--board2);border:1px solid var(--line);color:var(--paper);padding:12px 15px;border-radius:4px;cursor:pointer;font:inherit;font-size:16px;text-align:left;transition:.12s;display:flex;gap:11px;align-items:center}
.opt:hover:not(:disabled){background:#243343;border-color:var(--amber)}
.opt .k{font-family:var(--mono);font-size:11px;color:#8FA5B8;border:1px solid var(--line);border-radius:3px;width:20px;height:20px;display:flex;align-items:center;justify-content:center;flex:0 0 auto}
.opt.ok{background:#1D4634;border-color:var(--green)}
.opt.no{background:#4A1F1C;border-color:var(--red)}
.opt:disabled{cursor:default}
.tin{width:100%;background:var(--board2);border:1px solid var(--line);color:var(--paper);font-family:var(--mono);font-size:19px;padding:13px 15px;border-radius:4px}
.tin:focus{outline:none;border-color:var(--amber)}
.tin.ok{border-color:var(--green);background:#1D4634}
.tin.no{border-color:var(--red);background:#4A1F1C}
.go{background:var(--amber);color:var(--board);border:0;font-family:var(--disp);font-weight:700;font-size:17px;letter-spacing:.06em;text-transform:uppercase;padding:11px 22px;border-radius:4px;cursor:pointer;margin-top:13px}
.go:hover{background:#FFD84D}
.go-ghost{background:var(--board2);color:var(--paper)}
.go-ghost:hover{background:#243343}
.fbactions{display:flex;gap:8px;flex-wrap:wrap}
.fb{margin-top:15px;padding:13px 15px;border-radius:4px;font-size:15px;line-height:1.5}
.fb.ok{background:#1D4634;border-left:3px solid var(--green)}
.fb.no{background:#4A1F1C;border-left:3px solid var(--red)}
.fb .ans{font-family:var(--mono);color:var(--amber);font-weight:600}
.fb .why{color:#B9C6D2;font-size:13.5px;margin-top:6px}
.skip{background:none;border:0;color:#8FA5B8;font-family:var(--mono);font-size:11px;cursor:pointer;text-decoration:underline;margin-top:14px;letter-spacing:.06em}
.skip:hover{color:var(--amber)}
.skip:disabled{cursor:default;text-decoration:none;opacity:.5}

.done-card{text-align:center;padding:24px 10px}
.done-num{font-family:var(--mono);font-size:46px;font-weight:600;color:var(--amber);line-height:1}
.done-lab{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:#8FA5B8;margin-top:6px}
.done-msg{margin:16px 0;font-size:15.5px;color:#C7D3DE}
.wrongs{text-align:left;background:var(--board2);border-radius:4px;padding:14px 16px;margin:16px 0;font-size:14px}
.wrongs h4{font-family:var(--mono);font-size:10px;letter-spacing:.12em;text-transform:uppercase;color:var(--amber);margin-bottom:9px}
.wrongs div{padding:5px 0;border-bottom:1px solid #2A3B4D;color:#C7D3DE}
.wrongs div:last-child{border:0}
.wrongs b{color:var(--paper)}

/* ---------- tutor chat panel ---------- */
#chatroot:empty{display:none}
.chatpanel{position:fixed;right:16px;bottom:16px;width:min(360px,calc(100vw - 32px));max-height:min(520px,calc(100vh - 32px));
  background:var(--board);color:var(--paper);border:1px solid var(--line);border-radius:8px;
  box-shadow:0 12px 32px rgba(0,0,0,.35);display:flex;flex-direction:column;z-index:100;overflow:hidden}
.chatpanel-head{display:flex;align-items:center;justify-content:space-between;padding:11px 14px;
  background:var(--board2);border-bottom:1px solid var(--line);font-family:var(--disp);font-weight:600;
  letter-spacing:.04em;text-transform:uppercase;font-size:14px}
.chatpanel-head button{background:none;border:0;color:#8FA5B8;font-size:20px;line-height:1;cursor:pointer}
.chatpanel-head button:hover{color:var(--amber)}
.chatpanel-log{flex:1;overflow-y:auto;padding:12px 14px;display:flex;flex-direction:column;gap:8px;min-height:120px}
.chatbubble{max-width:88%;padding:9px 12px;border-radius:8px;font-size:14px;line-height:1.45;white-space:pre-wrap}
.chatbubble.student{align-self:flex-end;background:var(--blue);color:#fff}
.chatbubble.tutor{align-self:flex-start;background:var(--board2);border:1px solid var(--line);color:var(--paper)}
.chatbubble.pending{opacity:.6}
.chatpanel-input{display:flex;gap:8px;padding:10px 12px;border-top:1px solid var(--line)}
.chatpanel-input input{flex:1;background:var(--board2);border:1px solid var(--line);color:var(--paper);
  font-family:var(--body);font-size:14px;padding:9px 11px;border-radius:4px}
.chatpanel-input input:focus{outline:none;border-color:var(--amber)}
.chatpanel-input .go{margin-top:0;padding:9px 14px;font-size:13px}

.foot{margin-top:36px;padding-top:18px;border-top:1px solid #CFD4DA;font-size:12.5px;color:var(--ink2);display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap}
.footbtns{display:flex;gap:8px}
.foot button{background:none;border:1px solid #CFD4DA;color:var(--ink2);font-family:var(--mono);font-size:11px;padding:5px 9px;border-radius:3px;cursor:pointer}
.foot button:hover{border-color:var(--red);color:var(--red)}
.hide{display:none!important}

@media(max-width:600px){
  .blogo{font-size:24px}.cdnum{font-size:24px}.lh1{font-size:22px}
  .teach{padding:16px}.drill{padding:16px}.q{font-size:17px}
  .mt{font-size:18px}.md{font-size:12px}
  table{font-size:13px}th,td{padding:5px 7px}
  .chatpanel{right:8px;left:8px;bottom:8px;width:auto}
}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}