/* =====================================================================
   Smart Study Assistant — Design System v2
   Concept: "Clear Sky". Clean, bright, Google-Workspace-inspired layout
   with a sky-blue + shiny-green palette. Signature: the GLOSS SWEEP — a
   glossy green highlight that sweeps in behind emphasised text, and a
   diagonal shine animation on primary buttons. Reused for: hero emphasis,
   active nav, correct quiz answers.
   ===================================================================== */

:root{
  --sky-50:#EAF4FF;
  --sky-100:#D9ECFF;
  --sky-300:#7EC1FF;
  --sky-500:#2E8CF0;      /* primary action — Google-blue adjacent */
  --sky-600:#1C6FDB;
  --sky-700:#154F9E;
  --ink:#10233F;          /* deep blue-slate ink, not pure black */
  --ink-2:#16305A;        /* raised dark surface (sidebar) */
  --green-300:#7CF2C3;
  --green-400:#34E6A6;    /* SHINY GREEN — the signature accent */
  --green-500:#12C98A;
  --green-600:#0AA873;
  --green-soft:#DEFBEE;
  --amber:#F5A623;
  --amber-soft:#FFF3DC;
  --coral:#EF5A50;
  --coral-soft:#FDE7E5;
  --paper:#F4F9FF;        /* cool sky-tinted white */
  --card:#FFFFFF;
  --rule:#DCEAFA;
  --text:#233B5E;
  --muted:#6B7C99;

  --r-s:10px; --r-m:14px; --r-l:20px; --r-xl:28px;
  --sh-s:0 1px 2px rgba(16,35,63,.06), 0 1px 3px rgba(16,35,63,.04);
  --sh-m:0 6px 22px rgba(28,111,219,.12), 0 2px 6px rgba(28,111,219,.08);
  --sh-l:0 22px 55px rgba(16,35,63,.16), 0 6px 16px rgba(16,35,63,.08);
  --sh-green:0 10px 24px rgba(18,201,138,.35);
  --sh-sky:0 10px 24px rgba(46,140,240,.32);
  --ease:cubic-bezier(.2,.7,.3,1);
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:'Roboto',system-ui,-apple-system,sans-serif;
  background:
    radial-gradient(1000px 460px at 92% -10%, rgba(52,230,166,.10), transparent),
    radial-gradient(900px 420px at -5% 8%, rgba(46,140,240,.12), transparent),
    var(--paper);
  color:var(--text);
  font-size:15.5px; line-height:1.65; -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:'Poppins',system-ui,sans-serif;font-weight:600;line-height:1.15;letter-spacing:-.01em;color:var(--ink)}
h1{font-size:clamp(2.3rem,5.5vw,4rem)}
h2{font-size:clamp(1.7rem,3.6vw,2.6rem)}
h3{font-size:1.3rem}
a{color:var(--sky-600);text-decoration:none}
.container{width:min(1120px,92%);margin-inline:auto}

/* ============ SIGNATURE: the gloss sweep ============ */
.mark{position:relative;display:inline-block;z-index:1;font-style:normal;font-weight:700;color:var(--ink)}
.mark::before{
  content:'';position:absolute;left:-.14em;right:-.14em;
  top:.14em;bottom:.06em;
  background:linear-gradient(100deg, var(--green-300), var(--green-400) 55%, var(--green-500));
  z-index:-1;
  border-radius:4px 10px 4px 10px;
  box-shadow:0 3px 10px rgba(18,201,138,.35) inset, 0 2px 6px rgba(18,201,138,.25);
  transform:rotate(-.6deg) scaleX(0);
  transform-origin:left center;
  animation:swipe .55s var(--ease) .4s forwards;
}
@keyframes swipe{to{transform:rotate(-.6deg) scaleX(1)}}
@media (prefers-reduced-motion:reduce){
  .mark::before{animation:none;transform:rotate(-.6deg) scaleX(1)}
}

/* eyebrow */
.eyebrow{
  font-family:'JetBrains Mono',ui-monospace,monospace;
  font-size:.7rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:var(--sky-600);display:inline-flex;align-items:center;gap:.5rem;margin-bottom:1rem
}
.eyebrow::before{content:'';width:18px;height:3px;background:linear-gradient(90deg,var(--sky-500),var(--green-400));border-radius:2px}

/* ============ Buttons (shiny, glossy, with a diagonal shine sweep) ============ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  padding:.75rem 1.4rem;border:none;border-radius:100px;cursor:pointer;
  font-family:'Roboto',inherit;font-size:.92rem;font-weight:700;
  position:relative;overflow:hidden;
  transition:transform .16s var(--ease),box-shadow .16s var(--ease),background .16s;
  white-space:nowrap;
}
.btn::after{ /* diagonal shine — the "shiny" signature */
  content:'';position:absolute;top:-60%;left:-40%;width:35%;height:220%;
  background:rgba(255,255,255,.35);transform:rotate(20deg) translateX(-140%);
  transition:transform .6s var(--ease);
}
.btn:hover::after{transform:rotate(20deg) translateX(340%)}
.btn:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0)}
.btn:focus-visible{outline:3px solid var(--green-400);outline-offset:2px}
.btn-primary{background:linear-gradient(135deg,var(--sky-300),var(--sky-600));color:#fff;box-shadow:var(--sh-sky)}
.btn-primary:hover{box-shadow:0 14px 30px rgba(28,111,219,.4)}
.btn-violet{background:linear-gradient(135deg,var(--sky-500),var(--sky-700));color:#fff;box-shadow:var(--sh-sky)}
.btn-violet:hover{box-shadow:0 14px 30px rgba(28,111,219,.4)}
.btn-hl{background:linear-gradient(135deg,var(--green-300),var(--green-500));color:#06341F;box-shadow:var(--sh-green)}
.btn-hl:hover{box-shadow:0 14px 30px rgba(18,201,138,.4)}
.btn-ghost{background:#fff;color:var(--ink);border:1.5px solid var(--rule)}
.btn-ghost:hover{border-color:var(--sky-500);background:var(--sky-50)}
.btn-danger{background:transparent;color:var(--coral);border:1.5px solid var(--coral-soft)}
.btn-danger:hover{background:var(--coral);color:#fff;border-color:var(--coral)}
.btn-sm{padding:.42rem .9rem;font-size:.82rem}
.btn-block{width:100%}
.btn[disabled]{opacity:.45;pointer-events:none}

/* ============ Nav ============ */
.nav{position:sticky;top:0;z-index:60;background:rgba(244,249,255,.85);backdrop-filter:blur(14px);border-bottom:1px solid var(--rule)}
.nav-in{display:flex;align-items:center;justify-content:space-between;height:68px}
.logo{display:flex;align-items:center;gap:.55rem;font-family:'Poppins',sans-serif;font-weight:600;font-size:1.3rem;color:var(--ink)}
.logo svg{width:30px;height:30px;flex:none}
.nav-links{display:flex;align-items:center;gap:1.5rem;list-style:none}
.nav-links a{color:var(--text);font-weight:500;font-size:.92rem;position:relative;padding:.2rem 0}
.nav-links a::after{content:'';position:absolute;left:0;bottom:-2px;width:0;height:3px;background:linear-gradient(90deg,var(--sky-500),var(--green-400));border-radius:2px;transition:width .25s var(--ease)}
.nav-links a:hover::after{width:100%}
.nav-actions{display:flex;align-items:center;gap:.6rem}
.burger{display:none;background:none;border:none;cursor:pointer;padding:.4rem}
.burger span{display:block;width:22px;height:2px;background:var(--ink);margin:5px 0;border-radius:2px}

/* ============ Hero — the thesis is a working ask box ============ */
.hero{padding:4.5rem 0 3.5rem;position:relative;overflow:hidden}
.hero::after{
  content:'';position:absolute;inset:0;z-index:-1;opacity:.6;
  background:radial-gradient(650px 300px at 15% 0%, rgba(46,140,240,.14), transparent),
             radial-gradient(650px 300px at 85% 10%, rgba(52,230,166,.16), transparent);
}
.hero-in{max-width:760px;margin-inline:auto;text-align:center}
.hero p.lead{color:var(--muted);font-size:1.1rem;margin:1.3rem auto 2.2rem;max-width:52ch}

/* the ask box */
.askbox{
  background:var(--card);border:1.5px solid var(--rule);border-radius:var(--r-xl);
  padding:1.1rem;box-shadow:var(--sh-l);text-align:left;
  transition:border-color .2s;
}
.askbox:focus-within{border-color:var(--sky-500);box-shadow:var(--sh-l), 0 0 0 4px rgba(46,140,240,.14)}
.askbox textarea{
  width:100%;border:none;outline:none;resize:none;background:transparent;
  font-family:inherit;font-size:1.02rem;color:var(--text);min-height:76px;padding:.5rem
}
.askbox textarea::placeholder{color:#8DA0BE}
.askbox-foot{display:flex;align-items:center;justify-content:space-between;gap:.8rem;flex-wrap:wrap;padding-top:.7rem;border-top:1px solid var(--rule)}

/* output-type picker (FR: option to select output type) */
.types{display:flex;gap:.3rem;background:var(--paper);padding:.28rem;border-radius:100px}
.types input{display:none}
.types label{
  padding:.45rem 1rem;border-radius:100px;cursor:pointer;font-size:.85rem;font-weight:600;
  color:var(--muted);transition:.18s;position:relative;white-space:nowrap
}
.types label:hover{color:var(--ink)}
.types input:checked + label{background:linear-gradient(135deg,var(--sky-500),var(--sky-700));color:#fff;box-shadow:var(--sh-sky)}

.chips{display:flex;gap:.5rem;justify-content:center;flex-wrap:wrap;margin-top:1.6rem}
.chip{
  background:#fff;border:1px solid var(--rule);border-radius:100px;padding:.4rem 1rem;
  font-size:.84rem;cursor:pointer;color:var(--muted);transition:.18s;font-family:inherit
}
.chip:hover{border-color:var(--green-500);color:var(--green-600);transform:translateY(-2px);box-shadow:var(--sh-s)}

/* ============ Sections / cards ============ */
.section{padding:4rem 0}
.section-alt{background:#fff;border-block:1px solid var(--rule)}
.section-head{max-width:620px;margin-bottom:2.6rem}
.section-head p{color:var(--muted);margin-top:.6rem}

.grid-3{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:1.2rem}
.grid-2{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:1.4rem}

.card{
  background:var(--card);border:1px solid var(--rule);border-radius:var(--r-l);
  padding:1.6rem;margin-bottom:1.3rem;position:relative;box-shadow:var(--sh-s)
}
/* MARGIN RULE: a soft sky-to-green gradient rule down the left of a result card */
.card-ruled{padding-left:2.2rem}
.card-ruled::before{
  content:'';position:absolute;left:1.1rem;top:1rem;bottom:1rem;
  width:3px;background:linear-gradient(180deg,var(--sky-500),var(--green-400));border-radius:3px
}
.card-head{display:flex;align-items:center;justify-content:space-between;gap:1rem;margin-bottom:1.1rem;flex-wrap:wrap}
.card-head h3{font-size:1.2rem}
.f-card{background:#fff;border:1px solid var(--rule);border-radius:var(--r-l);padding:1.7rem;transition:.25s var(--ease)}
.f-card:hover{box-shadow:var(--sh-m);transform:translateY(-3px);border-color:var(--sky-300)}
.f-icon{width:42px;height:42px;border-radius:12px;display:grid;place-items:center;background:linear-gradient(135deg,var(--sky-100),var(--sky-300));color:var(--sky-700);margin-bottom:1rem;font-size:1.2rem;box-shadow:var(--sh-s)}
.f-icon.hl{background:linear-gradient(135deg,var(--green-300),var(--green-500));color:#06341F}
.f-icon.mint{background:var(--green-soft);color:#0A7A54}
.f-icon.coral{background:var(--coral-soft);color:#C4453A}

/* ============ Forms ============ */
.auth{min-height:100vh;display:grid;grid-template-columns:1fr 1fr}
.auth-art{
  background:linear-gradient(160deg,var(--ink-2),var(--sky-700));color:#fff;padding:3.2rem;display:flex;flex-direction:column;
  justify-content:space-between;position:relative;overflow:hidden
}
.auth-art::before{
  content:'';position:absolute;inset:0;opacity:.5;
  background:radial-gradient(500px 260px at 90% 0%, rgba(52,230,166,.22), transparent),
             radial-gradient(400px 220px at 0% 100%, rgba(46,140,240,.25), transparent)
}
.auth-art > *{position:relative;z-index:2}
.auth-art blockquote{font-family:'Poppins',sans-serif;font-weight:500;font-size:1.7rem;line-height:1.3}
.auth-art .mark::before{background:linear-gradient(100deg,var(--green-300),var(--green-500));opacity:.95}
.auth-art cite{display:block;margin-top:1rem;font-style:normal;font-size:.85rem;color:#AFC6E8}
.auth-form{display:flex;align-items:center;justify-content:center;padding:2.6rem 1.8rem;overflow-y:auto}
.auth-box{width:min(450px,100%)}

.fg{margin-bottom:1rem}
.frow{display:grid;grid-template-columns:1fr 1fr;gap:.9rem}
label{display:block;font-size:.82rem;font-weight:700;color:var(--ink);margin-bottom:.35rem}
input,select,textarea{
  width:100%;padding:.78rem 1rem;border:1.5px solid var(--rule);border-radius:var(--r-m);
  font-family:inherit;font-size:.93rem;background:#fff;color:var(--text);transition:.18s
}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--sky-500);box-shadow:0 0 0 4px rgba(46,140,240,.14)}
textarea{resize:vertical;min-height:100px}
.hint{font-size:.78rem;color:var(--muted);margin-top:.3rem}

/* ============ Notes / alerts ============ */
.note{padding:.85rem 1.1rem;border-radius:var(--r-m);font-size:.9rem;margin-bottom:1.1rem;font-weight:500;border:1px solid}
.note-ok{background:var(--green-soft);color:#0A6E4C;border-color:#A6EED0}
.note-err{background:var(--coral-soft);color:#B23C32;border-color:#FFC7C1}
.note-warn{background:var(--amber-soft);color:#8A5B0A;border-color:#F4D896}
.note-info{background:var(--sky-50);color:var(--sky-700);border-color:var(--sky-100)}

/* ============ App shell (logged in) ============ */
.shell{display:grid;grid-template-columns:242px 1fr;min-height:100vh}
.side{background:linear-gradient(180deg,var(--ink-2),#0C1E3B);color:#9DB2D6;padding:1.5rem 1rem;position:sticky;top:0;height:100vh;display:flex;flex-direction:column;overflow-y:auto}
.side .logo{color:#fff;padding:0 .5rem;margin-bottom:.3rem}
.side .who{font-size:.74rem;color:#7C90B5;padding:0 .5rem;margin-bottom:1.6rem}
.side nav{display:grid;gap:.15rem}
.side a{display:flex;align-items:center;gap:.65rem;padding:.68rem .85rem;border-radius:11px;color:#9DB2D6;font-size:.9rem;font-weight:500;transition:.18s}
.side a:hover{background:rgba(255,255,255,.07);color:#fff}
.side a.on{background:linear-gradient(135deg,var(--sky-500),var(--sky-700));color:#fff;font-weight:700;box-shadow:var(--sh-sky)}
.side a .ic{width:16px;text-align:center;flex:none}
.side .out{margin-top:auto;padding-top:1rem;border-top:1px solid rgba(255,255,255,.12)}
.main{padding:2rem 2.2rem;overflow-x:hidden}

.page-head{display:flex;align-items:flex-start;justify-content:space-between;gap:1rem;flex-wrap:wrap;margin-bottom:1.6rem}
.page-head h1{font-size:2rem}
.page-head p{color:var(--muted);font-size:.92rem;margin-top:.2rem}

.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:.9rem;margin-bottom:1.6rem}
.stat{background:linear-gradient(160deg,#fff,var(--paper));border:1px solid var(--rule);border-radius:var(--r-l);padding:1.1rem 1.3rem;box-shadow:var(--sh-s)}
.stat .k{font-family:'JetBrains Mono',monospace;font-size:.68rem;color:var(--muted);letter-spacing:.06em;text-transform:uppercase}
.stat .v{font-family:'Poppins',sans-serif;font-weight:700;font-size:2rem;color:var(--sky-700);line-height:1.1;margin-top:.2rem}

/* ============ QUIZ — signature reused on the correct answer ============ */
.q{border:1px solid var(--rule);border-radius:var(--r-l);padding:1.3rem;margin-bottom:1rem;background:#fff;box-shadow:var(--sh-s)}
.q-num{font-family:'JetBrains Mono',monospace;font-size:.72rem;color:var(--sky-600);letter-spacing:.1em;margin-bottom:.5rem}
.q-text{font-weight:700;font-size:1.02rem;color:var(--ink);margin-bottom:1rem;line-height:1.45}
.opts{display:grid;gap:.5rem}
.opt{
  display:flex;align-items:flex-start;gap:.75rem;padding:.75rem 1rem;
  border:1.5px solid var(--rule);border-radius:var(--r-m);cursor:pointer;
  background:#fff;transition:.16s var(--ease);font-size:.93rem;text-align:left;
  font-family:inherit;color:var(--text);width:100%
}
.opt:hover:not(:disabled){border-color:var(--sky-500);transform:translateX(3px);box-shadow:var(--sh-s)}
.opt .ltr{
  font-family:'JetBrains Mono',monospace;font-size:.78rem;font-weight:700;
  width:22px;height:22px;border-radius:6px;background:var(--paper);color:var(--muted);
  display:grid;place-items:center;flex:none;margin-top:1px
}
.opt.correct{border-color:var(--green-500);background:var(--green-soft)}
.opt.correct .ltr{background:linear-gradient(135deg,var(--green-400),var(--green-600));color:#fff}
/* the gloss sweep, reused: the right answer gets marked */
.opt.correct .txt{position:relative;z-index:1;font-weight:700}
.opt.correct .txt::before{
  content:'';position:absolute;left:-.15em;right:-.15em;top:.2em;bottom:.05em;
  background:linear-gradient(100deg,var(--green-300),var(--green-500));z-index:-1;border-radius:3px 9px 4px 8px;
  box-shadow:0 2px 8px rgba(18,201,138,.3) inset;
  transform:rotate(-.5deg) scaleX(0);transform-origin:left center;
  animation:swipe .45s var(--ease) forwards
}
.opt.wrong{border-color:var(--coral);background:var(--coral-soft)}
.opt.wrong .ltr{background:var(--coral);color:#fff}
.opt:disabled{cursor:default}
.q-reason{
  margin-top:.9rem;padding:.8rem 1rem;background:var(--paper);border-radius:var(--r-m);
  font-size:.88rem;color:var(--muted);display:none
}
.q-reason.show{display:block}
.q-reason b{color:var(--ink)}

.score{
  background:linear-gradient(135deg,var(--ink-2),var(--sky-700));color:#fff;border-radius:var(--r-l);padding:1.4rem 1.6rem;
  display:flex;align-items:center;justify-content:space-between;gap:1rem;flex-wrap:wrap;box-shadow:var(--sh-l)
}
.score .big{font-family:'Poppins',sans-serif;font-weight:700;font-size:2.6rem;line-height:1}

/* ============ Chat ============ */
.chat-wrap{display:flex;flex-direction:column;height:calc(100vh - 8rem);background:#fff;border:1px solid var(--rule);border-radius:var(--r-l);overflow:hidden;box-shadow:var(--sh-s)}
.chat-feed{flex:1;overflow-y:auto;padding:1.4rem;display:flex;flex-direction:column;gap:.9rem}
.bub{max-width:74%;padding:.8rem 1.1rem;border-radius:18px;font-size:.94rem;line-height:1.55;white-space:pre-wrap;word-wrap:break-word}
.bub-user{align-self:flex-end;background:linear-gradient(135deg,var(--sky-500),var(--sky-700));color:#fff;border-bottom-right-radius:5px;box-shadow:var(--sh-sky)}
.bub-ai{align-self:flex-start;background:var(--paper);color:var(--text);border:1px solid var(--rule);border-bottom-left-radius:5px}
.bub-err{align-self:flex-start;background:var(--coral-soft);color:#B23C32;border:1px solid #FFC7C1;border-bottom-left-radius:5px}
.chat-bar{display:flex;gap:.6rem;padding:1rem;border-top:1px solid var(--rule);background:#fff}
.chat-bar input{flex:1}
.typing{display:flex;gap:4px;align-self:flex-start;padding:.9rem 1.1rem;background:var(--paper);border:1px solid var(--rule);border-radius:18px}
.typing i{width:6px;height:6px;background:var(--green-500);border-radius:50%;animation:blink 1.2s infinite}
.typing i:nth-child(2){animation-delay:.2s}
.typing i:nth-child(3){animation-delay:.4s}
@keyframes blink{0%,60%,100%{opacity:.25}30%{opacity:1}}

/* ============ History ============ */
.hist{background:#fff;border:1px solid var(--rule);border-radius:var(--r-l);padding:1.2rem 1.4rem;margin-bottom:.8rem;transition:.2s var(--ease);position:relative;box-shadow:var(--sh-s)}
.hist:hover{box-shadow:var(--sh-m);transform:translateY(-2px);border-color:var(--sky-300)}
.hist-top{display:flex;align-items:center;justify-content:space-between;gap:1rem;flex-wrap:wrap}
.hist h3{font-size:1.08rem;margin-bottom:.2rem}
.hist .meta{font-family:'JetBrains Mono',monospace;font-size:.72rem;color:var(--muted);display:flex;gap:.7rem;flex-wrap:wrap}
.hist p{font-size:.89rem;color:var(--muted);margin-top:.5rem}

.tag{
  display:inline-block;padding:.18rem .6rem;border-radius:100px;font-size:.7rem;font-weight:700;
  font-family:'JetBrains Mono',monospace;letter-spacing:.03em;text-transform:uppercase
}
.tag-violet{background:var(--sky-50);color:var(--sky-700)}
.tag-hl{background:var(--amber-soft);color:#8A5B0A}
.tag-mint{background:var(--green-soft);color:#0A7A54}
.tag-coral{background:var(--coral-soft);color:#C4453A}
.tag-grey{background:var(--paper);color:var(--muted);border:1px solid var(--rule)}

.empty{text-align:center;padding:3rem 1rem;color:var(--muted)}
.empty .big{font-size:2.6rem;opacity:.35;margin-bottom:.5rem}
.empty h3{margin-bottom:.4rem}
.empty p{font-size:.92rem;margin-bottom:1.2rem}

/* prose (AI output) */
.prose p{margin-bottom:.9rem;line-height:1.75}
.prose p:last-child{margin-bottom:0}

/* ============ Loading ============ */
.load{display:none;text-align:center;padding:2.5rem 1rem}
.load.on{display:block}
.load .bar{width:180px;height:4px;background:var(--rule);border-radius:2px;margin:0 auto 1rem;overflow:hidden;position:relative}
.load .bar::after{
  content:'';position:absolute;inset:0;width:40%;background:linear-gradient(90deg,var(--sky-500),var(--green-400));border-radius:2px;
  animation:slide 1.1s var(--ease) infinite
}
@keyframes slide{0%{left:-40%}100%{left:100%}}
.load p{font-size:.9rem;color:var(--muted)}

/* ============ Footer ============ */
footer{background:linear-gradient(180deg,var(--ink-2),#0C1E3B);color:#8DA0C4;padding:3rem 0 1.6rem;margin-top:3.5rem}
footer .cols{display:grid;grid-template-columns:1.7fr 1fr 1fr;gap:2rem;padding-bottom:2rem;border-bottom:1px solid rgba(255,255,255,.12)}
footer h4{color:#fff;font-family:'JetBrains Mono',monospace;font-size:.72rem;text-transform:uppercase;letter-spacing:.1em;margin-bottom:.9rem;font-weight:500}
footer a{color:#8DA0C4;display:block;padding:.22rem 0;font-size:.88rem}
footer a:hover{color:var(--green-400)}
footer .bottom{padding-top:1.3rem;font-size:.8rem;display:flex;justify-content:space-between;flex-wrap:wrap;gap:.5rem}

/* ============ Utilities ============ */
.mt-1{margin-top:.5rem}.mt-2{margin-top:1rem}.mt-3{margin-top:1.6rem}
.mb-2{margin-bottom:1rem}.mb-0{margin-bottom:0}
.text-c{text-align:center}.muted{color:var(--muted)}
.flex{display:flex;gap:.6rem;align-items:center;flex-wrap:wrap}
.between{justify-content:space-between}
.small{font-size:.84rem}
.mono{font-family:'JetBrains Mono',ui-monospace,monospace}

/* ============ Responsive ============ */
@media (max-width:900px){
  .auth{grid-template-columns:1fr}
  .auth-art{display:none}
  .shell{grid-template-columns:1fr}
  .side{position:fixed;left:0;top:0;width:242px;z-index:100;transform:translateX(-100%);transition:transform .28s var(--ease)}
  .side.open{transform:translateX(0);box-shadow:var(--sh-l)}
  .main{padding:1.3rem}
  .mobile-bar{display:flex !important}
  footer .cols{grid-template-columns:1fr 1fr}
}
@media (max-width:700px){
  .nav-links{position:absolute;top:68px;left:0;right:0;background:#fff;flex-direction:column;align-items:stretch;padding:1rem;gap:.2rem;border-bottom:1px solid var(--rule);box-shadow:var(--sh-m);display:none}
  .nav-links.open{display:flex}
  .nav-links a{padding:.7rem}
  .burger{display:block}
  .nav .btn-ghost{display:none}
  .frow{grid-template-columns:1fr}
  .types{width:100%}
  .types label{flex:1;text-align:center;padding:.45rem .5rem;font-size:.8rem}
  .askbox-foot{flex-direction:column;align-items:stretch}
  .askbox-foot .btn{width:100%}
  .bub{max-width:88%}
  .section{padding:2.8rem 0}
  footer .cols{grid-template-columns:1fr}
  .chat-wrap{height:calc(100vh - 10rem)}
  h1{font-size:clamp(1.9rem,8vw,2.6rem)}
  .stats{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:480px){
  .stats{grid-template-columns:1fr}
  .card,.f-card,.hist{padding:1.2rem}
}
.mobile-bar{display:none;align-items:center;gap:.8rem;padding:.9rem 1.2rem;background:linear-gradient(135deg,var(--ink-2),var(--sky-700));color:#fff;position:sticky;top:0;z-index:50}
.mobile-bar button{background:none;border:none;cursor:pointer;padding:.2rem}
.mobile-bar button span{display:block;width:20px;height:2px;background:#fff;margin:4px 0;border-radius:2px}
.backdrop{display:none;position:fixed;inset:0;background:rgba(16,35,63,.5);z-index:99}
.backdrop.on{display:block}