/* ===========================================================
   qtwillyG — Mountain bike tools
   =========================================================== */
:root{
  --bg:#0a0c0f;
  --bg-soft:#0e1116;
  --surface:#14181e;
  --surface-2:#1a1f27;
  --surface-3:#222a34;
  --border:rgba(255,255,255,.08);
  --border-strong:rgba(255,255,255,.16);
  --text:#eef2f5;
  --text-dim:#aab3bf;
  --text-faint:#717b88;
  --accent:#ff3b3b;
  --accent-press:#e22b2b;
  --accent-2:#ff9d2e;
  --danger:#ff6b6b;
  --warn:#ffd166;
  --good:#38b6f0;
  --grad:linear-gradient(135deg,var(--accent),var(--accent-2));
  --radius:16px;
  --radius-sm:11px;
  --shadow:0 18px 50px -12px rgba(0,0,0,.6);
  --shadow-sm:0 6px 20px -8px rgba(0,0,0,.5);
  --maxw:1180px;
  --nav-h:64px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
h1,h2,h3,h4,.brand-text{font-family:'Sora','Inter',system-ui,sans-serif;line-height:1.12;letter-spacing:-.02em;font-weight:700;margin:0}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
button{font-family:inherit}
em{color:var(--text);font-style:normal;font-weight:600}

.grad-text{
  background:var(--grad);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}

/* ---------- NAV ---------- */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  height:var(--nav-h);
  background:transparent;
  border-bottom:1px solid transparent;
  transition:background .35s ease,border-color .35s ease,backdrop-filter .35s ease;
}
.nav.scrolled{
  background:rgba(10,12,15,.9);
  backdrop-filter:blur(16px) saturate(140%);
  -webkit-backdrop-filter:blur(16px) saturate(140%);
  border-color:var(--border);
}
.nav-inner{
  max-width:var(--maxw);margin:0 auto;height:100%;
  display:flex;align-items:center;justify-content:space-between;
  padding:0 22px;gap:18px;
}
.brand{display:flex;align-items:center;gap:10px;flex-shrink:0}
.brand-mark{width:34px;height:34px}
.brand-text{font-size:1.28rem;font-weight:800;letter-spacing:-.03em}
.brand-hi{color:var(--accent)}
.nav-links{display:flex;align-items:center;gap:4px}
.nav-link{
  position:relative;padding:8px 14px;border-radius:999px;
  color:var(--text-dim);font-weight:500;font-size:.93rem;
  transition:color .2s,background .2s;
}
.nav-link:hover{color:var(--text);background:rgba(255,255,255,.05)}
.nav-link.active{color:#fff;background:var(--accent);font-weight:600}

.hamburger{
  display:none;flex-direction:column;gap:5px;
  width:42px;height:42px;align-items:center;justify-content:center;
  background:transparent;border:1px solid var(--border);border-radius:11px;cursor:pointer;
}
.hamburger span{width:19px;height:2px;background:var(--text);border-radius:2px;transition:.25s var(--ease)}
.hamburger[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.hamburger[aria-expanded="true"] span:nth-child(2){opacity:0}
.hamburger[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* ---------- VIEWS ---------- */
.view{display:none;animation:fade .45s var(--ease)}
.view.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---------- scroll-reveal ---------- */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .7s ease,transform .75s cubic-bezier(.22,.61,.36,1)}
.reveal.in{opacity:1;transform:none}

/* ---------- HERO ---------- */
.hero{position:relative;min-height:92vh;display:flex;align-items:center;overflow:hidden;padding-top:var(--nav-h)}
.hero-bg{position:absolute;inset:0;background-size:cover;background-position:center 30%;opacity:0;transition:opacity 1.8s ease-in-out;will-change:opacity;animation:heroZoom 20s ease-in-out infinite alternate}
.hero-bg.show{opacity:1}
@keyframes heroZoom{from{transform:scale(1.04)}to{transform:scale(1.1)}}
.hero-overlay{position:absolute;inset:0;background:
  linear-gradient(100deg,rgba(8,10,13,.94) 0%,rgba(8,10,13,.74) 38%,rgba(8,10,13,.32) 70%,rgba(8,10,13,.55) 100%),
  linear-gradient(0deg,rgba(8,10,13,.9) 0%,transparent 32%);
}
.hero-content{position:relative;max-width:var(--maxw);margin:0 auto;padding:40px 22px;width:100%}
.eyebrow{
  display:inline-block;font-size:.78rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:var(--accent);padding:6px 14px;border:1px solid rgba(255,59,59,.3);border-radius:999px;
  background:rgba(255,59,59,.07);margin-bottom:22px;
}
.hero-title{font-size:clamp(2.6rem,7vw,5.2rem);font-weight:800;letter-spacing:-.04em;margin-bottom:18px}
.hero-sub{font-size:clamp(1rem,1.5vw,1.18rem);color:var(--text-dim);max-width:620px;margin-bottom:30px}
.hero-cta{display:flex;flex-wrap:wrap;gap:14px;margin-bottom:46px}
.hero-stats{display:flex;flex-wrap:wrap;gap:34px}
.stat{display:flex;flex-direction:column}
.stat strong{font-family:'Sora';font-size:1.35rem;font-weight:700}
.stat span{font-size:.85rem;color:var(--text-faint)}

.scroll-cue{position:absolute;bottom:22px;left:50%;transform:translateX(-50%);width:26px;height:42px;border:2px solid rgba(255,255,255,.3);border-radius:14px;display:flex;justify-content:center;padding-top:7px}
.scroll-cue span{width:4px;height:8px;background:var(--accent);border-radius:2px;animation:scroll 1.9s cubic-bezier(.4,0,.2,1) infinite;will-change:transform,opacity}
@keyframes scroll{0%{opacity:0;transform:translateY(0)}18%{opacity:1}50%{opacity:1;transform:translateY(11px)}78%{opacity:0;transform:translateY(11px)}100%{opacity:0;transform:translateY(0)}}

/* ---------- BUTTONS ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 24px;border-radius:999px;font-weight:600;font-size:.96rem;
  cursor:pointer;border:1px solid transparent;transition:transform .18s var(--ease),box-shadow .25s,background .2s,border-color .2s;
}
.btn:active{transform:translateY(1px) scale(.99)}
.btn-accent{background:var(--accent);color:#fff;box-shadow:0 8px 26px -8px rgba(255,59,59,.5)}
.btn-accent:hover{background:#ff5454;transform:translateY(-2px);box-shadow:0 14px 32px -8px rgba(255,59,59,.6)}
.btn-ghost{background:rgba(255,255,255,.04);color:var(--text);border-color:var(--border-strong)}
.btn-ghost:hover{background:rgba(255,255,255,.1);transform:translateY(-2px)}

/* ---------- SECTIONS ---------- */
.section{max-width:var(--maxw);margin:0 auto;padding:90px 22px}
.section-head{text-align:center;max-width:680px;margin:0 auto 52px}
.kicker{display:inline-block;font-size:.78rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--accent-2);margin-bottom:14px}
.section-head h2{font-size:clamp(1.8rem,3.6vw,2.7rem);margin-bottom:14px}
.section-lead{color:var(--text-dim);font-size:1.05rem}

/* ---------- TOOLS GRID ---------- */
.tools-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.tool-card{
  position:relative;background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius);padding:26px;overflow:hidden;
  transition:transform .25s var(--ease),border-color .25s,background .25s;
  display:flex;flex-direction:column;
}
.tool-card::after{content:"";position:absolute;inset:0;border-radius:inherit;padding:1px;background:var(--grad);
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;
  opacity:0;transition:opacity .25s}
.tool-card:hover{transform:translateY(-5px);background:var(--surface-2)}
.tool-card:hover::after{opacity:1}
.tool-ic{
  width:50px;height:50px;border-radius:13px;display:flex;align-items:center;justify-content:center;
  background:rgba(255,59,59,.12);color:var(--accent);margin-bottom:18px;
}
.tool-ic svg{width:26px;height:26px}
.tool-card h3{font-size:1.22rem;margin-bottom:9px}
.tool-card p{color:var(--text-dim);font-size:.94rem;margin:0 0 18px;flex:1}
.tool-go{display:inline-flex;align-items:center;gap:7px;color:var(--accent);font-weight:600;font-size:.92rem}
.tool-go .arr{transition:transform .2s var(--ease)}
.tool-card:hover .tool-go .arr{transform:translateX(4px)}
.tool-card-cta{background:linear-gradient(150deg,rgba(255,157,46,.1),rgba(255,59,59,.07));border-color:rgba(255,59,59,.22)}

/* ---------- GALLERY ---------- */
.gallery-section{padding-top:30px}
.gallery{display:grid;grid-template-columns:repeat(4,1fr);grid-auto-rows:180px;gap:14px}
.g-tile{position:relative;margin:0;border-radius:14px;overflow:hidden;background:var(--surface-2)}
.g-tile img{width:100%;height:100%;object-fit:cover;transition:transform .6s var(--ease)}
.g-tile.tall{grid-row:span 2}
.g-tile.wide{grid-column:span 2}
.g-tile figcaption{
  position:absolute;left:0;right:0;bottom:0;padding:26px 16px 14px;
  font-size:.86rem;font-weight:600;color:#fff;
  background:linear-gradient(0deg,rgba(0,0,0,.7),transparent);
  opacity:0;transform:translateY(8px);transition:.3s var(--ease);
}
.g-tile::before{content:"";position:absolute;inset:0;box-shadow:inset 0 0 0 1px rgba(255,255,255,.05);border-radius:inherit;z-index:2;pointer-events:none}
.g-tile:hover img{transform:scale(1.08)}
.g-tile:hover figcaption{opacity:1;transform:none}

/* ---------- CTA BAND ---------- */
.cta-band{position:relative;margin:40px 0 0;min-height:380px;display:flex;align-items:center;overflow:hidden}
.cta-bg{position:absolute;inset:0;background-size:cover;background-position:center}
.cta-overlay{position:absolute;inset:0;background:linear-gradient(90deg,rgba(8,10,13,.92),rgba(8,10,13,.6))}
.cta-content{position:relative;max-width:var(--maxw);margin:0 auto;padding:60px 22px;width:100%}
.cta-content h2{font-size:clamp(1.9rem,4vw,3rem);margin-bottom:14px}
.cta-content p{color:var(--text-dim);font-size:1.08rem;max-width:520px;margin-bottom:26px}

/* ===========================================================
   CALCULATOR PAGES
   =========================================================== */
.calc-wrap{max-width:var(--maxw);margin:0 auto;padding:calc(var(--nav-h) + 40px) 22px 90px}
.back-link{display:inline-flex;color:var(--text-dim);font-size:.9rem;font-weight:500;margin-bottom:24px;transition:color .2s}
.back-link:hover{color:var(--accent)}
.calc-head{max-width:760px;margin-bottom:30px}
.calc-head h1{font-size:clamp(2rem,4.4vw,3rem);margin-bottom:14px}
.calc-head p{color:var(--text-dim);font-size:1.05rem}

/* tabs */
.tabs{display:inline-flex;gap:4px;background:var(--surface);border:1px solid var(--border);border-radius:999px;padding:5px;margin-bottom:26px}
.tab{padding:9px 22px;border-radius:999px;background:transparent;border:none;color:var(--text-dim);font-weight:600;font-size:.92rem;cursor:pointer;transition:.2s}
.tab.active{background:var(--accent);color:#fff}
.tab-panel{display:none}
.tab-panel.active{display:block;animation:fade .35s var(--ease)}

/* grid: form + results */
.calc-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:24px;align-items:start}
.calc-form{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:26px}

.field{margin-bottom:20px}
.field:last-child{margin-bottom:0}
.field-2col{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-bottom:20px}
.field-2col .field{margin-bottom:0}
.field>label{display:block;font-weight:600;font-size:.9rem;margin-bottom:9px;color:var(--text)}
.field .opt{color:var(--text-faint);font-weight:400;font-size:.85em}
.hint{display:block;font-size:.8rem;color:var(--text-faint);margin-top:7px}

input[type=number],select{
  width:100%;padding:12px 14px;font-size:1rem;font-family:inherit;
  background:var(--bg-soft);border:1px solid var(--border-strong);border-radius:var(--radius-sm);
  color:var(--text);transition:border-color .2s,box-shadow .2s;
}
input[type=number]:focus,select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(255,59,59,.18)}
select{appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 24 24' fill='none' stroke='%23aab3bf' stroke-width='2.5' stroke-linecap='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 14px center;padding-right:38px;cursor:pointer}
.input-row{display:flex;gap:10px;align-items:stretch}
.input-row input{flex:1}

.suffixed{position:relative;flex:1}
.suffixed input{padding-right:36px}
.suffixed span{position:absolute;right:13px;top:50%;transform:translateY(-50%);color:var(--text-faint);font-size:.88rem;pointer-events:none}

/* segmented control */
.seg{display:inline-flex;background:var(--bg-soft);border:1px solid var(--border-strong);border-radius:var(--radius-sm);padding:3px;flex-shrink:0}
.seg-wide{display:flex;width:100%}
.seg-btn{flex:1;padding:9px 16px;border:none;background:transparent;color:var(--text-dim);font-weight:600;font-size:.9rem;border-radius:8px;cursor:pointer;transition:.18s;white-space:nowrap}
.seg-btn.active{background:var(--accent);color:#fff}

.check{display:flex;align-items:flex-start;gap:9px;font-size:.86rem;color:var(--text-dim);font-weight:500;margin-top:12px;cursor:pointer;line-height:1.45}
.check input{margin-top:2px;width:17px;height:17px;accent-color:var(--accent);flex-shrink:0;cursor:pointer}

.form-note{font-size:.84rem;color:var(--text-faint);margin:18px 0 0;padding-top:16px;border-top:1px solid var(--border);line-height:1.55}

/* results */
.calc-results{position:sticky;top:calc(var(--nav-h) + 16px);background:linear-gradient(165deg,var(--surface-2),var(--surface));border:1px solid var(--border-strong);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow-sm)}
.res-title{font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;color:var(--text-faint);font-weight:600;margin-bottom:18px}
.res-hero{display:flex;gap:14px;margin-bottom:8px}
.res-block{flex:1;background:var(--bg-soft);border:1px solid var(--border);border-radius:var(--radius-sm);padding:16px}
.res-block .lbl{font-size:.8rem;color:var(--text-dim);font-weight:600;margin-bottom:6px;display:flex;align-items:center;gap:6px}
.res-block .big{font-family:'Sora';font-size:2.1rem;font-weight:800;line-height:1;letter-spacing:-.03em}
.res-block .big small{font-size:.95rem;font-weight:600;color:var(--text-dim);letter-spacing:0}
.res-block .sub{font-size:.82rem;color:var(--text-faint);margin-top:6px}
.res-block.accent{border-color:rgba(255,59,59,.38);background:rgba(255,59,59,.07)}
.res-block.accent .big{color:var(--accent)}
.res-block.teal{border-color:rgba(255,157,46,.38);background:rgba(255,157,46,.07)}
.res-block.teal .big{color:var(--accent-2)}

.res-rows{margin-top:16px;display:flex;flex-direction:column;gap:1px;border-radius:var(--radius-sm);overflow:hidden}
.res-row{display:flex;justify-content:space-between;align-items:center;gap:14px;padding:12px 14px;background:var(--bg-soft);font-size:.92rem}
.res-row .k{color:var(--text-dim)}
.res-row .v{font-weight:700;font-family:'Sora';text-align:right}
.res-row .v small{font-weight:500;color:var(--text-faint);font-family:'Inter'}

.callout{margin-top:16px;padding:13px 15px;border-radius:var(--radius-sm);font-size:.88rem;line-height:1.5;border:1px solid;display:flex;gap:10px}
.callout .ic{flex-shrink:0;font-size:1rem;line-height:1.4}
.callout.ok{background:rgba(56,182,240,.09);border-color:rgba(56,182,240,.32);color:#c4e6f8}
.callout.warn{background:rgba(255,209,102,.08);border-color:rgba(255,209,102,.3);color:#f0e0bd}
.callout.info{background:rgba(120,148,184,.09);border-color:rgba(120,148,184,.3);color:#cfdaea}
.callout.bad{background:rgba(255,107,107,.08);border-color:rgba(255,107,107,.3);color:#f4cccc}
.callout strong{color:#fff}

/* how-to / reference */
.howto,.reference{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:26px 28px;margin-top:24px}
.howto h3,.reference h3{font-size:1.2rem;margin-bottom:16px}
.howto ol{margin:0;padding-left:20px;color:var(--text-dim)}
.howto li{margin-bottom:10px;padding-left:4px}
.howto li::marker{color:var(--accent);font-weight:700}
.bullets{list-style:none;margin:0;padding:0;display:grid;gap:12px}
.bullets li{position:relative;padding-left:26px;color:var(--text-dim);font-size:.95rem}
.bullets li::before{content:"";position:absolute;left:0;top:9px;width:9px;height:9px;border-radius:3px;background:var(--grad)}
.bullets strong,.howto strong{color:var(--text)}

.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch}
.ref-table{width:100%;border-collapse:collapse;font-size:.92rem;min-width:380px}
.ref-table th,.ref-table td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--border)}
.ref-table th{color:var(--text-faint);font-weight:600;font-size:.8rem;letter-spacing:.05em;text-transform:uppercase}
.ref-table td{color:var(--text-dim)}
.ref-table tbody tr:hover{background:rgba(255,255,255,.02)}
.ref-table td:first-child{color:var(--text);font-weight:600}
.fine{font-size:.86rem;color:var(--text-faint);margin:16px 0 0}

.hidden{display:none!important}

/* ---------- FOOTER ---------- */
.footer{border-top:1px solid var(--border);background:var(--bg-soft);margin-top:40px}
.footer-inner{max-width:var(--maxw);margin:0 auto;padding:54px 22px 34px;display:grid;grid-template-columns:1.4fr 1fr 1.6fr;gap:40px}
.footer-brand .brand-text{font-size:1.4rem;font-weight:800}
.footer-brand p{color:var(--text-faint);font-size:.92rem;margin:12px 0 0;max-width:280px}
.footer-links h4,.footer-note h4{font-size:.82rem;letter-spacing:.1em;text-transform:uppercase;color:var(--text-faint);margin-bottom:16px}
.footer-links{display:flex;flex-direction:column;gap:10px}
.footer-links a{color:var(--text-dim);font-size:.94rem;transition:color .2s;width:fit-content}
.footer-links a:hover{color:var(--accent)}
.footer-note p{color:var(--text-faint);font-size:.88rem;margin:0;line-height:1.6}
.footer-bar{border-top:1px solid var(--border);padding:20px 22px;max-width:var(--maxw);margin:0 auto;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;color:var(--text-faint);font-size:.83rem}

/* ===========================================================
   RESPONSIVE
   =========================================================== */
@media(max-width:880px){
  .nav-links{
    position:fixed;top:var(--nav-h);left:0;right:0;
    flex-direction:column;align-items:stretch;gap:6px;
    background:rgba(10,12,15,.97);backdrop-filter:blur(16px);
    padding:16px 18px 24px;border-bottom:1px solid var(--border);
    transform:translateY(-130%);transition:transform .32s var(--ease);
    box-shadow:var(--shadow);
  }
  .nav-links.open{transform:translateY(0)}
  .nav-link{padding:13px 16px;font-size:1rem}
  .nav-link.active{background:rgba(255,59,59,.16);color:var(--accent)}
  .hamburger{display:flex}
  .tools-grid{grid-template-columns:1fr 1fr}
  .footer-inner{grid-template-columns:1fr 1fr}
  .footer-note{grid-column:1/-1}
}
@media(max-width:760px){
  .calc-grid{grid-template-columns:1fr}
  .calc-results{position:static}
  .hero{min-height:88vh}
  .hero-stats{gap:22px}
  .section{padding:64px 20px}
  .gallery{grid-template-columns:repeat(2,1fr);grid-auto-rows:150px}
  .g-tile.wide{grid-column:span 2}
  .g-tile.tall{grid-row:span 2}
}
@media(max-width:560px){
  .tools-grid{grid-template-columns:1fr}
  .footer-inner{grid-template-columns:1fr}
  .footer-bar{flex-direction:column;gap:6px}
  .res-hero{flex-direction:column}
  .field-2col{grid-template-columns:1fr}
  .hero-title{font-size:clamp(2.3rem,11vw,3rem)}
  .brand-text{font-size:1.12rem}
}
/* Animations are intentionally always on, even when the OS "reduce motion"
   / Windows animation-effects setting is turned off, per request. */