/* BioSensei — biosensei.org · design tokens drawn from the mascot itself:
   ring orange, robe leaf-green, lab-coat foam, and the app's live teal. */
:root{
  --abyss:#06302B; --abyss-2:#0B4238; --abyss-3:#0E5246;
  --foam:#F3F8F5; --foam-2:#E7F1EB;
  --ink:#10302A; --ink-soft:#4C6A61;
  --ring:#ED8B2D; --ring-deep:#B45E0F; --ring-soft:#F6B35C;
  --teal:#0FBFAD; --teal-deep:#0A8A7D;
  --leaf:#3E7C4F;
  --on-dark:#EAF4EF; --on-dark-soft:rgba(234,244,239,.66);
  --maxw:1080px;
  --radius:14px;
  --display:"Fraunces",Georgia,serif;
  --body:"Albert Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:var(--body);font-size:17px;line-height:1.65;color:var(--ink);background:var(--foam)}
img{max-width:100%;height:auto;display:block}
a{color:var(--teal-deep)}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}
h1,h2,h3{font-family:var(--display);font-weight:600;line-height:1.14;letter-spacing:-.01em;margin:0 0 .5em}
h1{font-size:clamp(2.2rem,5.6vw,3.6rem)}
h2{font-size:clamp(1.65rem,3.4vw,2.35rem)}
h3{font-size:1.22rem;line-height:1.3}
p{margin:0 0 1em}
.lead{font-size:1.14rem;max-width:62ch}
:focus-visible{outline:3px solid var(--ring);outline-offset:3px;border-radius:4px}

/* ── nav ── */
.nav{position:sticky;top:0;z-index:40;background:rgba(6,48,43,.92);backdrop-filter:blur(10px);border-bottom:1px solid rgba(234,244,239,.12)}
.nav .wrap{display:flex;align-items:center;gap:26px;min-height:62px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--display);font-weight:700;font-size:1.3rem;color:var(--on-dark);text-decoration:none;letter-spacing:.01em}
.brand svg{flex:none}
.nav-links{display:flex;gap:22px;margin-left:auto;align-items:center}
.nav-links a{color:var(--on-dark-soft);text-decoration:none;font-size:.98rem;white-space:nowrap}
.nav-links a:hover,.nav-links a[aria-current]{color:var(--on-dark)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;font-family:var(--body);font-weight:700;font-size:1rem;
  padding:12px 22px;border-radius:999px;text-decoration:none;white-space:nowrap;flex-shrink:0;border:2px solid transparent;cursor:pointer;min-height:44px}
.btn-ring{background:var(--ring);color:#241300}
.btn-ring:hover{background:var(--ring-deep);color:#fff}
.btn-ghost{border-color:rgba(234,244,239,.4);color:var(--on-dark)}
.btn-ghost:hover{border-color:var(--on-dark)}
.btn-ghost-dark{border-color:rgba(16,48,42,.35);color:var(--ink)}
.btn-ghost-dark:hover{border-color:var(--ink)}
.nav .btn{padding:9px 18px;min-height:38px;font-size:.95rem}
@media(max-width:700px){.nav-links > a:not(.btn){display:none}.nav-links{gap:8px}}
@media(max-width:430px){.brand .brand-word{display:none}.nav .btn{padding:8px 14px;font-size:.9rem}}

/* ── hero ── */
.hero{position:relative;overflow:hidden;background:
  radial-gradient(1200px 600px at 78% 108%,#10564A 0%,transparent 60%),
  linear-gradient(176deg,#052722 0%,var(--abyss) 46%,#0B443A 100%);
  color:var(--on-dark)}
.hero .wrap{display:grid;grid-template-columns:1.08fr .92fr;gap:34px;align-items:center;padding-top:72px;padding-bottom:84px;position:relative}
.hero p{color:var(--on-dark-soft);max-width:54ch}
.hero .kicker{font-family:var(--display);font-style:italic;font-size:1.06rem;color:var(--ring-soft);margin-bottom:14px}
.hero-ctas{display:flex;gap:14px;flex-wrap:wrap;margin-top:26px}
.hero-note{font-size:.92rem;color:var(--on-dark-soft);margin-top:18px}
.hero-note b{color:var(--on-dark)}
/* signature: the sensei inside his sonar rings */
.sensei{position:relative;width:min(430px,86vw);margin:0 auto}
.sensei img{position:relative;z-index:2;filter:drop-shadow(0 18px 42px rgba(0,0,0,.45))}
.rings{position:absolute;inset:-14%;z-index:1}
.rings circle{fill:none;stroke:var(--ring);transform-origin:50% 50%}
.r1{stroke-width:2.4;opacity:.85;animation:breathe 7s ease-in-out infinite}
.r2{stroke-width:1.6;opacity:.45;stroke:var(--ring-soft);animation:breathe 7s ease-in-out -2.3s infinite}
.r3{stroke-width:1;opacity:.22;stroke:var(--teal);animation:breathe 7s ease-in-out -4.6s infinite}
@keyframes breathe{0%,100%{transform:scale(.985)}50%{transform:scale(1.03)}}
.bubble{position:absolute;bottom:-30px;border-radius:50%;background:radial-gradient(circle at 32% 30%,rgba(255,255,255,.5),rgba(255,255,255,.06) 62%);animation:rise linear infinite;z-index:0}
@keyframes rise{to{transform:translateY(-118vh)}}
@media(prefers-reduced-motion:reduce){.r1,.r2,.r3,.bubble{animation:none}.bubble{display:none}}
@media(max-width:860px){.hero .wrap{grid-template-columns:1fr;padding-top:46px;padding-bottom:56px}.sensei{order:-1;width:min(300px,70vw)}}

/* ── sections ── */
.section{padding:78px 0}
.section-dark{background:var(--abyss);color:var(--on-dark)}
.section-dark p{color:var(--on-dark-soft)}
.section-foam2{background:var(--foam-2)}
.section h2{max-width:24ch}
.sub{color:var(--ink-soft);max-width:66ch}
.section-dark .sub{color:var(--on-dark-soft)}

/* habitats — specimen tiles, no card chrome */
.habitats{display:grid;grid-template-columns:repeat(4,1fr);gap:8px 28px;margin-top:40px}
.habitat{border-top:3px solid var(--leaf);padding-top:16px}
.habitat:nth-child(2){border-color:var(--teal)}
.habitat:nth-child(3){border-color:var(--ring)}
.habitat:nth-child(4){border-color:var(--ring-soft)}
.habitat .glyph{font-size:2rem;line-height:1;margin-bottom:10px}
.habitat h3{margin-bottom:6px}
.habitat p{font-size:.95rem;color:var(--ink-soft);margin-bottom:10px}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{font-size:.78rem;font-weight:600;padding:3px 10px;border-radius:999px;background:rgba(15,191,173,.12);color:var(--teal-deep)}
@media(max-width:860px){.habitats{grid-template-columns:repeat(2,1fr)}}
@media(max-width:480px){.habitats{grid-template-columns:1fr}}

/* two ways */
.ways{display:grid;grid-template-columns:1fr 1fr;gap:30px;margin-top:38px}
.way{background:rgba(234,244,239,.055);border:1px solid rgba(234,244,239,.14);border-radius:var(--radius);padding:28px}
.way h3{color:var(--on-dark)}
.way .tag{display:inline-block;font-size:.8rem;font-weight:700;padding:3px 12px;border-radius:999px;margin-bottom:14px}
.tag-manual{background:rgba(246,179,92,.18);color:var(--ring-soft)}
.tag-live{background:rgba(15,191,173,.18);color:var(--teal)}
.way ul{margin:0;padding-left:20px;color:var(--on-dark-soft)}
.way li{margin-bottom:8px}
@media(max-width:780px){.ways{grid-template-columns:1fr}}

/* flow line */
.flow{display:flex;align-items:center;gap:0;margin-top:34px;flex-wrap:wrap;row-gap:18px}
.flow-node{text-align:center;flex:1;min-width:120px}
.flow-node .dot{width:52px;height:52px;border-radius:50%;margin:0 auto 10px;display:flex;align-items:center;justify-content:center;font-size:1.4rem;background:rgba(15,191,173,.12);border:1.5px solid rgba(15,191,173,.45)}
.flow-node b{display:block;font-size:.96rem}
.flow-node span{font-size:.84rem;color:var(--ink-soft)}
.flow-link{flex:0 0 34px;height:2px;background:linear-gradient(90deg,var(--teal),var(--ring));opacity:.5;margin-top:-44px}
@media(max-width:700px){.flow-link{display:none}.flow-node{flex-basis:45%}}

/* Dr quote */
.drsays{display:grid;grid-template-columns:120px 1fr;gap:26px;align-items:start;margin-top:34px;max-width:860px}
.drsays img{width:120px;border-radius:50%;background:radial-gradient(circle,#0E5246,transparent 72%)}
.drsays blockquote{margin:0;font-family:var(--display);font-size:1.3rem;line-height:1.5;font-style:italic;color:var(--on-dark)}
.drsays cite{display:block;margin-top:14px;font-family:var(--body);font-style:normal;font-size:.95rem;color:var(--on-dark-soft)}
@media(max-width:600px){.drsays{grid-template-columns:1fr}.drsays img{width:96px}}

/* HDS band */
.hds{background:linear-gradient(160deg,#4A2B08,#7A4710 55%,#9A5A12);color:#FFF4E3}
.hds .wrap{display:grid;grid-template-columns:1.2fr .8fr;gap:40px;align-items:center;padding-top:72px;padding-bottom:72px}
.hds h2{color:#fff}
.hds p{color:rgba(255,244,227,.82)}
.hds .sun{font-size:3rem;margin-bottom:12px}
.hds .btn-ring{background:#fff;color:#7A4710}
.hds .btn-ring:hover{background:#FFE9C8;color:#4A2B08}
.kitlist{list-style:none;margin:0;padding:0}
.kitlist li:first-child{border-top:none;padding-top:0}
.kitlist li{padding:10px 0;border-top:1px solid rgba(255,244,227,.22);font-size:.98rem}
.kitlist b{color:#fff}
@media(max-width:780px){.hds .wrap{grid-template-columns:1fr}}

/* makers / sysops */
.makers{display:grid;grid-template-columns:1fr 340px;gap:44px;align-items:center}
.makers .frame{border-radius:var(--radius);overflow:hidden;box-shadow:0 24px 60px rgba(3,22,19,.5);transform:rotate(1.4deg)}
@media(max-width:820px){.makers{grid-template-columns:1fr}.makers .frame{max-width:320px}}

/* roadmap FYI */
.fyi{border-left:4px solid var(--ring);background:#fff;border-radius:0 var(--radius) var(--radius) 0;padding:24px 28px;max-width:820px;margin-top:34px}
.fyi h3{margin-bottom:8px}
.fyi p{margin-bottom:0;color:var(--ink-soft)}

/* beta band */
.beta{background:var(--abyss);color:var(--on-dark);text-align:center}
.beta .wrap{padding-top:84px;padding-bottom:84px}
.beta h2{max-width:none}
.beta p{max-width:56ch;margin-left:auto;margin-right:auto;color:var(--on-dark-soft)}
.beta .hero-ctas{justify-content:center}

/* footer */
footer{background:#041F1B;color:var(--on-dark-soft);font-size:.92rem}
footer .wrap{display:flex;flex-wrap:wrap;gap:18px 40px;align-items:center;padding-top:34px;padding-bottom:40px}
footer a{color:var(--on-dark-soft)}
footer a:hover{color:var(--on-dark)}
footer .fbrand{display:flex;align-items:center;gap:10px;color:var(--on-dark);font-family:var(--display);font-weight:600}
footer .spacer{flex:1}

/* ── tutorial ── */
.page-head{background:linear-gradient(176deg,#052722,var(--abyss));color:var(--on-dark)}
.page-head .wrap{padding-top:58px;padding-bottom:58px}
.page-head p{color:var(--on-dark-soft);max-width:60ch}
.steps{counter-reset:step;max-width:800px}
.step{position:relative;padding:0 0 46px 76px;counter-increment:step}
.step::before{content:counter(step);position:absolute;left:0;top:-2px;width:52px;height:52px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;font-family:var(--display);font-weight:700;font-size:1.35rem;
  background:var(--abyss);color:var(--ring-soft)}
.step::after{content:"";position:absolute;left:25px;top:56px;bottom:10px;width:2px;background:linear-gradient(var(--teal),rgba(15,191,173,.1))}
.step:last-child::after{display:none}
.step h3{padding-top:8px}
.step p,.step ul{color:var(--ink-soft)}
.step ul{padding-left:20px}
.step li{margin-bottom:6px}
.hint{background:rgba(237,139,45,.1);border-radius:10px;padding:14px 18px;font-size:.95rem;color:#7A4710;margin-top:10px}
.hint b{color:#4A2B08}
@media(max-width:560px){.step{padding-left:0;padding-top:64px}.step::after{display:none}}

/* ── contact ── */
.contact-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:52px;align-items:start}
@media(max-width:820px){.contact-grid{grid-template-columns:1fr}}
.field{margin-bottom:18px}
.field label{display:block;font-weight:700;font-size:.95rem;margin-bottom:6px}
.field input,.field select,.field textarea{width:100%;font:inherit;padding:12px 14px;border:1.5px solid #C6D8CF;border-radius:10px;background:#fff;color:var(--ink)}
.field textarea{resize:vertical;min-height:140px}
.field input:focus,.field select:focus,.field textarea:focus{border-color:var(--teal);outline:none;box-shadow:0 0 0 3px rgba(15,191,173,.18)}
.mail-fallback{margin-top:14px;font-size:.95rem;color:var(--ink-soft)}
.mail-fallback code{background:#fff;padding:2px 8px;border-radius:6px;font-size:.92rem}
.reasons{list-style:none;margin:26px 0 0;padding:0}
.reasons li{display:grid;grid-template-columns:40px 1fr;gap:14px;padding:16px 0;border-top:1px solid #D7E6DE}
.reasons .glyph{font-size:1.5rem}
.reasons b{display:block}
.reasons span{font-size:.95rem;color:var(--ink-soft)}
.copy-ok{display:none;margin-left:10px;color:var(--teal-deep);font-weight:700}

/* ── language switcher (v2 trilingual) ── */
.lang-switch{display:flex;border:1px solid rgba(234,244,239,.28);border-radius:999px;overflow:hidden;font-size:.82rem;flex-shrink:0}
.lang-switch a{color:var(--on-dark-soft);text-decoration:none;padding:6px 11px;line-height:1;font-weight:600}
.lang-switch a[aria-current]{background:var(--ring);color:#241300;font-weight:700}
.lang-switch a:not([aria-current]):hover{color:var(--on-dark)}
@media(max-width:700px){.lang-switch a{padding:6px 9px}}

/* ── Chinese (zh) typography ── */
html[lang="zh"] body{font-family:"Noto Sans SC","Albert Sans",system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;line-height:1.8;letter-spacing:.01em}
html[lang="zh"] h1,html[lang="zh"] h2,html[lang="zh"] h3,
html[lang="zh"] .brand,html[lang="zh"] .fbrand,
html[lang="zh"] .drsays blockquote,html[lang="zh"] .kicker{font-family:"Noto Serif SC","Fraunces",serif}
html[lang="zh"] h1{line-height:1.28;letter-spacing:.02em}
html[lang="zh"] h2,html[lang="zh"] h3{line-height:1.38;letter-spacing:.02em}
html[lang="zh"] .drsays blockquote,html[lang="zh"] .kicker{font-style:normal}
html[lang="zh"] .lead,html[lang="zh"] .sub{max-width:40em}

h1,h2,h3{text-wrap:balance}
.lead,.sub,.hero p{text-wrap:pretty}