/* ============================================================
   Upwell · Blubuu Finance — official site
   Deep-sea theme, shared by index.html and whitepaper.html.
   Palette + fonts mirror the app (app/src/index.css).
   ============================================================ */

:root {
  --abyss: #04141f;
  --deep: #06283a;
  --mid: #0a4c63;
  --teal: #1aa6cf;
  --surface: #2a7d97;
  --foam: #d6f7ff;
  --bio-cyan: #7fe9ff;
  --bio-green: #73f5c4;
  --bio-lime: #a6ff8f;
  --coral: #ff8aa0;
  --ink: #eaffff;
  --ink-dim: #9fc6d4;
  --glass: rgba(8, 38, 54, 0.62);
  --glass-2: rgba(6, 40, 58, 0.5);
  --glass-line: rgba(127, 233, 255, 0.28);
  --hand: 'Gloria Hallelujah', cursive;
  --display: 'Caveat', cursive;
  --ui: 'Nunito', system-ui, -apple-system, 'Noto Sans TC', sans-serif;
  --maxw: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body { margin: 0; padding: 0; }

body {
  font-family: var(--ui);
  color: var(--ink);
  background: var(--abyss);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--bio-cyan); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--bio-green); text-decoration: underline; }

h1, h2, h3 { line-height: 1.2; font-weight: 800; }
::selection { background: rgba(127, 233, 255, 0.3); color: #fff; }

/* ============ Ocean backdrop (fixed) ============ */
.ocean {
  position: fixed; inset: 0; z-index: 0; overflow: hidden;
  background: linear-gradient(
    to bottom,
    #2a7d97 0%, #146684 14%, #0a4c63 36%, #06283a 64%, #04141f 100%
  );
}
.rays { position: absolute; inset: 0; mix-blend-mode: screen; pointer-events: none; }
.ray {
  position: absolute; top: -10%; width: 150px; height: 130%;
  background: linear-gradient(to bottom, rgba(190, 250, 255, 0.20), rgba(190, 250, 255, 0));
  transform: skewX(-12deg); filter: blur(7px);
  animation: sway 13s ease-in-out infinite;
}
@keyframes sway {
  0%, 100% { opacity: .3; transform: skewX(-12deg) translateX(0); }
  50% { opacity: .65; transform: skewX(-9deg) translateX(28px); }
}
.drift-field { position: absolute; inset: 0; pointer-events: none; }
.drift-bubble {
  position: absolute; bottom: -50px; border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, rgba(255,255,255,.85), rgba(127,233,255,.25) 60%, rgba(127,233,255,0) 75%);
  border: 1px solid rgba(214, 247, 255, 0.35);
  animation: rise linear infinite;
}
@keyframes rise {
  0% { transform: translateY(0) translateX(0); opacity: 0; }
  10% { opacity: .8; } 90% { opacity: .6; }
  100% { transform: translateY(-106vh) translateX(var(--drift, 0)); opacity: 0; }
}

/* ============ Top nav ============ */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 14px clamp(16px, 4vw, 40px);
  background: rgba(4, 20, 31, 0.55);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(127, 233, 255, 0.14);
}
.brand { display: flex; align-items: center; gap: 11px; }
.brand img { width: 38px; height: 38px; filter: drop-shadow(0 0 10px rgba(127, 233, 255, .5)); }
.brand-name { font-family: var(--display); font-size: 30px; font-weight: 700; line-height: .85; color: var(--foam); text-shadow: 0 0 16px rgba(127, 233, 255, .4); }
.brand-sub { font-size: 11.5px; color: var(--ink-dim); letter-spacing: .3px; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { color: var(--ink-dim); font-weight: 700; font-size: 14.5px; }
.nav-links a:hover { color: var(--bio-cyan); text-decoration: none; }
.nav-cta {
  padding: 9px 17px; border-radius: 12px; color: #032 !important; font-weight: 800;
  background: linear-gradient(135deg, #7fe9ff, #73f5c4);
  box-shadow: 0 6px 20px rgba(127, 233, 255, .3);
}
.nav-cta:hover { filter: brightness(1.07); text-decoration: none; }
.nav-toggle { display: none; background: none; border: 0; color: var(--ink); font-size: 26px; cursor: pointer; }

/* ============ Social icons ============ */
.socials { display: flex; align-items: center; gap: 10px; }
.social-ic {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 11px;
  background: var(--glass); border: 1px solid var(--glass-line); color: var(--ink);
  transition: transform .12s ease, box-shadow .2s ease, color .15s ease, border-color .15s ease;
}
.social-ic:hover { transform: translateY(-2px); color: var(--bio-cyan); border-color: rgba(127,233,255,.55); box-shadow: 0 8px 20px rgba(0,0,0,.3); text-decoration: none; }
.social-ic svg { width: 18px; height: 18px; fill: currentColor; }
.nav .social-ic { width: 36px; height: 36px; }
.footer-social { margin-top: 16px; }


/* ============ Layout shell ============ */
.wrap { position: relative; z-index: 1; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(16px, 4vw, 32px); }
section { position: relative; padding: clamp(56px, 8vw, 104px) 0; }
.eyebrow {
  display: inline-block; font-family: var(--hand); font-size: 15px;
  color: var(--bio-cyan); letter-spacing: 1px; margin-bottom: 14px;
}
.section-title { font-size: clamp(28px, 4.4vw, 46px); margin: 0 0 18px; color: var(--foam); }
.section-lead { font-size: clamp(16px, 2vw, 19px); color: var(--ink-dim); max-width: 720px; }

/* ============ Hero ============ */
.hero { padding-top: clamp(48px, 7vw, 86px); padding-bottom: clamp(40px, 6vw, 72px); }
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: clamp(28px, 5vw, 64px); align-items: center; }
.hero h1 { font-size: clamp(40px, 6.6vw, 76px); margin: 0 0 8px; color: #fff; letter-spacing: -1px; }
.hero h1 .accent {
  background: linear-gradient(120deg, #7fe9ff, #73f5c4 60%, #a6ff8f);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-tag { font-family: var(--hand); font-size: clamp(16px, 2.4vw, 22px); color: var(--foam); margin: 0 0 22px; opacity: .92; }
.hero-lead { font-size: clamp(16px, 2.1vw, 20px); color: var(--ink-dim); margin: 0 0 30px; max-width: 560px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--ui); font-weight: 800; font-size: 15.5px;
  padding: 14px 24px; border-radius: 14px; cursor: pointer;
  border: 1px solid var(--glass-line); transition: transform .08s ease, filter .2s ease, box-shadow .2s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { color: #032; border: none; background: linear-gradient(135deg, #7fe9ff, #73f5c4); box-shadow: 0 8px 26px rgba(127, 233, 255, .35); }
.btn-primary:hover { filter: brightness(1.07); text-decoration: none; color: #032; }
.btn-ghost { background: var(--glass); color: var(--ink); }
.btn-ghost:hover { box-shadow: 0 0 0 1px var(--bio-cyan) inset; text-decoration: none; color: var(--ink); }
.hero-stats { display: flex; gap: 26px; margin-top: 34px; flex-wrap: wrap; }
.hero-stat .n { font-family: var(--display); font-size: 36px; font-weight: 700; color: var(--bio-cyan); line-height: 1; }
.hero-stat .l { font-size: 12.5px; color: var(--ink-dim); }

/* ============ Hero ladder visual ============ */
.ladder-card {
  position: relative; padding: 18px; border-radius: 24px;
  background: var(--glass); border: 1px solid var(--glass-line);
  box-shadow: 0 24px 60px rgba(0,0,0,.45); backdrop-filter: blur(8px);
}
.ladder-card svg { width: 100%; height: auto; display: block; }
.ladder-cap { margin-top: 8px; font-size: 12px; color: var(--ink-dim); text-align: center; font-style: italic; }
.bub-name { font-family: var(--ui); font-weight: 800; font-size: 11px; fill: var(--foam); paint-order: stroke; stroke: rgba(4,20,31,.55); stroke-width: 3px; }
.axis-cap { font-family: var(--hand); font-size: 13px; fill: var(--bio-cyan); }
.axis-hint { font-family: var(--ui); font-size: 11px; fill: var(--ink-dim); font-weight: 700; }
@keyframes bob { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-6px); } }
.floatb { animation: bob 4s ease-in-out infinite; transform-box: fill-box; transform-origin: center; }

/* ============ Generic cards / grids ============ */
.card {
  padding: 26px; border-radius: 20px; height: 100%;
  background: var(--glass-2); border: 1px solid var(--glass-line);
  backdrop-filter: blur(6px); transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.card:hover { transform: translateY(-4px); border-color: rgba(127,233,255,.5); box-shadow: 0 16px 40px rgba(0,0,0,.35); }
.card .ic { font-size: 30px; margin-bottom: 12px; display: block; filter: drop-shadow(0 0 10px rgba(127,233,255,.5)); }
.card h3 { font-size: 19px; margin: 0 0 8px; color: var(--foam); }
.card p { margin: 0; font-size: 14.5px; color: var(--ink-dim); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.mt-l { margin-top: 44px; }

/* ============ Two-dimension feature ============ */
.dims-band { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 40px; }
.dim-card { padding: 24px; border-radius: 20px; background: var(--glass-2); border: 1px solid var(--glass-line); }
.dim-pill { display: inline-block; padding: 3px 11px; border-radius: 999px; font-weight: 800; font-size: 12px; margin-bottom: 12px; }
.pill-y { background: rgba(115,245,196,.18); color: var(--bio-green); }
.pill-x { background: rgba(127,233,255,.18); color: var(--bio-cyan); }
.pill-r { background: rgba(166,255,143,.16); color: var(--bio-lime); }
.dim-card h3 { font-size: 18px; margin: 0 0 6px; color: var(--foam); }
.dim-card p { margin: 0; font-size: 14px; color: var(--ink-dim); }

/* ============ Steps (how it works) ============ */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin-top: 40px; counter-reset: step; }
.step { position: relative; padding: 24px 20px; border-radius: 18px; background: var(--glass-2); border: 1px solid var(--glass-line); }
.step::before {
  counter-increment: step; content: counter(step);
  font-family: var(--display); font-size: 30px; font-weight: 700; color: var(--bio-cyan);
  display: block; margin-bottom: 8px;
}
.step h3 { font-size: 16.5px; margin: 0 0 6px; color: var(--foam); }
.step p { margin: 0; font-size: 13.5px; color: var(--ink-dim); }

/* ============ Real-data / verify band ============ */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 5vw, 56px); align-items: center; }
.tag-list { list-style: none; padding: 0; margin: 22px 0 0; display: grid; gap: 14px; }
.tag-list li { display: flex; gap: 12px; font-size: 15px; color: var(--ink); }
.tag-list .ck { color: var(--bio-green); font-weight: 900; flex-shrink: 0; }
.code-card {
  border-radius: 18px; overflow: hidden; border: 1px solid var(--glass-line);
  background: rgba(4,20,31,.62); box-shadow: 0 16px 40px rgba(0,0,0,.4);
}
.code-card .bar { display: flex; gap: 7px; padding: 12px 16px; border-bottom: 1px solid rgba(127,233,255,.12); }
.code-card .bar i { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }
.code-card .bar .t { margin-left: 10px; font-size: 12px; color: var(--ink-dim); font-family: var(--ui); }
.code-card pre { margin: 0; padding: 18px 20px; overflow-x: auto; font-size: 12.5px; line-height: 1.65;
  font-family: ui-monospace, 'SFMono-Regular', Menlo, Consolas, monospace; color: #cfeefb; }
.code-card .c { color: #6f93a3; } .code-card .k { color: var(--bio-cyan); } .code-card .g { color: var(--bio-green); } .code-card .o { color: var(--coral); }

/* ============ Architecture ============ */
.arch { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 40px; }
.layer { padding: 22px; border-radius: 18px; background: var(--glass-2); border: 1px solid var(--glass-line); }
.layer .lk { font-family: var(--hand); font-size: 14px; color: var(--bio-cyan); }
.layer h3 { font-size: 18px; margin: 4px 0 12px; color: var(--foam); }
.layer ul { margin: 0; padding-left: 18px; font-size: 13.5px; color: var(--ink-dim); }
.layer ul li { margin-bottom: 7px; }
.layer code { font-family: ui-monospace, Menlo, monospace; font-size: 12px; color: var(--bio-green); }

/* ============ Deploy / addresses table ============ */
.addr-table { width: 100%; border-collapse: collapse; margin-top: 22px; font-size: 13.5px; }
.addr-table th, .addr-table td { text-align: left; padding: 12px 14px; border-bottom: 1px solid rgba(127,233,255,.12); }
.addr-table th { color: var(--ink-dim); font-weight: 700; font-size: 12.5px; }
.addr-table td code { font-family: ui-monospace, Menlo, monospace; font-size: 12px; color: var(--bio-cyan); word-break: break-all; }
.badge { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 11.5px; font-weight: 800;
  background: rgba(115,245,196,.16); color: var(--bio-green); border: 1px solid rgba(115,245,196,.3); }

/* ============ CTA band ============ */
.cta-band { text-align: center; }
.cta-band .container { padding-top: 8px; padding-bottom: 8px; }
.cta-box {
  padding: clamp(36px, 6vw, 64px); border-radius: 28px; text-align: center;
  background: linear-gradient(135deg, rgba(127,233,255,.12), rgba(115,245,196,.08));
  border: 1px solid var(--glass-line);
}
.cta-box h2 { font-size: clamp(26px, 4vw, 40px); color: #fff; margin: 0 0 14px; }
.cta-box p { color: var(--ink-dim); font-size: 17px; margin: 0 auto 28px; max-width: 560px; }

/* ============ Footer ============ */
.footer { position: relative; z-index: 1; border-top: 1px solid rgba(127,233,255,.14); background: rgba(4,20,31,.6); }
.footer .container { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; padding-top: 40px; padding-bottom: 28px; }
.footer .brand-name { font-size: 26px; }
.footer-cols { display: flex; gap: 56px; flex-wrap: wrap; }
.footer-col h4 { font-size: 13px; color: var(--ink); margin: 0 0 12px; text-transform: uppercase; letter-spacing: .8px; }
.footer-col a { display: block; color: var(--ink-dim); font-size: 14px; margin-bottom: 9px; }
.footer-col a:hover { color: var(--bio-cyan); }
.footer-legal { width: 100%; border-top: 1px solid rgba(127,233,255,.1); margin-top: 8px; padding-top: 18px; font-size: 12.5px; color: var(--ink-dim); }
.footer-legal b { color: var(--coral); }

/* ============ Whitepaper layout ============ */
.wp { position: relative; z-index: 1; }
.wp-hero { padding: clamp(48px, 7vw, 80px) 0 clamp(20px, 3vw, 32px); text-align: center; }
.wp-hero .kicker { font-family: var(--hand); color: var(--bio-cyan); letter-spacing: 1px; }
.wp-hero h1 { font-size: clamp(34px, 5.5vw, 58px); color: #fff; margin: 10px 0 12px; }
.wp-hero p { color: var(--ink-dim); font-size: 17px; max-width: 640px; margin: 0 auto; }
.wp-meta { margin-top: 18px; font-size: 13px; color: var(--ink-dim); }
.wp-meta span { margin: 0 10px; }
.wp-layout { display: grid; grid-template-columns: 240px 1fr; gap: 48px; align-items: start; padding-bottom: 80px; }
.toc { position: sticky; top: 84px; font-size: 14px; }
.toc h4 { font-size: 12px; text-transform: uppercase; letter-spacing: .8px; color: var(--ink-dim); margin: 0 0 12px; }
.toc a { display: block; color: var(--ink-dim); padding: 5px 0; border-left: 2px solid transparent; padding-left: 12px; margin-left: -2px; }
.toc a:hover, .toc a.active { color: var(--bio-cyan); border-left-color: var(--bio-cyan); text-decoration: none; }
.doc { max-width: 760px; }
.doc h2 { font-size: clamp(24px, 3.4vw, 32px); color: var(--foam); margin: 52px 0 16px; padding-top: 12px; }
.doc h2:first-child { margin-top: 0; }
.doc h3 { font-size: 20px; color: var(--foam); margin: 30px 0 10px; }
.doc p { color: #d3e9f1; font-size: 16px; margin: 0 0 16px; }
.doc ul, .doc ol { color: #d3e9f1; font-size: 16px; padding-left: 24px; margin: 0 0 16px; }
.doc li { margin-bottom: 8px; }
.doc strong { color: var(--foam); }
.doc code { font-family: ui-monospace, Menlo, monospace; font-size: 13.5px; color: var(--bio-green); background: rgba(4,20,31,.5); padding: 1px 6px; border-radius: 6px; }
.doc .num { color: var(--bio-cyan); font-family: var(--display); font-size: .85em; margin-right: 8px; }
.callout { padding: 16px 20px; border-radius: 14px; margin: 22px 0; font-size: 15px;
  background: rgba(127,233,255,.08); border: 1px solid var(--glass-line); border-left: 4px solid var(--bio-cyan); }
.callout.warn { background: rgba(255,138,160,.08); border-left-color: var(--coral); }
.callout b { color: var(--foam); }
.doc table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14px; }
.doc table th, .doc table td { text-align: left; padding: 10px 12px; border-bottom: 1px solid rgba(127,233,255,.14); }
.doc table th { color: var(--ink-dim); font-weight: 700; }
.doc table td code { background: none; padding: 0; word-break: break-all; }
.back-top { display: inline-block; margin-top: 40px; font-size: 14px; }

/* ============ Reveal on scroll ============ */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ============ Responsive ============ */
@media (max-width: 920px) {
  .hero-grid { grid-template-columns: 1fr; }
  .ladder-card { order: -1; max-width: 520px; }
  .grid-3, .dims-band, .arch { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr 1fr; }
  .grid-2, .split { grid-template-columns: 1fr; }
  .wp-layout { grid-template-columns: 1fr; }
  .toc { position: relative; top: 0; margin-bottom: 24px; }
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-links.open {
    display: flex; flex-direction: column; align-items: flex-start; gap: 16px;
    position: absolute; top: 100%; left: 0; right: 0; padding: 20px clamp(16px,4vw,40px);
    background: rgba(4,20,31,.96); border-bottom: 1px solid var(--glass-line);
  }
}
@media (max-width: 560px) {
  .steps { grid-template-columns: 1fr; }
  .hero-stats { gap: 18px; }
}
@media (prefers-reduced-motion: reduce) {
  .ray, .drift-bubble, .floatb { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}