/* =========================================================
   voltflat — design system
   Dark, calm, radically simple. One bright signal colour.
   Display: Bricolage Grotesque · Body: Hanken Grotesk
   ========================================================= */

:root {
  --bg:          #0B130E;
  --bg-2:        #0F1A13;
  --surface:     #13211A;
  --surface-2:   #18291F;
  --line:        rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.14);

  --cream:       #F3F6F1;
  --ink:         #0B130E;

  --accent:      #1FE06A;
  --accent-press:#16C95B;
  --accent-soft: rgba(31, 224, 106, 0.12);
  --accent-glow: rgba(31, 224, 106, 0.35);

  --text:        #EAF1EA;
  --muted:       #94A99C;
  --muted-2:     #6B8073;

  --maxw: 1180px;
  --radius: 18px;
  --radius-sm: 12px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);

  --font-display: "Bricolage Grotesque", system-ui, sans-serif;
  --font-body: "Hanken Grotesk", system-ui, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

::selection { background: var(--accent); color: var(--ink); }

a { color: inherit; text-decoration: none; }
strong { font-weight: 700; color: var(--text); }
.accent { color: var(--accent); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.02em;
}

/* ---------- ambient background ---------- */
.bg-field { position: fixed; inset: 0; z-index: -1; overflow: hidden; }
.bg-grid {
  position: absolute; inset: -2px;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 0%, transparent 70%);
  opacity: 0.5;
}
.bg-glow { position: absolute; border-radius: 50%; filter: blur(110px); opacity: 0.5; }
.bg-glow--1 { width: 520px; height: 520px; top: -180px; right: -120px; background: var(--accent-glow); }
.bg-glow--2 { width: 460px; height: 460px; bottom: 10%; left: -160px; background: rgba(31, 224, 106, 0.14); }

/* ---------- layout helpers ---------- */
section { padding: clamp(72px, 11vw, 140px) clamp(22px, 6vw, 80px); max-width: var(--maxw); margin: 0 auto; }
.section-title { font-size: clamp(2rem, 5vw, 3.4rem); max-width: 16ch; }
.eyebrow {
  display: inline-block;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--font-body);
  font-weight: 700; font-size: 0.97rem;
  padding: 0.85em 1.5em;
  border-radius: 999px;
  cursor: pointer; border: 1px solid transparent;
  transition: transform 0.2s var(--ease), background 0.2s, box-shadow 0.25s, color 0.2s;
  white-space: nowrap;
}
.btn--solid {
  background: var(--accent); color: var(--ink);
  box-shadow: 0 0 0 0 var(--accent-glow);
}
.btn--solid:hover {
  background: var(--accent-press);
  transform: translateY(-2px);
  box-shadow: 0 12px 30px -8px var(--accent-glow);
}
.btn--ghost {
  background: transparent; color: var(--text);
  border-color: var(--line-strong);
}
.btn--ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.btn--block { width: 100%; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 24px;
  padding: 16px clamp(22px, 6vw, 80px);
  max-width: var(--maxw); margin: 0 auto;
  backdrop-filter: blur(12px);
}
.nav::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0;
  height: 1px; background: var(--line);
  opacity: 0; transition: opacity 0.3s;
}
.nav.is-stuck::after { opacity: 1; }
.nav.is-stuck { background: rgba(11, 19, 14, 0.72); }

.brand { display: inline-flex; align-items: center; gap: 9px; margin-right: auto; }
.brand__mark {
  display: grid; place-items: center;
  width: 30px; height: 30px; border-radius: 8px;
  background: var(--accent); color: var(--ink);
}
.brand__mark svg { width: 18px; height: 18px; }
.brand__word {
  font-family: var(--font-display); font-weight: 800;
  font-size: 1.32rem; letter-spacing: -0.04em;
}
.nav__links { display: flex; gap: 28px; }
.nav__links a {
  font-size: 0.95rem; font-weight: 500; color: var(--muted);
  transition: color 0.2s; position: relative;
}
.nav__links a:hover { color: var(--text); }
.nav__cta { padding: 0.6em 1.2em; }

/* ---------- hero ---------- */
.hero {
  display: grid; grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(32px, 6vw, 80px); align-items: center;
  padding-top: clamp(48px, 8vw, 96px);
  padding-bottom: clamp(56px, 9vw, 120px);
}
.hero h1 { font-size: clamp(2.7rem, 6.6vw, 5.2rem); }
.hero__lead {
  margin-top: 22px; max-width: 46ch;
  font-size: clamp(1.05rem, 1.6vw, 1.22rem); color: var(--muted);
}
.hero__trust {
  list-style: none; display: flex; flex-wrap: wrap; gap: 22px;
  margin-top: 26px; color: var(--muted-2);
  font-size: 0.86rem; font-weight: 600; letter-spacing: 0.02em;
}
.hero__trust li { display: flex; align-items: center; gap: 8px; }
.hero__trust li::before {
  content: ""; width: 7px; height: 7px; border-radius: 50%;
  background: var(--accent); box-shadow: 0 0 8px var(--accent-glow);
}

/* waitlist form */
.waitlist { margin-top: 32px; max-width: 480px; }
.waitlist--center { margin-inline: auto; }
.waitlist__row {
  display: flex; gap: 8px;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 999px; padding: 6px 6px 6px 18px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.waitlist__row:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}
.waitlist__row input {
  flex: 1; background: transparent; border: none; outline: none;
  color: var(--text); font-family: var(--font-body); font-size: 1rem;
  min-width: 0;
}
.waitlist__row input::placeholder { color: var(--muted-2); }
.waitlist__hint { margin-top: 12px; font-size: 0.82rem; color: var(--muted-2); }
.waitlist--center .waitlist__hint { text-align: center; }
.waitlist__msg {
  margin-top: 12px; font-size: 0.9rem; font-weight: 600;
  min-height: 1.2em; transition: opacity 0.2s;
}
.waitlist__msg.is-ok { color: var(--accent); }
.waitlist__msg.is-err { color: #ff7a6b; }

/* hero visual: chaos -> order */
.hero__visual { position: relative; min-height: 420px; }
.chaos { position: absolute; inset: 0; }
.tag {
  position: absolute;
  left: var(--x); top: var(--y);
  transform: rotate(var(--r));
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.82rem; font-weight: 600;
  padding: 7px 13px; border-radius: 9px;
  white-space: nowrap;
  box-shadow: 0 8px 24px -12px rgba(0,0,0,0.6);
  opacity: 0;
  animation: tag-in 0.7s var(--ease) forwards;
  animation-delay: var(--d);
}
@keyframes tag-in {
  from { opacity: 0; transform: rotate(var(--r)) translateY(14px) scale(0.9); }
  to   { opacity: 0.62; transform: rotate(var(--r)) translateY(0) scale(1); }
}

.order-card {
  position: relative; z-index: 2;
  max-width: 360px; margin: 60px auto 0;
  background: linear-gradient(160deg, var(--surface-2), var(--surface));
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  padding: 26px 26px 22px;
  box-shadow: 0 30px 80px -30px var(--accent-glow), 0 0 0 6px rgba(31,224,106,0.06);
  opacity: 0; transform: translateY(20px) scale(0.96);
  animation: card-in 0.8s var(--ease) 0.85s forwards;
}
@keyframes card-in { to { opacity: 1; transform: translateY(0) scale(1); } }
.order-card__top { display: flex; justify-content: space-between; align-items: center; }
.order-card__mark { font-family: var(--font-display); font-weight: 800; font-size: 1.05rem; }
.order-card__badge {
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.06em;
  background: var(--accent); color: var(--ink);
  padding: 3px 10px; border-radius: 999px;
}
.order-card__price { display: flex; align-items: baseline; gap: 8px; margin: 18px 0 2px; }
.order-card__amount { font-family: var(--font-display); font-weight: 800; font-size: 3.2rem; letter-spacing: -0.03em; }
.order-card__per { color: var(--muted); font-weight: 600; }
.order-card__kwh { color: var(--accent); font-weight: 700; margin-bottom: 18px; }
.order-card__line {
  display: flex; justify-content: space-between;
  padding: 11px 0; border-top: 1px solid var(--line);
  font-size: 0.92rem; color: var(--muted);
}
.order-card__line span:last-child { color: var(--text); font-weight: 600; }

/* ---------- problem ---------- */
.problem__grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 48px; }
.problem__card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 30px 26px;
  position: relative; overflow: hidden;
  transition: transform 0.3s var(--ease), border-color 0.3s;
}
.problem__card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--accent); transform: scaleX(0); transform-origin: left;
  transition: transform 0.4s var(--ease);
}
.problem__card:hover { transform: translateY(-4px); border-color: var(--line-strong); }
.problem__card:hover::before { transform: scaleX(1); }
.problem__icon {
  display: grid; place-items: center; width: 44px; height: 44px;
  border-radius: 12px; background: var(--bg); color: var(--accent);
  font-size: 1.3rem; margin-bottom: 18px;
}
.problem__card h3 { font-size: 1.3rem; margin-bottom: 10px; }
.problem__card p { color: var(--muted); font-size: 0.98rem; }

/* ---------- how ---------- */
.how__head { margin-bottom: 12px; }
.how__head .eyebrow { margin-bottom: 14px; }
.how__steps { list-style: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 18px; margin-top: 40px; }
.how__step {
  border-top: 1px solid var(--line-strong); padding-top: 24px;
  position: relative;
}
.how__num {
  font-family: var(--font-display); font-weight: 800;
  font-size: 1rem; color: var(--accent);
  letter-spacing: 0.04em;
}
.how__step h3 { font-size: 1.45rem; margin: 16px 0 10px; }
.how__step p { color: var(--muted); font-size: 0.98rem; }

/* ---------- pricing ---------- */
.pricing__head { text-align: center; }
.pricing__head .eyebrow { margin-bottom: 14px; }
.pricing__head .section-title { margin-inline: auto; }
.pricing__sub { color: var(--muted); margin-top: 14px; }
.pricing__grid {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px; margin-top: 48px; max-width: 880px; margin-inline: auto;
}
.plan {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 32px 30px;
  display: flex; flex-direction: column;
  transition: transform 0.3s var(--ease), border-color 0.3s;
}
.plan:hover { transform: translateY(-4px); }
.plan--featured {
  background: linear-gradient(165deg, var(--surface-2), var(--surface));
  border-color: var(--accent);
  box-shadow: 0 30px 70px -34px var(--accent-glow);
  position: relative;
}
.plan__ribbon {
  position: absolute; top: 22px; right: 24px;
  background: var(--accent); color: var(--ink);
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.06em;
  padding: 4px 12px; border-radius: 999px;
}
.plan__head { display: flex; align-items: center; gap: 12px; }
.plan__icon {
  display: grid; place-items: center; width: 40px; height: 40px;
  border-radius: 10px; background: var(--accent-soft); color: var(--accent);
  font-size: 1.2rem;
}
.plan__name { font-family: var(--font-display); font-weight: 800; font-size: 1.15rem; }
.plan__price { display: flex; align-items: baseline; gap: 8px; margin: 22px 0 24px; }
.plan__amount { font-family: var(--font-display); font-weight: 800; font-size: 3.4rem; letter-spacing: -0.03em; }
.plan__per { color: var(--muted); font-weight: 600; }
.plan__feats { list-style: none; display: grid; gap: 13px; margin-bottom: 26px; }
.plan__feats li { position: relative; padding-left: 30px; color: var(--muted); font-size: 0.97rem; }
.plan__feats li::before {
  content: ""; position: absolute; left: 0; top: 3px;
  width: 19px; height: 19px; border-radius: 50%;
  background: var(--accent-soft);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%231FE06A' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E");
  background-size: 12px; background-repeat: no-repeat; background-position: center;
}
.plan__feats li strong { color: var(--text); }
.plan__for { color: var(--muted-2); font-style: italic; font-size: 0.9rem; margin-bottom: 22px; margin-top: auto; }

/* ---------- stats ---------- */
.stats { text-align: center; }
.stats .section-title { margin-inline: auto; }
.stats__grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
  margin: 48px 0 30px;
}
.stat {
  background: var(--surface); border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm); padding: 30px 20px;
  text-align: left;
}
.stat__num { display: block; font-family: var(--font-display); font-weight: 800; font-size: clamp(2.4rem, 5vw, 3.4rem); color: var(--accent); line-height: 1; }
.stat__label { display: block; margin-top: 12px; color: var(--muted); font-size: 0.94rem; font-weight: 600; }
.stats__note { color: var(--muted-2); font-style: italic; max-width: 56ch; margin-inline: auto; }

/* ---------- faq ---------- */
.faq .section-title { margin-bottom: 36px; }
.faq__list { display: grid; gap: 12px; max-width: 780px; }
.faq__list details {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 4px 22px;
  transition: border-color 0.25s;
}
.faq__list details[open] { border-color: var(--line-strong); }
.faq__list summary {
  list-style: none; cursor: pointer;
  font-family: var(--font-display); font-weight: 700; font-size: 1.08rem;
  padding: 18px 0; display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq__list summary::-webkit-details-marker { display: none; }
.faq__list summary::after {
  content: "+"; color: var(--accent); font-size: 1.5rem; font-weight: 400;
  transition: transform 0.3s var(--ease); line-height: 1;
}
.faq__list details[open] summary::after { transform: rotate(45deg); }
.faq__list details p { color: var(--muted); padding-bottom: 20px; max-width: 64ch; }

/* ---------- final cta ---------- */
.cta { max-width: 100%; padding-inline: 0; }
.cta__inner {
  max-width: 760px; margin: 0 auto; text-align: center;
  background: linear-gradient(165deg, var(--surface-2), var(--bg-2));
  border: 1px solid var(--line-strong);
  border-radius: 28px;
  padding: clamp(40px, 7vw, 72px) clamp(24px, 6vw, 64px);
  position: relative; overflow: hidden;
}
.cta__inner::before {
  content: ""; position: absolute; top: -50%; left: 50%; transform: translateX(-50%);
  width: 420px; height: 420px; border-radius: 50%;
  background: var(--accent-glow); filter: blur(120px); opacity: 0.45;
}
.cta__inner > * { position: relative; }
.cta h2 { font-size: clamp(2rem, 4.5vw, 3.2rem); }
.cta p { color: var(--muted); max-width: 50ch; margin: 18px auto 6px; }

/* ---------- footer ---------- */
.footer {
  max-width: var(--maxw); margin: 0 auto;
  padding: 64px clamp(22px, 6vw, 80px) 48px;
  display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px;
  border-top: 1px solid var(--line);
}
.footer__brand .brand__word { font-size: 1.5rem; }
.footer__brand p { color: var(--muted); margin-top: 12px; max-width: 32ch; font-size: 0.95rem; }
.footer__col h4 { font-family: var(--font-body); font-size: 0.78rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted-2); margin-bottom: 16px; }
.footer__col a { display: block; color: var(--muted); padding: 6px 0; font-size: 0.95rem; transition: color 0.2s; }
.footer__col a:hover { color: var(--accent); }
.footer__legal { grid-column: 1 / -1; color: var(--muted-2); font-size: 0.85rem; padding-top: 28px; border-top: 1px solid var(--line); margin-top: 12px; }

/* ---------- reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(24px); }
.reveal.is-in {
  opacity: 1; transform: none;
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  transition-delay: var(--d, 0s);
}

/* ---------- responsive ---------- */
@media (max-width: 920px) {
  .hero { grid-template-columns: 1fr; }
  .hero__visual { min-height: 380px; margin-top: 20px; order: 2; }
  .order-card { margin-top: 40px; }
  .problem__grid, .how__steps { grid-template-columns: 1fr; }
  .stats__grid { grid-template-columns: repeat(2, 1fr); }
  .footer { grid-template-columns: 1fr 1fr; }
  .footer__brand { grid-column: 1 / -1; }
}
@media (max-width: 620px) {
  .nav__links { display: none; }
  .pricing__grid { grid-template-columns: 1fr; }
  .waitlist__row { flex-direction: column; padding: 10px; border-radius: 16px; }
  .waitlist__row input { padding: 10px 8px; text-align: center; }
  .waitlist__row .btn { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .reveal { opacity: 1; transform: none; }
  .tag { opacity: 0.62; }
  .order-card { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}