/* ── Battery Banq — Flat Industrial Design System ────────── */

:root {
  --black: #0a0a0a;
  --dark: #111111;
  --dark-2: #1a1a1a;
  --dark-3: #222222;
  --grey-1: #2a2a2a;
  --grey-2: #3a3a3a;
  --grey-3: #666666;
  --grey-4: #999999;
  --grey-5: #cccccc;
  --white: #f0f0f0;
  --pure-white: #ffffff;
  --accent: #00c853;
  --accent-dim: rgba(0, 200, 83, 0.12);
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.16);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--black);
  color: var(--grey-5);
  line-height: 1.6;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
ul { list-style: none; padding: 0; }

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── TYPOGRAPHY ──────────────────────────────────────────── */

h1, h2, h3, h4 {
  color: var(--pure-white);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
h1 { font-size: clamp(36px, 5vw, 64px); }
h2 { font-size: clamp(28px, 3.5vw, 44px); }
h3 { font-size: 20px; }
h4 { font-size: 12px; text-transform: uppercase; letter-spacing: 0.1em; color: var(--grey-4); font-weight: 600; }
p { color: var(--grey-4); }

.label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--accent);
  margin-bottom: 12px;
}

.meta {
  font-weight: 600;
  color: var(--grey-5);
  margin-bottom: 12px;
}

.tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 4px 10px;
  margin-bottom: 16px;
}

/* ── BUTTONS ─────────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.btn-fill {
  background: var(--pure-white);
  color: var(--black);
}
.btn-fill:hover {
  background: var(--grey-5);
}

.btn-ghost {
  border-color: var(--border-hover);
  color: var(--pure-white);
  background: transparent;
}
.btn-ghost:hover {
  border-color: var(--pure-white);
  background: rgba(255, 255, 255, 0.04);
}

.btn-row {
  display: flex;
  gap: 12px;
  margin-top: 24px;
  flex-wrap: wrap;
}

/* ── HEADER ──────────────────────────────────────────────── */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: transparent;
  transition: background 0.3s, border-color 0.3s;
  border-bottom: 1px solid transparent;
}
.site-header.scrolled {
  background: rgba(10, 10, 10, 0.95);
  backdrop-filter: blur(8px);
  border-bottom-color: var(--border);
}

.header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  height: 44px;
  width: auto;
  transition: height 0.3s;
}
.site-header.scrolled .brand-logo { height: 36px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-link {
  font-size: 13px;
  font-weight: 500;
  color: var(--grey-4);
  padding: 8px 16px;
  transition: color 0.2s;
  letter-spacing: 0.02em;
}
.nav-link:hover,
.nav-link.active { color: var(--pure-white); }

.btn-nav {
  margin-left: 8px;
  border: 1px solid var(--border-hover);
  padding: 8px 20px;
  color: var(--pure-white);
  font-weight: 600;
}
.btn-nav:hover {
  background: var(--pure-white);
  color: var(--black);
  border-color: var(--pure-white);
}

/* ── BURGER ──────────────────────────────────────────────── */

.burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  z-index: 110;
}
.burger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--pure-white);
  transition: transform 0.3s, opacity 0.3s;
}
.burger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger.open span:nth-child(2) { opacity: 0; }
.burger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── HERO ────────────────────────────────────────────────── */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(10,10,10,0.7) 0%, rgba(10,10,10,0.9) 100%),
    url('https://images.unsplash.com/photo-1473341304170-971dccb5ac1e?auto=format&fit=crop&w=1600&q=80') center/cover no-repeat;
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: 48px;
  align-items: center;
}

.hero-content h1 {
  margin-bottom: 20px;
  max-width: 14ch;
}

.hero-sub {
  font-size: 17px;
  line-height: 1.7;
  max-width: 52ch;
  margin-bottom: 32px;
}

.hero-btns {
  display: flex;
  gap: 12px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.hero-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.hero-tags span {
  font-size: 12px;
  font-weight: 500;
  color: var(--grey-4);
  padding: 6px 12px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
}

/* ── HERO STATS ──────────────────────────────────────────── */

.hero-stats {
  background: var(--dark);
  border: 1px solid var(--border);
  padding: 28px;
}

.hero-stats .label { margin-bottom: 20px; }

.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
}

.stat {
  background: var(--dark);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.stat strong {
  font-size: 24px;
  color: var(--pure-white);
  font-weight: 800;
}
.stat span {
  font-size: 13px;
  color: var(--grey-4);
}

/* ── SECTIONS ────────────────────────────────────────────── */

.section {
  padding: 100px 0;
}

.section-dark {
  background: var(--dark);
}

.section-alt {
  background: var(--dark-2);
}

.section-head {
  margin-bottom: 48px;
}
.section-head h2 { margin-bottom: 12px; }
.section-head p { max-width: 56ch; font-size: 16px; }

/* ── CARDS ───────────────────────────────────────────────── */

.card {
  background: var(--dark-2);
  border: 1px solid var(--border);
  padding: 32px;
  transition: border-color 0.25s;
}
.card:hover {
  border-color: var(--border-hover);
}

.section-dark .card { background: var(--dark-3); }
.section-alt .card { background: var(--grey-1); }

.card h3 { margin-bottom: 12px; }
.card p { font-size: 15px; line-height: 1.65; }
.card ul { margin-top: 12px; }
.card li {
  padding: 6px 0;
  padding-left: 16px;
  position: relative;
  font-size: 14px;
  color: var(--grey-4);
}
.card li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 14px;
  width: 4px;
  height: 1px;
  background: var(--grey-3);
}

/* ── GRIDS ───────────────────────────────────────────────── */

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  margin-bottom: 1px;
}
.grid-2 > * { background: var(--black); }
.section-alt .grid-2 > * { background: var(--dark-2); }

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
}
.grid-3 > * { background: var(--black); }
.section-dark .grid-3 > * { background: var(--dark); }
.section-alt .grid-3 > * { background: var(--dark-2); }

/* ── SPLIT LAYOUT ────────────────────────────────────────── */

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.split h2 { margin-bottom: 16px; }

/* ── QUOTE BLOCK ─────────────────────────────────────────── */

.quote-block {
  border-left: 3px solid var(--accent);
  padding: 32px;
  background: var(--dark-2);
}
.quote-block blockquote {
  font-size: 22px;
  font-weight: 700;
  color: var(--pure-white);
  line-height: 1.35;
}

/* ── ARCHITECTURE BLOCK ──────────────────────────────────── */

.arch-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  margin-top: 48px;
  border: 1px solid var(--border);
}
.arch-text {
  padding: 40px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.arch-text p { max-width: 50ch; }
.arch-text ul { margin-top: 8px; }
.arch-text li {
  padding: 5px 0 5px 16px;
  position: relative;
  font-size: 14px;
  color: var(--grey-4);
}
.arch-text li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 13px;
  width: 4px;
  height: 1px;
  background: var(--accent);
}
.arch-media {
  overflow: hidden;
}
.arch-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ── PRODUCT HERO ────────────────────────────────────────── */

.product-hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border: 1px solid var(--border);
  margin-bottom: 1px;
}
.product-info {
  border: none;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.product-img {
  overflow: hidden;
  background: var(--dark-3);
}
.product-img img {
  width: 100%;
  height: 100%;
  min-height: 400px;
  object-fit: cover;
}
.product-img-contain img {
  object-fit: contain;
  padding: 24px;
  min-height: 300px;
}

/* ── SPEC LIST ───────────────────────────────────────────── */

.spec-list {
  display: flex;
  flex-direction: column;
}
.spec-list > div {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  display: grid;
  gap: 4px;
}
.spec-list > div:last-child { border-bottom: 0; }
.spec-list dt {
  font-size: 13px;
  font-weight: 600;
  color: var(--pure-white);
}
.spec-list dd {
  font-size: 14px;
  color: var(--grey-4);
}

/* ── TABLE ───────────────────────────────────────────────── */

.table-card {
  margin-bottom: 1px;
}
.table-card h3 { margin-bottom: 20px; }
.table-wrap { overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 680px;
}
th, td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
th {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--grey-4);
  background: var(--dark-3);
}
td { color: var(--grey-5); }
tbody tr { transition: background 0.15s; }
tbody tr:hover { background: rgba(255, 255, 255, 0.03); }

.table-note {
  margin-top: 16px;
  font-size: 13px;
  color: var(--grey-3);
}

/* ── TIMELINE ────────────────────────────────────────────── */

.timeline {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
}
.timeline-step {
  background: var(--black);
  padding: 32px;
  transition: background 0.25s;
}
.timeline-step:hover {
  background: var(--dark-2);
}
.step-num {
  display: inline-block;
  font-size: 32px;
  font-weight: 900;
  color: var(--dark-3);
  margin-bottom: 16px;
  line-height: 1;
  -webkit-text-stroke: 1px var(--grey-2);
}
.timeline-step:hover .step-num { color: var(--accent); -webkit-text-stroke: 0; }
.timeline-step h3 { margin-bottom: 8px; }
.timeline-step p { font-size: 14px; }

/* ── CASE STUDIES ────────────────────────────────────────── */

.project-stack {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.case-study { padding: 0; }

.cs-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  padding: 32px;
  gap: 24px;
}
.cs-header h3 { margin-bottom: 4px; }

.cs-stat {
  flex-shrink: 0;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  padding: 16px 20px;
  min-width: 140px;
}
.cs-stat strong {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--pure-white);
}
.cs-stat span {
  font-size: 12px;
  color: var(--grey-4);
}

.cs-body {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--border);
}
.cs-body > div {
  padding: 24px 32px;
  border-right: 1px solid var(--border);
}
.cs-body > div:last-child { border-right: 0; }
.cs-body h4 { margin-bottom: 8px; }
.cs-body p { font-size: 14px; }

/* ── MARKET GRID ─────────────────────────────────────────── */

.market-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
}
.market-grid span {
  font-size: 14px;
  font-weight: 500;
  color: var(--grey-5);
  padding: 12px 20px;
  border: 1px solid var(--border);
  margin: -0.5px;
  transition: background 0.2s, border-color 0.2s;
}
.market-grid span:hover {
  background: var(--dark-2);
  border-color: var(--border-hover);
  position: relative;
  z-index: 1;
}

/* ── CONTACT ─────────────────────────────────────────────── */

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 0;
  overflow: hidden;
}
.contact-links a {
  padding: 18px 24px;
  font-size: 15px;
  font-weight: 500;
  border-bottom: 1px solid var(--border);
  transition: background 0.2s, padding-left 0.2s;
}
.contact-links a:last-child { border-bottom: 0; }
.contact-links a:hover {
  background: rgba(255, 255, 255, 0.03);
  padding-left: 32px;
}

/* ── FOOTER ──────────────────────────────────────────────── */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer-logo { height: 28px; width: auto; opacity: 0.5; }
.footer-nav {
  display: flex;
  gap: 24px;
}
.footer-nav a {
  font-size: 13px;
  color: var(--grey-3);
  transition: color 0.2s;
}
.footer-nav a:hover { color: var(--pure-white); }

/* ── SCROLL PROGRESS ─────────────────────────────────────── */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  background: var(--accent);
  z-index: 200;
  width: 0;
  pointer-events: none;
}

/* ── BACK TO TOP ─────────────────────────────────────────── */

.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 44px;
  height: 44px;
  background: var(--dark-2);
  border: 1px solid var(--border);
  color: var(--pure-white);
  display: grid;
  place-items: center;
  cursor: pointer;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.3s, transform 0.3s, background 0.2s;
  z-index: 50;
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}
.back-to-top:hover { background: var(--grey-1); }

/* ── REVEAL ANIMATIONS ───────────────────────────────────── */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.25, 1, 0.5, 1),
              transform 0.6s cubic-bezier(0.25, 1, 0.5, 1);
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ── RESPONSIVE ──────────────────────────────────────────── */

@media (max-width: 980px) {
  .hero-inner,
  .split,
  .grid-3,
  .grid-2,
  .timeline,
  .arch-block,
  .product-hero,
  .cs-body {
    grid-template-columns: 1fr;
  }

  .grid-2, .grid-3, .timeline { background: none; gap: 1px; }
  .grid-2 > *, .grid-3 > *, .timeline-step {
    border: 1px solid var(--border);
  }

  .section { padding: 72px 0; }

  .cs-body > div { border-right: 0; border-bottom: 1px solid var(--border); }
  .cs-body > div:last-child { border-bottom: 0; }

  .burger { display: flex; }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100dvh;
    flex-direction: column;
    align-items: stretch;
    background: rgba(10, 10, 10, 0.98);
    backdrop-filter: blur(12px);
    padding: 80px 24px 24px;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.25, 1, 0.5, 1);
    border-left: 1px solid var(--border);
    z-index: 105;
    gap: 0;
  }
  .nav-links.open { transform: translateX(0); }

  .nav-link {
    padding: 14px 0;
    font-size: 15px;
    border-bottom: 1px solid var(--border);
  }
  .btn-nav {
    margin-left: 0;
    margin-top: 16px;
    text-align: center;
    border: 1px solid var(--border-hover);
    padding: 14px;
  }
}

@media (max-width: 640px) {
  .container { padding: 0 16px; }
  .hero { padding-top: 88px; }
  .hero-btns { flex-direction: column; }
  .hero-btns .btn { width: 100%; }
  .cs-header { flex-direction: column; }
  .footer-inner { flex-direction: column; gap: 16px; }
  .footer-nav { flex-wrap: wrap; justify-content: center; }
}

body.menu-lock { overflow: hidden; }