:root {
  --bg: #070d14;
  --bg-elevated: #0d1622;
  --panel: #111d2c;
  --panel-hover: #16263a;
  --surface-glass: rgba(13, 22, 34, 0.88);
  --text: #f3f7fb;
  --text-muted: #9bb0c4;
  --border: rgba(84, 122, 160, 0.26);
  --border-strong: rgba(0, 229, 255, 0.42);
  --cyan: #00e5ff;
  --blue: #0077fe;
  --deep-blue: #0047ff;
  --coral: #ff3366;
  --green: #3ddc84;
  --amber: #ffc247;
  --red: #ff6b60;
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.55);
  --shadow-glow: 0 0 32px rgba(0, 119, 254, 0.22);
  --radius-lg: 18px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: ui-monospace, 'Cascadia Mono', 'SFMono-Regular', Consolas, monospace;
}

:root[data-site-theme='light'] {
  --bg: #f3f6fa;
  --bg-elevated: #ffffff;
  --panel: #ffffff;
  --panel-hover: #eaf1f8;
  --surface-glass: rgba(255, 255, 255, 0.92);
  --text: #091420;
  --text-muted: #485c70;
  --border: rgba(18, 48, 80, 0.15);
  --border-strong: rgba(0, 119, 254, 0.42);
  --cyan: #0066db;
  --blue: #0058c4;
  --green: #0a7a35;
  --amber: #945d00;
  --red: #b3261e;
  --shadow-lg: 0 18px 42px rgba(11, 22, 34, 0.1);
  --shadow-glow: 0 8px 26px rgba(0, 119, 254, 0.12);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  margin: 0;
  background-color: var(--bg);
  background-image:
    radial-gradient(circle at 18% 8%, rgba(0, 229, 255, 0.08), transparent 36%),
    radial-gradient(circle at 82% 18%, rgba(0, 119, 254, 0.12), transparent 42%);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 16px;
}

/* ==================== STICKY HEADER ==================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 12px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.brand-link img {
  width: 32px;
  height: 32px;
}

.brand-tag {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: lowercase;
  padding: 3px 8px;
  border-radius: 999px;
  background: rgba(0, 229, 255, 0.12);
  color: var(--cyan);
  border: 1px solid rgba(0, 229, 255, 0.28);
}

.site-nav {
  display: none;
  align-items: center;
  gap: 6px;
}

@media (min-width: 900px) {
  .site-nav {
    display: flex;
  }
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background 0.15s ease;
}

.nav-link:hover {
  color: var(--text);
  background: var(--panel-hover);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Language selector */
.lang-selector {
  display: inline-flex;
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 2px;
  gap: 2px;
}

.lang-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.76rem;
  font-weight: 700;
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.lang-btn.active {
  background: var(--blue);
  color: #ffffff;
}

.theme-btn,
.mobile-menu-btn {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 7px 11px;
  cursor: pointer;
  font-size: 0.95rem;
}

.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
  font-weight: 700;
  font-size: 0.92rem;
  padding: 9px 18px;
  border-radius: var(--radius-sm);
  transition: transform 0.12s ease, box-shadow 0.15s ease, background 0.15s ease;
  white-space: nowrap;
  border: none;
  cursor: pointer;
}

.btn-cta:active {
  transform: scale(0.97);
}

.btn-cta-primary {
  background: var(--blue);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(0, 119, 254, 0.35);
}

.btn-cta-primary:hover {
  background: #1a85ff;
}

.btn-cta-secondary {
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-cta-secondary:hover {
  background: var(--panel-hover);
}

/* ==================== SECTIONS ==================== */
.section {
  padding: 64px 0;
}

@media (min-width: 768px) {
  .section {
    padding: 88px 0;
  }
}

.section-alt {
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-head {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 48px;
}

.section-head h2 {
  font-size: 1.85rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 10px 0 14px;
}

@media (min-width: 768px) {
  .section-head h2 {
    font-size: 2.3rem;
  }
}

.section-head p {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin: 0;
}

.eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 800;
  color: var(--cyan);
  text-transform: lowercase;
  letter-spacing: 0.04em;
  margin-bottom: 6px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--cyan) 0%, var(--blue) 50%, #9b72ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ==================== HERO SECTION ==================== */
.hero {
  padding: 48px 0 64px;
}

@media (min-width: 768px) {
  .hero {
    padding: 72px 0 96px;
  }
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  align-items: center;
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 48px;
  }
}

.hero-title {
  font-size: 2.2rem;
  font-weight: 850;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: 12px 0 20px;
}

@media (min-width: 768px) {
  .hero-title {
    font-size: 3.1rem;
  }
}

.hero-lead {
  color: var(--text-muted);
  font-size: 1.12rem;
  line-height: 1.6;
  margin: 0 0 28px;
}

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

.proof-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.proof-item {
  display: flex;
  flex-direction: column;
}

.proof-num {
  font-size: 1.35rem;
  font-weight: 850;
  color: var(--text);
  line-height: 1.1;
}

.proof-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Tablet Preview Frame */
.tablet-preview {
  position: relative;
  background: #000000;
  border-radius: 20px;
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.tablet-screen {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  background: #070c12;
  aspect-ratio: 16 / 10;
}

.tablet-screen img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.tablet-caption-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 4px 2px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ==================== FEATURE CARDS ==================== */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 640px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.card:hover {
  border-color: var(--border-strong);
  transform: translateY(-2px);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 14px;
  display: inline-block;
}

.card h3 {
  font-size: 1.22rem;
  font-weight: 750;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
}

.card p {
  color: var(--text-muted);
  font-size: 0.94rem;
  margin: 0 0 14px;
  line-height: 1.55;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 6px;
  background: var(--bg);
  color: var(--text-muted);
  border: 1px solid var(--border);
}

/* ==================== DEPTH SECTION ==================== */
.depth-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  align-items: center;
}

@media (min-width: 900px) {
  .depth-grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }
}

.spec-list {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
}

.spec-row {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

.spec-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.spec-title {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.spec-desc {
  font-size: 0.86rem;
  color: var(--text-muted);
  margin: 0;
}

/* ==================== INTERACTIVE CALCULATOR ==================== */
.calc-box {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  max-width: 900px;
  margin: 0 auto;
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 768px) {
  .calc-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

.calc-control {
  display: grid;
  gap: 6px;
  margin-bottom: 16px;
}

.calc-label {
  font-size: 0.84rem;
  font-weight: 700;
  color: var(--text);
  display: flex;
  justify-content: space-between;
}

.calc-val {
  color: var(--cyan);
  font-family: var(--font-mono);
}

.calc-range {
  width: 100%;
  accent-color: var(--blue);
}

.calc-results {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px;
  display: grid;
  gap: 14px;
}

.calc-stat {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 1px solid var(--border);
  padding-bottom: 10px;
}

.calc-stat:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.calc-stat-label {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.calc-stat-val {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text);
  font-family: var(--font-mono);
}

/* ==================== SCREENSHOT SHOWCASE ==================== */
.shots-nav {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 20px;
}

.shot-tab {
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.88rem;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.shot-tab.active {
  background: var(--blue);
  color: #ffffff;
  border-color: var(--blue);
}

.shot-display {
  background: #000000;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 12px;
  box-shadow: var(--shadow-lg);
}

.shot-img-wrap {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: #070c12;
}

.shot-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.shot-meta {
  padding: 16px 8px 8px;
  display: grid;
  gap: 6px;
}

.shot-meta h3 {
  font-size: 1.15rem;
  font-weight: 800;
  margin: 0;
}

.shot-meta p {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin: 0;
}

/* ==================== FAQ ACCORDION ==================== */
.faq-wrap {
  max-width: 820px;
  margin: 0 auto;
  display: grid;
  gap: 12px;
}

.faq-item {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-q {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  color: var(--text);
  font-size: 1.02rem;
  font-weight: 750;
  padding: 18px 20px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
}

.faq-q:hover {
  background: var(--panel-hover);
}

.faq-icon {
  font-size: 1.2rem;
  color: var(--cyan);
  transition: transform 0.2s ease;
}

.faq-item.open .faq-icon {
  transform: rotate(180deg);
}

.faq-a {
  display: none;
  padding: 0 20px 20px;
  color: var(--text-muted);
  font-size: 0.94rem;
  line-height: 1.6;
}

.faq-item.open .faq-a {
  display: block;
}

/* ==================== FOOTER ==================== */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
  padding: 48px 0 32px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

@media (min-width: 768px) {
  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-copy {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.footer-nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.86rem;
}

.footer-nav a:hover {
  color: var(--text);
}