/* ==========================================================================
   QUANTUM-BACKUP.COM / LEDGER THEME REPLICA
   Clean Matte-Black Styling, Zero Overlapping Elements, Bulletproof Mobile
   ========================================================================== */

:root {
  --bg-black: #000000;
  --bg-carbon: #121316;
  --bg-secondary: #191a1e;
  --bg-card: #1c1d22;

  --border-color: #2d2f36;

  --color-white: #ffffff;
  --color-text-main: #ededed;
  --color-text-sub: #9e9fa6;
  --color-text-muted: #6c6d75;

  --color-orange: #ff5500;
  --color-orange-hover: #e04b00;

  --font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
  --max-w: 1240px;
}

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

body {
  background-color: var(--bg-black);
  color: var(--color-text-main);
  font-family: var(--font-family);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  width: 100%;
}

.text-center {
  text-align: center;
}
.bg-black {
  background-color: var(--bg-black);
}
.bg-carbon {
  background-color: var(--bg-carbon);
}
.bg-secondary {
  background-color: var(--bg-secondary);
}
.bg-light-grey {
  background-color: #f5f5f7;
  color: #111;
}
.mt-2 {
  margin-top: 0.5rem;
}
.mt-4 {
  margin-top: 1.5rem;
}

/* --------------------------------------------------------------------------
   HEADER & NAVIGATION
   -------------------------------------------------------------------------- */
.dark-header {
  height: 75px;
  background-color: var(--bg-black);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-row {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  height: 24px;
  width: auto;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-menu > li > a {
  color: var(--color-white);
  font-size: 0.88rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0;
}

.has-children {
  position: relative;
}

.sub-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  min-width: 210px;
  padding: 0.5rem 0;
  display: none;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
}

.has-children:hover .sub-menu {
  display: block;
}

.sub-menu a {
  display: block;
  padding: 0.5rem 1.25rem;
  font-size: 0.85rem;
  color: var(--color-text-sub);
}

.sub-menu a:hover {
  background-color: var(--bg-secondary);
  color: var(--color-white);
}

.lang-select {
  background-color: var(--color-white);
  color: #000;
  border: 1px solid var(--color-white);
  border-radius: 30px;
  padding: 0.5rem 1.25rem;
  font-weight: 700;
  font-size: 0.85rem;
  cursor: pointer;
  outline: none;
}

.mobile-toggle {
  display: none;
  color: var(--color-white);
  font-size: 1.5rem;
  cursor: pointer;
}

/* --------------------------------------------------------------------------
   HERO SECTION
   -------------------------------------------------------------------------- */
.section-introduction {
  padding: 4.5rem 0 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.hero-flexbox {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 3rem;
  align-items: center;
}

.hero-title {
  font-size: 2.35rem;
  font-weight: 900;
  line-height: 1.2;
  color: var(--color-white);
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}

.hero-desc {
  font-size: 1rem;
  color: var(--color-text-sub);
  line-height: 1.6;
  margin-bottom: 2rem;
  max-width: 540px;
}

.hero-actions-row {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.button-orange {
  background-color: var(--color-orange);
  color: var(--color-white);
  border-radius: 30px;
  padding: 0.9rem 2rem;
  font-size: 0.95rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  transition: background-color 0.2s ease;
}

.button-orange:hover {
  background-color: var(--color-orange-hover);
}

.button-white {
  background-color: var(--color-white);
  color: #000;
  border-radius: 30px;
  padding: 0.75rem 1.75rem;
  font-size: 0.88rem;
  font-weight: 700;
  display: inline-block;
}

.button-white:hover {
  background-color: #e5e5e5;
}

.qr-box {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.qr-box span {
  font-size: 0.8rem;
  font-weight: 600;
  margin-top: 0.35rem;
  color: var(--color-white);
}

.hero-illustration {
  width: 100%;
}

.hero-illustration iframe {
  width: 100%;
  height: 320px;
  border-radius: 8px;
  background-color: #000;
  border: 1px solid var(--border-color);
}

/* --------------------------------------------------------------------------
   FEATURES MARQUEE / GRID
   -------------------------------------------------------------------------- */
.section-features {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.feature-item {
  border-left: 2px solid var(--color-white);
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
}

.feat-img {
  width: 38px;
  height: 38px;
  margin-bottom: 0.75rem;
}

.feat-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--color-white);
  text-transform: uppercase;
}

.feat-subtitle {
  font-size: 0.88rem;
  color: var(--color-text-sub);
  margin-top: 0.25rem;
}

/* --------------------------------------------------------------------------
   CALLOUT & WIDGET
   -------------------------------------------------------------------------- */
.section-callout {
  padding: 3.5rem 0;
  border-bottom: 1px solid var(--border-color);
}

.callout-text {
  font-size: 1.35rem;
  font-weight: 700;
  max-width: 820px;
  margin: 0 auto 1.5rem auto;
  line-height: 1.4;
  color: var(--color-white);
}

.widget-container {
  width: 100%;
  border-bottom: 1px solid var(--border-color);
}

/* --------------------------------------------------------------------------
   CRYPTO GALLERY / COINS
   -------------------------------------------------------------------------- */
.crypto-gallery {
  padding: 4rem 0;
}

.crypto-flex {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.crypto-text .h4 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.crypto-text .h6 {
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  color: #444;
}

.read-more {
  font-weight: 700;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

/* --------------------------------------------------------------------------
   DIAGONAL BLOCKS
   -------------------------------------------------------------------------- */
.section-video-embed {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.section-video-embed iframe {
  border-radius: 8px;
}

.c-diagonal-bloc {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.bloc-grid {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.bloc-item {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 2.5rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
  align-items: center;
}

.bloc-illustration {
  height: 240px;
  background-size: cover;
  background-position: center;
}

.bloc-content {
  padding: 2rem;
}

.bloc-content .h4 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 0.75rem;
}

.bloc-content .h6 {
  font-size: 0.95rem;
  color: var(--color-text-sub);
  line-height: 1.6;
}

.super-small-text {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

/* --------------------------------------------------------------------------
   DOWNLOAD SECTION
   -------------------------------------------------------------------------- */
.download-section {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--border-color);
}

.download-section .h4 {
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--color-white);
  margin-bottom: 0.5rem;
}

.download-section .subtitle {
  font-size: 1rem;
  color: var(--color-text-sub);
  margin-bottom: 3rem;
}

.download-flex {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.download-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.download-card .h5 {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 1.5rem;
}

.download-actions {
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.badges-row {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 1rem;
}

.qr-block-download {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.qr-block-download span {
  font-size: 0.75rem;
  margin-top: 0.25rem;
}

/* --------------------------------------------------------------------------
   PREFOOTER
   -------------------------------------------------------------------------- */
.prefooter-blocks {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.prefooter-flex {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.prefooter-col .h5 {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 0.75rem;
}

.prefooter-col p {
  color: var(--color-text-sub);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.social-icons {
  display: flex;
  gap: 1rem;
  margin-top: 1.25rem;
}

.social-icons a {
  font-size: 1.35rem;
  color: var(--color-white);
}

.newsletter-form {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.newsletter-form input {
  flex-grow: 1;
  background-color: var(--bg-black);
  border: 1px solid var(--border-color);
  border-radius: 30px;
  padding: 0.75rem 1.25rem;
  color: var(--color-white);
  font-size: 0.88rem;
}

.disclaimer-text {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* --------------------------------------------------------------------------
   FOOTER
   -------------------------------------------------------------------------- */
.site-footer {
  padding: 4rem 0 2rem 0;
  background-color: var(--bg-black);
}

.footer-flex {
  display: grid;
  grid-template-columns: 1.2fr 3fr;
  gap: 3rem;
}

.copyright-p {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-top: 1.5rem;
}

.footer-nav-cols {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1.5rem;
}

.f-col h4 {
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 1rem;
  text-transform: uppercase;
}

.f-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.f-col a {
  font-size: 0.82rem;
  color: var(--color-text-sub);
}

.f-col a:hover {
  color: var(--color-white);
}

/* --------------------------------------------------------------------------
   MOBILE RESPONSIVENESS
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .hero-flexbox {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-actions-row {
    justify-content: center;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .crypto-flex {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .bloc-item {
    grid-template-columns: 1fr;
  }

  .download-flex {
    grid-template-columns: 1fr;
  }

  .prefooter-flex {
    grid-template-columns: 1fr;
  }

  .footer-flex {
    grid-template-columns: 1fr;
  }

  .footer-nav-cols {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .mobile-toggle {
    display: block;
  }

  .main-navigation {
    position: fixed;
    top: 75px;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--bg-black);
    padding: 2rem;
    display: none;
    overflow-y: auto;
  }

  .main-navigation.open {
    display: block;
  }

  .nav-menu {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .sub-menu {
    position: static;
    display: block;
    background: transparent;
    border: none;
    box-shadow: none;
    padding-left: 1rem;
  }

  .hero-title {
    font-size: 1.75rem;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .newsletter-form {
    flex-direction: column;
  }

  .footer-nav-cols {
    grid-template-columns: 1fr;
  }

  .app-badges-mobile {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 1.5rem;
  }
}