:root {
  --black: #070604;
  --black-soft: #100d09;
  --gold: #dcae58;
  --gold-light: #f8dfa1;
  --cream: #f3e5c6;
  --line: rgba(225, 177, 87, .38);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  background: var(--black);
  color: var(--cream);
  font-family: "Times New Roman", Times, serif;
}

a { color: inherit; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 8px;
  left: 8px;
  padding: 10px 14px;
  border: 1px solid var(--gold);
  background: #090704;
  transform: translateY(-150%);
}

.skip-link:focus { transform: translateY(0); }

.desktop-poster {
  position: relative;
  width: 100%;
  min-height: 100vh;
  background: #050403;
  overflow: hidden;
}

.desktop-poster > img {
  display: block;
  width: 100%;
  height: auto;
  min-height: 100vh;
  object-fit: cover;
  object-position: top center;
}

.hotspot {
  position: absolute;
  z-index: 2;
  border: 1px solid transparent;
  border-radius: 6px;
  outline: none;
  transition: background-color .2s ease, border-color .2s ease, box-shadow .2s ease;
}

.hotspot:hover,
.hotspot:focus-visible {
  background: rgba(235, 184, 83, .08);
  border-color: rgba(255, 216, 137, .6);
  box-shadow: 0 0 22px rgba(219, 164, 58, .28), inset 0 0 18px rgba(219, 164, 58, .08);
}

.nav-home { left: 29.7%; top: .7%; width: 5.4%; height: 3.3%; }
.nav-download { left: 37.2%; top: .7%; width: 5.4%; height: 3.3%; }
.nav-features { left: 44.2%; top: .7%; width: 5.9%; height: 3.3%; }
.nav-community { left: 52.4%; top: .7%; width: 6.4%; height: 3.3%; }
.nav-support { left: 61%; top: .7%; width: 5%; height: 3.3%; }
.nav-login { left: 74.7%; top: .7%; width: 7.1%; height: 3.5%; }
.nav-register { left: 82.8%; top: .7%; width: 6.7%; height: 3.5%; }

.hero-download { left: 35.5%; top: 39.4%; width: 13.3%; height: 4.5%; }
.hero-community { left: 50.3%; top: 39.4%; width: 14%; height: 4.5%; }

.feature-nostalgia { left: 7.5%; top: 46.9%; width: 20.4%; height: 17.9%; }
.feature-community { left: 29.1%; top: 46.9%; width: 20.6%; height: 17.9%; }
.feature-events { left: 50.5%; top: 46.9%; width: 20.8%; height: 17.9%; }
.feature-support { left: 72.3%; top: 46.9%; width: 20.5%; height: 17.9%; }

.mobile-site { display: none; }

.language-picker { position: relative; }

.desktop-language {
  position: absolute;
  z-index: 20;
  top: .8%;
  right: 1.25%;
}

.language-toggle {
  min-width: 88px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 11px;
  border: 1px solid rgba(222, 173, 79, .58);
  border-radius: 4px;
  background: rgba(7, 5, 3, .88);
  color: var(--gold-light);
  font: 700 12px/1 Arial, sans-serif;
  letter-spacing: .08em;
  cursor: pointer;
  box-shadow: inset 0 0 12px rgba(220, 174, 88, .07);
}

.language-toggle:hover,
.language-toggle:focus-visible,
.language-toggle[aria-expanded="true"] {
  border-color: var(--gold-light);
  background: rgba(28, 18, 8, .96);
  outline: none;
}

.language-flag { width: 22px; height: 15px; border: 1px solid rgba(255, 255, 255, .28); border-radius: 1px; object-fit: cover; }
.language-chevron { margin-left: 1px; color: var(--gold); font-size: 13px; transition: transform .2s ease; }
.language-toggle[aria-expanded="true"] .language-chevron { transform: rotate(180deg); }

.language-menu {
  position: absolute;
  z-index: 30;
  top: calc(100% + 7px);
  right: 0;
  width: 164px;
  padding: 6px;
  border: 1px solid rgba(222, 173, 79, .6);
  border-radius: 4px;
  background: rgba(7, 5, 3, .98);
  box-shadow: 0 16px 36px rgba(0, 0, 0, .48);
  opacity: 0;
  transform: translateY(-7px);
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
}

.language-menu.open { opacity: 1; transform: translateY(0); pointer-events: auto; }

.language-menu button {
  width: 100%;
  min-height: 40px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border: 0;
  border-radius: 3px;
  background: transparent;
  color: #d7c6a6;
  font: 13px/1.2 Arial, sans-serif;
  text-align: left;
  cursor: pointer;
}

.language-menu button img { width: 23px; height: 16px; border: 1px solid rgba(255, 255, 255, .24); border-radius: 1px; object-fit: cover; }
.language-menu button:hover,
.language-menu button:focus-visible { background: rgba(220, 174, 88, .12); color: var(--gold-light); outline: none; }
.language-menu button[aria-selected="true"] { background: rgba(220, 174, 88, .09); color: var(--gold-light); }

.download-section {
  position: relative;
  scroll-margin-top: 66px;
  border-top: 1px solid rgba(224, 174, 80, .28);
  border-bottom: 1px solid rgba(224, 174, 80, .2);
  background:
    radial-gradient(circle at 50% 0, rgba(115, 71, 24, .33), transparent 43%),
    linear-gradient(rgba(7, 5, 3, .95), rgba(7, 5, 3, .99)),
    url("assets/bach-duong-homepage-logo-v2.png") center 48% / cover;
}

.download-section::before,
.download-section::after {
  content: "";
  position: absolute;
  left: 50%;
  width: min(240px, 45vw);
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  transform: translateX(-50%);
}

.download-section::before { top: 0; }
.download-section::after { bottom: 0; }

.download-inner {
  width: min(1320px, calc(100% - 64px));
  margin: auto;
  padding: 82px 0 76px;
}

.download-heading {
  max-width: 760px;
  margin: 0 auto 38px;
  text-align: center;
}

.download-kicker {
  margin: 0 0 10px;
  color: var(--gold);
  font: 700 12px/1.4 Arial, sans-serif;
  letter-spacing: .24em;
  text-transform: uppercase;
}

.download-heading h2 {
  margin: 0;
  color: var(--gold-light);
  font-size: clamp(34px, 3.2vw, 54px);
  font-weight: 500;
}

.download-heading > p:last-child {
  margin: 16px auto 0;
  color: #c2b294;
  font: 15px/1.7 Arial, sans-serif;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.download-card {
  position: relative;
  min-height: 238px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 28px 28px 25px;
  border: 1px solid rgba(222, 173, 79, .52);
  background: linear-gradient(145deg, rgba(51, 33, 15, .82), rgba(8, 6, 3, .96) 66%);
  color: var(--cream);
  text-decoration: none;
  overflow: hidden;
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}

.download-card::before {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px solid rgba(225, 176, 83, .12);
  pointer-events: none;
}

.download-card:hover,
.download-card:focus-visible {
  transform: translateY(-5px);
  border-color: var(--gold-light);
  box-shadow: 0 18px 46px rgba(0, 0, 0, .36), 0 0 26px rgba(221, 168, 71, .12);
  outline: none;
}

.download-icon {
  width: 55px;
  height: 55px;
  display: grid;
  place-items: center;
  margin-bottom: 22px;
  border: 1px solid var(--gold);
  border-radius: 50%;
  color: var(--gold-light);
  font: 400 30px/1 Arial, sans-serif;
  box-shadow: inset 0 0 16px rgba(220, 174, 88, .1);
}

.download-icon-text { font-size: 21px; font-weight: 700; }
.download-copy { display: grid; gap: 6px; padding-right: 110px; }
.download-copy small { color: #a78d60; font: 700 10px/1.3 Arial, sans-serif; letter-spacing: .17em; text-transform: uppercase; }
.download-copy strong { color: var(--gold-light); font-size: 22px; font-weight: 500; text-transform: uppercase; }
.download-copy em { color: #c0b092; font: normal 13px/1.55 Arial, sans-serif; }
.download-status { position: absolute; right: 27px; bottom: 26px; color: var(--gold); font: 700 10px/1.2 Arial, sans-serif; letter-spacing: .1em; text-transform: uppercase; }

.community-section {
  position: relative;
  border-top: 1px solid rgba(224, 174, 80, .28);
  border-bottom: 1px solid rgba(224, 174, 80, .2);
  background:
    radial-gradient(circle at 50% 0, rgba(102, 61, 19, .34), transparent 43%),
    linear-gradient(rgba(6, 5, 3, .93), rgba(6, 5, 3, .98)),
    url("assets/bach-duong-homepage-logo-v2.png") center 53% / cover;
}

.community-section::before,
.community-section::after {
  content: "";
  position: absolute;
  left: 50%;
  width: min(240px, 45vw);
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  transform: translateX(-50%);
}

.community-section::before { top: 0; }
.community-section::after { bottom: 0; }

.community-inner {
  width: min(1480px, calc(100% - 64px));
  margin: auto;
  padding: 88px 0 76px;
}

.community-heading { max-width: 760px; margin: 0 auto 42px; text-align: center; }
.community-kicker { margin: 0 0 10px; color: var(--gold); font: 700 12px/1.4 Arial, sans-serif; letter-spacing: .24em; text-transform: uppercase; }
.community-heading h2 { margin: 0; color: var(--gold-light); font-size: clamp(34px, 3.2vw, 54px); font-weight: 500; }
.community-heading > p:last-child { margin: 16px auto 0; color: #b9aa8e; font: 15px/1.7 Arial, sans-serif; }

.social-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }
.social-card {
  position: relative;
  min-height: 210px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 27px 26px 24px;
  border: 1px solid rgba(222, 173, 79, .5);
  background: linear-gradient(145deg, rgba(48, 31, 14, .8), rgba(8, 6, 3, .94) 64%);
  color: var(--cream);
  text-decoration: none;
  overflow: hidden;
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}

.social-card::before { content: ""; position: absolute; inset: 6px; border: 1px solid rgba(225, 176, 83, .12); pointer-events: none; }
.social-card:hover, .social-card:focus-visible { transform: translateY(-5px); border-color: var(--gold-light); box-shadow: 0 18px 46px rgba(0, 0, 0, .36), 0 0 26px rgba(221, 168, 71, .12); outline: none; }
.social-icon { width: 54px; height: 54px; display: grid; place-items: center; margin-bottom: 22px; border: 1px solid var(--gold); border-radius: 50%; color: var(--gold-light); font: 700 27px/1 Arial, sans-serif; box-shadow: inset 0 0 16px rgba(220, 174, 88, .1); }
.social-icon.zalo { font-size: 12px; }
.social-icon.music { font-size: 29px; }
.social-copy { display: grid; gap: 6px; }
.social-copy small { color: #9e855a; font: 700 10px/1.3 Arial, sans-serif; letter-spacing: .17em; text-transform: uppercase; }
.social-copy strong { color: var(--gold-light); font-size: 21px; font-weight: 500; text-transform: uppercase; }
.social-copy em { color: #b9aa8e; font: normal 13px/1.5 Arial, sans-serif; }
.social-arrow { position: absolute; top: 29px; right: 27px; color: var(--gold); font-size: 19px; transition: transform .2s ease; }
.social-card:hover .social-arrow { transform: translate(3px, -3px); }
.community-note { margin: 28px 0 0; color: #887657; font: 12px/1.5 Arial, sans-serif; letter-spacing: .08em; text-align: center; }
.mobile-community { display: none; }

.toast {
  position: fixed;
  z-index: 120;
  left: 50%;
  bottom: 28px;
  max-width: calc(100% - 32px);
  padding: 12px 18px;
  border: 1px solid var(--gold);
  border-radius: 5px;
  background: rgba(7, 6, 4, .96);
  color: var(--gold-light);
  letter-spacing: .04em;
  opacity: 0;
  transform: translate(-50%, 20px);
  pointer-events: none;
  transition: opacity .25s ease, transform .25s ease;
}

.toast.visible { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 900px) {
  .desktop-poster,
  .desktop-download,
  .desktop-community { display: none; }
  .mobile-site { display: block; overflow: hidden; }

  .mobile-header {
    position: fixed;
    z-index: 30;
    top: 0;
    left: 0;
    width: 100%;
    height: 66px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 18px;
    border-bottom: 1px solid var(--line);
    background: rgba(6, 5, 3, .91);
    backdrop-filter: blur(12px);
  }

  .mobile-brand {
    display: flex;
    align-items: center;
    gap: 9px;
    text-decoration: none;
  }

  .mobile-brand img { filter: drop-shadow(0 0 8px rgba(220, 174, 88, .35)); }
  .mobile-brand span { display: grid; gap: 1px; }
  .mobile-brand strong { color: var(--gold-light); font-size: 16px; letter-spacing: .08em; }
  .mobile-brand small { color: #a9946a; font-size: 8px; letter-spacing: .2em; text-transform: uppercase; }

  .mobile-header-actions { display: flex; align-items: center; gap: 8px; }
  .mobile-language .language-toggle { min-width: 72px; height: 42px; padding: 0 8px; gap: 6px; }
  .mobile-language .language-menu { right: 0; }

  .menu-button {
    width: 42px;
    height: 42px;
    display: grid;
    place-content: center;
    gap: 5px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: rgba(216, 166, 72, .06);
  }

  .menu-button span { width: 19px; height: 1px; background: var(--gold-light); transition: transform .2s ease, opacity .2s ease; }
  .menu-button[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
  .menu-button[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .menu-button[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

  .mobile-menu {
    position: absolute;
    top: 65px;
    left: 0;
    width: 100%;
    display: grid;
    padding: 10px 18px 16px;
    border-bottom: 1px solid var(--line);
    background: rgba(8, 6, 3, .98);
    opacity: 0;
    transform: translateY(-12px);
    pointer-events: none;
    transition: opacity .2s ease, transform .2s ease;
  }

  .mobile-menu.open { opacity: 1; transform: translateY(0); pointer-events: auto; }
  .mobile-menu a { padding: 13px 4px; border-bottom: 1px solid rgba(220, 174, 88, .12); color: var(--cream); text-decoration: none; text-transform: uppercase; letter-spacing: .12em; font-size: 13px; }

  .mobile-hero {
    position: relative;
    min-height: 560px;
    text-align: center;
  }

  .hero-art,
  .hero-overlay { position: absolute; inset: 0; }

  .hero-art {
    background-image: url("assets/bach-duong-homepage-logo-v2.png");
    background-size: auto 900px;
    background-position: 50% top;
    background-repeat: no-repeat;
    filter: saturate(.9) contrast(1.04);
  }

  .hero-overlay {
    background: linear-gradient(180deg, rgba(3, 2, 1, .08) 0%, rgba(5, 4, 2, .02) 60%, #080603 100%);
  }

  .mobile-hero-link { position: absolute; z-index: 3; top: 350px; height: 52px; border: 1px solid transparent; border-radius: 3px; }
  .mobile-hero-link:focus-visible { border-color: var(--gold-light); box-shadow: 0 0 18px rgba(222, 168, 71, .45); outline: none; }
  .mobile-hero-download { left: 0; width: 47%; }
  .mobile-hero-community { right: 0; width: 48%; }

  .button { min-height: 52px; display: grid; place-items: center; padding: 13px 18px; border-radius: 3px; font-weight: 700; text-decoration: none; text-transform: uppercase; letter-spacing: .08em; }
  .button-gold { border: 1px solid #f4cf7b; background: linear-gradient(180deg, #efca77, #b77927); color: #171005; box-shadow: 0 0 22px rgba(222, 168, 71, .3); }
  .button-dark { border: 1px solid var(--gold); background: rgba(4, 3, 2, .76); color: var(--gold-light); }

  .mobile-content { padding: 68px 18px 42px; background: radial-gradient(circle at 50% 0, #24170b 0, #090704 36%); }
  .section-title { text-align: center; margin-bottom: 28px; }
  .section-title p { margin: 0 0 7px; color: var(--gold); font-size: 11px; letter-spacing: .22em; text-transform: uppercase; }
  .section-title h2 { margin: 0; font-size: 31px; font-weight: 500; }
  .feature-grid { display: grid; gap: 13px; }
  .feature-card { position: relative; padding: 25px 22px 24px 72px; border: 1px solid var(--line); background: linear-gradient(135deg, rgba(45, 29, 13, .72), rgba(8, 6, 3, .93)); }
  .feature-card::after { content: ""; position: absolute; inset: 5px; border: 1px solid rgba(219, 169, 76, .12); pointer-events: none; }
  .feature-card span { position: absolute; left: 20px; top: 25px; color: var(--gold); font-size: 13px; letter-spacing: .12em; }
  .feature-card h3 { margin: 0 0 7px; color: var(--gold-light); font-size: 19px; font-weight: 500; text-transform: uppercase; }
  .feature-card p { margin: 0; color: #b9aa8f; font-family: Arial, sans-serif; font-size: 13px; line-height: 1.55; }

  .mobile-download { scroll-margin-top: 66px; }
  .download-inner { width: auto; padding: 62px 18px 56px; }
  .download-heading { margin-bottom: 27px; }
  .download-heading h2 { font-size: 30px; }
  .download-heading > p:last-child { font-size: 13px; line-height: 1.55; }
  .download-grid { grid-template-columns: 1fr; gap: 12px; }
  .download-card {
    min-height: 0;
    display: grid;
    grid-template-columns: 48px minmax(0, 1fr);
    align-items: center;
    gap: 15px;
    padding: 20px 19px 46px;
  }
  .download-icon { width: 46px; height: 46px; margin: 0; font-size: 25px; }
  .download-icon-text { font-size: 18px; }
  .download-copy { gap: 4px; padding-right: 0; }
  .download-copy strong { font-size: 17px; }
  .download-copy em { font-size: 12px; }
  .download-status { left: 82px; right: auto; bottom: 19px; }

  .mobile-community { display: block; scroll-margin-top: 66px; }
  .community-inner { width: auto; padding: 62px 18px 56px; }
  .community-heading { margin-bottom: 27px; }
  .community-heading h2 { font-size: 30px; }
  .community-heading > p:last-child { font-size: 13px; line-height: 1.55; }
  .social-grid { grid-template-columns: 1fr; gap: 12px; }
  .social-card { min-height: 0; display: grid; grid-template-columns: 48px 1fr 18px; align-items: center; gap: 15px; padding: 20px 19px; }
  .social-icon { width: 46px; height: 46px; margin: 0; font-size: 23px; }
  .social-copy { gap: 4px; }
  .social-copy strong { font-size: 17px; }
  .social-copy em { font-size: 12px; }
  .social-arrow { position: static; justify-self: end; }
  .community-note { margin-top: 22px; }

  .mobile-cta { padding: 70px 24px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: linear-gradient(rgba(7, 5, 3, .85), rgba(7, 5, 3, .96)), url("assets/bach-duong-homepage-logo-v2.png") center 55% / auto 720px; text-align: center; }
  .mobile-cta img { filter: drop-shadow(0 0 12px rgba(220, 174, 88, .4)); }
  .mobile-cta h2 { max-width: 430px; margin: 14px auto 10px; font-size: 29px; font-weight: 500; }
  .mobile-cta p { margin: 0 auto 25px; color: #b7a88d; font-family: Arial, sans-serif; font-size: 14px; }
  .mobile-cta .button { max-width: 330px; margin: auto; }

  footer { padding: 32px 20px 38px; text-align: center; background: #050403; }
  footer strong { color: var(--gold-light); letter-spacing: .15em; }
  footer p { margin: 9px 0 0; color: #786a52; font-family: Arial, sans-serif; font-size: 11px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}