/* ==========================================================================
   WEBIFIO — BlueYard Capital Style System
   Theme: Sunset editorial observatory.
   Only Hero & Footer: Vast white canvas with full-screen warm sunset wash,
   oversized Instrument Sans display question, unconstrained 3D celestial planet,
   and minimalist footer. 0px radius, 98% achromatic.
   ========================================================================== */

:root {
  /* Colors */
  --color-canvas-white: #ffffff;
  --color-graphite-ink: #3a3a3e;
  --color-deep-carbon: #090b11;
  --color-ash-veil: #b5b0b0;
  --color-apricot-wash: #ffcf9e;
  --color-crimson-accent: #e11d48;
  --color-subtle-border: rgba(58, 58, 62, 0.2);

  /* Typography — Font Families (Plus Jakarta Sans & Be Vietnam Pro have 100% native Vietnamese diacritic support) */
  --font-editorial-sans: 'Plus Jakarta Sans', 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-instrument-sans: 'Instrument Sans', 'Plus Jakarta Sans', 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-geist-mono: 'Geist Mono', monospace;

  /* Typography — Scale */
  --text-caption: 12px;
  --tracking-caption: -0.36px;
  --text-display: 56px;
  --leading-display: 1.05;
  --tracking-display: -1.62px;

  /* Typography — Weights */
  --font-weight-light: 300;
  --font-weight-regular: 400;
  --font-weight-medium: 500;

  /* Border Radius: Strictly 0px across everything */
  --radius-tags: 0px;
  --radius-cards: 0px;
  --radius-buttons: 0px;

  --content-max: 1200px;
}

/* Editorial text column (home + blog) */
.by-content-1200 {
  width: 100%;
  max-width: var(--content-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
  box-sizing: border-box;
}

/* Base Reset & Core Editorial Foundation */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  background-color: var(--color-canvas-white);
  color: var(--color-graphite-ink);
  overflow-x: hidden;
}

/* When switching to Vietnamese, use Plus Jakarta Sans / Be Vietnam Pro for flawless diacritics */
html[lang="vi"] {
  --font-instrument-sans: 'Plus Jakarta Sans', 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --tracking-display: -0.6px;
}

body {
  font-family: var(--font-instrument-sans);
  font-weight: var(--font-weight-regular);
  background-color: var(--color-canvas-white);
  color: var(--color-graphite-ink);
  line-height: 1.5;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Atmospheric Peach Horizon Wash Bleed — Full Height Sunset Sky */
.hero-atmospheric-wash {
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse 120% 90% at 50% 20%, #fed7aa 0%, #ffedd5 45%, #fff7ed 75%, #ffffff 100%);
  pointer-events: none;
  z-index: 0;
}

/* ==========================================================================
   NAVIGATION: BLUEYARD WORDMARK LOCKUP & 40x40 HAMBURGER SQUARE
   ========================================================================== */
.by-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 24px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  pointer-events: none;
}

/* Wordmark Wrapper: Height matches 40px hamburger button */
.by-wordmark-wrapper {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  height: 40px;
  pointer-events: auto;
}

/* Top-Left wordmark (homepage header — text only, no favicon) */
.by-wordmark {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  height: 40px;
  text-decoration: none;
  color: var(--color-graphite-ink);
  font-family: var(--font-instrument-sans);
  font-weight: var(--font-weight-medium);
  font-size: 15px;
  line-height: 1.15;
  letter-spacing: -0.2px;
  transition: opacity 0.2s ease;
}

.by-wordmark:hover {
  opacity: 0.65;
}

.by-wordmark-line {
  display: block;
}

.by-wordmark-sub {
  color: var(--color-graphite-ink);
  font-size: 13px;
  opacity: 0.65;
  margin-top: 1px;
}

/* In-line 3D Color Palette Cycle Button (Right of Wordmark) */
.by-color-dice-btn {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-subtle-border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--color-graphite-ink);
  transition: all 0.2s ease;
  box-shadow: none;
  padding: 0;
}

.by-color-dice-btn svg {
  width: 18px;
  height: 18px;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.by-color-dice-btn:hover {
  border-color: var(--color-graphite-ink);
  background-color: var(--color-graphite-ink);
  color: var(--color-canvas-white);
}

.by-color-dice-btn:hover svg {
  transform: rotate(90deg) scale(1.1);
}

.by-color-dice-btn:active svg {
  transform: rotate(180deg) scale(0.95);
}

/* Header Right Actions Group (Lang Switcher + 40x40 Hamburger) */
.by-header-actions {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  height: 40px;
  pointer-events: auto;
}

/* EN / VI Language Switcher */
.by-lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  height: 40px;
  padding: 0 10px;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-subtle-border);
  font-family: var(--font-geist-mono);
  font-size: 13px;
  color: var(--color-graphite-ink);
  transition: border-color 0.2s ease;
}

.by-lang-switcher:hover {
  border-color: var(--color-graphite-ink);
}

.by-lang-btn {
  background: none;
  border: none;
  font-family: inherit;
  font-size: 13px;
  color: var(--color-graphite-ink);
  opacity: 0.5;
  cursor: pointer;
  padding: 2px 4px;
  font-weight: 500;
  transition: opacity 0.2s ease, font-weight 0.2s ease;
}

.by-lang-btn:hover {
  opacity: 0.9;
}

.by-lang-btn.is-active {
  opacity: 1;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.by-lang-sep {
  opacity: 0.3;
  user-select: none;
}

/* Top-Right 40x40 Square Hamburger Button */
.by-hamburger-btn {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-subtle-border);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  pointer-events: auto;
  transition: all 0.2s ease;
  box-shadow: none;
}

.by-hamburger-btn:hover {
  border-color: var(--color-graphite-ink);
  background-color: var(--color-graphite-ink);
}

.by-hamburger-btn:hover .by-hamburger-line {
  background-color: var(--color-canvas-white);
}

.by-hamburger-line {
  width: 16px;
  height: 1px;
  background-color: var(--color-graphite-ink);
  display: block;
  transform-origin: center;
  transition:
    transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    opacity 0.25s ease,
    background-color 0.2s ease;
}

.by-hamburger-btn.is-active .by-hamburger-line:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}

.by-hamburger-btn.is-active .by-hamburger-line:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.by-hamburger-btn.is-active .by-hamburger-line:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* Navigation Drawer Modal */
.by-nav-drawer {
  position: fixed;
  inset: 0;
  background: rgba(9, 11, 17, 0.45);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  pointer-events: auto;
  display: flex;
  justify-content: flex-end;
}

.by-nav-drawer.is-open {
  opacity: 1;
  visibility: visible;
}

.by-drawer-inner {
  width: 100%;
  max-width: 440px;
  height: 100%;
  background: var(--color-canvas-white);
  border-left: 1px solid var(--color-graphite-ink);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transform: translateX(100%);
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.by-nav-drawer.is-open .by-drawer-inner {
  transform: translateX(0);
}

.by-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-graphite-ink);
  padding-bottom: 16px;
}

.by-drawer-title {
  font-family: var(--font-instrument-sans);
  font-weight: var(--font-weight-medium);
  font-size: var(--text-caption);
  letter-spacing: var(--tracking-caption);
  color: var(--color-graphite-ink);
}

.by-drawer-close-btn {
  background: none;
  border: none;
  font-size: 1.2rem;
  color: var(--color-graphite-ink);
  cursor: pointer;
  padding: 4px;
  line-height: 1;
}

.by-drawer-nav {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin: 40px 0;
}

.by-drawer-link {
  display: flex;
  align-items: baseline;
  gap: 16px;
  text-decoration: none;
  color: var(--color-graphite-ink);
  border-bottom: 1px solid rgba(58, 58, 62, 0.15);
  padding-bottom: 14px;
  opacity: 0;
  transform: translateX(24px);
  transition:
    opacity 0.45s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.45s cubic-bezier(0.16, 1, 0.3, 1);
}

.by-nav-drawer.is-open .by-drawer-link {
  opacity: 1;
  transform: translateX(0);
}

.by-nav-drawer.is-open .by-drawer-link:nth-child(1) { transition-delay: 0.06s; }
.by-nav-drawer.is-open .by-drawer-link:nth-child(2) { transition-delay: 0.11s; }
.by-nav-drawer.is-open .by-drawer-link:nth-child(3) { transition-delay: 0.16s; }
.by-nav-drawer.is-open .by-drawer-link:nth-child(4) { transition-delay: 0.21s; }
.by-nav-drawer.is-open .by-drawer-link:nth-child(5) { transition-delay: 0.26s; }

.by-nav-drawer:not(.is-open) .by-drawer-link {
  transition-delay: 0s;
}

.by-drawer-link:hover {
  opacity: 0.65;
  transform: translateX(6px);
}

.by-drawer-header,
.by-drawer-foot {
  opacity: 0;
  transform: translateY(-10px);
  transition:
    opacity 0.4s ease,
    transform 0.45s cubic-bezier(0.16, 1, 0.3, 1);
}

.by-nav-drawer.is-open .by-drawer-header {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 0.04s;
}

.by-nav-drawer.is-open .by-drawer-foot {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 0.32s;
}

.by-nav-drawer:not(.is-open) .by-drawer-header,
.by-nav-drawer:not(.is-open) .by-drawer-foot {
  transition-delay: 0s;
}

.by-link-num {
  font-family: var(--font-geist-mono);
  font-size: var(--text-caption);
  color: var(--color-graphite-ink);
  opacity: 0.6;
}

.by-link-text {
  font-size: 20px;
  font-weight: var(--font-weight-regular);
  letter-spacing: -0.3px;
}

.by-drawer-foot {
  font-family: var(--font-geist-mono);
  font-size: var(--text-caption);
  color: var(--color-ash-veil);
  border-top: 1px solid rgba(58, 58, 62, 0.15);
  padding-top: 14px;
}

/* ==========================================================================
   ABOUT APPIFIO NETWORK MODAL (Editorial Monograph Card)
   ========================================================================== */
.by-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(9, 11, 17, 0.45);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 2500;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  pointer-events: auto;
}

.by-modal-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.by-modal-dialog {
  width: 100%;
  max-width: 540px;
  max-height: min(92dvh, 920px);
  background: var(--color-canvas-white);
  border: 1px solid var(--color-graphite-ink);
  padding: 32px 32px 36px;
  transform: translateY(20px);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 16px 48px rgba(58, 58, 62, 0.14);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.by-modal-body {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  padding-right: 2px;
}

.by-modal-overlay.is-open .by-modal-dialog {
  transform: translateY(0);
}

.by-modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(58, 58, 62, 0.2);
  padding-bottom: 16px;
  margin-bottom: 24px;
}

.by-modal-label {
  font-family: var(--font-geist-mono);
  font-size: var(--text-caption);
  color: var(--color-graphite-ink);
  letter-spacing: -0.2px;
}

.by-modal-title {
  font-family: var(--font-instrument-sans);
  font-size: 28px;
  font-weight: var(--font-weight-light);
  line-height: 1.15;
  letter-spacing: -0.8px;
  color: var(--color-graphite-ink);
  margin-bottom: 24px;
}

.by-modal-section {
  border-left: 2px solid var(--color-graphite-ink);
  padding-left: 14px;
  margin-bottom: 20px;
}

.by-modal-section-tag {
  font-family: var(--font-geist-mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--color-graphite-ink);
  letter-spacing: 0.5px;
  margin-bottom: 4px;
}

.by-modal-desc {
  font-size: 14px;
  line-height: 1.55;
  color: var(--color-graphite-ink);
  opacity: 0.88;
}

.by-modal-desc code {
  font-family: var(--font-geist-mono);
  font-size: 12px;
  background: rgba(58, 58, 62, 0.08);
  padding: 2px 6px;
}

.by-modal-actions {
  border-top: 1px solid rgba(58, 58, 62, 0.2);
  padding-top: 24px;
  margin-top: 28px;
  display: flex;
  justify-content: flex-end;
}

.by-modal-btn {
  padding: 12px 24px;
  font-size: 14px;
  max-width: 100%;
  white-space: normal;
  text-align: left;
  line-height: 1.35;
}

.by-modal-btn .by-cta-arrow {
  flex-shrink: 0;
  margin-left: auto;
}

body.nav-locked {
  overflow: hidden;
  touch-action: none;
}

@media (max-width: 768px) {
  .by-modal-overlay {
    align-items: flex-end;
    justify-content: center;
    padding: 0;
    overflow-y: auto;
    overscroll-behavior: contain;
  }

  .by-modal-dialog {
    max-width: none;
    width: 100%;
    max-height: min(94dvh, 100%);
    margin: 0;
    padding: 18px 18px max(22px, env(safe-area-inset-bottom, 0px));
    border-left: none;
    border-right: none;
    border-bottom: none;
    transform: translateY(100%);
    box-shadow: 0 -8px 40px rgba(9, 11, 17, 0.12);
  }

  .by-modal-overlay.is-open .by-modal-dialog {
    transform: translateY(0);
  }

  .by-modal-head {
    margin-bottom: 16px;
    padding-bottom: 12px;
    gap: 12px;
  }

  .by-modal-label {
    font-size: 11px;
    line-height: 1.35;
    flex: 1;
    min-width: 0;
  }

  .by-modal-title {
    font-size: clamp(22px, 6.4vw, 28px);
    line-height: 1.2;
    margin-bottom: 18px;
    text-wrap: balance;
  }

  .by-modal-section {
    margin-bottom: 16px;
    padding-left: 12px;
  }

  .by-modal-section-tag {
    font-size: 10px;
    line-height: 1.45;
    letter-spacing: 0.35px;
    text-wrap: pretty;
  }

  .by-modal-desc {
    font-size: 14px;
    line-height: 1.6;
  }

  .by-modal-desc code {
    display: inline-block;
    max-width: 100%;
    overflow-wrap: anywhere;
    word-break: break-word;
    margin: 2px 0;
  }

  .by-modal-actions {
    flex-shrink: 0;
    margin-top: 12px;
    padding-top: 16px;
    justify-content: stretch;
  }

  .by-modal-btn.by-hero-cta-btn {
    width: 100%;
    justify-content: flex-start;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    font-size: 14px;
  }

  .by-modal-btn.by-hero-cta-btn > span:first-of-type {
    flex: 1;
    min-width: 0;
  }
}

/* ==========================================================================
   HERO: PURE BLUEYARD EDITORIAL OBSERVATORY
   Centered 56px Instrument Sans question headline, unconstrained 3D celestial planet
   ========================================================================== */
.by-hero {
  position: relative;
  min-height: calc(100vh - 100px);
  padding-top: 120px;
  padding-bottom: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  z-index: 1;
  width: 100vw;
  overflow: visible;
}

.by-hero-content {
  max-width: var(--content-max);
  width: 100%;
  margin: 0 auto;
  text-align: center;
  padding: 0 24px;
  z-index: 10;
  position: relative;
}

/* 56px Display Headline: Pure Instrument Sans, weight 300/400, line-height 1.05, tracking -1.62px */
.by-hero-headline {
  font-family: var(--font-instrument-sans);
  font-size: clamp(34px, 5.2vw, var(--text-display));
  font-weight: var(--font-weight-light);
  line-height: var(--leading-display);
  letter-spacing: var(--tracking-display);
  color: var(--color-graphite-ink);
  margin-bottom: 0;
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
}

/* Unconstrained full-viewport 3D hanging celestial body stage (Zero clipping) */
.by-stage-container {
  position: relative;
  width: 100vw;
  height: min(68vh, 640px);
  min-height: 480px;
  margin-top: 10px;
  margin-bottom: 24px;
  z-index: 1;
  pointer-events: auto;
  overflow: visible; /* Ensure NO clipping boundaries */
}

.by-stage-container::before {
  content: "";
  position: absolute;
  inset: -260px 0 0;
  z-index: -1;
  background:
    radial-gradient(circle at 5% 23%, #cfdfff 0 1px, transparent 1.6px),
    radial-gradient(circle at 12% 61%, #b7c9ee 0 .7px, transparent 1.3px),
    radial-gradient(circle at 18% 14%, #fff 0 1px, transparent 1.7px),
    radial-gradient(circle at 23% 78%, #9ab3e0 0 .7px, transparent 1.3px),
    radial-gradient(circle at 29% 33%, #d5e3ff 0 .8px, transparent 1.4px),
    radial-gradient(circle at 34% 8%, #afc8f6 0 .7px, transparent 1.3px),
    radial-gradient(circle at 37% 68%, #fff 0 1px, transparent 1.6px),
    radial-gradient(circle at 43% 43%, #a8bee8 0 .7px, transparent 1.4px),
    radial-gradient(circle at 48% 16%, #d6e3ff 0 .8px, transparent 1.4px),
    radial-gradient(circle at 53% 85%, #c5d9ff 0 .8px, transparent 1.4px),
    radial-gradient(circle at 58% 29%, #fff 0 1px, transparent 1.6px),
    radial-gradient(circle at 62% 65%, #a9c0ec 0 .7px, transparent 1.3px),
    radial-gradient(circle at 67% 10%, #cfdeff 0 .8px, transparent 1.4px),
    radial-gradient(circle at 71% 47%, #fff 0 1px, transparent 1.7px),
    radial-gradient(circle at 76% 77%, #aabfe7 0 .7px, transparent 1.3px),
    radial-gradient(circle at 82% 21%, #dce7ff 0 .8px, transparent 1.5px),
    radial-gradient(circle at 86% 59%, #a8bee7 0 .7px, transparent 1.3px),
    radial-gradient(circle at 91% 12%, #fff 0 1px, transparent 1.7px),
    radial-gradient(circle at 95% 72%, #bdcef1 0 .8px, transparent 1.4px),
    radial-gradient(ellipse at 50% 48%, #111a32 0%, #050814 65%, #02040b 100%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.7s ease;
}

body.is-solar-journey .by-stage-container::before { opacity: 1; }
body.is-solar-journey .by-hero-headline { color: #f3f5fb; transition: color 0.7s ease; }
body.is-solar-journey .by-header { background: rgba(2, 4, 11, 0.94); }
body.is-solar-journey .by-wordmark,
body.is-solar-journey .by-header-actions { color: #f3f5fb; }

body.is-solar-journey .by-wordmark-sub {
  color: rgba(243, 245, 251, 0.82);
  opacity: 1;
}

.by-canvas-viewport canvas { cursor: pointer; }
body.is-solar-journey .by-canvas-viewport canvas { cursor: default; }

.solar-journey-start,
.solar-journey-replay {
  position: absolute;
  z-index: 5;
  left: 50%;
  bottom: 14px;
  transform: translateX(-50%);
  border: 1px solid currentColor;
  padding: 10px 16px;
  background: rgba(255, 255, 255, 0.7);
  color: var(--color-graphite-ink);
  font: 500 11px var(--font-geist-mono);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  white-space: nowrap;
}
.solar-journey-start:hover { background: #fff; }
.solar-journey-replay { background: rgba(4, 8, 20, 0.75); color: #f3f5fb; }
.solar-journey-replay:hover { background: #15203b; }
.solar-journey-replay[hidden] { display: none; }
body.is-solar-journey .solar-journey-start { display: none; }

.solar-journey-caption {
  position: absolute;
  z-index: 5;
  left: 50%;
  bottom: 70px;
  transform: translateX(-50%);
  color: #f3f5fb;
  font: 500 clamp(12px, 2vw, 17px) var(--font-geist-mono);
  letter-spacing: 0.11em;
  text-align: center;
  text-shadow: 0 2px 12px #000;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.25s ease;
  white-space: nowrap;
}
body.is-solar-journey .solar-journey-caption:not(:empty) { opacity: 1; }

.by-canvas-viewport {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  overflow: visible;
}

#three-bg-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* ==========================================================================
   BLUEYARD EDITORIAL SHOWCASE & LAUNCH CTA SECTION
   Rich monograph narrative, 3 architectural pillars, dual action buttons
   ========================================================================== */
.by-cta-showcase-section {
  position: relative;
  z-index: 20;
  width: 100%;
  max-width: var(--content-max);
  margin: 30px auto 40px;
  padding: 0 24px;
  box-sizing: border-box;
}

.by-cta-card {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-subtle-border);
  padding: 40px 36px 44px;
  text-align: left;
  box-shadow: 0 12px 40px rgba(58, 58, 62, 0.08);
  transition: border-color 0.25s ease;
}

.by-cta-card:hover {
  border-color: rgba(58, 58, 62, 0.35);
}

.by-cta-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-geist-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.6px;
  color: var(--color-graphite-ink);
  margin-bottom: 16px;
}

.by-cta-kicker-dot {
  width: 7px;
  height: 7px;
  background-color: var(--color-crimson-accent);
  display: inline-block;
}

.by-cta-heading {
  font-family: var(--font-instrument-sans);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: var(--font-weight-light);
  line-height: 1.15;
  letter-spacing: -1px;
  color: var(--color-graphite-ink);
  margin-bottom: 16px;
  max-width: 820px;
}

.by-cta-narrative {
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-graphite-ink);
  opacity: 0.88;
  max-width: 860px;
  margin-bottom: 32px;
}

.by-cta-narrative code {
  font-family: var(--font-geist-mono);
  font-size: 13px;
  background: rgba(58, 58, 62, 0.08);
  padding: 2px 6px;
}

.by-cta-pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  border-top: 1px solid rgba(58, 58, 62, 0.2);
  border-bottom: 1px solid rgba(58, 58, 62, 0.2);
  padding: 24px 0;
  margin-bottom: 36px;
}

.by-cta-pillar {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.by-pillar-label {
  font-family: var(--font-geist-mono);
  font-size: 11px;
  color: var(--color-graphite-ink);
  opacity: 0.6;
}

.by-cta-pillar strong {
  font-family: var(--font-instrument-sans);
  font-size: 17px;
  font-weight: var(--font-weight-medium);
  letter-spacing: -0.2px;
  color: var(--color-graphite-ink);
}

.by-cta-pillar p {
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--color-graphite-ink);
  opacity: 0.8;
}

.by-cta-button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

.by-hero-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 28px;
  background-color: var(--color-canvas-white);
  color: var(--color-graphite-ink);
  border: 1px solid var(--color-graphite-ink);
  text-decoration: none;
  font-family: var(--font-instrument-sans);
  font-size: 15px;
  font-weight: var(--font-weight-medium);
  letter-spacing: -0.2px;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 2px 12px rgba(58, 58, 62, 0.04);
}

.by-hero-cta-btn:hover {
  background-color: var(--color-graphite-ink);
  color: var(--color-canvas-white);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(58, 58, 62, 0.12);
}

.by-btn-primary {
  background-color: var(--color-graphite-ink);
  color: var(--color-canvas-white);
}

.by-btn-primary:hover {
  background-color: #1e1e22;
  color: var(--color-canvas-white);
}

.by-btn-secondary {
  background-color: transparent;
  color: var(--color-graphite-ink);
}

.by-cta-arrow {
  font-family: var(--font-geist-mono);
  font-size: 16px;
  line-height: 1;
  transition: transform 0.2s ease;
}

.by-hero-cta-btn:hover .by-cta-arrow {
  transform: translate(2px, -2px);
}

@media (max-width: 768px) {
  .by-cta-card {
    padding: 28px 20px 32px;
  }

  .by-cta-pillars {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .by-cta-button-group {
    flex-direction: column;
    align-items: stretch;
  }

  .by-hero-cta-btn {
    justify-content: center;
  }
}

/* ==========================================================================
   FREQUENTLY ASKED QUESTIONS: MONOGRAPH EDITORIAL GRID
   Clean, 0px radius, 98% achromatic with subtle border separators
   ========================================================================== */
.by-faq-section {
  width: 100%;
  max-width: var(--content-max);
  margin: 40px auto 60px;
  padding: 0 24px;
  box-sizing: border-box;
  position: relative;
  z-index: 10;
}

.by-faq-header {
  border-top: 1px solid rgba(58, 58, 62, 0.2);
  padding-top: 24px;
  margin-bottom: 32px;
}

.by-faq-tag {
  font-family: var(--font-geist-mono);
  font-size: var(--text-caption);
  letter-spacing: var(--tracking-caption);
  color: var(--color-graphite-ink);
  opacity: 0.7;
  display: block;
  margin-bottom: 6px;
}

.by-faq-title {
  font-family: var(--font-instrument-sans);
  font-size: clamp(26px, 3.5vw, 36px);
  font-weight: var(--font-weight-light);
  letter-spacing: -0.8px;
  color: var(--color-graphite-ink);
}

.by-faq-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.by-faq-card {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(58, 58, 62, 0.2);
  padding: 28px 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.by-faq-card:hover {
  border-color: var(--color-graphite-ink);
  transform: translateY(-2px);
}

.by-faq-num {
  font-family: var(--font-geist-mono);
  font-size: var(--text-caption);
  color: var(--color-graphite-ink);
  opacity: 0.6;
  margin-bottom: 12px;
  display: block;
}

.by-faq-q {
  font-family: var(--font-instrument-sans);
  font-size: 20px;
  font-weight: var(--font-weight-medium);
  letter-spacing: -0.4px;
  color: var(--color-graphite-ink);
  line-height: 1.3;
  margin-bottom: 14px;
}

.by-faq-a {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-graphite-ink);
  opacity: 0.85;
  margin-bottom: 20px;
  flex-grow: 1;
}

.by-faq-a code {
  font-family: var(--font-geist-mono);
  font-size: 12px;
  background: rgba(58, 58, 62, 0.08);
  padding: 2px 6px;
}

.by-faq-anchor {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  font-family: var(--font-geist-mono);
  font-size: 12px;
  color: var(--color-graphite-ink);
  border-bottom: 1px solid var(--color-graphite-ink);
  padding-bottom: 2px;
  width: fit-content;
  transition: opacity 0.2s ease, gap 0.2s ease;
}

.by-faq-anchor:hover {
  opacity: 0.65;
  gap: 12px;
}

.by-faq-arrow {
  font-size: 13px;
  line-height: 1;
}

@media (max-width: 768px) {
  .by-faq-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
}

/* ==========================================================================
   FOOTER: MONOGRAPH RESTRAINT
   ========================================================================== */
.by-footer {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 32px 48px;
  position: relative;
  z-index: 10;
  background: transparent;
}

.by-footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
  border-top: 1px solid rgba(58, 58, 62, 0.2);
  padding-top: 24px;
}

.by-footer-col {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: var(--text-caption);
  color: var(--color-graphite-ink);
}

.by-footer-center {
  max-width: 480px;
  line-height: 1.6;
}

.by-footer-right {
  font-family: var(--font-geist-mono);
  text-align: right;
  opacity: 0.65;
}

.by-text-link {
  color: var(--color-graphite-ink);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* SEO overview blocks (crawlable anchors; below FAQ) */
.by-seo-overview {
  max-width: var(--content-max);
  margin: 48px auto 0;
  padding: 32px 24px 0;
  border-top: 1px solid var(--color-subtle-border);
  box-sizing: border-box;
}

/* Main sections below hero — full 1200px column (not flex-shrunk inside .by-hero) */
main > .by-cta-showcase-section,
main > .by-faq-section,
main > .by-seo-overview,
main > .by-blog-section {
  width: 100%;
  max-width: var(--content-max);
  margin-left: auto;
  margin-right: auto;
  box-sizing: border-box;
}

/* Home blog list (above footer) */
.by-blog-section {
  margin: 56px auto 24px;
  padding: 0 24px 48px;
  position: relative;
  z-index: 10;
}

.by-blog-header {
  border-top: 1px solid rgba(58, 58, 62, 0.2);
  padding-top: 28px;
  margin-bottom: 28px;
}

.by-blog-category {
  margin-bottom: 36px;
}

.by-blog-category-title {
  font-family: var(--font-instrument-sans);
  font-size: 20px;
  font-weight: var(--font-weight-medium);
  letter-spacing: -0.03em;
  margin: 0 0 16px;
  color: var(--color-graphite-ink);
}

.by-blog-card-cat {
  font-family: var(--font-geist-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.72;
}

.by-blog-kicker {
  font-family: var(--font-geist-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 0 0 10px;
  opacity: 0.75;
}

.by-blog-title {
  font-family: var(--font-instrument-sans);
  font-size: clamp(26px, 3.5vw, 34px);
  font-weight: var(--font-weight-light);
  letter-spacing: -0.04em;
  margin: 0;
  color: var(--color-graphite-ink);
}

.by-blog-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 20px;
}

.by-blog-item {
  margin: 0;
}

.by-blog-card {
  display: grid;
  grid-template-columns: minmax(140px, 280px) 1fr;
  gap: 24px;
  align-items: start;
  text-decoration: none;
  color: inherit;
  border: 1px solid var(--color-subtle-border);
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(8px);
  padding: 20px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.by-blog-card:hover {
  border-color: rgba(58, 58, 62, 0.45);
  box-shadow: 0 10px 32px rgba(58, 58, 62, 0.08);
}

.by-blog-card-media {
  display: block;
  overflow: hidden;
  border: 1px solid var(--color-subtle-border);
  aspect-ratio: 1200 / 630;
  background: #f6f6f6;
}

.by-blog-card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.by-blog-card-body {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.by-blog-card-date {
  font-family: var(--font-geist-mono);
  font-size: 11px;
  opacity: 0.65;
}

.by-blog-card-title {
  font-family: var(--font-instrument-sans);
  font-size: 22px;
  font-weight: var(--font-weight-medium);
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.by-blog-card-excerpt {
  font-size: 15px;
  line-height: 1.55;
  opacity: 0.88;
}

.by-blog-card-more {
  font-family: var(--font-geist-mono);
  font-size: 12px;
  margin-top: 4px;
}

@media (max-width: 768px) {
  .by-blog-card {
    grid-template-columns: 1fr;
  }
}

.by-seo-overview-title {
  font-family: var(--font-instrument-sans);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.4px;
  color: var(--color-deep-carbon);
  margin: 0 0 12px;
}

.by-seo-overview-text {
  font-size: 15px;
  line-height: 1.65;
  color: var(--color-graphite-ink);
  margin: 0 0 24px;
}

/* ==========================================================================
   RESPONSIVE DESIGN (MOBILE & TABLET)
   ========================================================================== */
@media (max-width: 768px) {
  .by-header {
    padding: 16px 20px;
  }

  .by-hero {
    padding-top: 100px;
    min-height: auto;
  }

  .by-hero-headline {
    font-size: clamp(30px, 8vw, 42px);
    letter-spacing: -1px;
  }

  .by-stage-container {
    height: 440px;
    min-height: 400px;
  }

  .by-footer {
    padding: 24px 20px 40px;
  }

  .by-footer-right {
    text-align: left;
  }
}

/* ==========================================================================
   Motion: hero entrance + scroll reveal
   ========================================================================== */
.wf-reveal {
  opacity: 0;
  transform: translate3d(0, 32px, 0);
  transition:
    opacity 0.9s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.9s cubic-bezier(0.16, 1, 0.3, 1);
  transition-delay: var(--wf-delay, 0s);
  will-change: opacity, transform;
}

.wf-reveal.is-visible {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.wf-reveal-hero {
  transform: translate3d(0, 48px, 0);
  transition-duration: 1.05s;
}

/* Page boot loader */
html.wf-boot-pending {
  overflow: hidden;
}

.wf-page-loader {
  position: fixed;
  inset: 0;
  z-index: 12000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  background: var(--color-canvas-white);
  transition: opacity 0.55s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.55s;
}

.wf-page-loader.is-done {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.wf-page-loader-mark {
  font-family: var(--font-instrument-sans);
  font-size: 13px;
  font-weight: var(--font-weight-medium);
  letter-spacing: 0.38em;
  text-indent: 0.38em;
  color: var(--color-graphite-ink);
}

.wf-page-loader-bar {
  width: min(220px, 52vw);
  height: 2px;
  background: rgba(58, 58, 62, 0.12);
  overflow: hidden;
}

.wf-page-loader-bar::after {
  content: "";
  display: block;
  width: 42%;
  height: 100%;
  background: var(--color-graphite-ink);
  animation: wf-loader-sweep 1.05s ease-in-out infinite;
}

@keyframes wf-loader-sweep {
  0% {
    transform: translateX(-110%);
  }
  100% {
    transform: translateX(260%);
  }
}

/* H1: sóng trái → phải, từng chữ cái nhảy lên (xuống dòng theo từ, không cắt giữa chữ) */
.by-hero-headline.wf-h1-chars {
  overflow: visible;
}

.by-hero-headline .wf-h1-word {
  display: inline-block;
  white-space: nowrap;
}

.by-hero-headline .wf-h1-char,
.by-hero-headline .wf-h1-space {
  display: inline-block;
}

.by-hero-headline.wf-h1-chars:not(.wf-h1-play):not(.wf-h1-settled) .wf-h1-char {
  opacity: 0;
  transform: translate3d(0, 0.55em, 0);
}

.by-hero-headline.wf-h1-play .wf-h1-char {
  animation: wf-h1-letter-wave 0.52s cubic-bezier(0.34, 1.35, 0.48, 1) both;
  animation-delay: calc(0.16s + 0.034s * var(--wf-i, 0));
}

@keyframes wf-h1-letter-wave {
  0% {
    opacity: 0;
    transform: translate3d(0, 0.62em, 0);
  }
  48% {
    opacity: 1;
    transform: translate3d(0, -0.2em, 0);
  }
  72% {
    transform: translate3d(0, 0.07em, 0);
  }
  100% {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

.by-hero-headline.wf-h1-settled .wf-h1-char,
body.is-solar-journey .by-hero-headline .wf-h1-char {
  animation: none;
  opacity: 1;
  transform: none;
}

.wf-reveal-fade {
  transform: translate3d(0, 12px, 0);
  transition-duration: 0.75s;
}

/* Stage + solar CTAs use left:50%; base wf-reveal must keep -50% on X */
.by-stage-container.wf-reveal,
.by-stage-container.wf-reveal.is-visible {
  transform: none;
}

.solar-journey-start.wf-reveal,
.solar-journey-replay.wf-reveal {
  transform: translate3d(-50%, 32px, 0);
}

.solar-journey-start.wf-reveal.wf-reveal-fade,
.solar-journey-replay.wf-reveal.wf-reveal-fade {
  transform: translate3d(-50%, 12px, 0);
}

.solar-journey-start.wf-reveal.is-visible,
.solar-journey-replay.wf-reveal.is-visible {
  transform: translate3d(-50%, 0, 0);
}

.solar-journey-caption.wf-reveal {
  transform: translate3d(-50%, 32px, 0);
}

.solar-journey-caption.wf-reveal.is-visible {
  transform: translate3d(-50%, 0, 0);
}