/* Zalo landing — hungw.id.vn/zalo */

@property --beam-angle { syntax: '<angle>'; initial-value: 0deg; inherits: false; }

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

html {
  overflow-x: clip;
}

body {
  overflow-x: clip;
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.7;
  background: var(--color-paper);
  color: var(--color-ink);
  transition: background-color var(--dur-short) var(--ease-out),
              color var(--dur-short) var(--ease-out);
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--color-ink);
  color: var(--color-accent-ink);
}

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 800;
  pointer-events: none;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- Layout ---------- */

.zalo {
  min-block-size: 100vh;
  min-block-size: 100svh;
  display: grid;
  place-items: center;
  padding: max(var(--space-xl), env(safe-area-inset-top, 0px)) var(--space-md) max(var(--space-xl), env(safe-area-inset-bottom, 0px));
  background:
    radial-gradient(circle at 20% 20%, var(--color-spot), transparent 55%),
    radial-gradient(circle at 80% 80%, var(--color-spot), transparent 55%),
    var(--color-paper);
}

.zalo__card {
  position: relative;
  isolation: isolate;
  inline-size: min(100%, 44rem);
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: clamp(var(--space-lg), 5vw, var(--space-xl));
  animation: zalo-in 0.6s var(--ease-out) both;
}

.zalo__card > * {
  position: relative;
  z-index: 1;
}

.zalo__back {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  min-block-size: 44px;
  padding-inline: var(--space-sm);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-pill);
  background: var(--color-paper-3);
  color: var(--color-muted);
  font-size: var(--text-sm);
  text-decoration: none;
  margin-block-end: var(--space-lg);
  transition: color var(--dur-micro) var(--ease-out),
              border-color var(--dur-micro) var(--ease-out),
              box-shadow var(--dur-short) var(--ease-out);
}

.zalo__back svg {
  inline-size: 14px;
  block-size: 14px;
}

.zalo__back:hover,
.zalo__back:focus-visible {
  color: var(--color-ink);
  border-color: var(--color-silver);
  box-shadow: 0 0 18px var(--color-glow-soft);
}

.zalo__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-xl);
  align-items: center;
}

@media (min-width: 40rem) {
  .zalo__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }
}

/* ---------- QR ---------- */

.zalo__qr {
  display: grid;
  gap: var(--space-sm);
  justify-items: center;
  animation: zalo-in 0.6s var(--ease-out) 70ms both;
}

.zalo__qr-frame {
  position: relative;
  inline-size: min(100%, 18rem);
  aspect-ratio: 1 / 1;
  padding: var(--space-sm);
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  transition: transform var(--dur-short) var(--ease-out),
              box-shadow var(--dur-short) var(--ease-out);
}

.zalo__qr-frame:hover,
.zalo__qr-frame:focus-within {
  transform: scale(1.02);
  box-shadow: var(--shadow-card-hover);
}

.zalo__qr-frame img {
  display: block;
  inline-size: 100%;
  block-size: 100%;
  object-fit: contain;
}

.zalo__qr-caption {
  color: var(--color-muted);
  font-size: var(--text-sm);
  text-align: center;
}

/* ---------- Info ---------- */

.zalo__info {
  display: grid;
  gap: var(--space-sm);
  justify-items: start;
  animation: zalo-in 0.6s var(--ease-out) 140ms both;
}

.zalo__eyebrow {
  color: var(--color-muted);
  font-family: var(--font-outlier);
  font-size: var(--text-sm);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.zalo__title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, var(--text-xl));
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
  text-wrap: balance;
}

.zalo__lede {
  color: var(--color-muted);
  max-inline-size: 34ch;
  text-wrap: pretty;
}

.zalo__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-block-start: var(--space-sm);
}

.zalo__btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  min-block-size: 48px;
  padding-inline: var(--space-md);
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  transition: border-color var(--dur-micro) var(--ease-out),
              box-shadow var(--dur-short) var(--ease-out),
              transform var(--dur-short) var(--ease-out);
}

.zalo__btn svg {
  inline-size: 16px;
  block-size: 16px;
  flex: none;
}

.zalo__btn:active {
  transform: translateY(1px);
}

.zalo__btn--primary {
  position: relative;
  background: var(--color-ink);
  color: var(--color-accent-ink);
  border: 1px solid var(--color-ink);
}

.zalo__btn--primary:hover,
.zalo__btn--primary:focus-visible {
  box-shadow: var(--shadow-glow);
}

.zalo__btn--chip {
  background: var(--color-paper-2);
  color: var(--color-muted);
  border: 1px solid var(--color-rule);
  box-shadow: var(--shadow-card);
  font-family: var(--font-body);
  font-weight: 500;
}

.zalo__btn--chip:hover,
.zalo__btn--chip:focus-visible {
  color: var(--color-ink);
  border-color: var(--color-silver);
  box-shadow: 0 0 18px var(--color-glow-soft);
}

.zalo__note {
  color: var(--color-muted);
  font-size: var(--text-sm);
}

/* ---------- FX: spotlight / beam / shine ---------- */

.fx-spot,
.fx-beam,
.fx-shine {
  position: relative;
}

/* Spotlight: hình tròn 440px di chuyển bằng transform — compositor, không
   repaint card khi rê chuột. --mx/--my = offset px từ tâm card. */
.fx-spot {
  overflow: hidden;
}

.fx-spot::after {
  content: '';
  position: absolute;
  inset-block-start: calc(50% - 220px);
  inset-inline-start: calc(50% - 220px);
  inline-size: 440px;
  block-size: 440px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--color-spot), transparent 65%);
  transform: translate(var(--mx, 0px), var(--my, 0px));
  opacity: 0;
  transition: opacity var(--dur-short) var(--ease-out);
  pointer-events: none;
}

.fx-spot:hover::after,
.fx-spot:focus-within::after,
.fx-spot:active::after {
  opacity: 1;
}

/* Promote layer chỉ khi hover: spotlight chạy bằng custom property cần hint. */
@media (hover: hover) and (pointer: fine) {
  .fx-spot:hover::after,
  .fx-spot:focus-within::after {
    will-change: transform;
  }
}
@media (hover: none) and (pointer: coarse) {
  .fx-spot:active::after {
    will-change: transform;
  }
}

.fx-beam::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: conic-gradient(from var(--beam-angle, 0deg),
    transparent 0deg, var(--color-silver) 55deg, var(--color-ink) 90deg, var(--color-silver) 125deg, transparent 180deg, transparent 360deg);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask-composite: exclude;
  opacity: 0;
  transition: opacity var(--dur-short) var(--ease-out);
  pointer-events: none;
}

.fx-beam:hover::before,
.fx-beam:focus-within::before,
.fx-beam:active::before {
  opacity: 1;
  animation: fx-beam-spin 3.2s linear infinite;
}

@keyframes fx-beam-spin {
  to { --beam-angle: 360deg; }
}

.fx-shine {
  overflow: hidden;
}

.fx-shine::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(115deg, transparent 42%, var(--color-shine) 50%, transparent 58%);
  transform: translateX(-110%);
  transition: transform 0.7s var(--ease-out);
  pointer-events: none;
}

.fx-shine:hover::after,
.fx-shine:focus-visible::after,
.fx-shine:active::after {
  transform: translateX(110%);
}

/* Touch: JS gắn .fx-press khi nhấn và giữ tới khi thả ngón tay — mô phỏng hover PC.
   Beam hiện tĩnh: animation --beam-angle repaint gradient mỗi frame, phone giật. */
@media (hover: none) and (pointer: coarse) {
  .fx-spot.fx-press::after {
    opacity: 1;
    will-change: transform;
  }
  .fx-beam.fx-press::before {
    opacity: 1;
  }
  .fx-shine.fx-press::after {
    transform: translateX(110%);
  }
  .zalo__back.fx-press {
    color: var(--color-ink);
    border-color: var(--color-silver);
    box-shadow: 0 0 18px var(--color-glow-soft);
  }
  .zalo__qr-frame.fx-press {
    transform: scale(1.02);
    box-shadow: var(--shadow-card-hover);
  }
  .zalo__btn--primary.fx-press {
    box-shadow: var(--shadow-glow);
  }
  .zalo__btn--chip.fx-press {
    color: var(--color-ink);
    border-color: var(--color-silver);
    box-shadow: 0 0 18px var(--color-glow-soft);
  }
}

/* ---------- Entry motion ---------- */

@keyframes zalo-in {
  from {
    opacity: 0;
    transform: translateY(0.6em);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 150ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 150ms !important;
  }

  .zalo__card,
  .zalo__qr,
  .zalo__info,
  .zalo__qr-frame,
  .zalo__btn {
    animation: none !important;
    transform: none !important;
  }

  .fx-beam:hover::before,
  .fx-beam:focus-within::before,
  .fx-beam:active::before {
    animation: none !important;
  }

  .fx-shine::after {
    display: none;
  }
}