@charset "UTF-8";

/* ==========================================================================
   Hero Grid - Multi-Subject Homepage Layout
   Bento grid: 4 columns on desktop, Piano and Đàn tranh are 2x2 feature cards.
   Each card sets its accent via --accent / --accent-2 / --accent-ink / --tint.
   ========================================================================== */

:root {
  --grid-bg: #0b0b0f;
  --grid-line: rgba(255, 255, 255, 0.08);
  --grid-line-strong: rgba(255, 255, 255, 0.16);
  --grid-text: #ffffff;
  --grid-text-muted: rgba(255, 255, 255, 0.72);
  --grid-text-faint: rgba(255, 255, 255, 0.5);
  --grid-radius: 22px;
  --grid-gap: 18px;
  --grid-ease: cubic-bezier(0.16, 1, 0.3, 1);
  --grid-transition: 0.5s var(--grid-ease);
}

/* Per-subject accents */
.hero-grid__card--piano     { --accent: #b9a2ff; --accent-2: #7c3aed; --accent-ink: #ffffff; --tint: 109, 40, 217; }
.hero-grid__card--vocal     { --accent: #f9a8d4; --accent-2: #db2777; --accent-ink: #ffffff; --tint: 190, 24, 93; }
.hero-grid__card--acoustic  { --accent: #e7b98a; --accent-2: #a16207; --accent-ink: #1c1406; --tint: 161, 98, 7; }
.hero-grid__card--electric  { --accent: #fca5a5; --accent-2: #dc2626; --accent-ink: #ffffff; --tint: 185, 28, 28; }
.hero-grid__card--ukulele   { --accent: #edc77f; --accent-2: #b8862e; --accent-ink: #1c1406; --tint: 15, 118, 110; }
.hero-grid__card--dantranh  { --accent: #6ee7b7; --accent-2: #059669; --accent-ink: #052e1f; --tint: 4, 120, 87; }
.hero-grid__card--dantyba   { --accent: #fcd34d; --accent-2: #d97706; --accent-ink: #1c1406; --tint: 180, 83, 9; }
.hero-grid__card--danbau    { --accent: #93c5fd; --accent-2: #2563eb; --accent-ink: #ffffff; --tint: 29, 78, 216; }
.hero-grid__card--dannguyet { --accent: #fbb6ce; --accent-2: #be185d; --accent-ink: #ffffff; --tint: 157, 23, 77; }
.hero-grid__card--saotruc   { --accent: #bef264; --accent-2: #65a30d; --accent-ink: #1a2e05; --tint: 77, 124, 15; }

/* Card photos not set inline in the view */
.hero-grid__card--piano .hero-grid__card-bg {
  background-image: url('https://images.unsplash.com/photo-1552422535-c45813c61732?w=1400&auto=format&fit=crop&q=80');
}

.hero-grid__card--vocal .hero-grid__card-bg {
  background-image: url('https://images.unsplash.com/photo-1516280440614-37939bbacd81?w=900&auto=format&fit=crop&q=80');
}

.hero-grid__card--acoustic .hero-grid__card-bg {
  background-image: url('https://images.unsplash.com/photo-1510915361894-db8b60106cb1?w=900&auto=format&fit=crop&q=80');
}

.hero-grid__card--electric .hero-grid__card-bg {
  background-image: url('https://images.unsplash.com/photo-1516924962500-2b4b3b99ea02?w=900&auto=format&fit=crop&q=80');
}

.hero-grid__card--danbau .hero-grid__card-bg {
  background-position: center 80%;
}

.hero-grid__card--saotruc .hero-grid__card-bg {
  background-position: 60% 30%;
}

/* Main Container */
.hero-grid {
  min-height: 100vh;
  min-height: 100dvh;
  background-color: var(--grid-bg);
  background-image:
    radial-gradient(60% 40% at 15% 0%, rgba(124, 58, 237, 0.14) 0%, transparent 70%),
    radial-gradient(50% 35% at 90% 55%, rgba(5, 150, 105, 0.1) 0%, transparent 70%),
    radial-gradient(45% 30% at 10% 100%, rgba(219, 39, 119, 0.08) 0%, transparent 70%);
  padding: 48px 1.5rem 4rem;
  position: relative;
  overflow: hidden;
  font-family: 'Be Vietnam Pro', system-ui, sans-serif;
}

/* Grid Container */
.hero-grid__container {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  grid-auto-rows: minmax(340px, auto);
  grid-auto-flow: row dense;
  gap: var(--grid-gap);
  max-width: 1360px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero-grid__card--feature {
  grid-column: span 2;
  grid-row: span 2;
}

/* Mirror the second feature card to the right so the grid reads as a zig-zag */
.hero-grid__card--dantranh {
  grid-column: 3 / span 2;
}

/* Individual Cards */
.hero-grid__card {
  position: relative;
  isolation: isolate;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  border-radius: var(--grid-radius);
  overflow: hidden;
  text-decoration: none;
  color: var(--grid-text);
  background: #16161c;
  box-shadow: 0 0 0 1px var(--grid-line), 0 20px 40px -24px rgba(0, 0, 0, 0.8);
  transition: transform var(--grid-transition), box-shadow var(--grid-transition);
}

.hero-grid__card:hover,
.hero-grid__card:focus-visible {
  color: var(--grid-text);
  transform: translateY(-6px);
  box-shadow:
    0 0 0 1px rgba(var(--tint), 0.9),
    0 30px 60px -20px rgba(var(--tint), 0.55);
}

.hero-grid__card:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* Card Backgrounds */
.hero-grid__card-bg {
  position: absolute;
  inset: 0;
  z-index: -2;
  background-size: cover;
  background-position: center;
  transform: scale(1.04);
  filter: saturate(0.9);
  transition: transform 1.2s var(--grid-ease), filter 0.6s ease;
}

.hero-grid__card:hover .hero-grid__card-bg {
  transform: scale(1.1);
  filter: saturate(1.1);
}

/* Card Overlays: neutral fade for legibility + a soft subject-coloured wash at the bottom */
.hero-grid__card-overlay {
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(120% 60% at 0% 100%, rgba(var(--tint), 0.55) 0%, transparent 65%),
    linear-gradient(180deg, rgba(10, 10, 14, 0.25) 0%, rgba(10, 10, 14, 0.15) 30%, rgba(10, 10, 14, 0.78) 62%, rgba(10, 10, 14, 0.96) 100%);
  transition: opacity 0.5s ease;
}

/* Card Icon/Logo: pinned top-left so the photo gets breathing room */
.hero-grid__card-icon {
  position: absolute;
  top: 1.5rem;
  left: 1.5rem;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  color: var(--accent);
  background: rgba(12, 12, 16, 0.45);
  border: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform var(--grid-transition);
}

.hero-grid__card-icon--logo {
  width: auto;
  height: 60px;
  padding: 0;
  background: none;
  border: 0;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.hero-grid__card:hover .hero-grid__card-icon {
  transform: translateY(-2px) rotate(-3deg);
}

.hero-grid__card-logo {
  height: 100%;
  width: auto;
  max-width: 130px;
  object-fit: contain;
  filter: drop-shadow(0 4px 14px rgba(0, 0, 0, 0.55));
}

.hero-grid__card-svg {
  width: 32px;
  height: 32px;
}

/* Card Content */
.hero-grid__card-content {
  position: relative;
  padding: 1.5rem;
  width: 100%;
}

/* Card Label */
.hero-grid__card-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.6rem;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.6);
}

.hero-grid__card-label::before {
  content: '';
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}

/* Card Title */
.hero-grid__card-title {
  font-family: 'Be Vietnam Pro', system-ui, sans-serif;
  font-size: 1.6rem;
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0 0 0.4rem;
  color: var(--grid-text);
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.35);
}

.hero-grid__card-title em {
  font-style: normal;
  color: var(--accent);
}

/* Card Description */
.hero-grid__card-desc {
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--grid-text-muted);
  margin: 0 0 0.9rem;
}

/* Card Tags */
.hero-grid__card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.1rem;
}

.hero-grid__card-tag {
  padding: 0.28rem 0.7rem;
  font-size: 0.72rem;
  font-weight: 600;
  border-radius: 999px;
  color: rgba(255, 255, 255, 0.82);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

/* Card CTA: text + accent arrow chip, fills with the accent on hover */
.hero-grid__card-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.35rem 0.35rem 0.35rem 1.1rem;
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: 999px;
  color: var(--grid-text);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.16);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background var(--grid-transition), color var(--grid-transition), border-color var(--grid-transition);
}

.hero-grid__card-cta-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  color: var(--accent-ink);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  transition: transform var(--grid-transition), background var(--grid-transition);
}

.hero-grid__card-cta-icon svg {
  width: 15px;
  height: 15px;
}

.hero-grid__card:hover .hero-grid__card-cta {
  color: var(--accent-ink);
  background: var(--accent);
  border-color: transparent;
}

.hero-grid__card:hover .hero-grid__card-cta-icon {
  transform: translateX(3px);
  color: var(--accent);
  background: var(--accent-ink);
}

/* Feature cards get more presence */
.hero-grid__card--feature .hero-grid__card-content {
  padding: 2.25rem;
}

.hero-grid__card--feature .hero-grid__card-icon {
  top: 2.25rem;
  left: 2.25rem;
  width: 64px;
  height: 64px;
  border-radius: 20px;
}

.hero-grid__card--feature .hero-grid__card-svg {
  width: 40px;
  height: 40px;
}

.hero-grid__card--feature .hero-grid__card-title {
  font-size: clamp(2.2rem, 3.6vw, 3.25rem);
  line-height: 1.05;
  margin-bottom: 0.6rem;
}

.hero-grid__card--feature .hero-grid__card-title em {
  display: block;
}

.hero-grid__card--feature .hero-grid__card-desc {
  font-size: 1.05rem;
  max-width: 34ch;
}

.hero-grid__card--feature .hero-grid__card-cta {
  font-size: 0.95rem;
  padding: 0.4rem 0.4rem 0.4rem 1.3rem;
}

.hero-grid__card--feature .hero-grid__card-cta-icon {
  width: 36px;
  height: 36px;
}

/* Stats Section */
.hero-grid__stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  max-width: 1360px;
  margin: 3.5rem auto 0;
  border-top: 1px solid var(--grid-line);
  border-bottom: 1px solid var(--grid-line);
  position: relative;
  z-index: 1;
}

.hero-grid__stat {
  padding: 1.75rem 1rem;
  text-align: center;
}

.hero-grid__stat + .hero-grid__stat {
  border-left: 1px solid var(--grid-line);
}

.hero-grid__stat-number {
  display: block;
  font-size: clamp(2rem, 3.2vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--grid-text);
  font-variant-numeric: tabular-nums;
}

.hero-grid__stat-label {
  display: block;
  margin-top: 0.6rem;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--grid-text-faint);
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media (max-width: 1199.98px) {
  .hero-grid__container {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    grid-auto-rows: minmax(320px, auto);
  }

  .hero-grid__card--feature,
  .hero-grid__card--dantranh {
    grid-column: 1 / -1;
    grid-row: span 1;
    min-height: 460px;
  }
}

@media (max-width: 767.98px) {
  .hero-grid {
    padding: 24px 1rem 2.5rem;
  }

  .hero-grid__container {
    grid-template-columns: minmax(0, 1fr);
    grid-auto-rows: auto;
    gap: 14px;
  }

  .hero-grid__card {
    min-height: 340px;
  }

  .hero-grid__card--feature,
  .hero-grid__card--dantranh {
    min-height: 420px;
  }

  .hero-grid__card-icon,
  .hero-grid__card--feature .hero-grid__card-icon {
    top: 1.25rem;
    left: 1.25rem;
  }

  .hero-grid__card-content,
  .hero-grid__card--feature .hero-grid__card-content {
    padding: 1.25rem;
  }

  .hero-grid__card--feature .hero-grid__card-title {
    font-size: 2rem;
  }

  .hero-grid__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    margin-top: 2.5rem;
  }

  .hero-grid__stat {
    padding: 1.25rem 0.5rem;
  }

  .hero-grid__stat:nth-child(3) {
    border-left: 0;
  }

  .hero-grid__stat:nth-child(n + 3) {
    border-top: 1px solid var(--grid-line);
  }
}

/* ==========================================================================
   Animations
   ========================================================================== */

.hero-grid__card {
  animation: cardFadeIn 0.8s var(--grid-ease) backwards;
}

.hero-grid__card:nth-child(1) { animation-delay: 0.05s; }
.hero-grid__card:nth-child(2) { animation-delay: 0.1s; }
.hero-grid__card:nth-child(3) { animation-delay: 0.15s; }
.hero-grid__card:nth-child(4) { animation-delay: 0.2s; }
.hero-grid__card:nth-child(5) { animation-delay: 0.25s; }
.hero-grid__card:nth-child(6) { animation-delay: 0.3s; }
.hero-grid__card:nth-child(7) { animation-delay: 0.35s; }
.hero-grid__card:nth-child(8) { animation-delay: 0.4s; }
.hero-grid__card:nth-child(9) { animation-delay: 0.45s; }
.hero-grid__card:nth-child(10) { animation-delay: 0.5s; }

@keyframes cardFadeIn {
  from {
    opacity: 0;
    transform: translateY(28px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-grid__stats {
  animation: statsSlideIn 0.8s var(--grid-ease) 0.55s backwards;
}

@keyframes statsSlideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero-grid__card,
  .hero-grid__stats {
    animation: none;
  }

  .hero-grid__card,
  .hero-grid__card-bg,
  .hero-grid__card-icon,
  .hero-grid__card-cta-icon {
    transition: none;
  }

  .hero-grid__card:hover,
  .hero-grid__card:hover .hero-grid__card-bg {
    transform: none;
  }
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}