/* =====================================================
   LuanSech.com — bảng màu & nền tảng
   ===================================================== */
:root {
  --bg: #0b0f1a;
  --bg-2: #101729;
  --card: #141c30;
  --card-2: #18213a;
  --line: rgba(255, 255, 255, 0.08);
  --text: #e9edf6;
  --muted: #98a4bd;
  --violet: #7c3aed;
  --cyan: #06b6d4;
  --pink: #ec4899;
  --grad: linear-gradient(100deg, var(--violet), var(--cyan));
  --radius: 16px;
  --font: "Be Vietnam Pro", "Segoe UI", system-ui, -apple-system, sans-serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; }
code {
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid var(--line);
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 0.85em;
  color: #bfe9f5;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

/* Chữ gradient */
.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* =====================================================
   Nền trang trí
   ===================================================== */
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 40%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 40%, transparent 100%);
  pointer-events: none;
}

.orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(110px);
  opacity: 0.5;
  z-index: -1;
  pointer-events: none;
  animation: drift 14s ease-in-out infinite alternate;
}
.orb-1 { width: 480px; height: 480px; top: -160px; left: -120px; background: rgba(124, 58, 237, 0.35); }
.orb-2 { width: 420px; height: 420px; top: 12%; right: -140px; background: rgba(6, 182, 212, 0.28); animation-delay: -7s; }

@keyframes drift {
  from { transform: translate(0, 0) scale(1); }
  to   { transform: translate(40px, 30px) scale(1.08); }
}

/* =====================================================
   Thanh menu
   ===================================================== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  transition: background 0.3s ease, border-color 0.3s ease;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(11, 15, 26, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
}
.logo-badge {
  display: grid;
  place-items: center;
  width: 38px; height: 38px;
  border-radius: 11px;
  background: var(--grad);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 800;
  box-shadow: 0 4px 18px rgba(124, 58, 237, 0.45);
}

.nav-links { display: flex; gap: 26px; }
.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 6px 0;
  position: relative;
  transition: color 0.2s ease;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 2px;
  border-radius: 2px;
  background: var(--grad);
  transition: width 0.25s ease;
}
.nav-links a:hover { color: var(--text); }
.nav-links a.active { color: var(--text); }
.nav-links a.active::after { width: 100%; }

/* Nút hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px; height: 42px;
  padding: 9px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 10px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: var(--text);
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* =====================================================
   HERO
   ===================================================== */
.hero { padding: 150px 0 70px; }

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 48px;
}

.pill {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: #c4b5fd;
  border: 1px solid rgba(139, 92, 246, 0.4);
  background: rgba(124, 58, 237, 0.12);
  padding: 7px 14px;
  border-radius: 999px;
  margin-bottom: 22px;
}

.hero-copy h1 {
  font-size: clamp(3.2rem, 9vw, 5.6rem);
  line-height: 0.98;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.tagline {
  color: var(--muted);
  font-size: 1.08rem;
  max-width: 46ch;
  margin-bottom: 30px;
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero-actions.center { justify-content: center; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 12px;
  font-weight: 700;
  font-size: 0.98rem;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}
.btn-primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 8px 26px rgba(124, 58, 237, 0.4);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(6, 182, 212, 0.4); }
.btn-outline {
  border: 1px solid var(--line);
  color: var(--text);
  background: rgba(255, 255, 255, 0.03);
}
.btn-outline:hover { border-color: rgba(6, 182, 212, 0.6); transform: translateY(-2px); }

.hero-socials { display: flex; gap: 12px; margin-top: 30px; }
.social {
  display: grid;
  place-items: center;
  width: 44px; height: 44px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  color: var(--muted);
  transition: color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}
.social:hover { color: #fff; border-color: rgba(139, 92, 246, 0.6); transform: translateY(-3px); }

/* Ảnh đại diện dạng minh hoạ (không dùng ảnh thật) */
.hero-visual { display: grid; place-items: center; position: relative; }

.avatar-ring {
  width: min(300px, 72vw);
  aspect-ratio: 1;
  border-radius: 50%;
  padding: 6px;
  background: conic-gradient(from 120deg, var(--violet), var(--cyan), var(--pink), var(--violet));
  animation: spinGlow 9s linear infinite;
  box-shadow: 0 0 70px rgba(124, 58, 237, 0.35);
}
@keyframes spinGlow { to { transform: rotate(360deg); } }

.avatar {
  width: 100%; height: 100%;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 25%, var(--card-2), var(--bg-2) 70%);
  border: 6px solid var(--bg);
  display: grid;
  place-content: center;
  text-align: center;
  animation: spinGlow 9s linear infinite reverse; /* giữ nội dung đứng yên */
}
.avatar-initials {
  font-size: 4.6rem;
  font-weight: 800;
  font-style: italic;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1;
}
.avatar-caption {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.chip {
  position: absolute;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(20, 28, 48, 0.9);
  border: 1px solid var(--line);
  backdrop-filter: blur(6px);
  white-space: nowrap;
  animation: float 5s ease-in-out infinite;
}
.chip-1 { top: 8%; left: 0; animation-delay: 0s; }
.chip-2 { bottom: 16%; left: -4%; animation-delay: -1.6s; }
.chip-3 { top: 42%; right: -6%; animation-delay: -3.2s; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

/* Số liệu */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 80px;
}
.stat {
  text-align: center;
  padding: 24px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.025);
}
.stat-num {
  display: block;
  font-size: 2.4rem;
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.15;
}
.stat-label { color: var(--muted); font-size: 0.88rem; }

/* =====================================================
   Các SECTION chung
   ===================================================== */
.section { padding: 90px 0; }
.section-alt {
  background: var(--bg-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-head { text-align: center; max-width: 640px; margin: 0 auto 54px; }
.section-head p { color: var(--muted); margin-top: 12px; font-size: 0.98rem; }

.kicker {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 12px;
}
.section-head h2, .contact-wrap h2 {
  font-size: clamp(1.8rem, 4.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

/* =====================================================
   GIỚI THIỆU
   ===================================================== */
.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.7fr;
  gap: 40px;
  align-items: start;
}
.about-text p { color: #c6cede; margin-bottom: 16px; }
.about-text em { color: #fff; font-style: italic; }

.traits { list-style: none; margin-top: 26px; display: grid; gap: 12px; }
.traits li { display: flex; gap: 12px; align-items: baseline; color: var(--text); }
.tick {
  flex: 0 0 auto;
  display: inline-grid;
  place-items: center;
  width: 22px; height: 22px;
  font-size: 0.7rem;
  font-weight: 800;
  color: #0b0f1a;
  background: var(--grad);
  border-radius: 50%;
  transform: translateY(3px);
}

.about-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 26px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.35);
}
.mini-avatar {
  width: 62px; height: 62px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.3rem;
  font-style: italic;
  color: #fff;
  background: var(--grad);
  margin-bottom: 18px;
  box-shadow: 0 8px 22px rgba(124, 58, 237, 0.4);
}
.about-card h3 { font-size: 1.15rem; margin-bottom: 16px; }
.info { display: grid; gap: 0; }
.info > div {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 0.92rem;
}
.info > div:last-child { border-bottom: none; }
.info dt { color: var(--muted); }
.info dd { text-align: right; font-weight: 600; }

/* =====================================================
   KÊNH NỘI DUNG
   ===================================================== */
.channels {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.channel-card {
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.channel-card:hover {
  transform: translateY(-6px);
  border-color: rgba(139, 92, 246, 0.55);
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.4);
}
.channel-icon {
  width: 58px; height: 58px;
  border-radius: 15px;
  display: grid;
  place-items: center;
  color: #fff;
  margin-bottom: 18px;
}
.channel-icon.fb { background: linear-gradient(135deg, #1877f2, #0e5fd8); }
.channel-icon.yt { background: linear-gradient(135deg, #ff4d4d, #c4302b); }
.channel-icon.tt { background: linear-gradient(135deg, var(--cyan), var(--pink)); }

.channel-card h3 { font-size: 1.2rem; margin-bottom: 8px; }
.channel-card p { color: var(--muted); font-size: 0.93rem; margin-bottom: 18px; }
.channel-cta {
  font-weight: 700;
  font-size: 0.9rem;
  color: #67e8f9;
}

/* =====================================================
   BỘ SƯU TẬP ẢNH
   ===================================================== */
.gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.gallery-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--card);
}
.thumb {
  position: relative;
  aspect-ratio: 4 / 3;
  background: repeating-linear-gradient(
    45deg,
    rgba(255, 255, 255, 0.02) 0 12px,
    rgba(255, 255, 255, 0.05) 12px 24px
  );
}
.ph-note {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 14px;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 500;
}
.thumb img {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  z-index: 1;
  transition: transform 0.4s ease;
}
.gallery-item:hover .thumb img { transform: scale(1.06); }
.gallery-item figcaption {
  padding: 13px 16px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--muted);
}

/* =====================================================
   LIÊN HỆ + FOOTER
   ===================================================== */
.contact-wrap { text-align: center; max-width: 640px; }
.contact-wrap p { color: var(--muted); margin: 14px 0 28px; }
.contact-wrap .note { font-size: 0.82rem; margin: 18px 0 0; }

.footer { padding: 40px 0 46px; text-align: center; }
.footer-inner p { color: var(--muted); font-size: 0.92rem; }
.footer-sub { margin-top: 6px; font-size: 0.82rem; opacity: 0.75; }

/* =====================================================
   HIỆU ỨNG XUẤT HIỆN
   ===================================================== */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: none; }
.delay-1 { transition-delay: 0.12s; }
.delay-2 { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}

/* =====================================================
   RESPONSIVE
   ===================================================== */
@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero { padding-top: 120px; }
  .hero-visual { order: -1; }
  .chip-2 { left: 2%; }
  .chip-3 { right: 2%; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; }
  .channels { grid-template-columns: 1fr; }
  .gallery { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 800px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: absolute;
    top: 72px; left: 0; right: 0;
    flex-direction: column;
    gap: 4px;
    background: rgba(11, 15, 26, 0.97);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
    padding: 14px 24px 20px;
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.25s ease, opacity 0.25s ease, visibility 0.25s;
  }
  .nav-links.open { transform: none; opacity: 1; visibility: visible; }
  .nav-links a { padding: 11px 4px; font-size: 1rem; }
}

@media (max-width: 560px) {
  .gallery { grid-template-columns: 1fr; }
  .hero-actions .btn { flex: 1; justify-content: center; }
  .stat-num { font-size: 2rem; }
}

/* =====================================================
   ẢNH ĐẠI DIỆN THẬT + VIDEO
   ===================================================== */
.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 68% 32%;
  border-radius: 50%;
}

.video-frame {
  max-width: 860px;
  margin: 0 auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #000;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
}
.video-frame video {
  display: block;
  width: 100%;
  max-height: 75vh;
  object-fit: contain;
  background: #000;
}