/**
 * Khả Văn — Premium layer (motion, depth, page chrome)
 * Taste Skill: premium consumer education, MOTION 6 / VARIANCE 7
 */
:root {
  --kv-ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --kv-ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --kv-reveal-y: 2.4rem;
  --kv-header-h: 4rem;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body.kv-premium {
  position: relative;
}

/* Grain overlay — phá flatness */
body.kv-premium::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 9998;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 128px 128px;
}

/* Header scroll */
.kv-site-header {
  transition: box-shadow 0.35s var(--kv-ease-out), background 0.35s var(--kv-ease-out), backdrop-filter 0.35s;
}

/* Khi cuộn: giữ tông trắng/kính đồng bộ với kv-header-shared.css,
   chỉ tăng nhẹ độ đặc + bóng đổ cho cảm giác "nổi khối" khi cuộn.
   KHÔNG đổi sang nền xanh (tránh vỡ đồng bộ header giữa các trang). */
.kv-site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.95) !important;
  backdrop-filter: blur(14px) saturate(1.2);
  box-shadow: 0 8px 32px rgba(0, 45, 24, 0.16);
}

/* Scroll reveal */
[data-kv-reveal],
.kv-premium.kv-js-ready .kv-stagger > *,
.kv-premium.kv-js-ready .kv-section__head,
.kv-premium.kv-js-ready .kv-course-card,
.kv-premium.kv-js-ready .kv-path-card,
.kv-premium.kv-js-ready .kv-commit-card,
.kv-premium.kv-js-ready .kv-process-card,
.kv-premium.kv-js-ready .kv-teacher-card,
.kv-premium.kv-js-ready .kv-testimonial,
.kv-premium.kv-js-ready .kv-room,
.kv-premium.kv-js-ready .kv-why-item,
.kv-premium.kv-js-ready .feat-card,
.kv-premium.kv-js-ready .lt-pillar,
.kv-premium.kv-js-ready .lt-prog,
.kv-premium.kv-js-ready .lt-stat,
.kv-premium.kv-js-ready .lt-review,
.kv-premium.kv-js-ready .kh-card,
.kv-premium.kv-js-ready .kd-rel-card,
.kv-premium.kv-js-ready .gv-pillar,
.kv-premium.kv-js-ready .vt-stat,
.kv-premium.kv-js-ready .vt-achieve-card {
  opacity: 0;
  transform: translateY(var(--kv-reveal-y));
  transition:
    opacity 0.95s var(--kv-ease-out),
    transform 0.95s var(--kv-ease-out);
}

.kv-premium .is-revealed,
.kv-premium [data-kv-reveal].is-revealed,
.kv-premium:not(.kv-js-ready) .kv-section__head,
.kv-premium:not(.kv-js-ready) .kv-course-card,
.kv-premium:not(.kv-js-ready) .kv-path-card,
.kv-premium:not(.kv-js-ready) .kv-commit-card,
.kv-premium:not(.kv-js-ready) .kv-process-card,
.kv-premium:not(.kv-js-ready) .kv-teacher-card,
.kv-premium:not(.kv-js-ready) .kv-testimonial,
.kv-premium:not(.kv-js-ready) .kv-room,
.kv-premium:not(.kv-js-ready) .kv-why-item,
.kv-premium:not(.kv-js-ready) .feat-card,
.kv-premium:not(.kv-js-ready) .lt-pillar,
.kv-premium:not(.kv-js-ready) .lt-prog,
.kv-premium:not(.kv-js-ready) .lt-stat,
.kv-premium:not(.kv-js-ready) .lt-review,
.kv-premium:not(.kv-js-ready) .kh-card,
.kv-premium:not(.kv-js-ready) .kd-rel-card,
.kv-premium:not(.kv-js-ready) .gv-pillar,
.kv-premium:not(.kv-js-ready) .vt-stat,
.kv-premium:not(.kv-js-ready) .vt-achieve-card {
  opacity: 1;
  transform: translateY(0);
}

.kv-premium .kv-stagger > *:nth-child(1) { transition-delay: 0.08s; }
.kv-premium .kv-stagger > *:nth-child(2) { transition-delay: 0.22s; }
.kv-premium .kv-stagger > *:nth-child(3) { transition-delay: 0.36s; }
.kv-premium .kv-stagger > *:nth-child(4) { transition-delay: 0.5s; }
.kv-premium .kv-stagger > *:nth-child(5) { transition-delay: 0.64s; }
.kv-premium .kv-stagger > *:nth-child(6) { transition-delay: 0.78s; }

/* "Vì sao chọn Khả Văn?" — từng dòng hiện lần lượt, không hiện cùng lúc */
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(1) { transition-delay: 0.06s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(2) { transition-delay: 0.22s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(3) { transition-delay: 0.38s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(4) { transition-delay: 0.54s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(5) { transition-delay: 0.7s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(6) { transition-delay: 0.86s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(7) { transition-delay: 1.02s; }
.kv-premium .kv-proof__why-list .kv-why-item:nth-child(8) { transition-delay: 1.18s; }

.kv-premium.kv-js-ready .kv-proof__why-list[data-kv-why-reveal] .kv-why-item {
  opacity: 0;
  transform: translate3d(0, 1.35rem, 0);
  transition:
    opacity 1s var(--kv-ease-out),
    transform 1s var(--kv-ease-out);
  transition-delay: var(--kv-why-delay, 0s);
  will-change: opacity, transform;
}

.kv-premium .kv-proof__why-list[data-kv-why-reveal].is-why-revealed .kv-why-item,
.kv-premium:not(.kv-js-ready) .kv-proof__why-list[data-kv-why-reveal] .kv-why-item {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.kv-premium .kv-proof__why-list[data-kv-why-reveal].is-why-revealed .kv-why-item__ic {
  animation: kv-why-check-pop 0.62s var(--kv-ease-spring) both;
  animation-delay: calc(var(--kv-why-delay, 0s) + 0.16s);
}

@keyframes kv-why-check-pop {
  0% { transform: scale(0.72); }
  65% { transform: scale(1.08); }
  100% { transform: scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  [data-kv-reveal],
  .kv-premium .kv-stagger > *,
  .kv-premium .kv-section__head,
  .kv-premium .kv-course-card,
  .kv-premium .kv-path-card,
  .kv-premium .kv-commit-card,
  .kv-premium .kv-step,
  .kv-premium .kv-teacher-card,
  .kv-premium .kv-testimonial,
  .kv-premium .kv-room,
  .kv-premium .kv-why-item,
  .kv-premium .feat-card,
  .kv-premium .lt-pillar,
  .kv-premium .lt-prog,
  .kv-premium .lt-stat,
  .kv-premium .lt-review,
  .kv-premium .kh-card,
  .kv-premium .kd-rel-card,
  .kv-premium .gv-pillar,
  .kv-premium .vt-stat,
  .kv-premium .vt-achieve-card {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* Mobile: luôn hiện nội dung trang con — tránh màn trắng khi reveal lỗi */
@media (max-width: 767px) {
  .kv-premium.kv-js-ready .feat-card,
  .kv-premium.kv-js-ready .kh-card,
  .kv-premium.kv-js-ready .kd-rel-card,
  .kv-premium.kv-js-ready .lt-pillar,
  .kv-premium.kv-js-ready .lt-prog,
  .kv-premium.kv-js-ready .lt-stat,
  .kv-premium.kv-js-ready .lt-review,
  .kv-premium.kv-js-ready .gv-pillar,
  .kv-premium.kv-js-ready .vt-stat,
  .kv-premium.kv-js-ready .vt-achieve-card,
  .kv-premium.kv-js-ready section.max-w-7xl > * {
    opacity: 1 !important;
    transform: none !important;
  }
}

/* Hero polish */
.kv-premium .kv-hero__title {
  animation: kv-hero-title-in 1s var(--kv-ease-out) both;
}

.kv-premium .kv-hero-kicker {
  animation: kv-hero-kicker-in 0.8s var(--kv-ease-out) 0.1s both;
}

.kv-premium .kv-hero__lead {
  animation: kv-hero-lead-in 0.9s var(--kv-ease-out) 0.2s both;
}

.kv-premium .kv-hero__actions {
  animation: kv-hero-lead-in 0.9s var(--kv-ease-out) 0.35s both;
}

.kv-premium .kv-hero-badge {
  animation: kv-badge-pop 0.6s var(--kv-ease-spring) both;
}

.kv-premium .kv-hero-badge:nth-child(1) { animation-delay: 0.45s; }
.kv-premium .kv-hero-badge:nth-child(2) { animation-delay: 0.55s; }
.kv-premium .kv-hero-badge:nth-child(3) { animation-delay: 0.65s; }
.kv-premium .kv-hero-badge:nth-child(4) { animation-delay: 0.75s; }

@keyframes kv-hero-title-in {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes kv-hero-kicker-in {
  from { opacity: 0; transform: translateY(12px); letter-spacing: 0.2em; }
  to { opacity: 1; transform: translateY(0); letter-spacing: 0.14em; }
}

@keyframes kv-hero-lead-in {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes kv-badge-pop {
  from { opacity: 0; transform: scale(0.85) translateY(12px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

/* Stats bar */
.kv-premium .kv-stats {
  animation: kv-stats-rise 0.9s var(--kv-ease-out) 0.5s both;
}

@keyframes kv-stats-rise {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.kv-stat__value.is-counting {
  color: var(--kv-yellow);
}

/* Cards — depth + spotlight hover */
.kv-premium .kv-course-card,
.kv-premium .kv-path-card,
.kv-premium .kv-teacher-card {
  position: relative;
  transition:
    transform 0.35s var(--kv-ease-out),
    box-shadow 0.35s var(--kv-ease-out),
    border-color 0.35s;
}

.kv-premium .kv-course-card::after,
.kv-premium .kv-path-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  background: radial-gradient(600px circle at var(--kv-spot-x, 50%) var(--kv-spot-y, 50%), rgba(255, 198, 23, 0.12), transparent 40%);
  pointer-events: none;
  transition: opacity 0.35s;
}

.kv-premium .kv-course-card:hover::after,
.kv-premium .kv-path-card:hover::after {
  opacity: 1;
}

.kv-premium .kv-btn,
.kv-premium .kd-btn,
.kv-premium .lt-btn {
  transition: transform 0.25s var(--kv-ease-out), box-shadow 0.25s, gap 0.2s;
}

.kv-premium .kv-btn:active,
.kv-premium .kd-btn:active,
.kv-premium .lt-btn:active {
  transform: scale(0.98) translateY(1px);
}

.kv-premium .kv-btn:focus-visible,
.kv-premium .kd-btn:focus-visible,
.kv-premium input:focus-visible,
.kv-premium select:focus-visible,
.kv-premium textarea:focus-visible {
  outline: 2px solid var(--kv-yellow);
  outline-offset: 2px;
}

/* Process timeline — trang chủ */
.kv-process-wrap {
  position: relative;
  overflow-x: auto;
  padding: 1.75rem 0 1rem;
  -webkit-overflow-scrolling: touch;
}

.kv-process-track {
  display: none;
  position: absolute;
  top: 2.75rem;
  left: 8%;
  right: 8%;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, #dceee4, #eef6f0);
  overflow: hidden;
  z-index: 0;
}

.kv-process-track::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--kv-green) 0%, #14b35a 45%, var(--kv-yellow) 100%);
  transform: scaleX(0);
  transform-origin: left center;
  box-shadow: 0 0 12px rgba(255, 198, 23, 0.45);
}

@media (min-width: 992px) {
  .kv-process-track { display: block; }
}

.kv-process {
  display: flex;
  gap: 0;
  min-width: min(100%, 900px);
  margin: 0 auto;
  justify-content: center;
  position: relative;
  z-index: 1;
}

@media (min-width: 992px) {
  .kv-process { min-width: 100%; }
}

.kv-process__step {
  flex: 1;
  min-width: 140px;
  max-width: 180px;
  text-align: center;
  padding: 0 0.65rem;
  position: relative;
  --kv-i: 0;
}

.kv-process--fx .kv-process__step {
  opacity: 0;
  transform: translateY(28px);
}

.kv-process--fx.is-active .kv-process__step {
  animation: kv-step-in 0.7s var(--kv-ease-out) forwards;
  animation-delay: calc(var(--kv-i) * 0.13s + 0.2s);
}

.kv-process--fx.is-active .kv-process-track::after {
  animation: kv-line-grow 2s var(--kv-ease-out) forwards;
  animation-delay: 0.35s;
}

@keyframes kv-step-in {
  0% { opacity: 0; transform: translateY(28px) scale(0.92); }
  70% { opacity: 1; transform: translateY(-4px) scale(1.02); }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes kv-line-grow {
  to { transform: scaleX(1); }
}

.kv-process__num-wrap {
  position: relative;
  width: 3rem;
  height: 3rem;
  margin: 0 auto 0.85rem;
}

.kv-process__ring {
  position: absolute;
  inset: -5px;
  border-radius: 50%;
  border: 2px solid rgba(255, 198, 23, 0.55);
  opacity: 0;
}

.kv-process--fx.is-active .kv-process__ring {
  animation: kv-pulse-ring 2.8s ease-out infinite;
  animation-delay: calc(var(--kv-i) * 0.4s + 1s);
}

@keyframes kv-pulse-ring {
  0% { transform: scale(0.85); opacity: 0.85; }
  70% { transform: scale(1.35); opacity: 0; }
  100% { transform: scale(1.35); opacity: 0; }
}

.kv-process__num {
  position: relative;
  z-index: 1;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: linear-gradient(145deg, #0d7a45, var(--kv-green) 55%, #003d22);
  color: #fff;
  font-size: 0.9375rem;
  font-weight: 900;
  display: grid;
  place-items: center;
  box-shadow: 0 6px 22px rgba(11, 110, 62, 0.35);
  transition: transform 0.35s var(--kv-ease-out), box-shadow 0.35s;
}

.kv-process__step:hover .kv-process__num {
  transform: scale(1.1);
  box-shadow: 0 0 0 8px rgba(255, 198, 23, 0.2), 0 10px 28px rgba(11, 110, 62, 0.45);
}

.kv-process__body h3 {
  font-size: 0.8125rem;
  font-weight: 900;
  color: var(--kv-green);
  margin: 0 0 0.5rem;
  line-height: 1.3;
}

.kv-process__body p {
  font-size: 0.75rem;
  color: var(--kv-muted);
  margin: 0;
  line-height: 1.45;
}

.kv-process__step:not(:last-child)::after {
  content: "\ea6c";
  font-family: remixicon;
  position: absolute;
  right: -4px;
  top: 2.25rem;
  font-size: 14px;
  opacity: 0.45;
  color: var(--kv-muted);
}

/* Page hero — subpages */
.kv-page-hero {
  position: relative;
  min-height: 280px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(125deg, #001a0e 0%, #005a32 38%, #0b8f4a 62%, #003d22 100%);
  color: #fff;
}

.kv-page-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 55% 45% at 8% 50%, rgba(255, 198, 23, 0.18), transparent 55%),
    radial-gradient(ellipse 40% 35% at 92% 15%, rgba(255, 255, 255, 0.08), transparent 50%);
  pointer-events: none;
}

.kv-page-hero__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 80rem;
  margin: 0 auto;
  padding: 4.5rem 1.5rem 5rem;
}

.kv-page-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  background: rgba(255, 198, 23, 0.15);
  border: 1px solid rgba(255, 198, 23, 0.35);
  color: var(--kv-yellow);
  font-size: 0.6875rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 0 0 0.85rem;
}

.kv-page-hero__kicker::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--kv-yellow);
  animation: kv-kicker-pulse 2s ease infinite;
}

@keyframes kv-kicker-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.35); }
}

.kv-page-hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 900;
  line-height: 1.15;
  margin: 0;
  letter-spacing: -0.02em;
}

.kv-page-hero p {
  margin: 1rem 0 0;
  max-width: 36rem;
  font-size: 1rem;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.88);
}

/* Detail breadcrumb */
.kv-crumb {
  font-size: 0.8125rem;
  color: var(--kv-muted);
  margin: 1.25rem 0 0;
}

.kv-crumb a {
  color: var(--kv-green);
  font-weight: 700;
  text-decoration: none;
}

.kv-crumb a:hover {
  text-decoration: underline;
}

/* Testimonial fade cycle */
.kv-testimonial-stack {
  position: relative;
  min-height: 12rem;
}

.kv-testimonial-stack .kv-testimonial {
  transition: opacity 0.5s var(--kv-ease-out), transform 0.5s var(--kv-ease-out);
}

.kv-testimonial-stack .kv-testimonial:not(.is-active) {
  position: absolute;
  inset: 0;
  opacity: 0;
  pointer-events: none;
  transform: translateX(12px);
}

.kv-testimonial-stack .kv-testimonial.is-active {
  opacity: 1;
  transform: translateX(0);
}

/* Section ambient backgrounds */
.kv-premium .kv-section--soft {
  position: relative;
  overflow: hidden;
}

.kv-premium .kv-section--soft::before {
  content: "";
  position: absolute;
  inset: -20% -10%;
  pointer-events: none;
  background: radial-gradient(circle at 20% 30%, rgba(255, 198, 23, 0.06), transparent 35%);
  animation: kv-bg-drift 18s ease-in-out infinite alternate;
}

@keyframes kv-bg-drift {
  to { transform: translate(2%, 1.5%); }
}

@media (prefers-reduced-motion: reduce) {
  .kv-premium .kv-hero__title,
  .kv-premium .kv-hero-kicker,
  .kv-premium .kv-hero__lead,
  .kv-premium .kv-hero__actions,
  .kv-premium .kv-hero-badge,
  .kv-premium .kv-stats,
  .kv-process--fx .kv-process__step,
  .kv-process--fx.is-active .kv-process__step,
  .kv-process--fx.is-active .kv-process__ring,
  .kv-process--fx.is-active .kv-process-track::after,
  .kv-page-hero__kicker::before,
  .kv-premium .kv-section--soft::before {
    animation: none !important;
  }

  .kv-process--fx .kv-process__step {
    opacity: 1;
    transform: none;
  }

  .kv-process--fx.is-active .kv-process-track::after {
    transform: scaleX(1);
  }
}