/* ============================================================================
   enhance.css — professional polish layer for the Vocab landing page.
   Loaded AFTER styles.css so it refines the existing design rather than
   replacing it. Every effect degrades safely: no JS required, motion is
   disabled under prefers-reduced-motion, and nothing here hides content.
   ========================================================================== */

:root {
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --ring: 0 0 0 1px rgba(255, 255, 255, 0.06);
  --glow-a: rgba(109, 139, 255, 0.5);
  --glow-b: rgba(155, 109, 255, 0.42);
  --sheen: linear-gradient(135deg, #ffffff 0%, #cfd6ff 45%, #9b6dff 100%);
}

/* ---------- Ambient background -------------------------------------------
   Two slow aurora blobs plus a fine grid. Fixed and non-interactive, so they
   add depth without affecting layout or clicks. */
body::before,
body::after {
  content: "";
  position: fixed;
  z-index: -2;
  pointer-events: none;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.5;
}
body::before {
  width: 60vw;
  height: 60vw;
  max-width: 780px;
  max-height: 780px;
  top: -22vw;
  left: -14vw;
  background: radial-gradient(circle, var(--glow-a), transparent 68%);
}
body::after {
  width: 52vw;
  height: 52vw;
  max-width: 680px;
  max-height: 680px;
  top: 8vw;
  right: -18vw;
  background: radial-gradient(circle, var(--glow-b), transparent 68%);
}

/* Fine grid overlay for texture. */
body {
  position: relative;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.022) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.022) 1px, transparent 1px);
  background-size: 64px 64px;
  background-attachment: fixed;
}

/* ---------- Typography ---------------------------------------------------- */
h1 {
  letter-spacing: -0.035em;
  line-height: 1.05;
}
h2 {
  letter-spacing: -0.028em;
}

/* Gradient sheen on the key phrase of the hero headline. */
.sheen {
  background: var(--sheen);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.lead {
  font-size: 1.075rem;
  max-width: 34em;
}

/* ---------- Header: frosted, condenses on scroll -------------------------- */
.site-header {
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  background: rgba(11, 12, 16, 0.62);
  border-bottom: 1px solid transparent;
  transition: background 240ms var(--ease), border-color 240ms var(--ease),
    box-shadow 240ms var(--ease);
}
.site-header.is-stuck {
  background: rgba(11, 12, 16, 0.9);
  border-bottom-color: var(--border);
  box-shadow: 0 10px 30px -18px rgba(0, 0, 0, 0.9);
}

/* Animated underline on nav links. */
.nav-links a {
  position: relative;
  padding-bottom: 2px;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1.5px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 260ms var(--ease);
}
.nav-links a:hover::after,
.nav-links a:focus-visible::after,
.nav-links a.is-active::after {
  transform: scaleX(1);
}
.nav-links a.is-active { color: var(--text); }

/* Scroll progress bar under the header. */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  z-index: 60;
  pointer-events: none;
}

/* ---------- Buttons ------------------------------------------------------- */
.btn {
  position: relative;
  overflow: hidden;
  transition: transform 200ms var(--ease), box-shadow 240ms var(--ease),
    background 200ms var(--ease), border-color 200ms var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-color: transparent;
  box-shadow: 0 10px 28px -12px var(--glow-a);
}
.btn-primary:hover {
  box-shadow: 0 18px 40px -14px var(--glow-a), 0 0 0 1px rgba(255, 255, 255, 0.1) inset;
}

/* Light sweep across the primary button on hover. */
.btn-primary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    100deg,
    transparent 20%,
    rgba(255, 255, 255, 0.28) 50%,
    transparent 80%
  );
  transform: translateX(-120%);
  transition: transform 620ms var(--ease);
}
.btn-primary:hover::after { transform: translateX(120%); }

.btn-ghost:hover {
  border-color: var(--border-strong);
  background: rgba(255, 255, 255, 0.04);
}

/* ---------- Cards: gradient border + cursor-following spotlight ----------- */
.card,
.step,
.privacy-card,
.faq-item {
  position: relative;
  isolation: isolate;
  transition: transform 300ms var(--ease), border-color 300ms var(--ease),
    box-shadow 300ms var(--ease);
}

/* Hairline gradient edge that brightens on hover. */
.card::before,
.privacy-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(
    140deg,
    rgba(109, 139, 255, 0.55),
    rgba(155, 109, 255, 0.28) 42%,
    transparent 72%
  );
  -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 320ms var(--ease);
  pointer-events: none;
  z-index: 1;
}
.card:hover::before,
.privacy-card:hover::before { opacity: 1; }

/* Spotlight that follows the pointer (coords set in enhance.js). */
.card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(
    260px circle at var(--mx, 50%) var(--my, 0%),
    rgba(129, 158, 255, 0.16),
    transparent 62%
  );
  opacity: 0;
  transition: opacity 320ms var(--ease);
  pointer-events: none;
  z-index: 0;
}
.card:hover::after { opacity: 1; }

.card:hover,
.privacy-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 26px 50px -26px rgba(0, 0, 0, 0.85);
}

/* Keep card content above the decorative layers. */
.card > *,
.privacy-card > * { position: relative; z-index: 2; }

/* Feature icons: gradient tile that lifts with the card. */
.card-icon {
  background: linear-gradient(140deg, rgba(109, 139, 255, 0.2), rgba(155, 109, 255, 0.12));
  border: 1px solid rgba(129, 158, 255, 0.24);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06);
  transition: transform 320ms var(--ease), box-shadow 320ms var(--ease);
}
.card:hover .card-icon {
  transform: translateY(-2px) scale(1.06);
  box-shadow: 0 12px 24px -14px var(--glow-a);
}

/* ---------- Hero visual: richer floating browser -------------------------- */
.hero-visual { perspective: 1400px; }
.browser {
  background: rgba(22, 24, 31, 0.82);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--border-strong);
  box-shadow: 0 50px 90px -40px rgba(0, 0, 0, 0.9),
    0 0 0 1px rgba(255, 255, 255, 0.04) inset;
}
/* Tilt + float only the hero showcase, not the feature screenshots. */
.hero-visual .browser {
  transform: rotateX(2.4deg) rotateY(-7deg) translateZ(0);
  transition: transform 700ms var(--ease), box-shadow 700ms var(--ease);
  animation: floaty 7s ease-in-out infinite;
}
.hero-visual:hover .browser {
  transform: rotateX(0deg) rotateY(0deg);
  box-shadow: 0 60px 110px -46px rgba(0, 0, 0, 0.95);
}
@keyframes floaty {
  0%, 100% { transform: rotateX(2.4deg) rotateY(-7deg) translateY(0); }
  50% { transform: rotateX(2.4deg) rotateY(-7deg) translateY(-12px); }
}

.browser-bar {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.01));
}
.dot {
  background: radial-gradient(circle at 35% 30%, #ff7a7a, #d6453f);
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.25) inset;
}
.dot:nth-child(2) { background: radial-gradient(circle at 35% 30%, #ffd479, #d6a23f); }
.dot:nth-child(3) { background: radial-gradient(circle at 35% 30%, #8ee29a, #4f9c5c); }

.popover {
  background: rgba(17, 19, 25, 0.96);
  border: 1px solid var(--border-strong);
  box-shadow: 0 24px 50px -20px rgba(0, 0, 0, 0.9);
  animation: popin 520ms var(--ease) both;
}
@keyframes popin {
  from { opacity: 0; transform: translateY(10px) scale(0.97); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
.hl {
  background: linear-gradient(transparent 62%, rgba(255, 213, 107, 0.32) 62%);
  border-radius: 2px;
  padding: 0 1px;
  color: var(--text);
}

/* Highlight pulse on the saved word to draw the eye. */
mark.hl {
  position: relative;
  animation: hl-pulse 2.6s ease-in-out infinite;
}
@keyframes hl-pulse {
  0%, 100% { background-color: rgba(255, 213, 107, 0.16); }
  50% { background-color: rgba(255, 213, 107, 0.38); }
}

/* ---------- Hero stats: pill chips ---------------------------------------- */
.hero-stats {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 20px;
}
.hero-stats > div {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 12px 18px;
  border-radius: 14px;
  min-width: 118px;
}
.hero-stats strong {
  font-size: 1.5rem;
  background: var(--sheen);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}
.hero-stats span { font-size: 0.82rem; color: var(--muted); }

/* ---------- Sections: gradient dividers + emphasized headings ------------- */
.section { padding: clamp(64px, 9vw, 110px) 0; }
.section-alt {
  background:
    radial-gradient(120% 80% at 50% -10%, rgba(109, 139, 255, 0.08), transparent 60%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.015), transparent 40%);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-head { margin-bottom: 46px; }
.section-head h2 {
  max-width: 18em;
  background: linear-gradient(180deg, #ffffff, #c7cde0);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

/* Eyebrow with a leading dash for a more editorial feel. */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1.5px;
  background: linear-gradient(90deg, var(--accent), transparent);
}

/* ---------- Steps: connected timeline ------------------------------------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 22px;
  text-align: left;
}
/* Numbered tile on the learning-loop steps. */
.loop-step .step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 10px 22px -10px var(--glow-a);
  margin-bottom: 14px;
}
.step:hover { transform: translateY(-5px); border-color: var(--border-strong); }

/* ---------- Privacy card -------------------------------------------------- */
.privacy-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 42px; align-items: center; }
.privacy-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
}
.privacy-badge {
  width: 54px; height: 54px;
  display: grid; place-items: center;
  border-radius: 16px;
  background: linear-gradient(140deg, rgba(109, 139, 255, 0.22), rgba(155, 109, 255, 0.14));
  border: 1px solid rgba(129, 158, 255, 0.3);
  color: var(--accent);
}
.checklist li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  margin: 10px 0;
}
.checklist [data-lucide], .faq-item [data-lucide], .privacy-badge [data-lucide] {
  color: var(--accent);
  flex: 0 0 auto;
  margin-top: 3px;
}

/* ---------- FAQ: smoother accordion + hover ------------------------------- */
.faq-item {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  overflow: hidden;
}
.faq-item:hover { border-color: var(--border-strong); }
.faq-item summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 18px 20px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item [data-lucide] {
  transition: transform 320ms var(--ease);
}
.faq-item[open] [data-lucide] { transform: rotate(180deg); }
.faq-item p { padding: 0 20px 18px; margin: 0; }

/* ---------- Final CTA: glowing panel -------------------------------------- */
.cta-inner {
  position: relative;
  text-align: center;
  border: 1px solid var(--border-strong);
  border-radius: 24px;
  padding: clamp(40px, 6vw, 72px);
  background:
    radial-gradient(120% 140% at 50% 0%, rgba(109, 139, 255, 0.18), transparent 58%),
    linear-gradient(180deg, rgba(28, 31, 41, 0.9), rgba(17, 19, 25, 0.92));
  box-shadow: 0 40px 80px -40px rgba(0, 0, 0, 0.9);
  overflow: hidden;
}
.cta-inner h2 {
  font-size: clamp(1.8rem, 3.6vw, 2.6rem);
  max-width: 16em;
  margin: 0 auto 12px;
  background: linear-gradient(180deg, #fff, #c7cde0);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}
.cta .hero-cta { justify-content: center; margin-top: 26px; }
.cta .hero-cta .btn { min-width: 210px; justify-content: center; }

/* ---------- Footer -------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.02));
}
.footer-grid { gap: 36px; }
.footer-col a { transition: color 200ms var(--ease); }
.footer-col a:hover { color: var(--text); }

/* ---------- Reveal: richer entrance --------------------------------------- */
.js .reveal {
  opacity: 0;
  transform: translateY(22px) scale(0.992);
  transition: opacity 720ms var(--ease), transform 720ms var(--ease);
  will-change: opacity, transform;
}
.js .reveal.in { opacity: 1; transform: none; }

/* Stagger siblings for a cascade. */
.js .grid .reveal:nth-child(2),
.js .steps .reveal:nth-child(2) { transition-delay: 70ms; }
.js .grid .reveal:nth-child(3),
.js .steps .reveal:nth-child(3) { transition-delay: 140ms; }
.js .grid .reveal:nth-child(4),
.js .steps .reveal:nth-child(4) { transition-delay: 210ms; }
.js .grid .reveal:nth-child(5) { transition-delay: 280ms; }
.js .grid .reveal:nth-child(6) { transition-delay: 350ms; }

/* ---------- Responsive ---------------------------------------------------- */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { order: -1; margin-bottom: 8px; }
  .hero-visual .browser { transform: none; animation: none; }
  .privacy-grid { grid-template-columns: 1fr; }
  .steps { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .steps { grid-template-columns: 1fr; }
  .hero-stats > div { flex: 1; min-width: 96px; }
  .cta .hero-cta { flex-direction: column; }
  .cta .hero-cta .btn { width: 100%; }
}

/* ---------- Reduced motion ------------------------------------------------ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .js .reveal { opacity: 1; transform: none; }
  .hero-visual .browser { transform: none; }
}

/* ---------- X-Ray Reading section ---------------------------------------- */
.xray {
  background:
    radial-gradient(120% 90% at 85% 0%, rgba(155, 109, 255, 0.12), transparent 55%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent 45%);
  border-top: 1px solid var(--border);
}
.xray-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.xray-copy .btn { margin-top: 8px; }

.xray-card {
  background: rgba(17, 19, 25, 0.92);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: 0 40px 80px -42px rgba(0, 0, 0, 0.95), 0 0 0 1px rgba(255, 255, 255, 0.04) inset;
  transform: rotate(-1.2deg);
  transition: transform 600ms var(--ease);
}
.xray-visual:hover .xray-card { transform: rotate(0deg); }

.xray-query {
  border-left: 3px solid var(--accent-2);
  padding: 4px 0 14px 14px;
  margin-bottom: 14px;
}
.xray-lang {
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  font-weight: 700;
  color: var(--accent-2);
}
.xray-query p { margin: 6px 0 0; color: var(--text); font-size: 1.02rem; }

.xray-result { display: grid; gap: 10px; }
.xray-row {
  display: grid;
  grid-template-columns: 92px 1fr;
  gap: 10px;
  font-size: 0.9rem;
  align-items: baseline;
}
.xray-row span {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}
.xray-level {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 6px;
  padding: 7px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  border: 1px solid rgba(109, 139, 255, 0.3);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.85rem;
  justify-self: start;
}

@media (max-width: 960px) {
  .xray-grid { grid-template-columns: 1fr; }
  .xray-card { transform: none; }
}