/* ==========================================================================
   IELTS Mentor AI — Landing Page Stylesheet
   Plain CSS, mobile-first, no framework, no build step.
   Table of contents:
     1. Design tokens / reset
     2. Base typography
     3. Layout helpers
     4. Buttons & badges
     5. Navbar
     6. Hero
     7. Key Insights
     8. Feature 1 (Know Exactly What To Learn)
     9. Dashboard rows (alternating)
     10. Feature 3 (Set / Track / Reach)
     11. Banner (Everything You Need)
     12. FAQ accordion
     13. CTA (dark)
     14. Footer
     15. Legal pages (privacy / terms)
     16. Voice waveform (AI Listens to Every Word)
     17. Scroll reveal
     18. Responsive breakpoints
   ========================================================================== */

/* -------------------------------------------------------------------------
   1. Design tokens / reset
   ------------------------------------------------------------------------- */
:root {
  --primary-color: #2862ef;
  --secondary-color: #86baff;
  --neutral-01: #ffffff;
  --neutral-02: #f9f9f9;
  --neutral-03: #505561;
  --neutral-04: #0a0a0a;
  --stroke: #eff0f1;

  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;

  --radius-sm: 12px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --container-width: 1200px;
  --section-padding-y: 96px;
  --section-padding-x: 24px;

  --shadow-card: 0 4px 24px rgba(10, 10, 10, 0.04);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-family);
  color: var(--neutral-03);
  background-color: var(--neutral-01);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
}

img,
svg {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

button {
  font-family: inherit;
  cursor: pointer;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  color: var(--neutral-04);
  font-weight: 700;
  line-height: 1.15;
}

p {
  margin: 0;
}

/* -------------------------------------------------------------------------
   2. Base typography
   ------------------------------------------------------------------------- */
h1, .h1 {
  font-size: 40px;
  letter-spacing: -0.02em;
}

h2, .h2 {
  font-size: 30px;
  letter-spacing: -0.01em;
}

h3, .h3 {
  font-size: 22px;
}

h5, .h5, .eyebrow {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--primary-color);
}

.section-sub {
  font-size: 17px;
  color: var(--neutral-03);
  line-height: 1.6;
}

.accent {
  color: var(--primary-color);
}

/* -------------------------------------------------------------------------
   3. Layout helpers
   ------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: var(--section-padding-x);
}

section {
  padding-block: 64px;
}

.section-head {
  max-width: 640px;
  margin-inline: auto;
  text-align: center;
  margin-bottom: 48px;
}

.section-head .eyebrow {
  display: block;
  margin-bottom: 12px;
}

.section-head h1,
.section-head h2 {
  margin-bottom: 16px;
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
}

.card {
  background: var(--neutral-01);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-md);
  padding: 28px;
}

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 20px;
}

.card h3 {
  margin: 4px 0 8px;
}

.card p {
  color: var(--neutral-03);
}

/* -------------------------------------------------------------------------
   4. Buttons & badges
   ------------------------------------------------------------------------- */
.store-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.store-badges img {
  height: 48px;
  width: auto;
}

.stars-row {
  display: flex;
  gap: 4px;
  align-items: center;
}

.stars-row img {
  width: 20px;
  height: 20px;
}

/* -------------------------------------------------------------------------
   5. Navbar
   ------------------------------------------------------------------------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--neutral-01);
  border-bottom: 1px solid var(--stroke);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: 16px;
  gap: 24px;
}

.navbar-logo img {
  height: 32px;
  width: auto;
}

.navbar-links {
  display: flex;
  gap: 32px;
  align-items: center;
}

.navbar-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--neutral-04);
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.navbar-actions img {
  height: 38px;
  width: auto;
}

/* Below 640px: hide the store badges in the navbar to avoid crowding —
   they're already in the hero, the mobile menu, and the footer. */
@media (max-width: 639px) {
  .navbar-actions a {
    display: none;
  }
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 8px;
  line-height: 0;
}

.nav-toggle img {
  width: 24px;
  height: 24px;
}

.nav-panel {
  display: none;
}

/* -------------------------------------------------------------------------
   6. Hero
   ------------------------------------------------------------------------- */
.hero {
  padding-block: 72px 48px;
  text-align: center;
  background-image: radial-gradient(circle at 50% 0%, rgba(40, 98, 239, 0.06), transparent 60%);
}

.hero .eyebrow {
  display: block;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 40px;
  max-width: 780px;
  margin-inline: auto;
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 18px;
  max-width: 480px;
  margin-inline: auto;
  margin-bottom: 32px;
}

.hero-sub.hero-sub-wide {
  max-width: 680px;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  margin-bottom: 48px;
}

.hero-actions .store-badges {
  justify-content: center;
}

.hero-image {
  max-width: 900px;
  margin-inline: auto;
}

/* AI-powered callout — compact card in the hero; reused (as plain text,
   see section 13) for the on-dark treatment in the CTA. */
.ai-callout {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  background: var(--neutral-01);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-md);
  padding: 16px 24px;
  margin-bottom: 32px;
}

.ai-callout .eyebrow {
  margin-bottom: 0;
}

.ai-callout-line {
  font-size: 15px;
  font-weight: 600;
  color: var(--neutral-04);
}

/* -------------------------------------------------------------------------
   7. Key Insights
   ------------------------------------------------------------------------- */
.key-insights {
  background: var(--neutral-02);
}

.key-insights .eyebrow,
.key-insights h2 {
  text-align: left;
}

.key-insights-text h2 {
  margin-bottom: 16px;
}

.key-insights-text p {
  margin-bottom: 28px;
}

.insight-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.insight-cards .card {
  background: var(--neutral-01);
}

.insight-cards .eyebrow {
  margin-bottom: 8px;
}

/* Contact page: two clickable contact cards (email / Instagram) */
.contact-cards {
  flex-direction: column;
}

.contact-card {
  display: block;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.contact-card:hover,
.contact-card:focus-visible {
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.contact-card h2,
.contact-card h3 {
  margin: 4px 0 8px;
  word-break: break-word;
}

/* -------------------------------------------------------------------------
   8. Feature 1 — two cards
   ------------------------------------------------------------------------- */
.feature-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.feature-card {
  background: var(--neutral-02);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.feature-card .eyebrow {
  margin-bottom: 12px;
}

.feature-card h2,
.feature-card h3 {
  margin-bottom: 12px;
}

.feature-card p {
  margin-bottom: 24px;
}

.feature-card img.feature-illustration {
  border-radius: var(--radius-md);
  margin-inline: auto;
}

/* -------------------------------------------------------------------------
   9. Dashboard rows (alternating)
   ------------------------------------------------------------------------- */
.dashboard-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
  padding-block: 40px;
}

.dashboard-row:not(:last-child) {
  border-bottom: 1px solid var(--stroke);
}

.dashboard-row h2,
.dashboard-row h3 {
  margin-bottom: 20px;
}

.dashboard-row .bullet-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.dashboard-row .bullet-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.dashboard-row .bullet-list img {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  margin-top: 2px;
}

.dashboard-row-image img {
  border-radius: var(--radius-md);
  max-width: 380px;
  width: 100%;
  margin-inline: auto;
}

/* -------------------------------------------------------------------------
   10. Feature 3 — Set / Track / Reach
   ------------------------------------------------------------------------- */
.feature3-text > h1,
.feature3-text > h2 {
  margin-bottom: 16px;
}

.feature3 .section-sub {
  margin-bottom: 32px;
}

.icon-box-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.icon-box {
  padding: 24px 0;
}

.icon-box img {
  width: 40px;
  height: 40px;
  margin-bottom: 16px;
}

.icon-box h2,
.icon-box h3 {
  margin-bottom: 8px;
  font-size: 20px;
}

.feature3-image img {
  border-radius: var(--radius-lg);
}

/* -------------------------------------------------------------------------
   11. Banner — Everything You Need
   ------------------------------------------------------------------------- */
.banner {
  background: var(--neutral-02);
}

.banner-image-wrap {
  position: relative;
  text-align: center;
}

.banner-image-wrap .bg-shape {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 90%;
  z-index: 0;
  opacity: 0.9;
}

.banner-image-wrap img.cta-phone {
  position: relative;
  z-index: 1;
  max-width: 340px;
  margin-inline: auto;
}

.banner-items {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.banner-item h2,
.banner-item h3 {
  margin-bottom: 8px;
  font-size: 20px;
}

/* -------------------------------------------------------------------------
   12. FAQ accordion
   ------------------------------------------------------------------------- */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

.faq-intro h2 {
  margin-bottom: 16px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  background: var(--neutral-01);
  overflow: hidden;
}

.faq-item summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 600;
  color: var(--neutral-04);
  font-size: 16px;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item .faq-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.faq-item .icon-minus {
  display: none;
}

.faq-item[open] .icon-plus {
  display: none;
}

.faq-item[open] .icon-minus {
  display: block;
}

.faq-answer {
  padding: 0 24px 20px;
  color: var(--neutral-03);
  font-size: 15px;
}

/* -------------------------------------------------------------------------
   13. CTA (dark)
   ------------------------------------------------------------------------- */
.cta-section {
  background: var(--neutral-04);
  border-radius: var(--radius-lg);
  margin-inline: var(--section-padding-x);
  overflow: hidden;
}

.cta-section .container {
  max-width: var(--container-width);
}

.cta-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
  padding-block: 56px;
}

.cta-text .eyebrow {
  color: var(--secondary-color);
  display: block;
  margin-bottom: 16px;
}

.cta-text h2 {
  color: var(--neutral-01);
  margin-bottom: 16px;
}

.cta-text p {
  color: #c7c9cf;
  margin-bottom: 28px;
}

.cta-text .ai-callout-line {
  color: var(--neutral-01);
  margin-bottom: 16px;
}

.cta-actions {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.cta-image img {
  margin-inline: auto;
  max-width: 320px;
  border-radius: var(--radius-md);
}

/* -------------------------------------------------------------------------
   14. Footer
   ------------------------------------------------------------------------- */
.site-footer {
  padding-top: 72px;
  border-top: 1px solid var(--stroke);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

.footer-brand > img {
  height: 32px;
  width: auto;
  margin-bottom: 16px;
}

.footer-brand p {
  max-width: 320px;
  margin-bottom: 20px;
  font-size: 15px;
}

.footer-social {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--stroke);
}

.footer-social img {
  width: 18px;
  height: 18px;
}

.footer-heading {
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--neutral-04);
  margin-bottom: 20px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  font-size: 15px;
  color: var(--neutral-03);
}

.footer-col a:hover {
  color: var(--primary-color);
}

.footer-download p {
  font-size: 15px;
  margin-bottom: 16px;
}

.footer-download .store-badges {
  flex-direction: column;
  align-items: flex-start;
}

.footer-bottom {
  margin-top: 56px;
  padding-block: 24px;
  border-top: 1px solid var(--stroke);
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 13px;
  color: var(--neutral-03);
}

.footer-disclaimer {
  max-width: 720px;
}

/* -------------------------------------------------------------------------
   15. Legal pages (privacy / terms)
   ------------------------------------------------------------------------- */
.legal-page {
  padding-block: 64px;
}

.legal-content {
  max-width: 720px;
  margin-inline: auto;
}

.legal-content h1 {
  margin-bottom: 8px;
}

.legal-content .legal-updated {
  color: var(--neutral-03);
  font-size: 14px;
  margin-bottom: 40px;
  display: block;
}

.legal-content h2 {
  font-size: 22px;
  margin-top: 40px;
  margin-bottom: 12px;
}

.legal-content p {
  margin-bottom: 16px;
}

.legal-content ul {
  margin-bottom: 16px;
  padding-left: 20px;
  list-style: disc;
}

.legal-content li {
  margin-bottom: 8px;
}

.legal-content a {
  color: var(--primary-color);
  text-decoration: underline;
}

/* -------------------------------------------------------------------------
   16. Voice waveform (AI Listens to Every Word)
   ------------------------------------------------------------------------- */
.waveform-panel {
  position: relative;
  background: var(--neutral-01);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-md);
  padding: 28px 20px 20px;
  overflow: hidden;
}

.waveform-mic {
  position: relative;
  width: 40px;
  height: 40px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-color);
  color: var(--neutral-01);
  border-radius: 50%;
}

.waveform-mic svg {
  position: relative;
  z-index: 1;
  display: block;
}

.waveform-mic-pulse {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: var(--primary-color);
  opacity: 0.5;
  animation: mic-pulse 2s ease-out infinite;
}

@keyframes mic-pulse {
  0% {
    transform: scale(1);
    opacity: 0.45;
  }
  100% {
    transform: scale(2.1);
    opacity: 0;
  }
}

.waveform-bars {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 4px;
  height: 72px;
  margin-bottom: 24px;
  padding: 0 4px;
}

.waveform-bars span {
  flex: 1 1 auto;
  max-width: 6px;
  height: 100%;
  border-radius: 3px;
  background: var(--primary-color);
  opacity: 0.75;
  transform-origin: center bottom;
  transform: scaleY(var(--h, 0.4));
  animation: wave-bar 1.1s ease-in-out infinite;
  animation-delay: var(--d, 0s);
}

@keyframes wave-bar {
  0%,
  100% {
    transform: scaleY(var(--h, 0.4));
    opacity: 0.55;
  }
  50% {
    transform: scaleY(1);
    opacity: 1;
  }
}

.waveform-criteria {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.criteria-chip {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: var(--neutral-02);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  color: var(--neutral-04);
}

.criteria-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary-color);
  flex-shrink: 0;
  animation: criteria-blink 1.6s ease-in-out infinite;
}

.criteria-chip:nth-child(2) .criteria-dot {
  animation-delay: 0.15s;
}

.criteria-chip:nth-child(3) .criteria-dot {
  animation-delay: 0.3s;
}

.criteria-chip:nth-child(4) .criteria-dot {
  animation-delay: 0.45s;
}

@keyframes criteria-blink {
  0%,
  100% {
    opacity: 0.35;
    transform: scale(0.85);
  }
  50% {
    opacity: 1;
    transform: scale(1);
  }
}

/* Respect reduced motion: freeze everything at varied static heights/positions
   so it still reads as a waveform, just not moving. */
@media (prefers-reduced-motion: reduce) {
  .waveform-mic-pulse {
    animation: none;
    opacity: 0.2;
  }

  .waveform-bars span {
    animation: none;
    transform: scaleY(var(--h, 0.6));
    opacity: 0.85;
  }

  .criteria-dot {
    animation: none;
    opacity: 1;
  }
}

/* -------------------------------------------------------------------------
   17. Scroll reveal
   ------------------------------------------------------------------------- */
/* Default: fully visible. Only hidden once JS confirms it can reveal them
   (html.js-reveal), so a no-JS visitor always sees complete content. */
.reveal {
  opacity: 1;
  transform: none;
}

.js-reveal .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.js-reveal .reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

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

/* -------------------------------------------------------------------------
   18. Responsive breakpoints
   ------------------------------------------------------------------------- */

/* ~640px — small phones up */
@media (min-width: 640px) {
  .hero h1 {
    font-size: 48px;
  }

  h1, .h1 {
    font-size: 44px;
  }
}

/* ~768px — tablets up: two-column grids kick in */
@media (min-width: 768px) {
  h1, .h1 {
    font-size: 52px;
  }

  h2, .h2 {
    font-size: 34px;
  }

  .grid-2 {
    grid-template-columns: 1fr 1fr;
  }

  .feature-cards {
    grid-template-columns: 1fr 1fr;
  }

  .contact-cards {
    flex-direction: row;
  }

  .contact-cards .card {
    flex: 1 1 0;
  }

  .icon-box-row {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .faq-grid {
    grid-template-columns: 0.8fr 1.2fr;
  }

  .cta-inner {
    grid-template-columns: 1.1fr 0.9fr;
  }

  .dashboard-row {
    grid-template-columns: 1fr 1fr;
  }

  .dashboard-row.reverse .dashboard-row-image {
    order: 2;
  }

  .dashboard-row.reverse .dashboard-row-text {
    order: 1;
  }

  .banner-items {
    padding-left: 24px;
  }
}

/* ~1024px — small desktop up */
@media (min-width: 1024px) {
  :root {
    --section-padding-x: 40px;
  }

  .hero h1 {
    font-size: 64px;
  }

  .navbar-links {
    display: flex;
  }

  .footer-grid {
    grid-template-columns: 1.4fr 0.8fr 0.8fr 1fr;
  }

  section {
    padding-block: 96px;
  }
}

/* ~1280px — large desktop up */
@media (min-width: 1280px) {
  .hero h1 {
    font-size: 72px;
  }
}

/* Mobile nav (below 1024px): hamburger shown, links collapse into panel */
@media (max-width: 1023px) {
  .navbar-links {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
  }

  .nav-panel {
    position: fixed;
    inset: 0;
    top: 65px;
    background: var(--neutral-01);
    padding: 24px;
    z-index: 99;
  }

  .nav-panel.is-open {
    display: flex;
    flex-direction: column;
    gap: 24px;
  }

  .nav-panel a {
    font-size: 18px;
    font-weight: 500;
    color: var(--neutral-04);
  }

  .nav-panel .store-badges {
    flex-direction: column;
    align-items: flex-start;
  }
}