/* ─────────────────────────────────────────────────────────────────────────────
   DidactPal Landing Page — landing.css
   Brand palette: Blue #4361EE · Purple #7048E8 · Navy #1A1C4E · Bg #F5F6FF
───────────────────────────────────────────────────────────────────────────── */

/* ── Reset ─────────────────────────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ── Design tokens ─────────────────────────────────────────────────────────── */
:root {
  --blue:        #4361EE;
  --purple:      #7048E8;
  --navy:        #1A1C4E;
  --light-bg:    #F5F6FF;
  --white:       #FFFFFF;
  --text-body:   #374151;
  --text-muted:  #6B7280;
  --border:      #E5E7EB;

  --gradient:    linear-gradient(135deg, var(--blue) 0%, var(--purple) 100%);

  --radius:      12px;
  --radius-lg:   20px;

  --shadow-sm:   0 1px 3px rgba(0,0,0,.07), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md:   0 4px 8px rgba(0,0,0,.07), 0 12px 28px rgba(0,0,0,.07);
  --shadow-lg:   0 8px 16px rgba(0,0,0,.06), 0 24px 48px rgba(0,0,0,.09);

  --max-w:       1120px;
  --section-py:  96px;
  --container-px: 24px;
}

/* ── Base ───────────────────────────────────────────────────────────────────── */
html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--navy);
  background: var(--white);
  line-height: 1.6;
  font-size: 16px;
}

img  { max-width: 100%; height: auto; display: block; }
a    { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

/* ── Layout helpers ─────────────────────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--container-px);
}

.section-label {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  color: var(--navy);
  line-height: 1.18;
  margin-bottom: 48px;
}

/* ── Buttons ────────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  transition: opacity .15s ease, transform .15s ease, box-shadow .15s ease;
  text-decoration: none;
  white-space: nowrap;
  line-height: 1;
}

.btn:hover:not(.btn--disabled) {
  opacity: .88;
  transform: translateY(-1px);
}

.btn--disabled {
  opacity: .45;
  pointer-events: none;
  cursor: default;
}

.btn--sm { font-size: 13px; padding: 8px 18px; }
.btn--lg { font-size: 15px; padding: 14px 28px; }

.btn--primary {
  background: var(--gradient);
  color: var(--white);
  box-shadow: 0 4px 14px rgba(67, 97, 238, .32);
}
.btn--primary:hover:not(.btn--disabled) {
  box-shadow: 0 6px 20px rgba(67, 97, 238, .44);
}

.btn--outline {
  background: transparent;
  color: var(--navy);
  border: 1.5px solid var(--border);
}
.btn--outline:hover:not(.btn--disabled) {
  border-color: var(--blue);
  color: var(--blue);
}

.btn--ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1.5px solid var(--border);
}

.btn--white {
  background: var(--white);
  color: var(--navy);
  box-shadow: var(--shadow-sm);
}
.btn--white:hover:not(.btn--disabled) {
  box-shadow: var(--shadow-md);
}

.btn--outline-white {
  background: transparent;
  color: var(--white);
  border: 1.5px solid rgba(255, 255, 255, .45);
}
.btn--outline-white:hover:not(.btn--disabled) {
  border-color: var(--white);
  background: rgba(255, 255, 255, .1);
}

/* ─────────────────────────────────────────────────────────────────────────────
   NAVBAR
───────────────────────────────────────────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, .96);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s, box-shadow .2s;
}

.nav--scrolled {
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 0;
  flex-shrink: 0;
}

.nav__logo-img {
  height: 38px;
  width: auto;
  object-fit: contain;
  object-position: left center;
}

/* Shown only if logo PNG fails to load */
.nav__logo-fallback {
  display: none;
  font-size: 18px;
  font-weight: 800;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ─────────────────────────────────────────────────────────────────────────────
   HERO
───────────────────────────────────────────────────────────────────────────── */
.hero {
  background: var(--light-bg);
  padding: 88px 0 100px;
  overflow: hidden;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}

@media (min-width: 900px) {
  .hero__inner {
    grid-template-columns: 1fr 1fr;
    gap: 64px;
  }
}

.hero__headline {
  font-size: clamp(36px, 5.5vw, 58px);
  font-weight: 800;
  line-height: 1.1;
  color: var(--navy);
  margin-bottom: 20px;
  letter-spacing: -.02em;
}

.hero__sub {
  font-size: 18px;
  color: var(--text-body);
  line-height: 1.7;
  margin-bottom: 36px;
  max-width: 500px;
}

.hero__ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

/* Decorative product preview cards */
.hero__visual {
  position: relative;
  height: 290px;
  flex-shrink: 0;
}

@media (max-width: 899px) {
  .hero__visual { display: none; }
}

.hero__card {
  position: absolute;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 20px 22px;
}

.hero__card--quiz {
  top: 0;
  left: 0;
  right: 36px;
}

.hero__card--live {
  bottom: 8px;
  right: 0;
  width: 190px;
  padding: 16px 18px;
}

.hero__card-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.hero__card-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gradient);
  flex-shrink: 0;
}

.hero__card-items {
  display: flex;
  flex-direction: column;
  gap: 8px;
  list-style: none;
}

.hero__card-items li {
  font-size: 13px;
  color: var(--navy);
  background: var(--light-bg);
  border-radius: 8px;
  padding: 9px 12px;
  line-height: 1.4;
}

.hero__live-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: #059669;
  background: #ECFDF5;
  border-radius: 6px;
  padding: 4px 8px;
  margin-bottom: 10px;
}

.hero__live-q {
  font-size: 15px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 10px;
}

.hero__progress-wrap {
  background: var(--border);
  border-radius: 4px;
  height: 5px;
  overflow: hidden;
  margin-bottom: 10px;
}

.hero__progress-bar {
  width: 40%;
  height: 100%;
  background: var(--gradient);
  border-radius: 4px;
}

.hero__live-counts {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
}

/* ─────────────────────────────────────────────────────────────────────────────
   PROBLEM
───────────────────────────────────────────────────────────────────────────── */
.problem {
  padding: var(--section-py) 0;
  background: var(--white);
}

.problem__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-bottom: 52px;
}

@media (min-width: 700px) {
  .problem__grid { grid-template-columns: repeat(3, 1fr); }
}

.problem__card {
  background: var(--light-bg);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.problem__icon {
  font-size: 28px;
  margin-bottom: 16px;
  line-height: 1;
}

.problem__card h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 10px;
}

.problem__card p {
  font-size: 15px;
  color: var(--text-body);
  line-height: 1.65;
}

.problem__bridge {
  font-size: 18px;
  color: var(--text-body);
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

.problem__bridge strong { color: var(--navy); }

/* ─────────────────────────────────────────────────────────────────────────────
   SOLUTION
───────────────────────────────────────────────────────────────────────────── */
.solution {
  padding: var(--section-py) 0;
  background: var(--navy);
}

.solution .section-label { color: rgba(255, 255, 255, .55); }
.solution .section-title { color: var(--white); }

.solution__steps {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

@media (min-width: 860px) {
  .solution__steps {
    flex-direction: row;
    align-items: flex-start;
    gap: 0;
  }
}

.solution__step {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.solution__step-icon {
  width: 52px;
  height: 52px;
  background: rgba(255, 255, 255, .1);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.solution__step-icon svg {
  width: 24px;
  height: 24px;
  color: var(--white);
}

.solution__step h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--white);
}

.solution__step p {
  font-size: 15px;
  color: rgba(255, 255, 255, .68);
  line-height: 1.65;
}

.solution__arrow {
  display: none;
  font-size: 22px;
  color: rgba(255, 255, 255, .2);
  align-self: center;
  padding: 0 20px;
  flex-shrink: 0;
}

@media (min-width: 860px) { .solution__arrow { display: block; } }

/* ─────────────────────────────────────────────────────────────────────────────
   FEATURES
───────────────────────────────────────────────────────────────────────────── */
.features {
  padding: var(--section-py) 0;
  background: var(--light-bg);
}

.features__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 620px) {
  .features__grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 980px) {
  .features__grid { grid-template-columns: repeat(3, 1fr); }
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s ease, transform .2s ease;
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.feature-card__icon {
  width: 44px;
  height: 44px;
  background: var(--light-bg);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  flex-shrink: 0;
}

.feature-card__icon svg {
  width: 21px;
  height: 21px;
  color: var(--blue);
}

.feature-card h3 {
  font-size: 15px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 8px;
  line-height: 1.3;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-body);
  line-height: 1.65;
}

/* ─────────────────────────────────────────────────────────────────────────────
   HOW IT WORKS
───────────────────────────────────────────────────────────────────────────── */
.how-it-works {
  padding: var(--section-py) 0;
  background: var(--white);
}

.steps {
  display: flex;
  flex-direction: column;
  max-width: 680px;
}

.step {
  display: flex;
  gap: 24px;
  padding-bottom: 40px;
  position: relative;
}

/* Vertical connector line between steps */
.step:not(:last-child)::after {
  content: '';
  position: absolute;
  left: 19px;
  top: 46px;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.step__num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gradient);
  color: var(--white);
  font-weight: 700;
  font-size: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
  box-shadow: 0 2px 8px rgba(67, 97, 238, .3);
}

.step__body { padding-top: 7px; }

.step__body h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 6px;
}

.step__body p {
  font-size: 15px;
  color: var(--text-body);
  line-height: 1.65;
}

/* ─────────────────────────────────────────────────────────────────────────────
   EARLY BIRD OFFER
───────────────────────────────────────────────────────────────────────────── */
.early-bird {
  padding: var(--section-py) 0;
  background: var(--gradient);
}

.early-bird__inner {
  max-width: 680px;
  margin: 0 auto;
  text-align: center;
}

.early-bird__badge {
  display: inline-block;
  background: rgba(255, 255, 255, .18);
  color: var(--white);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: 6px 16px;
  border-radius: 999px;
  margin-bottom: 22px;
}

.early-bird__title {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800;
  color: var(--white);
  line-height: 1.1;
  margin-bottom: 12px;
  letter-spacing: -.02em;
}

.early-bird__sub {
  font-size: 18px;
  color: rgba(255, 255, 255, .8);
  margin-bottom: 40px;
  line-height: 1.6;
}

.early-bird__list {
  background: rgba(255, 255, 255, .12);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 32px;
  text-align: left;
}

.early-bird__item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px 24px;
  border-bottom: 1px solid rgba(255, 255, 255, .1);
}

.early-bird__item:last-child { border-bottom: none; }

.early-bird__check {
  width: 26px;
  height: 26px;
  background: rgba(255, 255, 255, .2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--white);
  flex-shrink: 0;
  margin-top: 1px;
}

.early-bird__item-body {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.early-bird__item-title {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.early-bird__item-title strong {
  font-size: 15px;
  color: var(--white);
  font-weight: 700;
}

.early-bird__cap {
  font-size: 12px;
  font-weight: 500;
  color: rgba(255, 255, 255, .65);
  background: rgba(255, 255, 255, .12);
  padding: 2px 8px;
  border-radius: 4px;
}

.early-bird__item-desc {
  font-size: 14px;
  color: rgba(255, 255, 255, .68);
  line-height: 1.55;
}

.early-bird__note {
  font-size: 15px;
  color: rgba(255, 255, 255, .8);
  margin-bottom: 36px;
  line-height: 1.7;
}

.early-bird__note a {
  color: var(--white);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.early-bird__ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

/* ─────────────────────────────────────────────────────────────────────────────
   APP DOWNLOAD
───────────────────────────────────────────────────────────────────────────── */
.download {
  padding: var(--section-py) 0;
  background: var(--light-bg);
  text-align: center;
}

.download__inner { max-width: 560px; margin: 0 auto; }

.download__title {
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 800;
  color: var(--navy);
  margin-bottom: 14px;
  line-height: 1.2;
}

.download__sub {
  font-size: 17px;
  color: var(--text-body);
  margin-bottom: 36px;
  line-height: 1.6;
}

.download__ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

/* ─────────────────────────────────────────────────────────────────────────────
   FOOTER
───────────────────────────────────────────────────────────────────────────── */
.footer {
  background: var(--navy);
  padding: 60px 0 40px;
}

.footer__inner {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

@media (min-width: 720px) {
  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }
}

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

/* CSS wordmark — used instead of logo PNG on dark background */
.footer__wordmark {
  font-size: 20px;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -.01em;
}

.footer__tagline {
  font-size: 14px;
  line-height: 1.65;
  color: rgba(255, 255, 255, .5);
  max-width: 240px;
}

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

@media (min-width: 720px) {
  .footer__links { align-items: flex-end; }
}

.footer__links a {
  font-size: 14px;
  color: rgba(255, 255, 255, .55);
  transition: color .15s;
}

.footer__links a:hover { color: var(--white); }

.footer__copy {
  font-size: 13px;
  color: rgba(255, 255, 255, .35);
  width: 100%;
  padding-top: 8px;
  border-top: 1px solid rgba(255, 255, 255, .08);
}

@media (min-width: 720px) { .footer__copy { text-align: center; } }

/* ─────────────────────────────────────────────────────────────────────────────
   RESPONSIVE — small screens
───────────────────────────────────────────────────────────────────────────── */
@media (max-width: 480px) {
  :root {
    --section-py: 64px;
  }

  .hero {
    padding: 56px 0 68px;
  }

  .hero__ctas,
  .early-bird__ctas,
  .download__ctas {
    flex-direction: column;
    align-items: stretch;
  }

  .btn--lg { width: 100%; }
}