/* Padhai Karlo landing system. Shared by /landing.html,
   /students.html, /parents.html. Strict design-system tokens —
   if you fork these tokens here, fork them in src/styles too. */

:root {
  --primary:        #4f46e5;
  --primary-dark:   #4338ca;
  --primary-soft:   #eef2ff;
  --ink:            #0f172a;
  --ink-2:          #1e293b;
  --ink-3:          #475569;
  --muted:          #94a3b8;
  --line:           #e2e8f0;
  --line-soft:      #f1f5f9;
  --bg:             #ffffff;
  --soft:           #f8fafc;
  --amber:          #f59e0b;
  --amber-soft:     #fef3c7;
  --green:          #16a34a;
  --green-soft:     #dcfce7;
  --red:            #dc2626;

  --radius-8:       8px;
  --radius-12:      12px;
  --radius-16:      16px;
  --radius-24:      24px;
  --radius-pill:    999px;

  --shadow-sm:      0 1px 2px rgba(15,23,42,0.06);
  --shadow-md:      0 8px 24px rgba(15,23,42,0.08);
  --shadow-lg:      0 24px 48px rgba(15,23,42,0.12);

  --space-1:  4px; --space-2:  8px; --space-3: 12px;
  --space-4: 16px; --space-5: 24px; --space-6: 32px;
  --space-7: 48px; --space-8: 64px; --space-9: 96px;

  --font-display: "Playfair Display", "Source Serif 4", "Georgia", serif;
  --font-ui:      -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI",
                  Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
img, svg, video { max-width: 100%; display: block; }

.container {
  inline-size: 100%;
  max-inline-size: 1120px;
  margin-inline: auto;
  padding-inline: var(--space-5);
}

/* Nav */
.nav {
  position: sticky;
  inset-block-start: 0;
  z-index: 10;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  border-block-end: 1px solid var(--line-soft);
}
.nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  block-size: 64px;
  gap: var(--space-4);
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
  text-decoration: none;
  color: var(--ink);
}
.brand img { block-size: 28px; inline-size: auto; }
.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.nav-row .btn { white-space: nowrap; }
/* Small phones (360-479px): the wordmark plus two login buttons must
   fit on one 64px row, so tighten the row gap and the buttons. */
@media (max-width: 479px) {
  .nav-row { gap: var(--space-2); padding-inline: var(--space-4); }
  .nav-row > div { gap: 6px !important; }
  .nav-row .btn-sm { padding: 8px 12px; font-size: 13px; }
  .brand { gap: 6px; }
  .brand img { block-size: 24px; }
  .brand-name { font-size: 17px; }
}
@media (max-width: 379px) {
  .nav-row .btn-sm { padding: 8px 10px; }
  .brand-name { font-size: 16px; }
}
.nav-links {
  display: none;
  gap: var(--space-5);
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-3);
}
.nav-links a:hover { color: var(--ink); }
@media (min-width: 880px) { .nav-links { display: flex; } }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 14px 22px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.01em;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 120ms ease, background-color 200ms ease, color 200ms ease;
  font-family: inherit;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--ink); border: 1.5px solid var(--line); }
.btn-ghost:hover { background: var(--soft); color: var(--ink); }
.btn-sm { padding: 10px 16px; font-size: 14px; }

/* Section shell */
section { padding-block: var(--space-8); }
.eyebrow {
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--primary);
}
h1, h2, h3 { color: var(--ink); }
h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(34px, 6.5vw, 60px);
  line-height: 1.05;
  letter-spacing: -0.025em;
  margin: 0;
}
h1 em { font-style: italic; color: var(--primary); font-family: var(--font-display); }
h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: var(--space-2) 0 var(--space-4);
}
.section-sub {
  color: var(--ink-3);
  font-size: 17px;
  max-inline-size: 38rem;
  margin: 0 0 var(--space-6);
}

/* Hero */
.hero {
  padding-block: var(--space-8) var(--space-9);
  background:
    radial-gradient(1200px 500px at 70% -10%, var(--primary-soft) 0%, transparent 60%),
    var(--bg);
}
.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: var(--radius-pill);
  background: var(--amber-soft);
  color: #7a4d00;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-block-end: var(--space-4);
}
.hero-tag::before {
  content: "";
  inline-size: 6px; block-size: 6px;
  border-radius: 50%;
  background: var(--amber);
}
.hero-sub {
  margin-block-start: var(--space-4);
  font-size: clamp(17px, 2vw, 19px);
  color: var(--ink-3);
  line-height: 1.55;
  max-inline-size: 32rem;
}
.hero-hindi {
  margin-block-start: var(--space-3);
  font-size: 14px;
  color: var(--muted);
  font-style: italic;
}
.hero-cta-row {
  display: flex;
  gap: var(--space-3);
  margin-block-start: var(--space-6);
  flex-wrap: wrap;
}

/* Persona pick row (minimal landing only) */
.persona-pick {
  margin-block-start: var(--space-6);
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
}
.persona-pick a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  background: var(--soft);
  border: 1px solid var(--line);
  color: var(--ink-2);
  font-size: 14px;
  font-weight: 600;
}
.persona-pick a:hover { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); }

/* "What's different" — minimal landing */
.different-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-block-start: var(--space-5);
}
@media (min-width: 720px) {
  .different-grid { grid-template-columns: repeat(3, 1fr); }
}
.different-card {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-16);
  padding: var(--space-5);
  display: grid;
  gap: var(--space-2);
  transition: border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}
.different-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.different-icon {
  inline-size: 36px; block-size: 36px;
  display: inline-flex;
  align-items: center; justify-content: center;
  border-radius: var(--radius-12);
  background: var(--primary-soft);
  color: var(--primary);
  font-weight: 800;
  font-size: 18px;
  margin-block-end: 4px;
}
.different-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.25;
  letter-spacing: -0.01em;
}
.different-body {
  font-size: 14px;
  color: var(--ink-3);
  line-height: 1.55;
}

/* Persona pages — pain/feature/benefit cards */
.persona-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-block-start: var(--space-5);
}
@media (min-width: 720px) {
  .persona-grid { grid-template-columns: repeat(3, 1fr); }
}
.pf-card {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-16);
  padding: var(--space-5);
  display: grid;
  gap: var(--space-3);
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}
.pf-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.pf-pain {
  font-size: 14px;
  color: var(--ink-3);
  font-style: italic;
  line-height: 1.5;
  border-inline-start: 3px solid var(--amber);
  padding-inline-start: 12px;
}
.pf-feature {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  color: var(--ink);
  letter-spacing: -0.01em;
  line-height: 1.25;
}
.pf-benefit {
  font-size: 14px;
  color: var(--ink-3);
  line-height: 1.55;
}

.slab-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  border-radius: var(--radius-pill);
  background: var(--primary-soft);
  color: var(--primary);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.slab-tag.parent-tag { background: var(--amber-soft); color: #7a4d00; }

/* Pricing */
.pricing-card {
  background: var(--bg);
  border: 2px solid var(--primary);
  border-radius: var(--radius-24);
  padding: var(--space-6);
  display: grid;
  gap: var(--space-4);
  max-inline-size: 480px;
  margin-inline: auto;
  box-shadow: var(--shadow-md);
  position: relative;
}
.pricing-pill {
  position: absolute;
  inset-block-start: -14px;
  inset-inline-start: 50%;
  transform: translateX(-50%);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.pricing-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  color: var(--ink);
}
.pricing-price { display: flex; align-items: baseline; gap: 6px; }
.pricing-amount {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 56px;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.03em;
}
.pricing-per { color: var(--ink-3); font-size: 15px; font-weight: 500; }
.pricing-tag {
  font-size: 13px;
  color: var(--ink-3);
  background: var(--soft);
  padding: 8px 12px;
  border-radius: var(--radius-8);
  font-weight: 500;
}
.pricing-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: var(--space-2);
}
.pricing-list li {
  display: flex;
  gap: var(--space-2);
  align-items: flex-start;
  font-size: 14px;
  color: var(--ink-2);
}
.pricing-list li::before {
  content: "✓";
  color: var(--green);
  font-weight: 800;
  flex-shrink: 0;
  inline-size: 18px; block-size: 18px;
  display: inline-flex;
  align-items: center; justify-content: center;
  background: var(--green-soft);
  border-radius: 50%;
  font-size: 11px;
  margin-block-start: 2px;
}
/* Tiered pricing: Free + Silver / Gold / Diamond. Cards stack on
 * phones, 2-up on tablets, 4-up on desktop. The featured card reuses
 * .pricing-card's primary border; plain tiers get a quiet line. */
.pricing-grid {
  display: grid;
  gap: var(--space-6) var(--space-4);
  grid-template-columns: 1fr;
  max-inline-size: 1120px;
  margin-inline: auto;
}
@media (min-width: 720px) { .pricing-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1080px) { .pricing-grid { grid-template-columns: repeat(4, 1fr); } }
.pricing-grid .pricing-card {
  max-inline-size: none;
  margin-inline: 0;
  align-content: start;
  padding: var(--space-5, 20px);
}
.pricing-grid .pricing-card.plain {
  border: 1px solid var(--line);
  box-shadow: none;
}
.pricing-grid .pricing-amount { font-size: 40px; }
.pricing-note {
  max-inline-size: 760px;
  margin: var(--space-6) auto 0;
  font-size: 13px;
  color: var(--ink-3);
  text-align: center;
  line-height: 1.6;
}
.pricing-foot {
  font-size: 12px;
  color: var(--muted);
  text-align: center;
  margin-block-start: var(--space-2);
}

/* FAQ */
.faq {
  display: grid;
  gap: var(--space-2);
  max-inline-size: 760px;
  margin-inline: auto;
}
.faq details {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-12);
  padding: var(--space-4) var(--space-5);
  transition: border-color 160ms ease;
}
.faq details[open] { border-color: var(--primary); }
.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  color: var(--ink);
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  font-size: 22px;
  font-weight: 400;
  color: var(--muted);
  transition: transform 200ms ease;
  flex-shrink: 0;
  line-height: 1;
}
.faq details[open] summary::after { content: "−"; color: var(--primary); }
.faq-body {
  padding-block-start: var(--space-3);
  color: var(--ink-3);
  font-size: 15px;
  line-height: 1.6;
}

/* Footer */
footer {
  background: var(--ink);
  color: rgba(255,255,255,0.85);
  padding-block: var(--space-7);
}
footer .container {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-5);
  justify-content: space-between;
  align-items: center;
}
footer .brand-name { color: #fff; }
footer a { color: rgba(255,255,255,0.85); }
footer a:hover { color: #fff; }
.foot-links { display: flex; gap: var(--space-4); flex-wrap: wrap; font-size: 14px; }
.foot-trust { font-size: 12px; opacity: 0.65; margin-inline-end: auto; }
.foot-tagline { font-size: 13px; opacity: 0.65; }

/* Returning-visitor bar — slim strip above the nav. Hidden by
   default; toggled on by the inline boot script when localStorage
   says the visitor has been here before but isn't signed in. */
.welcome-back {
  display: none;
  background: var(--primary-soft);
  border-block-end: 1px solid var(--line-soft);
  font-size: 13px;
  color: var(--ink-2);
}
.welcome-back[data-show="1"] { display: block; }
.welcome-back .container {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding-block: 8px;
  flex-wrap: wrap;
}
.welcome-back-msg {
  flex: 1 1 auto;
  min-inline-size: 0;
  font-weight: 500;
}
.welcome-back-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.welcome-back-link {
  font-weight: 700;
  text-decoration: underline;
}
.welcome-back-dismiss {
  background: transparent;
  border: none;
  color: var(--muted);
  cursor: pointer;
  font-size: 18px;
  line-height: 1;
  padding: 4px 6px;
  font-family: inherit;
}
.welcome-back-dismiss:hover { color: var(--ink); }