/* ============================================================
   JoyStella — design system
   Black / white / gray UI, color lives in the imagery.
   Typography & layout rhythm inspired by youmind.com
   ============================================================ */

:root {
  --bg: #ffffff;
  --bg-soft: #f6f6f7;
  --ink: #111114;
  --ink-2: #2a2a2e;
  --muted: #5f6065;
  --faint: #9b9ca1;
  --line: #e9e9ec;
  --line-strong: #d6d6da;
  --radius: 16px;
  --radius-lg: 24px;
  --wrap: 1120px;
  --shadow: 0 1px 2px rgba(17, 17, 20, .04), 0 12px 32px rgba(17, 17, 20, .08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "cv11", "ss01";
}

img { max-width: 100%; display: block; }

a { color: var(--ink); text-decoration: none; }
a:hover { text-decoration: none; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .86);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; align-items: center; gap: 12px;
  height: 68px; max-width: var(--wrap); margin: 0 auto; padding: 0 24px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 17px; letter-spacing: -.01em; color: var(--ink);
}
.brand img { width: 32px; height: 32px; }
.nav { margin-left: auto; display: flex; align-items: center; gap: 30px; }
.nav a:not(.btn) { color: var(--muted); font-size: 15px; font-weight: 500; transition: color .15s ease; }
.nav a:not(.btn):hover { color: var(--ink); }
.nav .btn-sm { color: #fff; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 14px 26px; border-radius: 999px;
  font-size: 16px; font-weight: 600; letter-spacing: -.005em;
  border: 1px solid transparent; cursor: pointer;
  transition: transform .12s ease, background .15s ease, border-color .15s ease, box-shadow .15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { background: var(--ink-2); box-shadow: 0 8px 20px rgba(17, 17, 20, .18); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--ink); }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-lg { padding: 17px 34px; font-size: 17px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }

/* ---------- hero ---------- */
.hero { padding: 96px 0 104px; }
.hero-center { text-align: center; max-width: 880px; margin: 0 auto; }
.hero-mark {
  width: 84px; height: 84px; margin: 0 auto 32px;
  filter: drop-shadow(0 12px 28px rgba(236, 130, 172, .35));
}
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 56px; align-items: center; }
.eyebrow {
  display: block; font-size: 13px; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--faint); margin-bottom: 20px;
}
h1 {
  font-size: clamp(44px, 6.5vw, 76px);
  line-height: 1.04; letter-spacing: -.035em; margin: 0 0 24px; font-weight: 700;
}
.lede { font-size: 20px; color: var(--muted); margin: 0 0 36px; }
.hero-center .lede { max-width: 640px; margin-left: auto; margin-right: auto; }
.trust { margin-top: 22px; font-size: 14px; color: var(--faint); }
.hero-phone {
  max-height: 540px; margin: 0 auto; width: auto;
  border-radius: 36px; box-shadow: var(--shadow);
}

/* ---------- sections ---------- */
section { padding: 104px 0; }
.section-alt { background: var(--bg-soft); }
.section-head { max-width: 720px; margin: 0 auto 56px; text-align: center; }
.section-head.left { margin-left: 0; text-align: left; }
h2 { font-size: clamp(30px, 4vw, 44px); line-height: 1.12; letter-spacing: -.025em; margin: 0 0 16px; font-weight: 700; }
h3 { font-size: 19px; margin: 0 0 8px; font-weight: 600; letter-spacing: -.01em; }
.section-head p { color: var(--muted); margin: 0; font-size: 18px; }

/* ---------- cards ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 30px;
  transition: box-shadow .2s ease, transform .2s ease, border-color .2s ease;
}
.card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.card p { margin: 0; color: var(--muted); font-size: 16px; }
.section-alt .card { background: var(--bg); }
.section-alt .card:hover { box-shadow: var(--shadow); }

.num {
  width: 36px; height: 36px; border-radius: 10px; background: var(--ink);
  color: #fff; font-weight: 700; font-size: 15px;
  display: flex; align-items: center; justify-content: center; margin-bottom: 18px;
}

/* ---------- app cards (homepage) ---------- */
.app-card .app-icon {
  width: 64px; height: 64px; border-radius: 16px; margin-bottom: 20px;
  box-shadow: 0 4px 14px rgba(17, 17, 20, .12);
}
.app-card h3 { font-size: 21px; margin: 0 0 8px; }
.app-card .tagline { font-size: 15px; color: var(--faint); margin-bottom: 14px; }
.more-link {
  display: inline-flex; align-items: center; gap: 6px;
  font-weight: 600; font-size: 15px; margin-top: 18px;
}
.more-link::after { content: "→"; transition: transform .15s ease; }
.more-link:hover::after { transform: translateX(3px); }
.card-soon {
  background: transparent; border: 1.5px dashed var(--line-strong);
  box-shadow: none; display: flex; flex-direction: column; justify-content: center;
}
.card-soon:hover { transform: none; box-shadow: none; border-color: var(--faint); }
.card-soon .app-icon {
  width: 64px; height: 64px; border-radius: 16px; margin-bottom: 20px;
  opacity: .35; filter: grayscale(1);
}

/* ---------- principles strip ---------- */
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden; }
.pillar { padding: 36px 32px; border-left: 1px solid var(--line); }
.pillar:first-child { border-left: none; }
.pillar h3 { font-size: 17px; }
.pillar p { color: var(--muted); font-size: 15px; margin: 0; }

/* ---------- curriculum ---------- */
.stage { display: grid; grid-template-columns: 200px 1fr; gap: 32px; padding: 30px 0; border-top: 1px solid var(--line); }
.stage:first-of-type { border-top: none; }
.stage-tag { font-weight: 600; font-size: 17px; letter-spacing: -.01em; }
.stage-tag span { display: block; font-weight: 400; color: var(--faint); font-size: 14px; }
.lesson { display: flex; gap: 16px; padding: 12px 0; }
.lesson .dot { flex: 0 0 auto; width: 8px; height: 8px; border-radius: 50%; background: var(--ink); margin-top: 11px; }
.lesson strong { font-weight: 600; }
.lesson p { margin: 2px 0 0; color: var(--muted); font-size: 16px; }

/* ---------- features ---------- */
.feature h3 { display: flex; align-items: center; gap: 10px; }
.feature h3::before {
  content: ""; width: 10px; height: 10px; flex: 0 0 auto;
  border-radius: 3px; background: var(--ink);
}

/* ---------- screenshots ---------- */
.shots { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; justify-items: center; }
.shots img { border-radius: 28px; box-shadow: var(--shadow); max-height: 460px; width: auto; }
.shot-wide { margin-top: 28px; text-align: center; }
.shot-wide img { border-radius: 24px; box-shadow: var(--shadow); max-height: 520px; margin: 0 auto; }

/* ---------- pricing ---------- */
.plans { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.plan { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 34px; }
.plan.featured { border: 1.5px solid var(--ink); box-shadow: var(--shadow); }
.plan .price { font-size: 14px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); margin-bottom: 6px; }
.plan ul { list-style: none; padding: 0; margin: 20px 0 28px; }
.plan li { padding: 8px 0 8px 26px; position: relative; color: var(--muted); }
.plan li::before {
  content: ""; position: absolute; left: 0; top: 14px;
  width: 14px; height: 8px; border-left: 2px solid var(--ink); border-bottom: 2px solid var(--ink);
  transform: rotate(-45deg);
}
.reassure { text-align: center; color: var(--faint); font-size: 15px; margin-top: 24px; }

/* ---------- faq ---------- */
.faq { max-width: 760px; margin: 0 auto; }
.faq details { border-bottom: 1px solid var(--line); padding: 4px 0; }
.faq summary {
  cursor: pointer; padding: 20px 0; font-weight: 600; font-size: 17px; letter-spacing: -.01em;
  list-style: none; display: flex; justify-content: space-between; gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--ink); font-size: 24px; font-weight: 400; line-height: 1.2; }
.faq details[open] summary::after { content: "\2013"; }
.faq details p { margin: 0 0 20px; color: var(--muted); }

/* ---------- final cta ---------- */
.final { background: var(--bg-soft); text-align: center; padding: 112px 0; }
.final h2 { max-width: 720px; margin: 0 auto; }
.final .cta-row { justify-content: center; margin-top: 32px; }
.note { color: var(--faint); font-size: 14px; margin-top: 24px; }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 44px 0; font-size: 15px; color: var(--muted); background: var(--bg); }
.footer-inner { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; }
.footer-inner nav { margin-left: auto; display: flex; gap: 24px; }
.footer-inner a { color: var(--muted); }
.footer-inner a:hover { color: var(--ink); }
.footer-legal { color: var(--faint); font-size: 13px; margin-top: 18px; }

/* ---------- prose (privacy / support) ---------- */
.prose { max-width: 720px; }
.prose h2 { font-size: 26px; margin-top: 44px; }
.prose h3 { font-size: 19px; margin-top: 28px; }
.prose p, .prose li { color: var(--muted); }
.prose ul { padding-left: 22px; }
.prose .meta { color: var(--faint); font-size: 14px; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero { padding: 64px 0 72px; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .grid-3, .grid-2, .plans, .shots { grid-template-columns: 1fr; }
  .pillars { grid-template-columns: 1fr; }
  .pillar { border-left: none; border-top: 1px solid var(--line); }
  .pillar:first-child { border-top: none; }
  .stage { grid-template-columns: 1fr; gap: 12px; }
  .hero-phone { max-height: 420px; }
  section { padding: 72px 0; }
  .shots img { max-height: none; }
}
@media (max-width: 560px) {
  .nav { display: none; }
  .lede { font-size: 18px; }
  .hero-mark { width: 68px; height: 68px; }
}