/* ============================================================
   Easy Learn IB — Design Tokens
   Soft neutrals + green accent · Friendly / education
   ============================================================ */

:root,
[data-theme="light"] {
  --color-bg: #f8f7f3;
  --color-surface: #ffffff;
  --color-surface-2: #fbfaf7;
  --color-surface-offset: #f1efe9;
  --color-surface-tint: #eef3ec;
  --color-divider: #e6e3dc;
  --color-border: #ddd9d0;

  --color-text: #1f2a22;
  --color-text-muted: #5f655d;
  --color-text-faint: #9aa097;
  --color-text-inverse: #f8f7f3;

  --color-primary: #2f7a4f;
  --color-primary-hover: #266542;
  --color-primary-active: #1d4e33;
  --color-primary-soft: #e3efe6;
  --color-primary-line: #cfe2d4;

  --color-star: #2f7a4f;

  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  --transition-interactive: 200ms cubic-bezier(0.16, 1, 0.3, 1);

  --shadow-sm: 0 1px 2px rgba(31, 42, 34, 0.05);
  --shadow-md: 0 6px 20px rgba(31, 42, 34, 0.07);
  --shadow-lg: 0 18px 44px rgba(31, 42, 34, 0.10);

  --content-wide: 1200px;
  --content-default: 980px;

  --font-display: "Clash Display", "General Sans", sans-serif;
  --font-body: "General Sans", "Inter", system-ui, sans-serif;

  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.83rem + 0.2vw, 0.95rem);
  --text-base: clamp(1rem, 0.96rem + 0.2vw, 1.0625rem);
  --text-lg: clamp(1.125rem, 1rem + 0.6vw, 1.375rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.1vw, 2.1rem);
  --text-2xl: clamp(2.1rem, 1.4rem + 2.6vw, 3.6rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
}

[data-theme="dark"] {
  --color-bg: #121512;
  --color-surface: #1a1e1a;
  --color-surface-2: #1f231e;
  --color-surface-offset: #1c201b;
  --color-surface-tint: #18211b;
  --color-divider: #2a2f29;
  --color-border: #313631;

  --color-text: #e7ebe6;
  --color-text-muted: #9aa298;
  --color-text-faint: #6b7268;
  --color-text-inverse: #121512;

  --color-primary: #5fb37e;
  --color-primary-hover: #74c191;
  --color-primary-active: #88cda2;
  --color-primary-soft: #1e2b21;
  --color-primary-line: #2c3e30;

  --color-star: #5fb37e;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 20px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 18px 44px rgba(0, 0, 0, 0.55);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg: #121512;
    --color-surface: #1a1e1a;
    --color-surface-2: #1f231e;
    --color-surface-offset: #1c201b;
    --color-surface-tint: #18211b;
    --color-divider: #2a2f29;
    --color-border: #313631;
    --color-text: #e7ebe6;
    --color-text-muted: #9aa298;
    --color-text-faint: #6b7268;
    --color-primary: #5fb37e;
    --color-primary-hover: #74c191;
    --color-primary-soft: #1e2b21;
    --color-primary-line: #2c3e30;
    --color-star: #5fb37e;
  }
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: 5.5rem;
}

body {
  min-height: 100dvh;
  line-height: 1.6;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-bg);
}

img, svg { display: block; max-width: 100%; height: auto; }
ul[role="list"] { list-style: none; }
input, button { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  text-wrap: balance;
  line-height: 1.08;
  font-weight: 600;
  letter-spacing: -0.01em;
}
p { text-wrap: pretty; }
a { color: inherit; text-decoration: none; }

::selection { background: var(--color-primary-soft); color: var(--color-text); }
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; border-radius: var(--radius-sm); }
a, button, input { transition: color var(--transition-interactive), background var(--transition-interactive), border-color var(--transition-interactive), box-shadow var(--transition-interactive), transform var(--transition-interactive); }

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.wrap { width: 100%; max-width: var(--content-wide); margin-inline: auto; padding-inline: var(--space-6); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}

/* ============ Buttons ============ */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); font-size: var(--text-sm); font-weight: 600; line-height: 1; padding: 0.85rem 1.4rem; border-radius: var(--radius-full); white-space: nowrap; }
.btn-primary { background: var(--color-primary); color: #fff; box-shadow: var(--shadow-sm); }
.btn-primary:hover { background: var(--color-primary-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }
[data-theme="dark"] .btn-primary { color: #0d130f; }
.btn-ghost { background: transparent; color: var(--color-text); border: 1px solid var(--color-border); }
.btn-ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }
.btn-lg { padding: 1rem 1.7rem; font-size: var(--text-base); }

/* ============ Header ============ */
.header { position: sticky; top: 0; z-index: 50; background: color-mix(in oklab, var(--color-bg) 88%, transparent); backdrop-filter: blur(14px); border-bottom: 1px solid transparent; transition: border-color var(--transition-interactive), box-shadow var(--transition-interactive); }
.header--scrolled { border-color: var(--color-divider); box-shadow: var(--shadow-sm); }
.header__inner { display: flex; align-items: center; gap: var(--space-5); height: 4.5rem; }

.logo { display: inline-flex; align-items: center; gap: 0.55rem; font-family: var(--font-display); font-weight: 600; font-size: 1.2rem; letter-spacing: -0.02em; white-space: nowrap; flex-shrink: 0; }
.logo svg { color: var(--color-primary); flex-shrink: 0; }
.logo span b { color: var(--color-primary); font-weight: 600; }

.nav-pills { display: flex; gap: 0.35rem; background: var(--color-surface-offset); padding: 0.3rem; border-radius: var(--radius-full); }
.nav-pill { display: inline-flex; align-items: center; gap: 0.4rem; font-size: var(--text-sm); font-weight: 500; color: var(--color-text-muted); padding: 0.45rem 0.85rem; border-radius: var(--radius-full); }
.nav-pill.is-active { background: var(--color-surface); color: var(--color-text); box-shadow: var(--shadow-sm); }
.nav-pill:hover { color: var(--color-text); }

.search { flex: 1; position: relative; max-width: 460px; }
.search input { width: 100%; border: 1px solid var(--color-border); background: var(--color-surface); border-radius: var(--radius-full); padding: 0.7rem 1rem 0.7rem 2.6rem; font-size: var(--text-sm); }
.search input::placeholder { color: var(--color-text-faint); }
.search input:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-soft); }
.search svg { position: absolute; left: 0.95rem; top: 50%; transform: translateY(-50%); color: var(--color-text-faint); }

.header__actions { display: flex; align-items: center; gap: var(--space-3); margin-left: auto; }
.link-quiet { font-size: var(--text-sm); font-weight: 500; color: var(--color-text-muted); }
.link-quiet:hover { color: var(--color-text); }
.theme-toggle { display: inline-flex; align-items: center; justify-content: center; width: 2.4rem; height: 2.4rem; border-radius: var(--radius-full); color: var(--color-text-muted); border: 1px solid transparent; }
.theme-toggle:hover { background: var(--color-surface-offset); color: var(--color-text); }
.burger { display: none; }

/* ============ Hero ============ */
.hero { background: linear-gradient(180deg, var(--color-surface-tint), var(--color-bg) 70%); }
.hero__inner { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: var(--space-16); align-items: center; padding-block: clamp(var(--space-16), 8vw, var(--space-24)); }

.rating { display: inline-flex; align-items: center; gap: 0.6rem; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-full); padding: 0.4rem 0.9rem 0.4rem 0.5rem; box-shadow: var(--shadow-sm); margin-bottom: var(--space-6); }
.rating__stars { display: inline-flex; gap: 2px; }
.rating__stars span { display: inline-flex; width: 1.15rem; height: 1.15rem; align-items: center; justify-content: center; background: var(--color-star); border-radius: 4px; }
.rating__stars svg { width: 0.8rem; height: 0.8rem; color: #fff; }
[data-theme="dark"] .rating__stars svg { color: #0d130f; }
.rating__text { font-size: var(--text-sm); font-weight: 500; color: var(--color-text-muted); }
.rating__text b { color: var(--color-text); font-weight: 600; }

.hero h1 { font-size: var(--text-2xl); margin-bottom: var(--space-5); }
.hero h1 em { font-style: normal; color: var(--color-primary); }
.hero__lead { font-size: var(--text-lg); color: var(--color-text-muted); max-width: 34ch; margin-bottom: var(--space-8); }
.hero__cta { display: flex; flex-wrap: wrap; gap: var(--space-3); }

.audience { display: flex; flex-direction: column; gap: var(--space-4); }
.aud-card { display: flex; align-items: center; gap: var(--space-4); background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--space-5); box-shadow: var(--shadow-sm); }
.aud-card:hover { border-color: var(--color-primary); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.aud-card__icon { flex-shrink: 0; width: 3rem; height: 3rem; border-radius: var(--radius-md); background: var(--color-primary-soft); color: var(--color-primary); display: grid; place-items: center; }
.aud-card__body { flex: 1; }
.aud-card__body h3 { font-size: var(--text-base); font-weight: 600; font-family: var(--font-body); }
.aud-card__body p { font-size: var(--text-sm); color: var(--color-text-muted); margin-top: 1px; }
.aud-card__arrow { color: var(--color-text-faint); flex-shrink: 0; transition: transform var(--transition-interactive), color var(--transition-interactive); }
.aud-card:hover .aud-card__arrow { color: var(--color-primary); transform: translateX(3px); }

/* ============ Section shell ============ */
.section { padding-block: clamp(var(--space-16), 8vw, var(--space-24)); }
.section__head { text-align: center; max-width: 56ch; margin: 0 auto var(--space-16); }
.section__head h2 { font-size: var(--text-xl); margin-bottom: var(--space-3); }
.section__head p { color: var(--color-text-muted); }
.eyebrow { display: inline-block; font-size: var(--text-xs); font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--color-primary); margin-bottom: var(--space-3); }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-6); }
.step { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: var(--space-8); box-shadow: var(--shadow-sm); display: flex; flex-direction: column; }
.step:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.step__illo { height: 150px; display: grid; place-items: center; margin-bottom: var(--space-5); }
.step__illo img { max-height: 150px; width: auto; }
.step__num { display: inline-flex; align-items: center; gap: 0.6rem; margin-bottom: var(--space-3); }
.step__num b { display: grid; place-items: center; width: 1.7rem; height: 1.7rem; background: var(--color-primary); color: #fff; border-radius: var(--radius-full); font-size: var(--text-sm); font-weight: 600; }
[data-theme="dark"] .step__num b { color: #0d130f; }
.step__num span { font-family: var(--font-display); font-weight: 600; font-size: var(--text-lg); }
.step__sub { font-size: var(--text-sm); color: var(--color-text-muted); margin-bottom: var(--space-4); }
.step p.step__desc { font-size: var(--text-sm); color: var(--color-text-muted); }
.step p.step__desc strong { color: var(--color-text); font-weight: 600; }

/* Founders */
.founders { background: var(--color-surface-2); border-block: 1px solid var(--color-divider); }
.founder-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-6); max-width: 880px; margin-inline: auto; }
.founder { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: var(--space-8); box-shadow: var(--shadow-sm); text-align: center; }
.founder:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.founder__photo { width: 7.5rem; height: 7.5rem; margin: 0 auto var(--space-5); border-radius: var(--radius-full); background: var(--color-primary-soft); border: 1px solid var(--color-primary-line); overflow: hidden; display: grid; place-items: center; }
.founder__photo img { width: 108%; height: 108%; object-fit: cover; object-position: center top; }
.founder h3 { font-size: var(--text-lg); font-family: var(--font-display); font-weight: 600; }
.founder__role { display: inline-block; font-size: var(--text-xs); font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--color-primary); margin-top: 0.4rem; margin-bottom: var(--space-2); }
.founder p.founder__bio { font-size: var(--text-sm); color: var(--color-text-muted); max-width: 36ch; margin-inline: auto; }
.founder__link { display: inline-flex; align-items: center; gap: 0.4rem; margin-top: var(--space-2); font-size: var(--text-sm); font-weight: 600; color: var(--color-primary); text-decoration: none; transition: color 0.18s ease; }
.founder__link:hover { color: var(--color-primary-hover); text-decoration: underline; }
.founder__link svg { flex-shrink: 0; }

.subjects { background: var(--color-bg); }
.subj-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-4); }
.subj { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--space-6); }
.subj:hover { border-color: var(--color-primary); transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.subj__icon { width: 2.6rem; height: 2.6rem; border-radius: var(--radius-md); background: var(--color-primary-soft); color: var(--color-primary); display: grid; place-items: center; margin-bottom: var(--space-4); }
.subj h3 { font-size: var(--text-base); font-weight: 600; font-family: var(--font-body); margin-bottom: 0.35rem; }
.subj p { font-size: var(--text-sm); color: var(--color-text-muted); }

.prog-list { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: center; margin-top: var(--space-8); }
.prog-badge { font-size: var(--text-sm); font-weight: 500; color: var(--color-text-muted); background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-full); padding: 0.5rem 1.1rem; }

.cta-band { background: var(--color-primary); color: #fff; border-radius: var(--radius-xl); padding: clamp(var(--space-10), 6vw, var(--space-20)); text-align: center; }
[data-theme="dark"] .cta-band { color: #0d130f; }
.cta-band h2 { font-size: var(--text-xl); margin-bottom: var(--space-3); color: inherit; }
.cta-band p { opacity: 0.9; max-width: 48ch; margin: 0 auto var(--space-8); }
.cta-band .btn-on-green { background: #fff; color: var(--color-primary); }
.cta-band .btn-on-green:hover { background: rgba(255,255,255,0.9); transform: translateY(-1px); }
[data-theme="dark"] .cta-band .btn-on-green { background: #0d130f; color: var(--color-primary); }
.cta-band__row { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: center; }
.btn-outline-green { background: transparent; border: 1px solid rgba(255,255,255,0.5); color: #fff; }
.btn-outline-green:hover { border-color: #fff; background: rgba(255,255,255,0.1); }
[data-theme="dark"] .btn-outline-green { border-color: rgba(13,19,15,0.4); color: #0d130f; }

/* ============ Footer ============ */
.footer { border-top: 1px solid var(--color-divider); padding-block: var(--space-12) var(--space-8); }
.footer__top { display: flex; flex-wrap: wrap; gap: var(--space-8); justify-content: space-between; align-items: flex-start; }
.footer__brand { max-width: 30ch; }
.footer__brand p { font-size: var(--text-sm); color: var(--color-text-muted); margin-top: var(--space-3); }
.footer__cols { display: flex; gap: var(--space-16); flex-wrap: wrap; }
.footer__col h4 { font-size: var(--text-xs); text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-text-faint); margin-bottom: var(--space-4); font-family: var(--font-body); font-weight: 600; }
.footer__col a { display: block; font-size: var(--text-sm); color: var(--color-text-muted); padding-block: 0.3rem; }
.footer__col a:hover { color: var(--color-primary); }
.footer__bottom { margin-top: var(--space-12); padding-top: var(--space-6); border-top: 1px solid var(--color-divider); display: flex; justify-content: space-between; flex-wrap: wrap; gap: var(--space-3); font-size: var(--text-xs); color: var(--color-text-faint); }

/* ============ Reveal ============ */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.16,1,0.3,1); }
.reveal.is-in { opacity: 1; transform: none; }

/* ============ Responsive ============ */
@media (max-width: 1080px) {
  .search { max-width: 280px; }
  .nav-pills { display: none; }
}
@media (max-width: 900px) {
  .hero__inner { grid-template-columns: 1fr; gap: var(--space-12); }
  .steps { grid-template-columns: 1fr; max-width: 480px; margin-inline: auto; }
  .subj-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 620px) {
  .founder-grid { grid-template-columns: 1fr; max-width: 420px; }
}
@media (max-width: 760px) {
  .search, .link-quiet { display: none; }
  .burger { display: inline-flex; align-items: center; justify-content: center; width: 2.4rem; height: 2.4rem; border-radius: var(--radius-full); color: var(--color-text); }
  .burger:hover { background: var(--color-surface-offset); }
  .footer__top { flex-direction: column; }
  .footer__cols { gap: var(--space-10); }
}
@media (max-width: 520px) {
  .subj-grid { grid-template-columns: 1fr; }
  .wrap { padding-inline: var(--space-4); }
}

.mobile-menu { display: none; }
.mobile-menu.is-open { display: block; border-top: 1px solid var(--color-divider); padding: var(--space-4) var(--space-6) var(--space-6); }
.mobile-menu a { display: block; padding: 0.7rem 0; font-size: var(--text-base); font-weight: 500; border-bottom: 1px solid var(--color-divider); }
.mobile-menu .btn { width: 100%; margin-top: var(--space-4); }