:root {
  --teal-deep: #0a4a3a;
  --teal-mid: #1a7a5e;
  --teal-bright: #2db38a;
  --teal-light: #a8ded0;
  --teal-pale: #e8f7f3;
  --white: #ffffff;
  --off-white: #f9faf8;
  --text-dark: #0f1f1a;
  --text-mid: #3d5a50;
  --text-light: #6b8a80;
  --gold: #c8a96e;
  --gold-light: #f0e6d0;
  --serif: 'Playfair Display', Georgia, serif;
  --sans: 'DM Sans', sans-serif;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--sans); color: var(--text-dark); background: var(--white); line-height: 1.6; }
a { color: var(--teal-mid); }

/* nav */
nav { position: sticky; top: 0; z-index: 100; display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1rem 4rem; background: rgba(255,255,255,0.96); border-bottom: 1px solid rgba(10,74,58,0.08); }
.nav-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.nav-logomark { width: 36px; height: 36px; border-radius: 50%; background: var(--teal-deep); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.nav-logomark svg { width: 20px; height: 20px; display: block; }
.nav-name { font-family: var(--serif); font-size: 16px; font-weight: 600; color: var(--teal-deep); line-height: 1.1; }
.nav-sub { font-size: 10px; color: var(--text-light); letter-spacing: 0.08em; text-transform: uppercase; }
.nav-right { display: flex; align-items: center; gap: 1.25rem; font-size: 13px; }
.nav-right a { color: var(--text-mid); text-decoration: none; }
.nav-right a:hover { color: var(--teal-mid); }
.lang { display: inline-flex; border: 1px solid var(--teal-light); border-radius: 4px; overflow: hidden; }
.lang a, .lang span { padding: 5px 10px; font-size: 12px; font-weight: 500; letter-spacing: 0.05em; }
.lang span { background: var(--teal-deep); color: var(--white); }

/* layout */
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 2rem; }
section { padding: 4.5rem 0; }
.eyebrow { display: flex; align-items: center; gap: 10px; margin-bottom: 1.25rem; font-size: 11px; font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--teal-mid); }
.eyebrow::before { content: ""; width: 32px; height: 2px; background: var(--gold); }
h1 { font-family: var(--serif); font-size: clamp(2.2rem, 4vw, 3.4rem); font-weight: 600; line-height: 1.12; color: var(--teal-deep); margin-bottom: 1.25rem; }
h1 em { font-style: italic; color: var(--teal-mid); }
h2 { font-family: var(--serif); font-size: clamp(1.7rem, 3vw, 2.3rem); font-weight: 600; line-height: 1.2; color: var(--teal-deep); margin-bottom: 1rem; }
h3 { font-family: var(--serif); font-size: 1.25rem; font-weight: 600; color: var(--teal-deep); }
.lead { font-size: 1.1rem; color: var(--text-mid); max-width: 680px; }
.muted { color: var(--text-light); font-size: 0.9rem; }

/* hero */
.hero { background: linear-gradient(180deg, var(--teal-pale) 0%, var(--white) 100%); padding: 5rem 0 4rem; }
.ages { display: inline-block; margin: 1.5rem 0 2rem; padding: 10px 16px; background: var(--white); border-left: 3px solid var(--gold); font-weight: 500; color: var(--teal-deep); }
.btns { display: flex; flex-wrap: wrap; gap: 12px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 22px; border-radius: 4px; font-size: 14px; font-weight: 500; text-decoration: none; border: 1px solid var(--teal-deep); transition: background 0.2s, color 0.2s; cursor: pointer; font-family: var(--sans); }
.btn-primary { background: var(--teal-deep); color: var(--white); }
.btn-primary:hover { background: var(--teal-mid); border-color: var(--teal-mid); }
.btn-ghost { background: transparent; color: var(--teal-deep); }
.btn-ghost:hover { background: var(--teal-pale); }
.btn-small { padding: 8px 14px; font-size: 13px; }

/* series */
.series-head { display: grid; grid-template-columns: 1fr auto; gap: 1.5rem; align-items: end; margin-bottom: 2rem; }
.tag { justify-self: start; display: inline-block; font-size: 11px; font-weight: 500; letter-spacing: 0.1em; text-transform: uppercase; padding: 4px 10px; border-radius: 3px; background: var(--gold-light); color: var(--teal-deep); }
.lessons { display: grid; gap: 1rem; }
.lesson { display: grid; grid-template-columns: 56px 1fr auto; gap: 1.25rem; align-items: center; padding: 1.4rem 1.5rem; border: 1px solid rgba(10,74,58,0.12); border-radius: 8px; background: var(--white); }
.lesson-num { width: 48px; height: 48px; border-radius: 50%; background: var(--teal-deep); color: var(--white); display: flex; align-items: center; justify-content: center; font-family: var(--serif); font-size: 1.3rem; font-weight: 600; }
.lesson p { color: var(--text-mid); font-size: 0.95rem; margin-top: 4px; }
.lesson .meta { font-size: 12px; color: var(--text-light); letter-spacing: 0.04em; }
.lesson-actions { display: flex; flex-direction: column; gap: 8px; align-items: stretch; min-width: 190px; }
.locked { font-size: 13px; color: var(--text-light); text-align: center; }
.locked a { font-weight: 500; }
.note { margin-top: 1.25rem; padding: 1rem 1.25rem; background: var(--off-white); border-radius: 6px; font-size: 0.92rem; color: var(--text-mid); }

/* series identity */
.series-kicker { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-bottom: 1rem; }
.series-num { font-family: var(--serif); font-size: 1rem; font-weight: 600; font-style: italic; color: var(--white); background: var(--teal-deep); padding: 6px 16px; border-radius: 20px; }
.series-sdg { font-size: 11px; font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--teal-mid); display: flex; align-items: center; gap: 10px; }
.series-sdg::before { content: ""; width: 32px; height: 2px; background: var(--gold); }
.series-facts { display: inline-flex; flex-wrap: wrap; gap: 0; margin: 0.25rem 0 1.25rem; border-top: 1px solid rgba(10,74,58,0.12); border-bottom: 1px solid rgba(10,74,58,0.12); }
.series-facts div { padding: 12px 22px 12px 0; margin-right: 22px; border-right: 1px solid rgba(10,74,58,0.12); color: var(--text-mid); font-size: 14px; }
.series-facts div:last-child { border-right: none; margin-right: 0; }
.series-facts strong { display: block; font-family: var(--serif); font-size: 1.5rem; font-weight: 600; color: var(--teal-deep); line-height: 1.1; }
.banner { display: flex; gap: 14px; align-items: flex-start; padding: 1rem 1.25rem; margin-bottom: 1.75rem; border-left: 3px solid var(--gold); background: var(--gold-light); border-radius: 0 6px 6px 0; color: var(--teal-deep); font-size: 0.95rem; }
.banner strong { display: block; font-family: var(--serif); font-size: 1.05rem; }
/* approach */
.approach { padding-top: 3.5rem; border-bottom: 1px solid rgba(10,74,58,0.08); }
.approach .note + .note { margin-top: 0.6rem; }
a.series-sdg { text-decoration: none; }
a.series-sdg:hover { color: var(--teal-deep); }
.aims { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.25rem; margin-top: 2rem; }
.aim { padding: 1.4rem; border-top: 2px solid var(--gold); background: var(--off-white); border-radius: 0 0 8px 8px; }
.aim h3 { font-size: 1.05rem; margin-bottom: 0.5rem; }
.aim p { font-size: 0.92rem; color: var(--text-mid); }

/* panels */
.panel { background: var(--off-white); border-radius: 10px; padding: 2.25rem; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; }
.list { list-style: none; display: grid; gap: 10px; margin-top: 1rem; }
.list li { padding-left: 22px; position: relative; color: var(--text-mid); }
.list li::before { content: ""; position: absolute; left: 0; top: 0.65em; width: 10px; height: 2px; background: var(--gold); }
.chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 1rem; }
.chip { padding: 8px 14px; border-radius: 20px; border: 1px dashed var(--teal-mid); color: var(--teal-deep); font-size: 14px; background: var(--white); }

/* forms */
form { display: grid; gap: 14px; margin-top: 1.25rem; }
label { display: grid; gap: 6px; font-size: 14px; font-weight: 500; color: var(--teal-deep); }
input[type=text], input[type=email], select, textarea { width: 100%; padding: 11px 12px; border: 1px solid rgba(10,74,58,0.25); border-radius: 4px; font-family: var(--sans); font-size: 15px; color: var(--text-dark); background: var(--white); }
textarea { min-height: 120px; resize: vertical; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--teal-bright); outline-offset: 1px; }
.check { display: flex; gap: 10px; align-items: flex-start; font-weight: 400; color: var(--text-mid); font-size: 14px; }
.check input { margin-top: 4px; width: 16px; height: 16px; flex-shrink: 0; }
.hidden { display: none; }
.privacy { font-size: 12px; color: var(--text-light); }

/* footer */
footer { background: var(--teal-deep); color: rgba(255,255,255,0.7); padding: 2.5rem 0; font-size: 13px; }
footer a { color: var(--white); }
.foot { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem; }
.foot-name { font-family: var(--serif); font-size: 15px; font-weight: 600; color: var(--white); }

@media (max-width: 900px) {
  nav { padding: 0.9rem 1rem; }
  .nav-sub, .nav-hide { display: none; }
  .wrap { padding: 0 1rem; }
  section { padding: 3rem 0; }
  .series-head, .grid-2 { grid-template-columns: 1fr; }
  .lesson { grid-template-columns: 44px 1fr; }
  .lesson-num { width: 40px; height: 40px; font-size: 1.1rem; }
  .lesson-actions { grid-column: 1 / -1; min-width: 0; }
  .panel { padding: 1.5rem; }
  .aims { grid-template-columns: 1fr 1fr; }
  .series-facts div { padding-right: 14px; margin-right: 14px; }
}