:root {
  --teal: #0F766E;
  --teal-soft: #CCFBF1;
  --teal-ink: #134E4A;
  --amber: #F59E0B;
  --amber-soft: #FEF3C7;
  --coral: #FB7185;
  --bg: #FFFBF5;
  --card: #FFFFFF;
  --ink: #18181B;
  --muted: #71717A;
  --line: #E4E4E7;
  --line-soft: #F4F4F5;
  --success: #16A34A;
  --warning: #D97706;
  --danger: #DC2626;
  --radius-xl: 24px;
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow: 0 12px 40px rgba(15, 118, 110, 0.08);
  --shadow-soft: 0 6px 20px rgba(24, 24, 27, 0.05);
  --shadow-warm: 0 12px 30px rgba(245, 158, 11, 0.18);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: "Inter", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

button { font-family: inherit; }

/* ============ Top Nav ============ */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 251, 245, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: 1240px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.025em;
  color: var(--ink);
}

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 11px;
  display: grid;
  place-items: center;
  color: white;
  font-weight: 900;
  background: linear-gradient(135deg, var(--teal), #0EA5A0);
  box-shadow: 0 6px 16px rgba(15, 118, 110, 0.30);
}

.nav-links {
  display: flex;
  gap: 4px;
  margin-left: auto;
  align-items: center;
}

.nav-link {
  padding: 8px 13px;
  border-radius: 10px;
  color: #3F3F46;
  font-weight: 600;
  font-size: 14px;
}

.nav-link:hover {
  background: var(--line-soft);
  text-decoration: none;
}

.nav-link.active {
  color: var(--teal);
  background: var(--teal-soft);
}

.nav-cta {
  padding: 9px 14px;
  border-radius: 10px;
  background: var(--ink);
  color: white;
  font-weight: 700;
  font-size: 14px;
  margin-left: 8px;
}

.nav-cta:hover { text-decoration: none; opacity: 0.92; }

/* ============ Layout ============ */

.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

.narrow {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============ Hero ============ */

.hero {
  padding: 56px 0 32px;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 13px;
  background: var(--teal-soft);
  color: var(--teal-ink);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 18px;
}

.hero h1 {
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1.05;
  letter-spacing: -0.04em;
  margin: 0 0 16px;
  font-weight: 850;
}

.hero h1 em {
  font-style: normal;
  background: linear-gradient(120deg, var(--teal), var(--amber));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p.lede {
  font-size: clamp(16px, 1.6vw, 19px);
  color: #3F3F46;
  max-width: 640px;
  margin: 0 auto 28px;
  line-height: 1.55;
}

/* ============ Homework Helper Card ============ */

.helper-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow);
  max-width: 760px;
  margin: 0 auto;
  text-align: left;
}

.helper-tabs {
  display: flex;
  gap: 6px;
  background: var(--line-soft);
  padding: 4px;
  border-radius: 12px;
  margin-bottom: 16px;
  width: fit-content;
}

.helper-tab {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--muted);
  cursor: pointer;
  border: 0;
  background: transparent;
}

.helper-tab.active {
  background: white;
  color: var(--ink);
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}

.helper-card label {
  font-size: 14px;
  font-weight: 700;
  color: #3F3F46;
  display: block;
  margin-bottom: 8px;
}

.helper-card textarea,
.helper-card input,
.helper-card select {
  width: 100%;
  border: 1.5px solid var(--line);
  border-radius: 14px;
  padding: 14px;
  font-family: inherit;
  font-size: 15px;
  background: var(--bg);
  resize: vertical;
  color: var(--ink);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.helper-card textarea {
  min-height: 130px;
}

.helper-card textarea:focus,
.helper-card input:focus,
.helper-card select:focus {
  outline: none;
  border-color: var(--teal);
  box-shadow: 0 0 0 4px rgba(15, 118, 110, 0.10);
}

.helper-card .row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 14px;
}

.helper-card .submit-row {
  margin-top: 18px;
  display: flex;
  gap: 10px;
  align-items: center;
}

.btn {
  border: 0;
  border-radius: 12px;
  padding: 13px 18px;
  font-weight: 750;
  font-size: 15px;
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.06s, opacity 0.15s, box-shadow 0.15s;
}

.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.55; cursor: not-allowed; }

.btn-primary {
  background: var(--teal);
  color: white;
  box-shadow: 0 6px 16px rgba(15, 118, 110, 0.25);
}

.btn-primary:hover:not(:disabled) {
  background: #0E6962;
  box-shadow: 0 8px 22px rgba(15, 118, 110, 0.32);
}

.btn-amber {
  background: var(--amber);
  color: #422006;
  box-shadow: var(--shadow-warm);
}

.btn-amber:hover:not(:disabled) { background: #E08907; }

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

.btn-ghost:hover { background: var(--line-soft); }

.helper-hint {
  font-size: 12px;
  color: var(--muted);
  margin-left: auto;
}

/* ============ Result Panel ============ */

.result {
  display: none;
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.result.show {
  display: block;
  animation: fadeUp 0.3s ease-out;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.result-section {
  margin-bottom: 22px;
}

.result-section h3 {
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--teal);
  margin: 0 0 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.result-section h3::before {
  content: "";
  width: 18px;
  height: 18px;
  border-radius: 6px;
  background: var(--teal-soft);
  display: inline-block;
}

.result-block {
  background: #FAFAF9;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px 18px;
  font-size: 15px;
  line-height: 1.65;
  color: #1C1917;
  white-space: pre-wrap;
}

.result-block.amber {
  background: var(--amber-soft);
  border-color: #FCD34D;
}

.result-block.teal {
  background: var(--teal-soft);
  border-color: #5EEAD4;
}

.result-block ol, .result-block ul {
  margin: 8px 0;
  padding-left: 22px;
}

.result-block li { margin: 6px 0; }

.result-block strong { color: var(--teal-ink); }

/* ============ Loader ============ */

.loader {
  display: none;
  margin-top: 24px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

.loader.show { display: block; }

.spinner {
  width: 26px;
  height: 26px;
  border: 3px solid var(--line);
  border-top-color: var(--teal);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  margin: 0 auto 8px;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ============ Module Grid ============ */

.section-head {
  margin: 80px 0 28px;
  text-align: center;
}

.section-head h2 {
  font-size: clamp(26px, 3.5vw, 36px);
  letter-spacing: -0.03em;
  margin: 0 0 8px;
  font-weight: 850;
}

.section-head p {
  color: var(--muted);
  margin: 0;
  font-size: 16px;
}

.modules {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px;
  padding-bottom: 60px;
}

.module {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s;
  text-decoration: none;
  color: inherit;
}

.module:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: var(--teal);
  text-decoration: none;
}

.module-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-size: 24px;
  background: var(--teal-soft);
  margin-bottom: 14px;
}

.module-icon.amber { background: var(--amber-soft); }
.module-icon.coral { background: #FFE4E6; }
.module-icon.violet { background: #EDE9FE; }

.module h3 {
  margin: 0 0 8px;
  font-size: 18px;
  letter-spacing: -0.02em;
}

.module p {
  color: var(--muted);
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.55;
  flex: 1;
}

.module-cta {
  font-weight: 700;
  font-size: 14px;
  color: var(--teal);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.module-cta::after {
  content: "→";
  transition: transform 0.15s;
}

.module:hover .module-cta::after {
  transform: translateX(3px);
}

.module .badge {
  display: inline-block;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--line-soft);
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 12px;
  width: fit-content;
}

.module .badge.parent { background: var(--amber-soft); color: #92400E; }
.module .badge.teacher { background: var(--teal-soft); color: var(--teal-ink); }
.module .badge.school { background: #EDE9FE; color: #5B21B6; }
.module .badge.adult { background: #FFE4E6; color: #9F1239; }

/* ============ Footer ============ */

.footer {
  border-top: 1px solid var(--line);
  padding: 32px 24px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  background: var(--card);
}

.footer .brand { justify-content: center; margin-bottom: 8px; }

/* ============ Toast / Alert ============ */

.alert {
  padding: 12px 14px;
  border-radius: 12px;
  font-size: 14px;
  margin-top: 12px;
  display: none;
}

.alert.show { display: block; }
.alert.error { background: #FEF2F2; border: 1px solid #FECACA; color: #991B1B; }
.alert.info { background: var(--teal-soft); border: 1px solid #5EEAD4; color: var(--teal-ink); }

/* ============ Generic Page ============ */

.page-head {
  padding: 40px 0 24px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}

.page-head h1 {
  font-size: clamp(28px, 4vw, 40px);
  letter-spacing: -0.035em;
  margin: 0 0 8px;
  font-weight: 850;
}

.page-head p {
  color: var(--muted);
  margin: 0;
  font-size: 16px;
  max-width: 640px;
}

.coming-soon {
  background: var(--card);
  border: 1px dashed var(--line);
  border-radius: var(--radius-xl);
  padding: 48px 32px;
  text-align: center;
  color: var(--muted);
  margin: 24px 0 60px;
}

.coming-soon h2 {
  color: var(--ink);
  margin: 0 0 8px;
  font-size: 22px;
}

/* ============ Prose / Legal pages ============ */

.prose {
  max-width: 720px;
  margin: 0 auto 80px;
  padding: 0 24px;
  line-height: 1.7;
  color: #27272A;
  font-size: 16px;
}

.prose h2 {
  font-size: 22px;
  letter-spacing: -0.02em;
  margin: 36px 0 10px;
  font-weight: 800;
  color: var(--ink);
}

.prose h3 {
  font-size: 17px;
  letter-spacing: -0.015em;
  margin: 22px 0 6px;
  font-weight: 800;
  color: var(--ink);
}

.prose p, .prose ul, .prose ol { margin: 0 0 14px; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin: 4px 0; }
.prose strong { color: var(--ink); }
.prose code { background: var(--line-soft); padding: 1px 6px; border-radius: 6px; font-size: 0.95em; }
.prose .updated { color: var(--muted); font-size: 13px; font-weight: 700; }

.prose .callout {
  background: var(--amber-soft);
  border-left: 3px solid var(--amber);
  padding: 14px 16px;
  border-radius: 0 12px 12px 0;
  margin: 18px 0;
  font-size: 15px;
}

.prose .callout strong { color: #92400E; }

/* ============ Responsive ============ */

@media (max-width: 720px) {
  .hero { padding: 32px 0 20px; }
  .nav-inner { padding: 12px 16px; gap: 12px; }
  .nav-links { gap: 0; }
  .nav-link { display: none; }
  .nav-link.always-show { display: inline-block; }
  .helper-card { padding: 20px; }
  .helper-card .row { grid-template-columns: 1fr; }
  .container { padding: 0 16px; }
}