:root {
  --ink: #16211d;
  --muted: #5d6b65;
  --paper: #f6f1e7;
  --surface: #fffdf8;
  --line: rgba(22, 33, 29, 0.12);
  --green: #215a48;
  --green-deep: #163d31;
  --amber: #c4842d;
  --rose: #9b4f3e;
  --sea: #2b6f7a;
  --shadow: 0 20px 52px rgba(22, 33, 29, 0.1);
  --radius: 8px;
  --max: 1160px;
  --display-font: "Georgia", "Palatino Linotype", serif;
  --body-font: "Aptos", "Trebuchet MS", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: light;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 12% 10%, rgba(255, 255, 255, 0.74), transparent 26%),
    linear-gradient(145deg, #fbf7ef, #edf4ef 42%, #f5efe5);
  color: var(--ink);
  font-family: var(--body-font);
  line-height: 1.55;
}

a {
  color: var(--ink);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

button,
input,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 253, 248, 0.84);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}

.nav,
.footer-inner {
  align-items: center;
  display: flex;
  gap: 16px;
  justify-content: space-between;
  margin: 0 auto;
  max-width: var(--max);
  padding: 14px 22px;
}

.brand {
  align-items: center;
  color: var(--ink);
  display: inline-flex;
  gap: 10px;
  font-weight: 800;
  text-decoration: none;
}

.brand-mark {
  align-items: center;
  background: var(--green);
  border-radius: 6px;
  color: #fff;
  display: inline-flex;
  height: 34px;
  justify-content: center;
  width: 34px;
}

.nav-links {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.94rem;
  text-decoration: none;
}

.page-shell {
  margin: 0 auto;
  max-width: var(--max);
  padding: 26px 22px 56px;
}

.hero {
  align-items: end;
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(0, 1fr) minmax(310px, 0.52fr);
  margin: 18px 0 28px;
}

.hero-copy h1,
.section-copy h2,
.control-panel h2,
.quiz-panel h2,
.faq-item h3,
.review-panel h3 {
  font-family: var(--display-font);
  letter-spacing: 0;
}

.eyebrow {
  color: var(--rose);
  font-size: 0.8rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  margin: 0 0 10px;
  text-transform: uppercase;
}

.hero-copy h1 {
  font-size: clamp(2.5rem, 5vw, 5rem);
  line-height: 0.94;
  margin: 0 0 16px;
  max-width: 740px;
}

.lead {
  color: var(--muted);
  font-size: 1.08rem;
  margin: 0;
  max-width: 680px;
}

.hero-side {
  display: grid;
  gap: 10px;
}

.hero-band,
.control-panel,
.quiz-panel,
.section-copy,
.faq-item {
  background: rgba(255, 253, 248, 0.9);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-band {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.94), rgba(237, 244, 239, 0.9));
  border-left: 5px solid var(--green);
  padding: 12px 14px;
}

.hero-band:nth-child(2) {
  border-left-color: var(--amber);
}

.hero-band:nth-child(3) {
  border-left-color: var(--sea);
}

.hero-band strong {
  display: block;
}

.hero-band span {
  color: var(--muted);
  display: block;
  margin-top: 4px;
}

.tool-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(300px, 360px) minmax(0, 1fr);
}

.control-panel,
.quiz-panel {
  padding: 18px;
}

.panel-heading h2 {
  font-size: 1.85rem;
  margin: 0 0 6px;
}

.panel-heading p,
.feedback-panel p,
.section-copy p,
.faq-item p {
  color: var(--muted);
}

.field {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.field label {
  font-size: 0.86rem;
  font-weight: 800;
}

.field select {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  min-height: 44px;
  padding: 10px 12px;
  width: 100%;
}

.toggle-row {
  align-items: center;
  display: flex;
  gap: 10px;
  margin-top: 16px;
}

.toggle-row input {
  accent-color: var(--green);
  height: 18px;
  width: 18px;
}

.summary-panel {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 16px;
}

.summary-panel div {
  background: #f1f5f1;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px;
}

.summary-panel strong {
  display: block;
  font-size: 1.28rem;
  line-height: 1;
}

.summary-panel span {
  color: var(--muted);
  font-size: 0.8rem;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.btn {
  align-items: center;
  border: 1px solid transparent;
  border-radius: 6px;
  display: inline-flex;
  font-weight: 850;
  justify-content: center;
  min-height: 44px;
  padding: 10px 14px;
}

.btn-primary {
  background: var(--green);
  color: #fff;
}

.btn-primary:hover {
  background: var(--green-deep);
}

.btn-secondary {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
}

.review-panel {
  border-top: 1px solid var(--line);
  margin-top: 18px;
  padding-top: 16px;
}

.review-panel h3 {
  font-size: 1.1rem;
  margin: 0 0 8px;
}

.review-suggestion {
  color: var(--muted);
  font-size: 0.96rem;
  margin: 0 0 12px;
}

.plain-list {
  margin: 0;
  padding-left: 20px;
}

.plain-list li + li {
  margin-top: 8px;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.meta-pill {
  background: #eef4ef;
  border: 1px solid rgba(22, 33, 29, 0.08);
  border-radius: 999px;
  display: inline-flex;
  font-size: 0.8rem;
  font-weight: 800;
  padding: 5px 10px;
}

.quiz-panel h2 {
  font-size: clamp(1.8rem, 3vw, 2.45rem);
  line-height: 1.02;
  margin: 16px 0;
}

.answers {
  display: grid;
  gap: 10px;
}

.answer-option {
  align-items: start;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  display: flex;
  gap: 10px;
  padding: 12px 14px;
  transition: border-color 150ms ease, background 150ms ease;
}

.answer-option input {
  margin-top: 3px;
}

.answer-option.is-correct {
  background: #e6f3ea;
  border-color: #5c9b7f;
}

.answer-option.is-wrong {
  background: #f8e6e2;
  border-color: #c77968;
}

.answer-option.is-muted {
  opacity: 0.72;
}

.feedback-panel {
  background: linear-gradient(135deg, rgba(237, 244, 239, 0.96), rgba(255, 253, 248, 0.98));
  border-top: 1px solid var(--line);
  margin-top: 18px;
  padding-top: 16px;
}

.feedback-panel strong {
  display: block;
  font-size: 1rem;
  margin-bottom: 6px;
}

.review-library {
  margin-top: 36px;
}

.review-shell {
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(290px, 340px) minmax(0, 1fr);
}

.review-nav,
.review-content,
.review-box,
.memory-box {
  background: rgba(255, 253, 248, 0.9);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.review-nav,
.review-content {
  padding: 18px;
}

.review-nav h2,
.review-content h2 {
  font-family: var(--display-font);
  letter-spacing: 0;
}

.review-nav h2 {
  font-size: clamp(1.8rem, 3vw, 2.45rem);
  line-height: 1.04;
  margin: 0 0 10px;
}

.review-lead,
.review-copy,
.memory-box p {
  color: var(--muted);
}

.review-tab-list {
  display: grid;
  gap: 10px;
  margin: 16px 0;
}

.review-tab {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  min-height: 44px;
  padding: 10px 12px;
  text-align: left;
}

.review-tab.is-active {
  background: #edf4ef;
  border-color: rgba(33, 90, 72, 0.34);
  box-shadow: inset 0 0 0 1px rgba(33, 90, 72, 0.16);
}

.review-content h2 {
  font-size: clamp(1.8rem, 3vw, 2.55rem);
  line-height: 1.02;
  margin: 0 0 10px;
}

.review-columns {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr 1fr;
  margin-top: 18px;
}

.review-box,
.memory-box {
  padding: 16px;
}

.review-box h3 {
  font-size: 1.08rem;
  margin: 0 0 8px;
}

.memory-box {
  margin-top: 14px;
  background: linear-gradient(135deg, rgba(237, 244, 239, 0.96), rgba(255, 253, 248, 0.98));
}

.memory-box strong {
  display: block;
  margin-bottom: 6px;
}

.topic-directory {
  margin-top: 36px;
}

.topic-card-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 16px;
}

.topic-card {
  background: rgba(255, 253, 248, 0.92);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: grid;
  gap: 10px;
  padding: 18px;
}

.topic-card h3 {
  font-family: var(--display-font);
  font-size: 1.6rem;
  line-height: 1.04;
  margin: 0;
}

.topic-card p {
  color: var(--muted);
  margin: 0;
}

.topic-kicker {
  color: var(--rose);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.topic-page-shell {
  display: grid;
  gap: 18px;
}

.study-sheet-shell {
  display: grid;
  gap: 18px;
}

.topic-hero {
  align-items: end;
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.48fr);
}

.topic-hero-copy h1 {
  font-family: var(--display-font);
  font-size: clamp(2.3rem, 5vw, 4.6rem);
  line-height: 0.95;
  margin: 0 0 14px;
  max-width: 760px;
}

.topic-hero-copy p,
.topic-panel p,
.note-strip span {
  color: var(--muted);
}

.topic-sidebar {
  display: grid;
  gap: 10px;
}

.topic-panel,
.note-strip,
.cta-strip {
  background: rgba(255, 253, 248, 0.92);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.topic-panel {
  padding: 18px;
}

.topic-panel h2 {
  font-family: var(--display-font);
  font-size: clamp(1.7rem, 3vw, 2.2rem);
  line-height: 1.05;
  margin: 0 0 10px;
}

.topic-columns {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr 1fr;
}

.topic-panel h3 {
  font-family: var(--display-font);
  font-size: 1.2rem;
  margin: 0 0 10px;
}

.note-strip {
  border-left: 5px solid var(--green);
  padding: 12px 14px;
}

.note-strip.alt {
  border-left-color: var(--amber);
}

.note-strip.deep {
  border-left-color: var(--sea);
}

.note-strip strong {
  display: block;
}

.cta-strip {
  background: linear-gradient(135deg, rgba(237, 244, 239, 0.98), rgba(255, 253, 248, 0.98));
  padding: 16px;
}

.cta-strip h3 {
  font-family: var(--display-font);
  font-size: 1.25rem;
  margin: 0 0 8px;
}

.sheet-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.sheet-card,
.sheet-summary,
.sheet-cta {
  background: rgba(255, 253, 248, 0.92);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.sheet-card,
.sheet-summary,
.sheet-cta {
  padding: 18px;
}

.sheet-card h2,
.sheet-summary h2,
.sheet-cta h2 {
  font-family: var(--display-font);
  font-size: clamp(1.65rem, 3vw, 2.2rem);
  line-height: 1.05;
  margin: 0 0 10px;
}

.sheet-card h3 {
  font-family: var(--display-font);
  font-size: 1.18rem;
  margin: 0 0 10px;
}

.sheet-card p,
.sheet-summary p,
.sheet-cta p {
  color: var(--muted);
}

.sheet-mini-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.sheet-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 14px;
}

.sheet-box strong {
  display: block;
  margin-bottom: 8px;
}

.print-note {
  color: var(--muted);
  font-size: 0.92rem;
  margin-top: 8px;
}

.content-band {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr 1fr;
  margin-top: 36px;
}

.faq-band {
  margin-top: 36px;
}

.section-copy,
.faq-item {
  padding: 18px;
}

.section-copy h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  line-height: 1.05;
  margin: 0 0 10px;
}

.section-copy p {
  margin: 0 0 12px;
}

.faq-grid {
  display: grid;
  gap: 12px;
}

.faq-heading h2 {
  font-family: var(--display-font);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  line-height: 1.05;
  margin: 0 0 12px;
}

.faq-item h3 {
  font-size: 1.08rem;
  margin: 0 0 8px;
}

.site-footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
  margin-top: 52px;
}

.legal-page {
  display: grid;
  gap: 18px;
}

.legal-card {
  background: rgba(255, 253, 248, 0.92);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
}

.legal-card h1,
.legal-card h2 {
  font-family: var(--display-font);
  letter-spacing: 0;
}

.legal-card h1 {
  font-size: clamp(2.2rem, 5vw, 4rem);
  line-height: 0.95;
  margin: 0 0 14px;
}

.legal-card h2 {
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  line-height: 1.05;
  margin: 28px 0 10px;
}

.legal-card p,
.legal-card li {
  color: var(--muted);
}

@media (max-width: 940px) {
  .hero,
  .tool-grid,
  .review-shell,
  .review-columns,
  .topic-card-grid,
  .topic-hero,
  .topic-columns,
  .sheet-grid,
  .sheet-mini-grid,
  .content-band,
  .faq-band {
    grid-template-columns: 1fr;
  }
}

@media print {
  .site-header,
  .site-footer,
  .button-row,
  .nav-links,
  .hero-side {
    display: none !important;
  }

  body {
    background: #fff;
  }

  .page-shell {
    max-width: none;
    padding: 0;
  }

  .sheet-card,
  .sheet-summary,
  .sheet-cta,
  .topic-panel,
  .section-copy,
  .faq-item {
    box-shadow: none;
    break-inside: avoid;
  }
}

@media (max-width: 620px) {
  .nav,
  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .page-shell {
    padding-inline: 14px;
  }

  .control-panel,
  .quiz-panel,
  .section-copy,
  .faq-item {
    padding: 14px;
  }

  .summary-panel {
    grid-template-columns: 1fr;
  }
}