:root {
  color-scheme: light;
  --bg: #f3efe6;
  --bg-soft: #fbfaf6;
  --panel: rgba(255, 255, 255, 0.9);
  --line: rgba(40, 51, 67, 0.12);
  --line-strong: rgba(112, 68, 37, 0.26);
  --text: #172232;
  --muted: #5d6977;
  --accent: #b45a28;
  --accent-deep: #7f3516;
  --accent-soft: #fff1e7;
  --shadow: 0 18px 40px rgba(33, 43, 58, 0.08);
  font-family: "IBM Plex Sans", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(circle at top left, rgba(255, 206, 153, 0.5), transparent 24%),
    linear-gradient(180deg, #f6f1e8 0%, #edf2f6 100%);
  color: var(--text);
}

body {
  min-width: 320px;
}

button,
input,
select,
textarea {
  font: inherit;
}

.page-shell {
  width: min(1440px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 28px 0 40px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.8fr);
  gap: 20px;
  margin-bottom: 22px;
}

.hero-copy,
.hero-card,
.panel {
  border: 1px solid var(--line);
  border-radius: 26px;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}

.hero-copy {
  padding: 30px;
}

.hero-card {
  padding: 24px;
  align-self: stretch;
}

.eyebrow,
.card-label {
  margin: 0;
  font-size: 0.76rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
}

.hero h1,
.section-heading h2,
.lesson-header h2 {
  margin: 10px 0 0;
  letter-spacing: -0.04em;
  line-height: 0.98;
}

.hero h1 {
  font-size: clamp(2.4rem, 4vw, 4.5rem);
  max-width: 11ch;
}

.hero-text {
  max-width: 60ch;
  margin: 16px 0 0;
  color: var(--muted);
  line-height: 1.7;
}

.compact-list,
.steps {
  margin: 14px 0 0;
  padding-left: 18px;
  color: var(--muted);
  line-height: 1.6;
}

.main-grid {
  display: grid;
  grid-template-columns: minmax(300px, 360px) minmax(0, 1fr);
  gap: 20px;
}

.onboarding-panel,
.engine-panel {
  padding: 24px;
}

.onboarding-panel {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.planner-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.planner-form label {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.planner-form span {
  font-weight: 600;
}

.planner-form input,
.planner-form select,
.sandbox-input {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--bg-soft);
  color: var(--text);
}

.range-row {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  color: var(--muted);
  font-size: 0.86rem;
}

.system-status,
.warning-card,
.flow-card,
.plan-summary,
.module-card,
.lesson-meta,
.sandbox-output {
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #f8fafc;
}

.system-status {
  padding: 18px;
}

.system-status h3 {
  margin: 8px 0 0;
}

.engine-panel {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.flow-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.flow-card,
.warning-card {
  padding: 18px;
}

.flow-card h3 {
  margin: 0 0 10px;
}

.flow-card p,
.warning-card li,
.plan-summary,
.lesson-body,
.sandbox-note,
.sandbox-output {
  color: var(--muted);
  line-height: 1.65;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(260px, 320px) minmax(0, 1fr) minmax(320px, 380px);
  gap: 20px;
  grid-column: 1 / -1;
}

.module-panel,
.lesson-panel,
.sandbox-panel {
  padding: 22px;
  min-height: 620px;
}

.module-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 16px;
}

.plan-summary {
  padding: 16px;
  margin-top: 16px;
}

.module-card {
  width: 100%;
  padding: 16px;
  text-align: left;
  background: #f8fafc;
  cursor: pointer;
}

.module-card:hover,
.module-card.active {
  border-color: var(--line-strong);
  background: linear-gradient(180deg, #fff8ef 0%, #ffffff 100%);
}

.module-card .step {
  display: block;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.module-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 1rem;
}

.module-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.lesson-panel {
  display: flex;
  flex-direction: column;
}

.lesson-header {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 18px;
}

.lesson-meta {
  padding: 12px 14px;
  min-width: 160px;
  text-align: right;
  font-size: 0.9rem;
}

.lesson-body {
  flex: 1;
  padding: 22px;
  overflow: auto;
}

.lesson-body h3 {
  color: var(--text);
  margin-top: 0;
}

.lesson-body ul {
  padding-left: 18px;
}

.sandbox-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.sandbox-input {
  min-height: 220px;
  resize: vertical;
}

.sandbox-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sandbox-output {
  flex: 1;
  padding: 18px;
  white-space: pre-wrap;
}

.primary-button {
  border: 0;
  border-radius: 999px;
  padding: 14px 18px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-deep) 100%);
  color: white;
  font-weight: 700;
  cursor: pointer;
}

.primary-button:hover {
  transform: translateY(-1px);
}

@media (max-width: 1200px) {
  .main-grid,
  .workspace,
  .hero,
  .flow-grid {
    grid-template-columns: 1fr;
  }

  .lesson-meta {
    text-align: left;
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(100vw - 20px, 1440px);
    padding-top: 14px;
  }

  .hero-copy,
  .hero-card,
  .onboarding-panel,
  .engine-panel,
  .module-panel,
  .lesson-panel,
  .sandbox-panel {
    padding: 18px;
  }
}