:root {
  --background: #f3f5f9;
  --surface: #ffffff;
  --text: #07172f;
  --muted: #647188;
  --border: #d8dee9;
  --accent: #365cff;
  --brand-dark: #07172f;
  --font-sans: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-width: 320px;
  background: var(--background);
  color: var(--text);
  font-family: var(--font-sans);
  font-weight: 300;
  line-height: 1.5;
}

a { color: inherit; }

button,
.button {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 10px 16px;
  border: 1px solid var(--accent);
  border-radius: 9999px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 500;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: background 280ms cubic-bezier(.22,.8,.22,1), color 280ms cubic-bezier(.22,.8,.22,1);
}

button:hover,
.button:hover { background: #294be0; }

.button--secondary {
  border-color: var(--border);
  background: var(--surface);
  color: var(--text);
}

.button--secondary:hover { background: var(--background); }

.container {
  width: min(100% - 32px, 1600px);
  margin-inline: auto;
}

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 16px;
}

.site-brand {
  color: var(--text);
  font-size: 18px;
  font-weight: 500;
  letter-spacing: -0.03em;
  text-decoration: none;
}

.start-screen {
  display: grid;
  min-height: calc(100vh - 65px);
  place-items: center;
  padding-block: 48px;
}

.start-screen__content {
  max-width: 720px;
  padding: clamp(32px, 6vw, 80px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.start-screen__eyebrow {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 500;
}

h1 {
  margin: 0;
  font-size: clamp(44px, 8vw, 96px);
  font-weight: 400;
  letter-spacing: -0.04em;
  line-height: .95;
}

.start-screen__lead {
  max-width: 42ch;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 24px);
}

.start-screen__benefits {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 40px 0;
  background: var(--border);
  border: 1px solid var(--border);
}

.start-screen__benefits p {
  margin: 0;
  padding: 16px;
  background: var(--surface);
  color: var(--text);
  font-size: 14px;
}

.start-screen__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.cabinet-page { padding: clamp(40px, 7vw, 96px) 0; }

.cabinet-page__content { display: grid; gap: clamp(40px, 6vw, 72px); }

.page-intro { max-width: 760px; }
.page-intro h1 { font-size: clamp(42px, 7vw, 80px); }
.page-intro > p:not(.page-intro__eyebrow):not(.status) { color: var(--muted); font-size: 20px; }
.page-intro__eyebrow,
.course-card__meta { margin: 0 0 12px; color: var(--accent); font-size: 14px; font-weight: 500; }

.section-heading { border-bottom: 1px solid var(--border); }
.section-heading h2,
.lesson-material h2 { margin: 0; font-size: clamp(24px, 3vw, 36px); font-weight: 400; letter-spacing: -.03em; }

.course-grid,
.program-list { display: grid; gap: 1px; margin-top: 24px; background: var(--border); border: 1px solid var(--border); }
.course-grid { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.course-card,
.program-module { padding: 24px; background: var(--surface); }
.course-card h3,
.program-module h3 { margin: 0; font-size: 22px; font-weight: 400; letter-spacing: -.02em; }
.course-card h3 a { text-decoration: none; }
.course-card > p:not(.course-card__meta),
.program-module li { color: var(--muted); }
.course-card form { margin-top: 20px; }
.status { margin: 20px 0 0; color: var(--accent); font-weight: 500; }
.empty-state { margin: 0; padding: 24px; background: var(--surface); color: var(--muted); }
.program-module ol { margin: 20px 0 0; padding-left: 22px; }
.program-module li + li { margin-top: 10px; }
.program-module a { color: var(--accent); }
.tag { display: inline-flex; padding: 3px 8px; border: 1px solid var(--border); border-radius: 9999px; color: var(--muted); font-size: 12px; font-weight: 500; vertical-align: middle; }

.lesson-page { max-width: 960px; }
.back-link { color: var(--accent); }
.lesson-material { padding: 24px 0; border-top: 1px solid var(--border); }
.lesson-material p { max-width: 680px; color: var(--muted); }
.lesson-video { display: block; width: 100%; margin-top: 20px; background: #111; aspect-ratio: 16 / 9; }
.workbook { display: grid; gap: 1px; margin-top: 20px; border: 1px solid var(--border); background: var(--border); }
.workbook__lead,
.workbook__section { margin: 0; padding: clamp(20px, 4vw, 32px); background: var(--surface); }
.workbook__lead { color: var(--text) !important; font-size: 18px; line-height: 1.5; }
.workbook__section { display: grid; gap: 12px; }
.workbook__section h3 { margin: 0; font-size: 22px; font-weight: 400; letter-spacing: -.02em; }
.workbook__section p { margin: 0; }
.workbook__number { color: var(--accent) !important; font-size: 13px; font-weight: 500; text-transform: uppercase; letter-spacing: .08em; }
.workbook__hint { padding-left: 14px; border-left: 2px solid var(--accent); font-size: 14px; }
.workbook__answers { display: grid; gap: 18px; margin-top: 12px; }
.workbook__answers span { display: block; min-height: 22px; border-bottom: 1px solid var(--border); }
.workbook__checklist { display: grid; gap: 12px; margin: 0; padding: 0; list-style: none; color: var(--muted); }
.workbook__checklist li { display: flex; gap: 10px; align-items: flex-start; }
.workbook__checklist span { flex: 0 0 16px; height: 16px; margin-top: 2px; border: 1px solid var(--accent); }
.transcript { max-width: 760px; margin-top: 20px; }
.transcript summary { cursor: pointer; color: var(--accent); font-weight: 500; }
.transcript p { margin: 16px 0 0; white-space: pre-wrap; }

.admin-page { padding: clamp(40px, 7vw, 96px) 0; }
.admin-page__content { display: grid; gap: 32px; }
.admin-page__narrow { max-width: 880px; }
.admin-nav, .admin-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.admin-section { display: grid; gap: 24px; }
.admin-stack { display: grid; gap: 1px; background: var(--border); border: 1px solid var(--border); }
.admin-module { display: grid; gap: 20px; }
.admin-form { display: grid; gap: 16px; max-width: 720px; padding: 24px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); }
.admin-form--compact { max-width: 100%; margin-top: 20px; padding: 20px; }
.admin-form h3, .admin-form h4 { margin: 0; font-weight: 400; }
.admin-form label { display: grid; gap: 7px; font-weight: 500; }
.admin-form input, .admin-form textarea, .admin-form select { width: 100%; padding: 10px 12px; border: 1px solid var(--border); border-radius: 2px; background: var(--surface); color: var(--text); font: inherit; font-weight: 300; }
.admin-form .checkbox-label { display: flex; align-items: center; gap: 8px; font-weight: 400; }
.admin-form .checkbox-label input { width: auto; }
.form-message { margin: 0; padding: 14px 16px; border: 1px solid var(--border); background: var(--surface); }
.form-message--error { color: #b42318; }
.form-message--notice { color: var(--accent); font-weight: 500; }
.student-card { display: grid; gap: 16px; padding: 24px; background: var(--surface); }
.student-card h3, .student-card p { margin: 0; }
.student-card p { color: var(--muted); }
.student-course { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding-top: 12px; border-top: 1px solid var(--border); }
.student-course span { flex: 1 1 220px; }
.student-course .button, .student-card > form .button { min-height: 34px; padding: 8px 12px; }

@media (max-width: 767px) {
  .container { width: min(100% - 24px, 1600px); }
  .start-screen { padding-block: 24px; }
  .start-screen__content { padding: 32px 24px; }
  .start-screen__benefits { grid-template-columns: 1fr; margin: 28px 0; }
  .course-grid { grid-template-columns: 1fr; }
  .course-card,
  .program-module { padding: 20px; }
  .admin-form, .student-card { padding: 20px; }
}