/* StudyPlatform layout system
 * This is the ONLY owner of page geometry and width-based responsive rules.
 *
 * Surface policy:
 * - Navigation chrome may use Liquid Glass material.
 * - Study/reading surfaces are opaque and are styled in components.css.
 *
 * Breakpoints:
 *   > 920px  desktop course sidebar
 *   <=920px  drawer / tablet
 *   <=720px  single-column content
 *   <=430px  iPhone compact contract (includes iPhone 17 Pro 402px portrait)
 */

/* ---------- Shared utility bar / glass chrome ---------- */
.study-utility-bar {
  position: sticky;
  inset-block-start: 0;
  z-index: 100;
  height: var(--utility-height);
  border-bottom: 1px solid var(--glass-border-muted);
  background: var(--glass-fill);
  box-shadow: 0 1px 0 var(--glass-highlight), 0 8px 28px color-mix(in srgb, var(--text) 5%, transparent);
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
}

.study-utility-inner {
  width: 100%;
  height: 100%;
  padding-inline: max(20px, env(safe-area-inset-left)) max(20px, env(safe-area-inset-right));
  display: grid;
  grid-template-columns: minmax(180px, 1fr) auto minmax(180px, 1fr);
  grid-template-areas: "start track theme";
  align-items: center;
  gap: 20px;
}

.study-utility-inner.is-home {
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas: "start theme";
}

.study-utility-start {
  grid-area: start;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 10px;
}

.study-product {
  min-width: 0;
  color: var(--text);
  text-decoration: none;
  font-size: 16.5px;
  font-weight: 780;
  letter-spacing: -0.025em;
  white-space: nowrap;
}

.study-current-track {
  grid-area: track;
  min-width: 0;
  justify-self: center;
  padding: 7px 12px;
  border: 1px solid var(--glass-border-muted);
  border-radius: 999px;
  background: var(--glass-fill-soft);
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.3;
  white-space: nowrap;
}

.study-theme-control {
  grid-area: theme;
  min-width: 0;
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.study-theme-control select {
  width: auto;
  min-width: 112px;
  min-height: 40px;
  padding: 7px 28px 7px 10px;
  border-color: var(--glass-border-muted);
  background: var(--glass-fill-strong);
  box-shadow: inset 0 1px 0 var(--glass-highlight);
  font-size: 14px;
  backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
  -webkit-backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
}

.study-nav-toggle,
.study-nav-scrim {
  display: none;
}

/* ---------- Home ---------- */
.home-shell {
  width: 100%;
  max-width: var(--home-max);
  margin-inline: auto;
  padding: 72px max(var(--page-gutter), env(safe-area-inset-right))
    max(52px, calc(26px + env(safe-area-inset-bottom)))
    max(var(--page-gutter), env(safe-area-inset-left));
}

.home-intro {
  max-width: 760px;
  margin-bottom: 40px;
}

.provider-list {
  display: grid;
  gap: 48px;
}

.provider-section {
  min-width: 0;
}

.provider-heading {
  min-width: 0;
  margin-bottom: 18px;
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  justify-content: space-between;
  gap: 12px 20px;
}

.provider-heading > div {
  min-width: 0;
}

.track-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
}

.home-footer {
  margin-top: 38px;
}

/* ---------- Course shell ---------- */
.app-shell {
  min-width: 0;
  min-height: calc(100dvh - var(--utility-height));
  margin-inline-start: var(--sidebar-width);
  padding-inline: max(var(--page-gutter), env(safe-area-inset-left))
    max(var(--page-gutter), env(safe-area-inset-right));
  background: transparent;
}

.app-route-nav {
  position: fixed;
  inset-block: var(--utility-height) 0;
  inset-inline-start: 0;
  z-index: 70;
  width: var(--sidebar-width);
  padding: 24px 16px max(32px, calc(18px + env(safe-area-inset-bottom)));
  display: flex;
  flex-direction: column;
  gap: 22px;
  overflow-y: auto;
  overflow-x: hidden;
  border-right: 1px solid var(--glass-border-muted);
  background: var(--glass-fill-strong);
  box-shadow: inset -1px 0 0 var(--glass-highlight);
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  -webkit-overflow-scrolling: touch;
}

.app-nav-brand {
  display: none;
}

.app-nav-course {
  padding: 0 8px 18px;
  border-bottom: 1px solid var(--glass-border-muted);
}

.app-nav-course small {
  display: block;
  margin-bottom: 6px;
  color: var(--faint);
  font-size: 12.5px;
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: 0.08em;
}

.app-nav-course strong {
  display: block;
  font-size: 19px;
  line-height: 1.35;
}

.app-nav-course span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.45;
}

.app-nav-group {
  display: grid;
  gap: 4px;
}

.app-nav-group-label {
  margin: 0 10px 6px;
  color: var(--faint);
  font-size: 13px;
  font-weight: 760;
  line-height: 1.35;
}

.app-route-nav .app-nav-group > a {
  min-width: 0;
  min-height: 46px;
  padding: 10px 11px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--muted);
  text-decoration: none;
  font-size: 15.5px;
  font-weight: 620;
  line-height: 1.4;
  transition: background 140ms ease, border-color 140ms ease, color 140ms ease;
}

.app-route-nav .app-nav-group > a:hover {
  border-color: var(--glass-border-muted);
  background: var(--glass-fill-soft);
  color: var(--text);
}

.app-route-nav .app-nav-group > a[aria-current="page"] {
  border-color: color-mix(in srgb, var(--accent) 24%, var(--glass-border-muted));
  background: color-mix(in srgb, var(--accent-soft) 72%, var(--glass-fill-soft));
  color: var(--text);
  font-weight: 760;
}

.app-route-nav .app-nav-group > a > span {
  min-width: 0;
}

.app-route-nav .app-nav-group > a > small {
  min-width: 38px;
  color: var(--faint);
  font-size: 13.5px;
  line-height: 1.2;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.app-route-nav .app-nav-group > a[data-complete="true"] small::after {
  content: " ✓";
  color: var(--success);
}

.app-route-nav .app-nav-group > a[data-skipped="true"] small {
  color: var(--muted);
  font-weight: 800;
  letter-spacing: 0.04em;
}

/* Shared content frame. The outer shell owns gutters; content only owns max-width. */
.hero,
.app-shell > main,
#apm-main,
.site-footer {
  width: 100%;
  max-width: var(--dashboard-max);
  margin-inline: auto;
}

.app-shell > main,
#apm-main {
  padding-block: 38px 76px;
  display: grid;
  gap: 24px;
}

.site-footer {
  padding: 28px 0 max(44px, calc(24px + env(safe-area-inset-bottom)));
  border-top: 1px solid color-mix(in srgb, var(--line) 74%, transparent);
}

.apm-track-page #apm-main > #hero .hero {
  max-width: 100%;
}

body[data-study-view="week"] .app-shell > main,
body[data-study-view="week"] #apm-main {
  max-width: var(--lesson-max);
}

body[data-study-view="exam"] .app-shell > main,
body[data-study-view="exam"] #apm-main {
  max-width: var(--exam-max);
}

.route-header {
  min-width: 0;
  width: 100%;
  padding-bottom: 20px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  gap: 20px;
  border-bottom: 1px solid color-mix(in srgb, var(--line) 74%, transparent);
}

.route-header > a {
  padding-top: 5px;
  font-size: 14.5px;
  font-weight: 700;
  text-decoration: none;
}

.route-header > div {
  min-width: 0;
}

.route-header small {
  display: block;
  margin-bottom: 3px;
  color: var(--faint);
  font-size: 13px;
}

.route-header strong {
  display: block;
  font-size: 25px;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.resume-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 28px;
}

.resume-action {
  min-width: 150px;
}

.block-head,
.readiness-dashboard .block-head {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  gap: 24px;
}

body[data-study-view="dashboard"] .chapter-body {
  display: none;
}

body[data-study-view="week"] details.chapter {
  border: 0;
  background: transparent;
  box-shadow: none;
}

body[data-study-view="week"] details.chapter > summary {
  display: none;
}

body[data-study-view="week"] .chapter-body {
  width: 100%;
  min-width: 0;
  padding: 0;
}

body[data-study-view="week"] .focus-grid[hidden],
body[data-study-view="week"] .chapter-body > .chapter-nav[hidden] {
  display: none !important;
}

.apm-track-page[data-study-view="week"] .focus-grid {
  display: none;
}

/* STEP navigation is navigation, so it may use the lighter glass material. */
.fundamentals-track-page[data-study-view="week"] .step-focus-nav,
.apm-track-page[data-study-view="week"] .chapter-step-nav,
body[data-study-view="week"] .chapter-body > .chapter-nav {
  position: static;
  width: 100%;
  margin: 0 0 24px;
  padding: 6px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 6px;
  overflow: visible;
  border: 1px solid var(--glass-border-muted);
  border-radius: var(--radius-md);
  background: var(--glass-fill-strong);
  box-shadow: var(--glass-shadow-compact);
  backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
  -webkit-backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
}

.fundamentals-track-page[data-study-view="week"] .step-focus-nav a,
.apm-track-page[data-study-view="week"] .chapter-step-nav a,
body[data-study-view="week"] .chapter-body > .chapter-nav a {
  min-width: 0;
  min-height: 52px;
  padding: 10px 12px;
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr) auto;
  align-items: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: 8px;
  color: var(--muted);
  text-decoration: none;
  font-size: 14.5px;
  font-weight: 650;
  line-height: 1.35;
  white-space: nowrap;
}

.fundamentals-track-page[data-study-view="week"] .step-focus-nav a:hover,
.apm-track-page[data-study-view="week"] .chapter-step-nav a:hover,
body[data-study-view="week"] .chapter-body > .chapter-nav a:hover {
  border-color: var(--glass-border-muted);
  background: var(--glass-fill-soft);
  color: var(--text);
}

.fundamentals-track-page[data-study-view="week"] .step-focus-nav a[aria-current="step"],
.apm-track-page[data-study-view="week"] .chapter-step-nav a[aria-current="step"],
body[data-study-view="week"] .chapter-body > .chapter-nav a[aria-current="step"] {
  border-color: color-mix(in srgb, var(--accent) 24%, var(--glass-border-muted));
  background: color-mix(in srgb, var(--accent-soft) 76%, var(--glass-fill-soft));
  color: var(--text);
}

.fundamentals-track-page[data-study-view="week"] .step-focus-nav a > span,
.apm-track-page[data-study-view="week"] .chapter-step-nav a > span,
body[data-study-view="week"] .chapter-body > .chapter-nav a > span {
  color: var(--faint);
  font-size: 12px;
  font-weight: 800;
}

.fundamentals-track-page[data-study-view="week"] .step-focus-nav a > small {
  min-width: 38px;
  color: var(--faint);
  font-size: 12.5px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.step-focus-footer {
  width: 100%;
  margin-top: 24px;
  justify-content: space-between;
}

/* ---------- Tablet / drawer ---------- */
@media (max-width: 920px) {
  :root {
    --utility-height: 60px;
    --page-gutter: 20px;
  }

  .study-utility-inner {
    padding-inline: max(16px, env(safe-area-inset-left)) max(16px, env(safe-area-inset-right));
    gap: 12px;
  }

  .study-nav-toggle {
    width: 40px;
    height: 40px;
    padding: 0;
    display: inline-grid;
    place-items: center;
    border: 1px solid var(--glass-border-muted);
    border-radius: var(--radius-sm);
    background: var(--glass-fill-strong);
    color: var(--text);
    box-shadow: inset 0 1px 0 var(--glass-highlight);
    font-size: 18px;
    backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
    -webkit-backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
  }

  .app-shell {
    width: 100%;
    margin-inline-start: 0;
    padding-inline: max(var(--page-gutter), env(safe-area-inset-left))
      max(var(--page-gutter), env(safe-area-inset-right));
  }

  body.study-nav-open {
    overflow: hidden;
  }

  .app-route-nav {
    inset-block-start: var(--utility-height);
    width: min(320px, calc(100vw - 24px));
    width: min(320px, calc(100dvw - 24px));
    max-width: calc(100vw - 24px);
    max-width: calc(100dvw - 24px);
    border-radius: 0 var(--radius-xl) var(--radius-xl) 0;
    transform: translateX(-102%);
    transition: transform 160ms ease;
    box-shadow: var(--glass-shadow);
  }

  body.study-nav-open .app-route-nav {
    transform: none;
  }

  .study-nav-scrim {
    position: fixed;
    inset: var(--utility-height) 0 0;
    z-index: 60;
    display: block;
    visibility: hidden;
    border: 0;
    background: rgba(4, 9, 16, 0.44);
    opacity: 0;
    transition: opacity 160ms ease, visibility 160ms ease;
  }

  body.study-nav-open .study-nav-scrim {
    visibility: visible;
    opacity: 1;
  }

  .home-shell {
    padding-top: 50px;
  }

  .track-grid {
    grid-template-columns: 1fr;
  }

  .hero-main,
  .resume-panel,
  .block-head,
  .readiness-dashboard .block-head,
  .quiz-head,
  .practice-headbar,
  .resource-top {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    justify-self: stretch;
  }

  .score-pill {
    width: min(180px, 100%);
    min-width: 0;
  }

  .stage-head {
    grid-template-columns: 38px minmax(0, 1fr);
  }

  .stage-progress {
    grid-column: 2;
    width: min(180px, 100%);
    min-width: 0;
  }

  .cert-overview {
    grid-template-columns: 1fr;
  }
}

/* ---------- Phone ---------- */
@media (max-width: 720px) {
  :root {
    --page-gutter: 16px;
  }

  body {
    font-size: 16.5px;
  }

  .study-current-track {
    display: none;
  }

  .study-utility-inner,
  .study-utility-inner.is-home {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas: "start theme";
    gap: 10px;
  }

  .study-theme-control > span {
    display: none;
  }

  .study-theme-control select {
    min-width: 102px;
    font-size: 16px;
  }

  .study-product {
    overflow: hidden;
    text-overflow: ellipsis;
    font-size: 15.5px;
  }

  .home-shell {
    padding-top: 38px;
  }

  .home-intro {
    margin-bottom: 28px;
  }

  .home-intro h1 {
    font-size: 34px;
  }

  .track-card {
    min-height: 0;
    padding: 22px;
  }

  .track-card-foot {
    align-items: flex-start;
    flex-direction: column;
  }

  .track-action {
    width: 100%;
  }

  .hero {
    padding-top: 32px;
  }

  .hero-stats {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-stat {
    min-width: 0;
    width: 100%;
  }

  .resume-panel,
  .readiness-dashboard,
  body[data-study-view="dashboard"] .block,
  .cert-phase {
    padding: 20px;
  }

  details.chapter > summary {
    min-height: 0;
    padding: 18px;
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 12px;
  }

  .chapter-progress {
    grid-column: 2;
    justify-self: start;
    text-align: left;
  }

  .focus-grid {
    grid-template-columns: 1fr;
  }

  .fundamentals-track-page[data-study-view="week"] .step-focus-nav,
  .apm-track-page[data-study-view="week"] .chapter-step-nav,
  body[data-study-view="week"] .chapter-body > .chapter-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .stage-head {
    padding: 20px;
  }

  .stage-content {
    padding: 20px;
  }

  .concept {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .route-header {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .cert-course {
    grid-template-columns: 1fr;
  }

  .cert-course select {
    width: 100%;
  }

  .future-certs,
  .goal-grid {
    grid-template-columns: 1fr;
  }
}

/* ---------- iPhone compact ---------- */
@media (max-width: 430px) {
  /* 402px iPhone 17 Pro portrait sits here. No element in the shell may
     create a second utility-bar row or depend on viewport overflow clipping. */
  :root {
    --page-gutter: 14px;
  }

  .study-utility-bar,
  .app-route-nav {
    backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
    -webkit-backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
  }

  .study-utility-inner,
  .study-utility-inner.is-home {
    grid-template-columns: minmax(0, 1fr) minmax(96px, 104px);
    grid-template-areas: "start theme";
    gap: 8px;
  }

  .study-utility-start {
    gap: 8px;
  }

  .study-product {
    font-size: 15px;
  }

  .study-theme-control {
    width: 100%;
  }

  .study-theme-control select {
    width: 100%;
    min-width: 0;
    max-width: 104px;
    padding-inline: 9px 24px;
  }

  .home-shell {
    padding-top: 30px;
  }

  .home-intro h1 {
    font-size: 32px;
    line-height: 1.2;
  }

  .home-lead {
    font-size: 16px;
  }

  .track-card {
    padding: 18px;
    border-radius: var(--radius-lg);
    box-shadow: var(--glass-shadow-compact);
    backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
    -webkit-backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
  }

  .track-card-head {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .track-status {
    justify-self: start;
  }

  .track-card h2 {
    font-size: 22px;
  }

  .track-description {
    font-size: 15.5px;
  }

  .hero-stats {
    grid-template-columns: 1fr;
  }

  .hero,
  .app-shell > main,
  #apm-main,
  .site-footer {
    min-width: 0;
  }

  .resume-panel,
  .readiness-dashboard,
  body[data-study-view="dashboard"] .block,
  .cert-phase {
    padding: 18px;
  }

  .resume-panel {
    box-shadow: var(--glass-shadow-compact);
    backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
    -webkit-backdrop-filter: blur(var(--glass-blur-compact)) saturate(var(--glass-saturation));
  }

  .resume-action,
  .quiz-actions > .btn,
  .practice-actions > .btn,
  .toolbar > .btn {
    width: 100%;
  }

  details.chapter > summary {
    padding: 16px;
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .chapter-index,
  .chapter-progress {
    grid-column: 1;
    justify-self: start;
    text-align: left;
  }

  .chapter-progress {
    min-width: 0;
    display: flex;
    align-items: baseline;
    gap: 8px;
  }

  .chapter-progress span {
    margin-top: 0;
  }

  .fundamentals-track-page[data-study-view="week"] .step-focus-nav,
  .apm-track-page[data-study-view="week"] .chapter-step-nav,
  body[data-study-view="week"] .chapter-body > .chapter-nav {
    grid-template-columns: 1fr;
  }

  .fundamentals-track-page[data-study-view="week"] .step-focus-nav a,
  .apm-track-page[data-study-view="week"] .chapter-step-nav a,
  body[data-study-view="week"] .chapter-body > .chapter-nav a {
    grid-template-columns: 28px minmax(0, 1fr) auto;
    white-space: normal;
    overflow-wrap: anywhere;
  }

  .stage-head {
    padding: 16px;
    grid-template-columns: 36px minmax(0, 1fr);
    gap: 10px;
  }

  .stage-progress {
    grid-column: 1 / -1;
    width: 100%;
    min-height: 0;
    justify-items: start;
    text-align: left;
  }

  .stage-content {
    padding: 16px;
  }

  .resource {
    padding: 16px;
  }

  .resource-progress {
    width: 100%;
    min-width: 0;
  }

  .resource-progress select,
  .cert-course select,
  .cert-tool input[type="number"],
  .cert-tool select {
    width: 100%;
    max-width: none;
  }

  .gate {
    grid-template-columns: 1fr;
  }

  .gate-icon {
    display: none;
  }

  .gate-bars {
    grid-template-columns: 1fr;
  }

  .gate-bar {
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 6px 12px;
  }

  .gate-bar > span {
    flex: 1 1 220px;
  }

  .route-header strong {
    font-size: 22px;
  }

  .step-focus-footer {
    flex-direction: column;
  }

  .step-focus-footer > *,
  .step-focus-footer .btn {
    width: 100%;
  }
}