/* All sizes use --u: 1u = 1 pixel of the 720px-wide design, scaled to the screen width. */
:root {
  --w: min(100vw, 1023px);
  --u: calc(var(--w) / 720);

  --cream: #fbf3de;
  --paper: #f9edd3;
  --navy: #03385a;
  --teal: #0b8a7e;
  --teal-deep: #046a5d;
  --teal-line: #0f7871;
  --font-display: "Poppins", "Nunito", system-ui, sans-serif;
  --font-body: "Nunito", system-ui, -apple-system, "Segoe UI", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--navy);
  font-family: var(--font-body);
  -webkit-tap-highlight-color: transparent;
}
img { display: block; max-width: none; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 3px solid #1f6fd1; outline-offset: 2px; border-radius: 10px; }

/* ---------- Phone-width shell ---------- */
.app {
  position: relative;
  width: 100%;
  margin: 0 auto;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  background: var(--paper);
  padding-top: env(safe-area-inset-top, 0px);
}

/* ---------- Header ---------- */
.topbar {
  position: relative;
  z-index: 20;
  flex: none;
  height: calc(var(--u) * 126);
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 calc(var(--u) * 28) 0 calc(var(--u) * 37);
  background: var(--cream);
}
.brand { display: flex; align-items: center; gap: calc(var(--u) * 15); min-width: 0; }
.brand img { width: calc(var(--u) * 98); height: calc(var(--u) * 98); min-width: 40px; min-height: 40px; }
.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 45);
  white-space: nowrap;
  color: var(--navy);
}
.actions { display: flex; align-items: center; }
.icon-btn {
  width: calc(var(--u) * 90); height: 44px; min-width: 40px;
  display: grid; place-items: center;
  padding: 0; border: 0; border-radius: 12px; background: transparent; cursor: pointer;
}
.icon-btn:active { background: rgba(11, 138, 126, .12); }
.icon-btn svg {
  width: calc(var(--u) * 56); height: calc(var(--u) * 56); min-width: 24px; min-height: 24px;
  fill: none; stroke: var(--teal); stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round;
}

.search { flex: 1; min-width: 0; margin: 0 6px 0 10px; }
.search[hidden] { display: none; }
.search input {
  width: 100%; height: 42px; padding: 0 14px;
  border: 2px solid var(--teal); border-radius: 12px;
  background: #fff; color: var(--navy);
  font: 700 15px var(--font-body);
}
.topbar.searching .brand-name { display: none; }

.menu {
  position: absolute; z-index: 15; left: 0; right: 0;
  top: 100%;
  display: flex; flex-direction: column;
  padding: 6px 18px 14px;
  background: var(--cream);
  box-shadow: 0 14px 24px -12px rgba(3, 56, 90, .35);
  transform-origin: top;
  animation: drop .22s ease-out;
}
.menu[hidden] { display: none; }
.menu a { padding: 14px 4px; font: 800 17px var(--font-body); border-bottom: 1px solid rgba(3, 56, 90, .1); }
.menu a:last-child { border-bottom: 0; }
@keyframes drop { from { opacity: 0; transform: scaleY(.92); } to { opacity: 1; transform: none; } }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: calc(var(--u) * 1154);
  padding-top: calc(var(--u) * 39);
  background:
    url("../images/bg-top.png") top center / 100% auto no-repeat,
    url("../images/bg-bottom.png") bottom center / 100% auto no-repeat,
    radial-gradient(120% 70% at 50% 28%, #fbf3de 0%, #f9edd3 60%, #f6e8c9 100%);
  isolation: isolate;
}

.hero-logo {
  width: calc(var(--u) * 310);
  height: calc(var(--u) * 310);
  animation: pop .6s cubic-bezier(.2, .9, .3, 1.2) both;
}
@keyframes pop { from { opacity: 0; transform: scale(.9); } to { opacity: 1; transform: none; } }

/* headline */
.headline {
  position: relative;
  isolation: isolate;
  width: 100%;
  margin: calc(var(--u) * 40) 0 0;
  text-align: center;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: calc(var(--u) * 62);
  line-height: calc(var(--u) * 76);
  letter-spacing: -.01em;
  color: var(--navy);
}
.headline .line { display: block; }

.usmle {
  display: inline-block;
  filter: drop-shadow(.05em 0 0 var(--navy)) drop-shadow(-.05em 0 0 var(--navy)) drop-shadow(0 .05em 0 var(--navy)) drop-shadow(0 -.05em 0 var(--navy));
}
.usmle i {
  font-size: 1.1em;
  font-style: normal;
  letter-spacing: .02em;
  -webkit-text-stroke: .15em #fff;
  paint-order: stroke fill;
}
.usmle i:nth-child(1) { color: #1f6fd1; }
.usmle i:nth-child(2) { color: #e5322d; }
.usmle i:nth-child(3) { color: #f4a90a; }
.usmle i:nth-child(4) { color: #1ea05a; }
.usmle i:nth-child(5) { color: #7b3fb3; }

.spark { position: absolute; width: calc(var(--u) * 100); height: calc(var(--u) * 100); fill: none; stroke-width: 4.5; stroke-linecap: round; }
.headline .spark-l { left: calc(var(--u) * 26); top: calc(var(--u) * -34); }
.headline .spark-r { right: calc(var(--u) * 26); top: calc(var(--u) * -34); }

/* tagline on the brush image */
.tagline {
  position: relative;
  margin: calc(var(--u) * 20) 0 0;
  width: calc(var(--u) * 558);
  aspect-ratio: 558 / 143;
  display: grid; place-items: center;
  background: url("../images/brush-banner.png") center / 100% 100% no-repeat;
}
.tagline span {
  display: block;
  white-space: nowrap;
  text-align: center;
  transform: rotate(-2deg);
  font: italic 700 calc(var(--u) * 32)/1.4 var(--font-body);
  color: #fff;
}

/* buttons */
.cta {
  width: calc(var(--u) * 424);
  margin-top: calc(var(--u) * 20);
  display: flex; flex-direction: column; gap: calc(var(--u) * 25);
}
.btn {
  display: flex; align-items: center; gap: calc(var(--u) * 14);
  height: calc(var(--u) * 87); min-height: 44px;
  padding: 0 calc(var(--u) * 24);
  border-radius: calc(var(--u) * 22);
  border: calc(var(--u) * 4) solid var(--teal-line);
  font: 800 calc(var(--u) * 27)/1 var(--font-body);
  box-shadow: 0 3px 8px rgba(3, 56, 90, .16);
  transition: transform .15s;
}
.btn span { flex: 1; min-width: 0; text-align: center; white-space: nowrap; }
.btn svg { flex: none; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.btn .ico { width: calc(var(--u) * 50); height: calc(var(--u) * 50); stroke-width: 1.7; }
.btn .arrow { width: calc(var(--u) * 32); height: calc(var(--u) * 32); stroke-width: 2.3; }
.btn:active { transform: scale(.97); }
.btn-light { background: #fffdf6; color: var(--teal-deep); }
.btn-light svg { stroke: var(--teal); }
.btn-solid { background: var(--teal); border-color: var(--teal); color: #fff; }
.btn-solid svg { stroke: #fff; }

/* bottom illustrations (same spots as the design) */
.books { position: absolute; left: calc(var(--u) * 2); bottom: calc(var(--u) * 2); width: calc(var(--u) * 229); height: auto; }
.steth { position: absolute; right: calc(var(--u) * 21); bottom: calc(var(--u) * 12); width: calc(var(--u) * 188); height: auto; }
.spark-steth { right: calc(var(--u) * 165); bottom: calc(var(--u) * 140); width: calc(var(--u) * 70); height: calc(var(--u) * 70); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ---------- Tablet (640px and up) ---------- */
@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- Content Sections ---------- */
.section {
  padding: calc(var(--u) * 64) calc(var(--u) * 28);
  background: var(--paper);
}
.section:nth-child(even) {
  background: var(--cream);
}

.section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: calc(var(--u) * 52);
  color: var(--navy);
  text-align: center;
  margin: 0 0 calc(var(--u) * 48);
}

/* Grid for cards */
.grid {
  display: grid;
  gap: calc(var(--u) * 24);
  align-items: stretch;
  align-content: start;
}

/* Tracks/Systems Grid - Mobile first: 1 column */
.grid-2 {
  grid-template-columns: 1fr;
}
.grid-3 {
  grid-template-columns: 1fr;
}

/* Tablet: 2 columns */
@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* Card styles */
.card {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  padding: calc(var(--u) * 32);
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
  transition: transform .2s, box-shadow .2s;
  border: 2px solid transparent;
  display: flex;
  flex-direction: column;
  height: 100%;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(3, 56, 90, .15);
  border-color: var(--teal);
}

.card-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 32);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 12);
}

.card-meta {
  font-size: calc(var(--u) * 26);
  color: var(--teal);
  margin: 0 0 calc(var(--u) * 16);
  font-weight: 600;
}

.card-desc {
  font-size: calc(var(--u) * 24);
  color: rgba(3, 56, 90, .7);
  line-height: 1.5;
  margin: 0;
}

/* Video Card */
.video-card {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
  transition: transform .2s, box-shadow .2s;
  display: flex;
  flex-direction: column;
  height: 100%;
}
.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(3, 56, 90, .15);
}

.video-thumb {
  aspect-ratio: 16 / 9;
  background: #e5e5e5;
  position: relative;
  overflow: hidden;
}
.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-duration {
  position: absolute;
  bottom: calc(var(--u) * 8);
  right: calc(var(--u) * 8);
  background: rgba(3, 56, 90, .85);
  color: #fff;
  font-size: calc(var(--u) * 22);
  font-weight: 600;
  padding: calc(var(--u) * 6) calc(var(--u) * 12);
  border-radius: calc(var(--u) * 8);
}

.video-content {
  padding: calc(var(--u) * 24);
}

.video-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 28);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 12);
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-instructor {
  font-size: calc(var(--u) * 24);
  color: var(--teal);
  margin: 0 0 calc(var(--u) * 12);
  font-weight: 600;
}

.video-tags {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--u) * 8);
}

.video-tag {
  font-size: calc(var(--u) * 20);
  background: rgba(11, 138, 126, .1);
  color: var(--teal-deep);
  padding: calc(var(--u) * 6) calc(var(--u) * 12);
  border-radius: calc(var(--u) * 8);
  font-weight: 600;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--navy);
  color: var(--cream);
  padding: calc(var(--u) * 64) calc(var(--u) * 28) calc(var(--u) * 40);
}
.footer-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: calc(var(--u) * 40);
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: calc(var(--u) * 12);
  margin-bottom: calc(var(--u) * 16);
}
.footer-brand img {
  width: calc(var(--u) * 64);
  height: calc(var(--u) * 64);
}
.footer-brand span {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 40);
}
.footer-desc {
  font-size: calc(var(--u) * 24);
  line-height: 1.6;
  color: rgba(251, 243, 222, .8);
}
.footer h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 36);
  margin: 0 0 calc(var(--u) * 24);
}
.footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer li {
  margin-bottom: calc(var(--u) * 16);
}
.footer a {
  color: var(--cream);
  font-size: calc(var(--u) * 24);
  transition: color .2s;
}
.footer a:hover {
  color: var(--teal);
}
.footer-bottom {
  border-top: 1px solid rgba(11, 138, 126, .5);
  margin-top: calc(var(--u) * 48);
  padding-top: calc(var(--u) * 32);
  text-align: center;
  font-size: calc(var(--u) * 22);
  color: rgba(251, 243, 222, .8);
}
.footer-bottom a {
  margin: 0 calc(var(--u) * 12);
}

/* ---------- Tablet Footer ---------- */
@media (min-width: 640px) {
  .footer-content {
    grid-template-columns: 1fr 1fr;
  }
}

/* ---------- Page Header ---------- */
.page-header {
  background: var(--navy);
  color: var(--cream);
  padding: calc(var(--u) * 80) calc(var(--u) * 28);
  text-align: center;
}
.page-header h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: calc(var(--u) * 56);
  margin: 0 0 calc(var(--u) * 16);
}
.page-header p {
  font-size: calc(var(--u) * 28);
  color: rgba(251, 243, 222, .9);
  margin: 0;
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  background: rgba(3, 56, 90, .05);
  border-bottom: 1px solid rgba(3, 56, 90, .1);
  padding: calc(var(--u) * 24) calc(var(--u) * 28);
}
.breadcrumb nav {
  display: flex;
  align-items: center;
  gap: calc(var(--u) * 12);
  font-size: calc(var(--u) * 24);
}
.breadcrumb a {
  color: var(--teal);
  transition: color .2s;
}
.breadcrumb a:hover {
  color: var(--teal-deep);
}
.breadcrumb span {
  color: rgba(3, 56, 90, .4);
}
.breadcrumb .current {
  color: var(--navy);
  font-weight: 600;
}

/* ---------- Sidebar ---------- */
.sidebar {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  padding: calc(var(--u) * 32);
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
}
.sidebar h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 36);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 24);
}
.sidebar ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.sidebar li {
  margin-bottom: calc(var(--u) * 8);
}
.sidebar a {
  display: block;
  padding: calc(var(--u) * 12) calc(var(--u) * 16);
  border-radius: calc(var(--u) * 12);
  color: var(--navy);
  font-size: calc(var(--u) * 26);
  transition: background .2s, color .2s;
}
.sidebar a:hover {
  background: var(--cream);
  color: var(--teal);
}

/* ---------- Section Content ---------- */
.content {
  padding: calc(var(--u) * 64) calc(var(--u) * 28);
}
.content h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 44);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 40);
}

/* ---------- Content with Sidebar ---------- */
.content-with-sidebar {
  display: grid;
  grid-template-columns: 1fr;
  gap: calc(var(--u) * 32);
}
@media (min-width: 1024px) {
  .content-with-sidebar {
    grid-template-columns: 2fr 1fr;
  }
}

/* ---------- Track Tags ---------- */
.track-tags {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--u) * 12);
  margin-top: calc(var(--u) * 24);
}
.track-tag {
  background: var(--teal);
  color: #fff;
  padding: calc(var(--u) * 12) calc(var(--u) * 24);
  border-radius: 999px;
  font-size: calc(var(--u) * 24);
  font-weight: 600;
}

/* ---------- Instructor Avatar ---------- */
.instructor-avatar {
  width: calc(var(--u) * 96);
  height: calc(var(--u) * 96);
  background: var(--teal);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 48);
}

/* ---------- Empty State ---------- */
.empty-state {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  padding: calc(var(--u) * 64);
  text-align: center;
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
}
.empty-state svg {
  width: calc(var(--u) * 96);
  height: calc(var(--u) * 96);
  margin: 0 auto calc(var(--u) * 24);
  color: rgba(3, 56, 90, .3);
}
.empty-state h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 36);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 12);
}
.empty-state p {
  font-size: calc(var(--u) * 26);
  color: rgba(3, 56, 90, .6);
  margin: 0 0 calc(var(--u) * 8);
}
.empty-state a {
  color: var(--teal);
  font-weight: 600;
}

/* ---------- Instructor Card (for search) ---------- */
.instructor-card {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  padding: calc(var(--u) * 32);
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
  transition: transform .2s, box-shadow .2s;
}
.instructor-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(3, 56, 90, .15);
}
.instructor-card-header {
  display: flex;
  align-items: center;
  gap: calc(var(--u) * 24);
  margin-bottom: calc(var(--u) * 24);
}
.instructor-card h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 32);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 8);
}
.instructor-card .meta {
  font-size: calc(var(--u) * 24);
  color: var(--teal);
  font-weight: 600;
}
.instructor-card .bio {
  font-size: calc(var(--u) * 24);
  color: rgba(3, 56, 90, .7);
  line-height: 1.5;
}

/* ---------- Term Card (for search) ---------- */
.term-card {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  padding: calc(var(--u) * 24);
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
  transition: transform .2s, box-shadow .2s;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.term-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(3, 56, 90, .15);
}
.term-card h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 28);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 8);
}
.term-card .type {
  font-size: calc(var(--u) * 22);
  color: rgba(3, 56, 90, .5);
  text-transform: capitalize;
}
.term-card .count {
  font-size: calc(var(--u) * 20);
  background: rgba(11, 138, 126, .1);
  color: var(--teal-deep);
  padding: calc(var(--u) * 8) calc(var(--u) * 16);
  border-radius: calc(var(--u) * 12);
  font-weight: 600;
}

/* ---------- Video Player ---------- */
.video-player {
  background: #000;
  border-radius: calc(var(--u) * 20);
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(3, 56, 90, .2);
  margin-bottom: calc(var(--u) * 32);
}
.video-player iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
}

/* ---------- Video Info Card ---------- */
.video-info {
  background: #fff;
  border-radius: calc(var(--u) * 20);
  padding: calc(var(--u) * 32);
  box-shadow: 0 4px 12px rgba(3, 56, 90, .08);
  margin-bottom: calc(var(--u) * 32);
}
.video-info h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 40);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 24);
  line-height: 1.3;
}
.video-meta {
  display: flex;
  align-items: center;
  gap: calc(var(--u) * 24);
  margin-bottom: calc(var(--u) * 24);
  flex-wrap: wrap;
}
.video-meta .instructor-link {
  display: flex;
  align-items: center;
  gap: calc(var(--u) * 12);
  color: var(--navy);
  transition: color .2s;
}
.video-meta .instructor-link:hover {
  color: var(--teal);
}
.video-meta .instructor-avatar {
  width: calc(var(--u) * 80);
  height: calc(var(--u) * 80);
  font-size: calc(var(--u) * 40);
}
.video-meta .duration {
  color: rgba(3, 56, 90, .6);
  font-size: calc(var(--u) * 26);
}
.video-tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--u) * 12);
  margin-bottom: calc(var(--u) * 24);
}
.video-tags-list a {
  background: rgba(11, 138, 126, .1);
  color: var(--teal-deep);
  padding: calc(var(--u) * 10) calc(var(--u) * 20);
  border-radius: 999px;
  font-size: calc(var(--u) * 22);
  font-weight: 600;
  transition: background .2s;
}
.video-tags-list a:hover {
  background: rgba(11, 138, 126, .2);
}
.video-description {
  font-size: calc(var(--u) * 26);
  color: rgba(3, 56, 90, .7);
  line-height: 1.6;
}

/* ---------- Related Video Item ---------- */
.related-item {
  display: flex;
  gap: calc(var(--u) * 24);
  margin-bottom: calc(var(--u) * 24);
}
.related-item:last-child {
  margin-bottom: 0;
}
.related-thumb {
  width: calc(var(--u) * 256);
  flex-shrink: 0;
  aspect-ratio: 16 / 9;
  background: #e5e5e5;
  border-radius: calc(var(--u) * 12);
  overflow: hidden;
  position: relative;
}
.related-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.related-thumb .duration {
  position: absolute;
  bottom: calc(var(--u) * 8);
  right: calc(var(--u) * 8);
  background: rgba(3, 56, 90, .85);
  color: #fff;
  font-size: calc(var(--u) * 20);
  font-weight: 600;
  padding: calc(var(--u) * 4) calc(var(--u) * 10);
  border-radius: calc(var(--u) * 6);
}
.related-content {
  flex: 1;
}
.related-content h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: calc(var(--u) * 26);
  color: var(--navy);
  margin: 0 0 calc(var(--u) * 8);
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.related-content p {
  font-size: calc(var(--u) * 22);
  color: rgba(3, 56, 90, .6);
  margin: 0;
}

/* ---------- Instructor Header ---------- */
.instructor-header {
  background: var(--navy);
  color: var(--cream);
  padding: calc(var(--u) * 80) calc(var(--u) * 28);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: calc(var(--u) * 32);
}
.instructor-header .avatar {
  width: calc(var(--u) * 192);
  height: calc(var(--u) * 192);
  background: var(--teal);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: calc(var(--u) * 96);
}
.instructor-header h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: calc(var(--u) * 56);
  margin: 0;
  text-align: center;
}
.instructor-header .meta {
  font-size: calc(var(--u) * 28);
  color: rgba(251, 243, 222, .9);
}

/* ---------- Social Link ---------- */
.social-link {
  display: flex;
  align-items: center;
  gap: calc(var(--u) * 16);
  padding: calc(var(--u) * 12) calc(var(--u) * 20);
  border-radius: calc(var(--u) * 12);
  color: var(--navy);
  font-size: calc(var(--u) * 26);
  transition: background .2s, color .2s;
}
.social-link:hover {
  background: var(--cream);
  color: var(--teal);
}
.social-link .icon {
  font-size: calc(var(--u) * 32);
}
.social-link .verified {
  color: var(--teal);
  font-weight: 700;
}

/* ================= Desktop (1024px and up) ================= */
@media (min-width: 1024px) {
  :root {
    --bw: clamp(300px, 27vw, 470px);      /* width of one bottom brush piece */
    --tw: clamp(170px, 16vw, 290px);      /* width of the top-left brush piece */
    --pad: max(clamp(24px, 6vw, 110px), calc((100vw - 1240px) / 2));
  }

  /* header: logo, inline links, search field */
  .topbar { height: 80px; padding: 0 var(--pad); gap: 28px; }
  .brand img { width: 54px; height: 54px; }
  .brand-name { font-size: 26px; }
  .actions { display: none; }
  .menu, .menu[hidden] {
    display: flex; position: static; flex-direction: row; align-items: center;
    gap: clamp(14px, 2.2vw, 34px); margin-left: auto;
    padding: 0; background: none; box-shadow: none; animation: none;
  }
  .menu a { padding: 8px 4px; border: 0; font: 800 16px var(--font-body); color: var(--navy); }
  .menu a:hover { color: var(--teal); }
  .search, .search[hidden] { display: block; flex: none; width: 240px; margin: 0; }
  .search input { height: 44px; }
  .topbar.searching .brand-name { display: block; }

  /* hero: text on the left, logo on the right */
  .hero {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    grid-template-areas: ". logo" "head logo" "tag logo" "cta logo" ". logo";
    grid-template-rows: 1fr auto auto auto 1fr;
    align-content: stretch;
    justify-items: start;
    column-gap: clamp(24px, 4vw, 70px);
    min-height: max(640px, calc(100vh - 80px));
    min-height: max(640px, calc(100svh - 80px));
    padding: 48px var(--pad) calc(var(--bw) * 0.62);
    background:
      url("../images/bg-top-left.png") top left / var(--tw) auto no-repeat,
      url("../images/bg-top-right.png") top right / calc(var(--tw) * .65) auto no-repeat,
      url("../images/bg-bottom-left.png") bottom left / var(--bw) auto no-repeat,
      url("../images/bg-bottom-right.png") bottom right / var(--bw) auto no-repeat,
      url("../images/bg-bottom-mid.png") left calc(var(--bw) - 1px) bottom 0 / calc(100% - var(--bw) * 2 + 2px) calc(var(--bw) * .986) no-repeat,
      radial-gradient(90% 80% at 70% 40%, #fbf3de 0%, #f9edd3 60%, #f6e8c9 100%);
  }

  .hero-logo {
    grid-area: logo; justify-self: center; align-self: center;
    width: clamp(300px, 32vw, 500px); height: clamp(300px, 32vw, 500px);
  }

  .headline {
    grid-area: head; align-self: end;
    margin: 0; width: auto; text-align: left;
    font-size: clamp(38px, 4.5vw, 68px);
    line-height: 1.2;
  }
  .headline .spark { display: none; }

  .tagline {
    grid-area: tag;
    margin: clamp(18px, 2vw, 30px) 0 0;
    width: clamp(380px, 33vw, 520px);
  }
  .tagline span { font-size: clamp(15px, 1.5vw, 22px); }

  .cta {
    grid-area: cta; align-self: start;
    width: auto; margin-top: clamp(20px, 2.2vw, 34px);
    flex-direction: row; gap: 18px;
  }
  .btn {
    width: clamp(230px, 19vw, 290px); height: 58px; min-height: 0;
    padding: 0 20px; gap: 12px; border-width: 2.5px; border-radius: 15px;
    font-size: 17px;
    transition: transform .15s, box-shadow .15s;
  }
  .btn:hover { transform: translateY(-2px); box-shadow: 0 8px 16px rgba(3, 56, 90, .2); }
  .btn .ico { width: 26px; height: 26px; }
  .btn .arrow { width: 18px; height: 18px; }

  /* books and stethoscope follow the brush pieces */
  .books { left: calc(var(--bw) * .0055); bottom: calc(var(--bw) * .0055); width: calc(var(--bw) * .636); }
  .steth { right: calc(var(--bw) * .058); bottom: calc(var(--bw) * .033); width: calc(var(--bw) * .522); }
  .spark-steth { right: calc(var(--bw) * .458); bottom: calc(var(--bw) * .39); width: calc(var(--bw) * .19); height: calc(var(--bw) * .19); }

  /* Content sections */
  .section {
    padding: 80px var(--pad);
  }
  .section-title {
    font-size: clamp(28px, 3vw, 42px);
    margin-bottom: 48px;
  }

  .grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

  .card {
    padding: 32px;
    border-radius: 16px;
  }
  .card-title { font-size: 22px; margin-bottom: 12px; }
  .card-meta { font-size: 16px; margin-bottom: 16px; }
  .card-desc { font-size: 15px; }

  .video-card { border-radius: 16px; }
  .video-duration { font-size: 14px; padding: 4px 10px; border-radius: 6px; }
  .video-content { padding: 20px; }
  .video-title { font-size: 18px; margin-bottom: 10px; }
  .video-instructor { font-size: 15px; margin-bottom: 10px; }
  .video-tag { font-size: 13px; padding: 4px 10px; border-radius: 6px; }

  /* Footer */
  .footer {
    background: var(--navy);
    color: var(--cream);
    padding: 48px var(--pad) 32px;
  }
  .footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 48px;
  }
  .footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
  }
  .footer-brand img {
    width: 32px;
    height: 32px;
  }
  .footer-brand span {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 20px;
  }
  .footer-desc {
    font-size: 14px;
    line-height: 1.6;
    color: rgba(251, 243, 222, .8);
  }
  .footer h3 {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 18px;
    margin: 0 0 16px;
  }
  .footer ul {
    list-style: none;
    padding: 0;
    margin: 0;
  }
  .footer li {
    margin-bottom: 10px;
  }
  .footer a {
    color: var(--cream);
    font-size: 14px;
    transition: color .2s;
  }
  .footer a:hover {
    color: var(--teal);
  }
  .footer-bottom {
    border-top: 1px solid rgba(11, 138, 126, .5);
    margin-top: 32px;
    padding-top: 24px;
    text-align: center;
    font-size: 13px;
    color: rgba(251, 243, 222, .8);
  }
  .footer-bottom a {
    margin: 0 8px;
  }

  /* Page header */
  .page-header {
    padding: 64px var(--pad);
  }
  .page-header h1 {
    font-size: clamp(32px, 3.5vw, 48px);
  }
  .page-header p {
    font-size: 16px;
  }

  /* Breadcrumb */
  .breadcrumb {
    padding: 16px var(--pad);
  }
  .breadcrumb nav {
    font-size: 14px;
  }

  /* Sidebar */
  .sidebar {
    padding: 24px;
    border-radius: 12px;
  }
  .sidebar h2 {
    font-size: 18px;
    margin-bottom: 16px;
  }
  .sidebar a {
    padding: 8px 12px;
    font-size: 14px;
  }

  /* Content */
  .content {
    padding: 48px var(--pad);
  }
  .content h2 {
    font-size: clamp(22px, 2.5vw, 32px);
    margin-bottom: 32px;
  }

  /* Track tags */
  .track-tag {
    padding: 6px 16px;
    font-size: 14px;
  }

  /* Instructor avatar */
  .instructor-avatar {
    width: 48px;
    height: 48px;
    font-size: 20px;
  }

  /* Empty state */
  .empty-state {
    padding: 48px;
    border-radius: 12px;
  }
  .empty-state svg {
    width: 48px;
    height: 48px;
  }
  .empty-state h3 {
    font-size: 18px;
  }
  .empty-state p {
    font-size: 14px;
  }

  /* Instructor card */
  .instructor-card {
    padding: 24px;
    border-radius: 12px;
  }
  .instructor-card-header {
    gap: 16px;
    margin-bottom: 16px;
  }
  .instructor-card h3 {
    font-size: 18px;
    margin-bottom: 6px;
  }
  .instructor-card .meta {
    font-size: 14px;
  }
  .instructor-card .bio {
    font-size: 14px;
  }

  /* Term card */
  .term-card {
    padding: 16px;
    border-radius: 12px;
  }
  .term-card h3 {
    font-size: 16px;
    margin-bottom: 4px;
  }
  .term-card .type {
    font-size: 13px;
  }
  .term-card .count {
    font-size: 12px;
    padding: 4px 10px;
    border-radius: 6px;
  }

  /* Video player */
  .video-player {
    border-radius: 12px;
    margin-bottom: 24px;
  }

  /* Video info */
  .video-info {
    padding: 24px;
    border-radius: 12px;
    margin-bottom: 24px;
  }
  .video-info h1 {
    font-size: 24px;
    margin-bottom: 16px;
  }
  .video-meta {
    gap: 16px;
    margin-bottom: 16px;
  }
  .video-meta .instructor-avatar {
    width: 40px;
    height: 40px;
    font-size: 20px;
  }
  .video-meta .duration {
    font-size: 14px;
  }
  .video-tags-list {
    gap: 8px;
    margin-bottom: 16px;
  }
  .video-tags-list a {
    padding: 6px 12px;
    font-size: 13px;
  }
  .video-description {
    font-size: 14px;
  }

  /* Related item */
  .related-item {
    gap: 16px;
    margin-bottom: 16px;
  }
  .related-thumb {
    width: 160px;
    border-radius: 8px;
  }
  .related-thumb .duration {
    font-size: 12px;
    padding: 2px 6px;
    border-radius: 4px;
  }
  .related-content h3 {
    font-size: 14px;
    margin-bottom: 4px;
  }
  .related-content p {
    font-size: 12px;
  }

  /* Instructor header */
  .instructor-header {
    padding: 48px var(--pad);
    gap: 24px;
  }
  .instructor-header .avatar {
    width: 96px;
    height: 96px;
    font-size: 48px;
  }
  .instructor-header h1 {
    font-size: 28px;
  }
  .instructor-header .meta {
    font-size: 14px;
  }

  /* Social link */
  .social-link {
    padding: 8px 12px;
    font-size: 14px;
  }
  .social-link .icon {
    font-size: 18px;
  }

  /* Responsive grid for content with sidebar */
  @media (min-width: 1024px) {
    .content-with-sidebar {
      grid-template-columns: 1fr 1fr;
    }
  }
}