@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;600&display=swap");

:root {
  --ink: #0b1b2b;
  --sky: #c8e0ff;
  --ice: #f0f6ff;
  --ember: #ff6b35;
  --coal: #1c2a3a;
  --glow: rgba(255, 107, 53, 0.35);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  color: var(--coal);
  background:
    radial-gradient(circle at top right, rgba(255, 107, 53, 0.2), transparent 45%),
    radial-gradient(circle at 20% 10%, rgba(11, 27, 43, 0.2), transparent 50%),
    linear-gradient(135deg, #f3f7ff, #e7f0ff 55%, #d7e8ff);
}

.shell {
  max-width: 1000px;
  margin: 0 auto;
  padding: 64px 24px 80px;
  display: grid;
  gap: 48px;
}

.hero {
  background: rgba(255, 255, 255, 0.85);
  border-radius: 28px;
  padding: 48px 48px 40px;
  box-shadow: 0 20px 40px rgba(11, 27, 43, 0.12);
  backdrop-filter: blur(14px);
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 20px 24px auto auto;
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 107, 53, 0.45), transparent 70%);
  filter: blur(10px);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 8px 16px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--ice);
  font-size: 12px;
}

h1 {
  margin: 24px 0 12px;
  font-size: clamp(2.2rem, 4vw, 3.6rem);
  color: var(--ink);
}

.lead {
  margin: 0;
  font-size: 1.1rem;
  max-width: 560px;
  line-height: 1.7;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 32px;
}

button {
  font: inherit;
  border: none;
  cursor: pointer;
  padding: 12px 22px;
  border-radius: 999px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button:active {
  transform: translateY(1px) scale(0.99);
}

.primary {
  background: var(--ember);
  color: white;
  box-shadow: 0 12px 20px var(--glow);
}

.ghost {
  background: white;
  color: var(--ink);
  border: 1px solid rgba(11, 27, 43, 0.2);
}

.grid {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.card {
  padding: 24px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 12px 24px rgba(11, 27, 43, 0.08);
}

.card.is-course-card {
  cursor: pointer;
}

.card.is-course-card:focus-visible {
  outline: 3px solid rgba(255, 107, 53, 0.6);
  outline-offset: 2px;
}

.modal {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.modal.is-open {
  opacity: 1;
  pointer-events: auto;
}

.modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(11, 27, 43, 0.5);
}

.modal__panel {
  position: relative;
  width: min(520px, 90vw);
  background: white;
  border-radius: 20px;
  padding: 24px;
  box-shadow: 0 24px 50px rgba(11, 27, 43, 0.2);
}

.modal__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.modal__close {
  background: transparent;
  border: 1px solid rgba(11, 27, 43, 0.2);
  color: var(--ink);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  padding: 0;
}

.modal__status {
  margin: 16px 0;
  color: rgba(28, 42, 58, 0.8);
}

.modal__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 10px;
}

.modal__list details {
  border: 1px solid rgba(11, 27, 43, 0.12);
  border-radius: 12px;
  background: rgba(240, 246, 255, 0.7);
  padding: 6px 10px;
}

.modal__list summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--ink);
  list-style: none;
}

.modal__list summary::-webkit-details-marker {
  display: none;
}

.modal__list summary::before {
  content: "▸";
  display: inline-block;
  margin-right: 8px;
  transform: rotate(90deg);
  transition: transform 0.2s ease;
}

.modal__list details:not([open]) summary::before {
  transform: rotate(0deg);
}

.modal__list .folder__list {
  list-style: none;
  margin: 10px 0 0;
  padding: 0 0 0 16px;
  display: grid;
  gap: 8px;
}

.modal__list .folder__empty {
  color: rgba(28, 42, 58, 0.7);
  font-size: 0.9rem;
}

.modal__list a {
  display: block;
  padding: 10px 14px;
  border-radius: 12px;
  border: 1px solid rgba(11, 27, 43, 0.12);
  color: var(--ink);
  text-decoration: none;
  background: rgba(240, 246, 255, 0.7);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.modal__list a:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 16px rgba(11, 27, 43, 0.12);
}

@media (max-width: 720px) {
  .hero {
    padding: 32px 24px;
  }
}