:root {
  --ink: #111827;
  --muted: #667085;
  --paper: #f7f8f3;
  --white: #ffffff;
  --line: #dfe3dc;
  --arduino: #008184;
  --arduino-dark: #006a6d;
  --lime: #c9f25f;
  --orange: #ff7a45;
  --blue: #3157d5;
  --shadow: 0 18px 50px rgba(17, 24, 39, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Space Grotesk", sans-serif;
  line-height: 1.5;
}

a {
  color: inherit;
}

main {
  display: flex;
  flex-direction: column;
}

.page-shell {
  width: min(1060px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 88px;
  border-bottom: 1px solid rgba(17, 24, 39, 0.12);
}

.brand,
.header-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand {
  font-size: 1.05rem;
  font-weight: 500;
}

.brand strong {
  color: var(--arduino-dark);
}

.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  color: var(--white);
  background: var(--arduino);
  border-radius: 10px;
  font-weight: 700;
}

.header-link {
  font-family: "DM Mono", monospace;
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.header-link:hover,
.header-link:focus-visible {
  color: var(--arduino-dark);
}

.site-nav {
  display: flex;
  gap: 24px;
}

.site-nav a {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 500;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--arduino-dark);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: clamp(36px, 7vw, 80px);
  align-items: center;
  order: 0;
  padding: 56px 0 64px;
}

.hero-copy {
  max-width: 720px;
}

.share-qr {
  display: flex;
  gap: 18px;
  align-items: center;
  max-width: 360px;
  padding: 16px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.qr-image-link {
  display: block;
  flex: 0 0 auto;
  line-height: 0;
}

.share-qr img {
  display: block;
  width: 112px;
  height: 112px;
}

.share-qr h2 {
  margin-bottom: 5px;
  font-size: 1rem;
}

.share-qr p {
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.76rem;
}

.share-qr div > a {
  color: var(--arduino-dark);
  font-size: 0.72rem;
  font-weight: 600;
  line-height: 1.35;
  text-underline-offset: 3px;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--arduino-dark);
  font-family: "DM Mono", monospace;
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.13em;
}

h1,
h2,
h3,
h4,
p {
  margin-top: 0;
}

h1 {
  max-width: 600px;
  margin-bottom: 18px;
  font-size: clamp(2.15rem, 4.2vw, 3.45rem);
  line-height: 1.06;
  letter-spacing: -0.045em;
}

.hero-description {
  max-width: 560px;
  margin-bottom: 26px;
  color: var(--muted);
  font-size: 1rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  min-height: 52px;
  padding: 0 22px;
  border: 1px solid var(--ink);
  border-radius: 8px;
  font-size: 0.93rem;
  font-weight: 600;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
}

.button-primary {
  color: var(--white);
  background: var(--ink);
}

.button-primary:hover,
.button-primary:focus-visible {
  background: var(--arduino-dark);
}

.button-secondary {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.55);
}

.button-secondary:hover,
.button-secondary:focus-visible {
  background: var(--white);
}

.challenge-section {
  order: 2;
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(50px, 9vw, 120px);
  padding: 72px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.challenge-intro {
  align-self: start;
}

.presented-by {
  display: inline-block;
  margin-bottom: 24px;
  padding: 6px 9px;
  color: var(--white);
  background: var(--arduino);
  border-radius: 4px;
  font-family: "DM Mono", monospace;
  font-size: 0.65rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.challenge-intro h2 {
  margin: 0;
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  line-height: 1.05;
  letter-spacing: -0.05em;
}

.challenge-copy {
  padding-top: 39px;
  color: var(--muted);
  font-size: 1rem;
}

.challenge-copy p {
  margin-bottom: 24px;
}

.challenge-copy a,
.requirements a {
  color: var(--arduino-dark);
  font-weight: 600;
  text-underline-offset: 3px;
}

.challenge-copy .challenge-lead {
  color: var(--ink);
  font-size: clamp(1.15rem, 2vw, 1.4rem);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.035em;
}

.section-heading h2 {
  margin-bottom: 32px;
  font-size: clamp(1.75rem, 3vw, 2.4rem);
  line-height: 1;
  letter-spacing: -0.05em;
}

.requirements,
.judging-note,
.challenge-prizes {
  margin-top: 30px;
}

.requirements h3,
.challenge-prizes h3 {
  margin-bottom: 14px;
  color: var(--ink);
  font-size: 1.05rem;
}

.requirements ul {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.requirements li {
  position: relative;
  padding-left: 24px;
  color: var(--ink);
  font-size: 0.9rem;
}

.requirements li::before {
  position: absolute;
  top: 0.28em;
  left: 0;
  width: 12px;
  height: 7px;
  border-bottom: 2px solid var(--arduino);
  border-left: 2px solid var(--arduino);
  content: "";
  transform: rotate(-45deg);
}

.judging-note {
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.judging-note p:last-child {
  margin-bottom: 0;
}

.challenge-prizes {
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.challenge-prizes dl {
  margin: 0;
}

.challenge-prizes dl > div {
  display: grid;
  grid-template-columns: 190px 1fr;
  gap: 20px;
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.challenge-prizes dt {
  color: var(--ink);
  font-size: 0.82rem;
  font-weight: 600;
}

.challenge-prizes dd {
  margin: 0;
  color: var(--muted);
  font-size: 0.82rem;
}

.schedule-section {
  order: 3;
  padding: 72px 0;
  border-bottom: 1px solid var(--line);
}

.schedule-list {
  display: grid;
  gap: 16px;
}

.event-card {
  position: relative;
  display: grid;
  grid-template-columns: 175px minmax(0, 1fr);
  gap: 40px;
  padding: 38px 72px 38px 38px;
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 10px;
}

.event-featured {
  border-left: 5px solid var(--arduino);
}

.coffee-card {
  background: #fff9ed;
  border-color: #eadcc1;
}

.event-time {
  display: flex;
  align-items: flex-start;
  flex-direction: column;
  padding-right: 28px;
  border-right: 1px solid var(--line);
}

.event-time span,
.event-time small,
.event-type {
  font-family: "DM Mono", monospace;
  font-size: 0.67rem;
  font-style: normal;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.event-time span {
  margin-bottom: 7px;
  color: var(--arduino-dark);
}

.event-time strong {
  font-size: 1.18rem;
  line-height: 1.3;
}

.event-time em {
  color: var(--muted);
  font-size: 0.72rem;
  font-style: normal;
  font-weight: 400;
}

.event-time small {
  margin-top: 8px;
  color: var(--muted);
}

.event-details {
  max-width: 710px;
}

.event-type {
  margin-bottom: 10px;
  color: var(--arduino-dark);
}

.event-details h3 {
  margin-bottom: 10px;
  font-size: clamp(1.35rem, 2.5vw, 1.9rem);
  letter-spacing: -0.035em;
}

.event-details p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.event-details .event-summary {
  margin-bottom: 15px;
  color: var(--ink);
  font-size: 1rem;
  font-weight: 500;
}

.event-number {
  position: absolute;
  top: 28px;
  right: 28px;
  color: #d0d5dd;
  font-family: "DM Mono", monospace;
  font-size: 0.68rem;
}

.resources-section {
  order: 1;
  padding: 72px 0;
  border-top: 1px solid var(--line);
}

.section-heading-wide {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 36px;
  margin-bottom: 42px;
}

.section-heading-wide h2 {
  margin: 0;
}

.section-heading-wide > p {
  max-width: 460px;
  margin: 0 0 4px;
  color: var(--muted);
}

.resource-group {
  display: grid;
  grid-template-columns: 230px 1fr;
  gap: 44px;
  margin-bottom: 56px;
}

.group-label {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.group-icon {
  display: grid;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  place-items: center;
  color: var(--white);
  border-radius: 10px;
  font-family: "DM Mono", monospace;
  font-size: 0.8rem;
  font-weight: 500;
}

.arduino-icon {
  background: var(--arduino);
  font-size: 1.5rem;
}

.qualcomm-icon {
  background: var(--blue);
}

.edge-impulse-icon {
  color: var(--ink);
  background: var(--lime);
}

.group-label h3 {
  margin: 1px 0 5px;
  font-size: 1.05rem;
}

.group-label p {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.resource-card {
  position: relative;
  display: flex;
  min-height: 190px;
  padding: 22px;
  overflow: hidden;
  flex-direction: column;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 10px;
  text-decoration: none;
  transition: border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

.resource-card:hover,
.resource-card:focus-visible {
  border-color: var(--arduino);
  outline: none;
  transform: translateY(-1px);
}

.resource-card.featured {
  color: var(--ink);
  background: var(--white);
  border-color: var(--arduino);
}

.resource-card.featured::after {
  content: none;
}

.card-index,
.card-tag {
  align-self: flex-start;
  margin-bottom: 20px;
  color: var(--arduino-dark);
  font-family: "DM Mono", monospace;
  font-size: 0.67rem;
}

.card-tag {
  padding: 5px 8px;
  color: var(--ink);
  background: var(--lime);
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.resource-card h4 {
  margin-bottom: 9px;
  font-size: 1.08rem;
  letter-spacing: -0.02em;
}

.resource-card p {
  margin-bottom: 20px;
  color: var(--muted);
  font-size: 0.88rem;
}

.resource-card.featured p {
  color: var(--muted);
}

.card-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  color: var(--arduino-dark);
  font-size: 0.8rem;
  font-weight: 600;
}

.featured .card-link {
  color: var(--arduino-dark);
}

.hackmit-banner {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 40px;
  padding: 32px;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 14px;
  text-decoration: none;
}

.hackmit-banner .eyebrow {
  color: var(--arduino-dark);
}

.hackmit-banner h3 {
  margin-bottom: 10px;
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  line-height: 1;
  letter-spacing: -0.05em;
}

.hackmit-banner p:last-child {
  margin: 0;
  color: var(--muted);
}

.banner-link {
  flex: 0 0 auto;
  padding: 13px 17px;
  color: var(--white);
  background: var(--ink);
  border-radius: 7px;
  font-size: 0.82rem;
  font-weight: 700;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  padding: 32px 0;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-family: "DM Mono", monospace;
  font-size: 0.66rem;
}

footer p {
  margin: 0;
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .challenge-section {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .challenge-copy {
    max-width: 740px;
    padding-top: 0;
  }

  .resource-group {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 680px) {
  .page-shell {
    width: min(100% - 28px, 1180px);
  }

  .site-header {
    min-height: 72px;
  }

  .site-nav {
    display: none;
  }

  .hero {
    gap: 32px;
    padding: 48px 0 56px;
  }

  h1 {
    font-size: clamp(2rem, 10vw, 3rem);
  }

  .share-qr {
    width: 100%;
    max-width: 440px;
  }

  .challenge-section,
  .schedule-section,
  .resources-section {
    padding: 72px 0;
  }

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

  .section-heading-wide {
    display: block;
    margin-bottom: 52px;
  }

  .section-heading-wide > p {
    margin-top: 18px;
  }

  .event-card {
    grid-template-columns: 1fr;
    gap: 26px;
    padding: 30px;
  }

  .event-time {
    padding: 0 40px 22px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .event-number {
    top: 30px;
  }

  .challenge-prizes dl > div {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .resource-group {
    margin-bottom: 64px;
  }

  .resource-card {
    min-height: 180px;
  }

  .hackmit-banner {
    align-items: flex-start;
    flex-direction: column;
  }

  footer {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}