/* Dr. Teach Tech — Programming Practice Cycle */
:root {
  --blue: #17324d;
  --blue-2: #244f70;
  --blue-light: #e7eff5;
  --green: #16826c;
  --green-dark: #0e6556;
  --green-light: #e2f2ed;
  --yellow: #f3c64e;
  --yellow-light: #fff5d8;
  --orange: #d96b3b;
  --orange-light: #fbe9df;
  --ink: #17324d;
  --muted: #526576;
  --paper: #fffef9;
  --canvas: #edf1ec;
  --line: #bdcac4;
  --shadow: 5px 6px 0 rgba(23, 50, 77, .14);
  --radius: 12px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  min-width: 320px;
  margin: 0;
  background-color: var(--canvas);
  background-image:
    linear-gradient(rgba(23, 50, 77, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 50, 77, .035) 1px, transparent 1px);
  background-size: 22px 22px;
  color: var(--ink);
  font-family: "Atkinson Hyperlegible", Arial, Helvetica, sans-serif;
  line-height: 1.58;
}
a { color: inherit; }
a:focus-visible { outline: 3px solid var(--yellow); outline-offset: 3px; }

.skip-link {
  position: fixed;
  left: 1rem;
  top: -5rem;
  z-index: 1000;
  padding: .65rem .9rem;
  background: var(--yellow);
  color: var(--blue);
  font-weight: 900;
}
.skip-link:focus { top: 1rem; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  min-height: 4.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border-bottom: 4px solid var(--green);
  padding: .55rem clamp(1rem, 2vw, 2rem);
  background: var(--blue);
  color: white;
  box-shadow: 0 3px 0 rgba(23, 50, 77, .2);
}
.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  color: white;
  line-height: 1.1;
  text-decoration: none;
}
.brand strong,
.brand small { display: block; }
.brand strong { font-size: .96rem; }
.brand small {
  margin-top: .15rem;
  color: #d9e5e9;
  font-size: .67rem;
  font-weight: 800;
  letter-spacing: .05em;
  text-transform: uppercase;
}
.brand-mark {
  position: relative;
  width: 2.6rem;
  height: 2.6rem;
  flex: 0 0 auto;
  border: 2px solid white;
  border-radius: 50%;
}
.brand-mark::before,
.brand-mark::after,
.brand-mark span {
  position: absolute;
  inset: 7px 11px;
  border-radius: 999px;
  background: white;
  content: "";
}
.brand-mark::before { transform: rotate(60deg); }
.brand-mark::after { transform: rotate(-60deg); }

.app-identity {
  flex: 0 0 auto;
  margin-right: auto;
  border-left: 1px solid rgba(255, 255, 255, .35);
  padding-left: 1rem;
  font-weight: 900;
}
.app-identity small {
  display: block;
  color: #d9e5e9;
  font: 700 .61rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .08em;
  text-transform: uppercase;
}
nav { display: flex; align-items: center; gap: .45rem; }
nav a {
  border: 1px solid rgba(255, 255, 255, .42);
  border-radius: 7px;
  padding: .43rem .68rem;
  color: white;
  font-size: .73rem;
  font-weight: 850;
  text-decoration: none;
}
nav a:hover { background: rgba(255, 255, 255, .12); }

.hero {
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(2.5rem, 5vw, 5rem);
  align-items: center;
  min-height: 610px;
  padding: clamp(4.5rem, 8vw, 7rem) max(1.25rem, calc((100vw - 1180px) / 2));
  background-color: var(--blue);
  background-image:
    linear-gradient(rgba(255, 255, 255, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .045) 1px, transparent 1px);
  background-size: 28px 28px;
  color: white;
}
.hero::after {
  position: absolute;
  right: -9rem;
  bottom: -13rem;
  width: 33rem;
  height: 33rem;
  border: 2px solid rgba(243, 198, 78, .24);
  border-radius: 50%;
  content: "";
}
.hero-copy,
.cycle-map { position: relative; z-index: 1; }
.eyebrow {
  margin: 0 0 .6rem;
  color: var(--yellow);
  font: 850 .76rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.eyebrow.dark { color: var(--green); }
h1, h2, h3 {
  font-family: "Atkinson Hyperlegible", Arial, Helvetica, sans-serif;
  font-weight: 900;
}
h1 { max-width: 760px; margin: 0; letter-spacing: -.055em; }
.hero-title-main,
.hero-title-sub { display: block; }
.hero-title-main {
  font-size: clamp(3.3rem, 7vw, 6.25rem);
  line-height: .9;
  white-space: nowrap;
}
.hero-title-sub {
  margin-top: .8rem;
  font-size: clamp(2rem, 4vw, 3.5rem);
  line-height: 1;
  letter-spacing: -.04em;
}
.hero-quote {
  max-width: 650px;
  margin: 1.35rem 0 0;
  color: var(--yellow);
  font-size: clamp(1.35rem, 2.4vw, 2rem);
  line-height: 1.18;
  letter-spacing: -.02em;
}
.hero-lead {
  max-width: 750px;
  margin: 1.5rem 0 0;
  color: #e1ebef;
  font-size: 1.12rem;
}
.hero-actions,
.start-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1.8rem;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  border: 1px solid transparent;
  border-radius: 7px;
  padding: .65rem 1rem;
  font-weight: 900;
  text-decoration: none;
  transition: transform .16s ease, box-shadow .16s ease, background .16s ease;
}
.button:hover {
  transform: translate(-1px, -1px);
  box-shadow: 3px 4px 0 rgba(0, 0, 0, .18);
}
.button.primary { background: var(--yellow); color: var(--blue); }
.button.primary:hover { background: #ffdc79; }
.button.secondary {
  border-color: rgba(255, 255, 255, .55);
  background: rgba(255, 255, 255, .06);
  color: white;
}
.button.secondary:hover { background: rgba(255, 255, 255, .14); }
.button.light { background: white; color: var(--blue); }

.cycle-map {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: .6rem .8rem;
  align-items: center;
  padding: 1.35rem;
  border: 2px solid rgba(255, 255, 255, .22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, .07);
  box-shadow: 8px 9px 0 rgba(0, 0, 0, .16);
}
.map-step {
  display: grid;
  grid-template-columns: 2.75rem 1fr;
  gap: 0 .8rem;
  align-items: center;
  min-height: 4.75rem;
  border: 1px solid rgba(23, 50, 77, .18);
  border-radius: 8px;
  padding: .8rem;
  background: var(--paper);
  color: var(--ink);
}
.map-step span {
  grid-row: 1 / 3;
  display: grid;
  width: 2.65rem;
  height: 2.65rem;
  place-items: center;
  border-radius: 50%;
  background: var(--green-light);
  color: var(--green-dark);
  font-weight: 900;
}
.map-step strong { align-self: end; font-size: 1.08rem; }
.map-step small { align-self: start; color: var(--muted); }
.map-step.rebuild span { background: var(--yellow-light); color: #765914; }
.map-step.trace span { background: var(--blue-light); color: var(--blue-2); }
.map-step.code span { background: var(--orange-light); color: var(--orange); }
.map-arrow {
  color: var(--yellow);
  font-size: 1.4rem;
  font-weight: 900;
  transform: rotate(90deg);
}

.cycle-section,
.research-section,
.courses-section {
  padding: 5.5rem max(1.25rem, calc((100vw - 1180px) / 2));
  scroll-margin-top: 5rem;
}
.section-heading { max-width: 880px; margin-bottom: 2.5rem; }
h2 {
  margin: 0;
  color: var(--blue);
  font-size: clamp(2.15rem, 4vw, 3.35rem);
  line-height: 1.08;
  letter-spacing: -.04em;
}
.section-heading > p:last-child { color: var(--muted); font-size: 1.08rem; }

.practice-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.practice-card {
  --accent: var(--green);
  --tint: var(--green-light);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 460px;
  border: 2px solid var(--line);
  border-top: 7px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.8rem;
  background: var(--paper);
  box-shadow: var(--shadow);
}
.practice-card::after {
  position: absolute;
  right: -3rem;
  top: -4.2rem;
  width: 11rem;
  height: 11rem;
  border-radius: 50%;
  background: var(--tint);
  content: "";
}
.rebuild-card { --accent: #b68613; --tint: var(--yellow-light); }
.trace-card { --accent: var(--blue-2); --tint: var(--blue-light); }
.code-card { --accent: var(--orange); --tint: var(--orange-light); }
.card-topline {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .75rem;
}
.number {
  display: grid;
  width: 2.9rem;
  height: 2.9rem;
  place-items: center;
  border-radius: 8px;
  background: var(--accent);
  color: white;
  font-weight: 900;
}
.skill-label {
  color: var(--accent);
  font: 850 .75rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.practice-card h3 {
  margin: 1.35rem 0 .45rem;
  color: var(--blue);
  font-size: 2rem;
  letter-spacing: -.03em;
}
.practice-card p { color: var(--muted); }
.practice-card ul { margin: .5rem 0 1.5rem; padding-left: 1.2rem; }
.practice-card li { margin: .4rem 0; }
.card-button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: auto;
  border-radius: 7px;
  padding: .8rem 1rem;
  background: var(--accent);
  color: white;
  font-weight: 900;
  text-decoration: none;
}
.card-button span { transition: transform .16s ease; }
.card-button:hover span { transform: translateX(4px); }
.code-note {
  margin-top: auto;
  border-left: 5px solid var(--accent);
  border-radius: 7px;
  padding: .9rem 1rem;
  background: var(--tint);
  color: var(--ink) !important;
}

.connection-section {
  display: grid;
  grid-template-columns: .85fr 1.15fr;
  gap: 4rem;
  align-items: center;
  padding: 5.25rem max(1.25rem, calc((100vw - 1180px) / 2));
  background-color: var(--green-dark);
  background-image:
    linear-gradient(rgba(255, 255, 255, .04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .04) 1px, transparent 1px);
  background-size: 24px 24px;
  color: white;
}
.connection-copy h2 { max-width: 540px; color: white; }
.connection-copy > p:not(.eyebrow) { color: #d6eee8; }
.ai-rationale {
  margin-top: 1.75rem;
  border: 1px solid rgba(243, 198, 78, .55);
  border-left: 6px solid var(--yellow);
  border-radius: 9px;
  padding: 1.25rem 1.4rem;
  background: rgba(23, 50, 77, .28);
}
.ai-rationale-label {
  margin: 0 0 .35rem;
  color: var(--yellow) !important;
  font: 850 .72rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .1em;
  text-transform: uppercase;
}
.ai-rationale h3 { margin: 0; font-size: 1.35rem; }
.ai-rationale p:last-child { margin-bottom: 0; color: #e2f0ec; }
.connection-example { display: grid; gap: .7rem; }
.connection-example p {
  margin: 0;
  border: 1px solid rgba(255, 255, 255, .24);
  border-radius: 8px;
  padding: 1rem 1.15rem;
  background: rgba(255, 255, 255, .09);
  box-shadow: 4px 5px 0 rgba(23, 50, 77, .2);
}
.connection-example span {
  display: inline-block;
  width: 5.5rem;
  color: var(--yellow);
  font-weight: 900;
}

.research-section { background: var(--paper); }
.research-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
}
.research-grid article {
  border: 2px solid var(--line);
  border-radius: var(--radius);
  padding: 1.7rem;
  background: #f4f7f3;
  box-shadow: 4px 5px 0 rgba(23, 50, 77, .08);
}
.research-number {
  color: var(--green);
  font: 900 .78rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .1em;
}
.research-grid h3 { margin: .75rem 0 .6rem; color: var(--blue); font-size: 1.35rem; }
.research-grid p { color: var(--muted); }
.research-grid a,
.course-grid a {
  color: var(--green-dark);
  font-weight: 900;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}
.research-caution {
  margin: 1.75rem 0 0;
  border: 1px solid #e1c368;
  border-left: 6px solid var(--yellow);
  border-radius: 8px;
  padding: 1rem 1.2rem;
  background: var(--yellow-light);
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.35rem;
}
.course-grid article {
  border: 2px solid var(--line);
  border-radius: var(--radius);
  padding: 2rem;
  background: var(--paper);
  box-shadow: var(--shadow);
}
.course-grid article:first-child { border-top: 7px solid var(--green); }
.course-grid article:last-child { border-top: 7px solid var(--blue-2); }
.course-grid h3 { margin: .45rem 0; color: var(--blue); font-size: 1.75rem; }
.course-grid p:not(.course-tag) { color: var(--muted); }
.course-tag {
  margin: 0;
  color: var(--green);
  font: 850 .75rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .09em;
  text-transform: uppercase;
}

.start-section {
  padding: 4.5rem 1.5rem;
  background: var(--orange);
  color: white;
  text-align: center;
}
.start-section .eyebrow { color: #fff2c8; }
.start-section h2 { max-width: 780px; margin: 0 auto; color: white; }
.start-section .start-actions { justify-content: center; }

footer {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  border-top: 4px solid var(--green);
  padding: 1.5rem max(1.25rem, calc((100vw - 1180px) / 2));
  background: var(--blue);
  color: #d9e5e9;
  font: 800 .75rem ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: .04em;
  text-transform: uppercase;
}
footer p { margin: 0; }
footer strong { color: white; }

@media (max-width: 1040px) {
  .app-identity small { display: none; }
  .hero { grid-template-columns: 1fr; min-height: auto; }
  .cycle-map { max-width: 620px; }
  .connection-section { grid-template-columns: 1fr; gap: 2.2rem; }
}

@media (max-width: 760px) {
  .site-header { position: static; flex-wrap: wrap; }
  .app-identity { order: 2; border-left: 0; padding-left: 0; }
  nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
    padding-bottom: .2rem;
  }
  nav a { flex: 0 0 auto; }
  .hero { padding-top: 4rem; padding-bottom: 4rem; }
  .hero-title-main { white-space: normal; }
  .practice-grid,
  .research-grid,
  .course-grid { grid-template-columns: 1fr; }
  .practice-card { min-height: auto; }
  .cycle-section,
  .research-section,
  .courses-section { padding-top: 4.25rem; padding-bottom: 4.25rem; }
  footer { flex-direction: column; }
}

@media (max-width: 480px) {
  .brand small { display: none; }
  .app-identity { width: 100%; }
  .cycle-map { padding: .9rem; }
  .map-arrow { display: none; }
  .map-step { grid-column: 1 / -1; }
  .connection-example span { display: block; width: auto; margin-bottom: .2rem; }
}

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