:root {
  --bg: #f9fbff;
  --surface: #ffffff;
  --surface-soft: #edf3ff;
  --text: #17223a;
  --muted: #5f6f82;
  --line: #d8e2f0;
  --blue: #203f9a;
  --blue-dark: #173075;
  --orange: #ff5a1f;
  --maroon: #9c1636;
  --gold: #b7791f;
  --green: #26724b;
  --radius: 8px;
  --shadow: 0 12px 32px rgba(31, 41, 55, 0.08);
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}

a {
  color: var(--blue);
  text-decoration: none;
}

a:hover {
  color: var(--blue-dark);
  text-decoration: underline;
}

a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 3px solid rgba(21, 94, 159, 0.35);
  outline-offset: 3px;
}

img {
  max-width: 100%;
  height: auto;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 10;
  padding: 0.65rem 0.9rem;
  background: var(--blue);
  color: #fff;
  border-radius: var(--radius);
}

.skip-link:focus {
  top: 1rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 8;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line);
}

.nav-wrap {
  width: min(var(--max), calc(100% - 2rem));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  line-height: 1.2;
  color: var(--text);
  font-weight: 800;
  letter-spacing: 0;
}

.brand:hover {
  text-decoration: none;
}

.brand img {
  width: 3.1rem;
  height: auto;
  flex: 0 0 auto;
}

.brand span {
  display: grid;
  gap: 0.05rem;
}

.brand strong {
  color: var(--blue);
  font-size: 1rem;
}

.brand small {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 700;
}

.nav-toggle {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.nav-button {
  display: inline-flex;
  width: 2.75rem;
  height: 2.75rem;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

.nav-toggle:focus-visible + .nav-button {
  outline: 3px solid rgba(21, 94, 159, 0.35);
  outline-offset: 3px;
}

.nav-button span,
.nav-button span::before,
.nav-button span::after {
  display: block;
  width: 1.25rem;
  height: 2px;
  background: currentColor;
  content: "";
  position: relative;
}

.nav-button span::before {
  position: absolute;
  top: -7px;
}

.nav-button span::after {
  position: absolute;
  top: 7px;
}

.nav-menu {
  position: absolute;
  left: 1rem;
  right: 1rem;
  top: 72px;
  display: none;
  margin: 0;
  padding: 0.75rem;
  list-style: none;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.nav-toggle:checked ~ .nav-menu {
  display: grid;
  gap: 0.2rem;
}

.nav-menu a {
  display: block;
  padding: 0.7rem 0.8rem;
  border-radius: 6px;
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 600;
}

.nav-menu a:hover,
.nav-menu a[aria-current="page"] {
  background: var(--surface-soft);
  color: var(--blue-dark);
  text-decoration: none;
}

.container {
  width: min(var(--max), calc(100% - 2rem));
  margin: 0 auto;
}

.hero {
  padding: 2.1rem 0 1.65rem;
  background:
    linear-gradient(90deg, rgba(32, 63, 154, 0.1), rgba(255, 90, 31, 0.09)),
    var(--surface);
  border-bottom: 1px solid var(--line);
}

.hero-grid {
  display: grid;
  gap: 1.35rem;
}

.hero-copy {
  max-width: 860px;
  margin: 0 auto;
  text-align: center;
}

.hero-iitb-logo {
  display: block;
  width: 4.25rem;
  height: auto;
  margin: 0 auto 0.85rem;
}

.hero-copy h1,
.hero-copy .lead {
  margin-inline: auto;
}

.hero-logo {
  display: block;
  width: min(100%, 520px);
  height: auto;
  margin-bottom: 1.15rem;
}

.eyebrow {
  margin: 0 0 0.45rem;
  color: var(--orange);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.2;
  letter-spacing: 0;
}

h1 {
  max-width: 820px;
  margin: 0;
  color: #142033;
  font-size: clamp(1.9rem, 5vw, 3.5rem);
  font-weight: 800;
}

h1 span {
  display: block;
  color: var(--blue);
  font-size: 0.52em;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lead {
  max-width: 760px;
  margin: 0.75rem 0 0;
  color: #3d4b5f;
  font-size: clamp(1rem, 1.6vw, 1.14rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.6rem;
  justify-content: center;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  max-width: 760px;
  margin: 0.35rem auto 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.hero-stats div {
  padding: 0.9rem 0.75rem;
  background: rgba(255, 255, 255, 0.82);
  text-align: center;
}

.hero-stats strong {
  display: block;
  color: var(--blue);
  font-size: 1.45rem;
  line-height: 1;
}

.hero-stats span {
  display: block;
  margin-top: 0.25rem;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 800;
}

@media (max-width: 520px) {
  .hero-stats {
    grid-template-columns: 1fr;
  }
}

.quick-links {
  display: grid;
  gap: 0.55rem;
  margin: 1.4rem 0 0;
  padding: 0;
  list-style: none;
}

.quick-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 800;
}

.quick-links a::before {
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--orange);
  content: "";
}

.button {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1rem;
  border: 1px solid var(--blue);
  border-radius: var(--radius);
  background: var(--blue);
  color: #fff;
  font-weight: 700;
}

.button:hover {
  background: var(--blue-dark);
  color: #fff;
  text-decoration: none;
}

.button.secondary {
  background: var(--surface);
  color: var(--blue);
}

.button.secondary:hover {
  background: var(--surface-soft);
  color: var(--blue-dark);
}

.hero-panel {
  align-self: start;
  padding: 1.2rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 5px solid var(--orange);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-panel dl {
  display: grid;
  gap: 0.75rem;
  margin: 0;
}

.hero-panel dt {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.hero-panel dd {
  margin: 0;
  font-weight: 700;
}

.section {
  padding: 2.75rem 0;
}

.section.alt {
  background: var(--surface);
  border-block: 1px solid var(--line);
}

.section-header {
  max-width: 760px;
  margin-bottom: 1.5rem;
}

.section-header h2 {
  margin: 0 0 0.55rem;
  font-size: clamp(1.6rem, 4vw, 2.35rem);
}

.section-header p {
  margin: 0;
  color: var(--muted);
}

.course-summary {
  max-width: 900px;
  padding: 1.35rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 5px solid var(--blue);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.course-summary p {
  margin: 0;
  color: #334155;
  font-size: 1.05rem;
}

.grid {
  display: grid;
  gap: 1rem;
}

.grid.two,
.grid.three,
.grid.four {
  grid-template-columns: 1fr;
}

.card {
  padding: 1.2rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.card:hover {
  border-color: rgba(21, 94, 159, 0.35);
}

.card h3 {
  margin: 0 0 0.55rem;
  font-size: 1.1rem;
}

.card p,
.card ul,
.card ol {
  margin-block: 0.45rem 0;
  color: var(--muted);
}

.card ul,
.card ol {
  padding-left: 1.2rem;
}

.card .meta {
  margin-top: 0.85rem;
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 700;
}

.repo-card {
  display: grid;
  gap: 0.45rem;
}

.repo-card a {
  font-weight: 800;
}

.repo-card .tag {
  width: fit-content;
  margin-bottom: 0.2rem;
}

.tag {
  display: inline-flex;
  margin-bottom: 0.75rem;
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--blue-dark);
  font-size: 0.78rem;
  font-weight: 800;
}

.notice {
  padding: 1rem;
  border-left: 5px solid var(--gold);
  border-radius: var(--radius);
  background: #fff8eb;
}

.notice p {
  margin: 0;
}

.timeline {
  display: grid;
  gap: 1rem;
}

.timeline-card {
  position: relative;
  padding: 1.2rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 5px solid var(--blue);
  border-radius: var(--radius);
}

.timeline-card strong {
  color: var(--orange);
  font-size: 0.85rem;
}

.timeline-card h3 {
  margin: 0.25rem 0 0.4rem;
}

.timeline-card p {
  margin: 0;
  color: var(--muted);
}

.phase-strip {
  display: grid;
  gap: 1rem;
}

.phase-strip article {
  padding: 1rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 5px solid var(--blue);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.phase-strip strong {
  display: inline-grid;
  width: 2rem;
  height: 2rem;
  margin-bottom: 0.8rem;
  place-items: center;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
}

.phase-strip span {
  display: block;
  color: #142033;
  font-weight: 800;
}

.phase-strip p {
  margin: 0.35rem 0 0;
  color: var(--muted);
}

.gantt-wrap {
  overflow-x: auto;
  padding-bottom: 0.4rem;
}

.gantt {
  display: grid;
  grid-template-columns: minmax(150px, 1.5fr) repeat(15, minmax(64px, 1fr));
  grid-auto-rows: minmax(58px, auto);
  min-width: 1120px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.gantt-corner,
.gantt-week,
.gantt-label {
  display: flex;
  align-items: center;
  padding: 0.7rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.gantt-corner,
.gantt-week {
  background: var(--surface-soft);
  color: #142033;
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.gantt-week {
  justify-content: center;
}

.gantt-label {
  color: #334155;
  font-weight: 800;
}

.gantt-bar,
.gantt-milestone {
  align-self: center;
  margin: 0.45rem;
  padding: 0.55rem 0.65rem;
  border-radius: 999px;
  color: #fff;
  font-size: 0.82rem;
  font-weight: 800;
  line-height: 1.2;
  text-align: center;
}

.gantt-bar.setup {
  background: var(--blue);
}

.gantt-bar.discovery {
  background: #0f766e;
}

.gantt-bar.prototype {
  background: var(--orange);
}

.gantt-bar.delivery {
  background: #6b46c1;
}

.gantt-bar.stabilize {
  background: var(--green);
}

.gantt-milestone {
  justify-self: center;
  min-width: 3.9rem;
  border-radius: var(--radius);
  background: var(--maroon);
}

.gantt-milestone.final {
  background: #14224a;
}

.milestone-grid {
  display: grid;
  gap: 1rem;
}

.milestone-card {
  padding: 1.1rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}

.milestone-card span {
  color: var(--orange);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
}

.milestone-card h3 {
  margin: 0.35rem 0;
}

.milestone-card p {
  margin: 0;
  color: var(--muted);
}

.milestone-card strong {
  display: block;
  margin-top: 0.9rem;
  color: var(--blue-dark);
  font-size: 0.88rem;
}

.phase {
  margin-top: 1.75rem;
}

.phase h2 {
  margin-bottom: 0.8rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--line);
  font-size: 1.35rem;
}

.policy-card {
  border-top: 5px solid var(--blue);
}

.policy-card.security {
  border-top-color: var(--maroon);
}

.policy-card.ethics {
  border-top-color: var(--blue);
}

.policy-card.access {
  border-top-color: var(--green);
}

.policy-card.ai {
  border-top-color: var(--gold);
}

.policy-card.plagiarism {
  border-top-color: #6b46c1;
}

.policy-card.ipr {
  border-top-color: #0f766e;
}

.rubric {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.rubric th,
.rubric td {
  padding: 0.8rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.rubric th {
  background: var(--surface-soft);
  color: #142033;
}

.table-wrap {
  overflow-x: auto;
}

.project-placeholder {
  display: grid;
  min-height: 170px;
  place-items: center;
  border: 1px dashed #9eb0c4;
  border-radius: var(--radius);
  background: #fbfdff;
  color: var(--muted);
  text-align: center;
}

.site-footer {
  padding: 2rem 0;
  background: #14224a;
  color: #dbe7f3;
}

.footer-grid {
  display: grid;
  gap: 1rem;
}

.site-footer a {
  color: #dbeafe;
}

.site-footer p {
  margin: 0.35rem 0 0;
  color: #b9c7d6;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.footer-brand img {
  width: 3.6rem;
  height: auto;
  flex: 0 0 auto;
}

@media (min-width: 760px) {
  .nav-button {
    display: none;
  }

  .nav-menu {
    position: static;
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.1rem;
    padding: 0;
    border: 0;
    box-shadow: none;
    background: transparent;
  }

  .nav-menu a {
    padding: 0.5rem 0.65rem;
    font-size: 0.88rem;
  }

  .hero {
    padding: 2.5rem 0 2rem;
  }

  .hero-grid {
    grid-template-columns: minmax(0, 1fr);
    align-items: center;
  }

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

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

  .grid.four {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .phase-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .timeline {
    position: relative;
    padding-left: 1.25rem;
  }

  .timeline::before {
    position: absolute;
    inset: 0 auto 0 0;
    width: 3px;
    background: var(--line);
    content: "";
  }

  .timeline-card::before {
    position: absolute;
    left: -1.58rem;
    top: 1.35rem;
    width: 0.8rem;
    height: 0.8rem;
    border: 3px solid var(--blue);
    border-radius: 50%;
    background: var(--surface);
    content: "";
  }

  .footer-grid {
    grid-template-columns: 1fr auto;
    align-items: start;
  }
}

@media (min-width: 1040px) {
  .nav-menu a {
    padding-inline: 0.78rem;
  }
}