/* ==========================================================================
   CAPE Robotics Lab - Clean Academic Light Theme
   Typography: Montserrat (Headings) & Roboto (Body copy), sans-serif
   ========================================================================== */

:root {
  --font-heading: 'Montserrat', sans-serif;
  --font-body: 'Roboto', sans-serif;

  /* Color Palette - Clean, Light & Academic */
  --bg-page: #ffffff;
  --bg-subtle: #f8fafc;
  --bg-card: #ffffff;
  --border-color: #e2e8f0;
  --border-darker: #cbd5e1;

  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-light: #94a3b8;

  /* Navy Blue Color & Accents */
  --color-primary: #1e3a8a;
  --color-primary-hover: #0f245c;
  --color-primary-soft: #f0f5ff;
  --color-primary-border: #dbeafe;

  --container-max: 1080px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* --------------------------------------------------------------------------
   Reset & Base Styles
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-page);
  color: var(--text-body);
  line-height: 1.65;
  font-weight: 400;
}

img, picture, svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.15s ease;
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--text-main);
  line-height: 1.25;
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   Layout & Container
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding: 4.5rem 0;
}

.section-alt {
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-heading {
  margin-bottom: 2.25rem;
  max-width: 760px;
}

.section-heading h2 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 0.65rem;
}

.section-heading p {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.6;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9375rem;
  padding: 0.65rem 1.35rem;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  cursor: pointer;
  text-decoration: none !important;
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff !important;
}

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  color: #ffffff !important;
}

.btn-secondary {
  background-color: var(--bg-subtle);
  color: var(--text-main) !important;
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background-color: #e2e8f0;
  color: var(--text-main) !important;
}

.btn-outline {
  background-color: transparent;
  color: var(--text-main) !important;
  border-color: var(--border-darker);
}

.btn-outline:hover {
  background-color: var(--bg-subtle);
  border-color: var(--text-muted);
}

.btn-sm {
  font-size: 0.8125rem;
  padding: 0.45rem 0.9rem;
}

/* --------------------------------------------------------------------------
   Site Header
   -------------------------------------------------------------------------- */
.site-header {
  background-color: #ffffff;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 50;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
  gap: 1.5rem;
}

.brand-text {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  color: var(--text-main);
  text-decoration: none !important;
  white-space: nowrap;
}

.brand-text:hover {
  color: var(--color-primary);
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-heading);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-body);
  text-decoration: none;
  padding: 0.25rem 0;
  position: relative;
}

.nav-links a:hover {
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   Notice Bar
   -------------------------------------------------------------------------- */
.notice-bar {
  background-color: var(--color-primary-soft);
  border-bottom: 1px solid var(--color-primary-border);
  padding: 0.65rem 0;
  font-size: 0.875rem;
  color: #1e3a8a;
}

.notice-bar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.notice-link {
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--color-primary);
  white-space: nowrap;
}

.notice-link:hover {
  text-decoration: underline;
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero-section {
  padding: 4.5rem 0 3.5rem;
}

.hero-affiliation {
  font-family: var(--font-heading);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.hero-logo-wrap {
  margin: 1.25rem 0 2rem;
  max-width: 520px;
}

.hero-logo {
  width: 100%;
  max-width: 520px;
  height: auto;
  display: block;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.hero-body {
  max-width: 760px;
  font-size: 1.125rem;
  color: var(--text-body);
  line-height: 1.75;
  margin-bottom: 2rem;
}

.hero-body p {
  margin-bottom: 1rem;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* --------------------------------------------------------------------------
   Prospective Research Topics Grid
   -------------------------------------------------------------------------- */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.75rem;
}

.topic-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.topic-item:hover {
  border-color: var(--border-darker);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
}

.topic-index {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 0.75rem;
}

.topic-item h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.topic-item p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* --------------------------------------------------------------------------
   PhD Opportunity / Advert Section
   -------------------------------------------------------------------------- */
.phd-card {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 2.5rem;
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.03);
}

.sub-label {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}

.phd-info h2 {
  font-size: 1.85rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.phd-lead {
  font-size: 1.05rem;
  color: var(--text-body);
  line-height: 1.65;
  margin-bottom: 1.5rem;
}

.phd-details-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  margin-bottom: 2rem;
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
}

.phd-details-list li {
  font-size: 0.9375rem;
  color: var(--text-body);
  line-height: 1.55;
}

.phd-details-list strong {
  color: var(--text-main);
}

.phd-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.phd-disclaimer {
  font-size: 0.8125rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.poster-link {
  display: block;
  text-decoration: none;
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.poster-link:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

.poster-link img {
  width: 100%;
  height: auto;
  display: block;
}

.poster-caption {
  display: block;
  font-family: var(--font-heading);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-body);
  text-align: center;
  padding: 0.65rem 0.75rem;
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
}

/* --------------------------------------------------------------------------
   People (Humble & Understated)
   -------------------------------------------------------------------------- */
.people-content {
  max-width: 680px;
}

.person-entry {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.person-photo-link {
  flex-shrink: 0;
  display: block;
}

.person-photo {
  width: 78px;
  height: 78px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--border-color);
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.person-photo-link:hover .person-photo {
  border-color: var(--color-primary);
  transform: scale(1.02);
}

.person-info {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.person-name {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.1rem;
}

.person-name a {
  color: var(--text-main);
  text-decoration: none;
}

.person-name a:hover {
  color: var(--color-primary);
}

.person-role {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: 0.1rem;
}

.person-dept {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.person-links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.65rem;
  font-size: 0.875rem;
}

.person-links .sep {
  color: var(--text-light);
}



/* --------------------------------------------------------------------------
   Contact Section
   -------------------------------------------------------------------------- */
.contact-container {
  max-width: 680px;
}

.contact-details {
  margin-top: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  font-size: 0.9375rem;
}

.contact-details strong {
  color: var(--text-main);
}

/* --------------------------------------------------------------------------
   Site Footer
   -------------------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 2.5rem 0;
  background-color: #ffffff;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-sub a {
  color: var(--text-muted);
}

.footer-sub a:hover {
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   Responsive Rules
   -------------------------------------------------------------------------- */
@media (max-width: 860px) {
  .topics-grid {
    grid-template-columns: 1fr;
  }

  .phd-card {
    grid-template-columns: 1fr;
    padding: 1.75rem;
  }

  .site-nav {
    display: none;
  }

  .hero-title {
    font-size: 2.25rem;
  }
}