:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --text: #1e2430;
  --muted: #5f6b7a;
  --line: #dde3ea;
  --accent: #0f5c7a;
  --accent-2: #1c8a7a;
  --max: 1100px;
  --shadow: 0 10px 30px rgba(21, 33, 53, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Inter, Arial, Helvetica, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

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

/* HEADER & NAVIGATION */
.site-header {
  background: #0d1c28;
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: 0 4px 18px rgba(0,0,0,0.12);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  gap: 1rem;
}

.brand {
  color: #fff;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand small {
  display: block;
  font-size: 0.78rem;
  font-weight: 500;
  color: rgba(255,255,255,0.72);
}

/* Added .site-nav here to fix the Publications page color */
.nav, .site-nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.nav a, .site-nav a {
  color: rgba(255,255,255,0.85);
  font-size: 0.95rem;
  font-weight: 500;
}

.nav a.active, .nav a:hover,
.site-nav a.active, .site-nav a:hover { 
  color: #fff; 
  text-decoration: none; 
}

/* UNIFORM HERO SECTION */
/* Standardized all banner classes to use the same gradient and height */
.hero, .page-hero, .hero-small {
  background: linear-gradient(135deg, #0d1c28 0%, #13354a 60%, #16596b 100%);
  color: #fff;
  padding: 4rem 0; /* Uniform height across all pages */
}

.hero h1, .page-hero h1, .hero-small h2 {
  margin: 0 0 1rem;
  line-height: 1.1;
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  color: #fff;
}

.hero p.lead, .page-hero p.lead, .hero-small p {
  font-size: 1.1rem;
  max-width: 58ch;
  color: rgba(255,255,255,0.9);
}

/* GRID & CARDS */
.section { padding: 4rem 0; }

.grid-3, .grid-2, .contact-grid {
  display: grid;
  gap: 1.5rem;
}

.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

/* Fix for Contact Page cards being side-by-side */
.contact-grid {
    grid-template-columns: repeat(2, 1fr);
    margin-top: 2rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.card h3 { margin-top: 0; color: var(--text); }

/* CONTENT STYLES */
.publication-list li { margin-bottom: 1.2rem; }

/* FOOTER */
.site-footer {
  background: #0d1c28;
  color: #fff;
  padding: 2.5rem 0;
  margin-top: 4rem;
}

/* RESPONSIVENESS */
@media (max-width: 900px) {
  .grid-3, .grid-2, .contact-grid { grid-template-columns: 1fr; }
  .nav-wrap { align-items: flex-start; flex-direction: column; }
}

/* ===== HERO IMAGE BANNER ===== */

.hero-banner {
    position: relative;
    min-height: 80vh;

    background:
        linear-gradient(rgba(10,20,30,0.55), rgba(10,20,30,0.65)),
        url("images/hero-earth.jpg");

    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;

    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-overlay {
    width: 100%;
    padding: 4rem 0;
}

.hero-content {
    text-align: center;
    color: white;
    max-width: 850px;
}

.hero-content .kicker {
    font-size: 0.95rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin-bottom: 1rem;
    color: rgba(255,255,255,0.85);
}

.hero-content h1 {
    font-size: clamp(2.8rem, 6vw, 4.8rem);
    line-height: 1.1;
    margin-bottom: 1.25rem;
    color: white;
}

.hero-content .lead {
    font-size: 1.2rem;
    color: rgba(255,255,255,0.9);
    max-width: 700px;
    margin: 0 auto 2rem auto;
}

.hero-content .button-row {
    justify-content: center;
}

/* MOBILE */
@media (max-width: 768px) {
  .research-hero,
  .projects-hero {
    min-height: 52vh;
    background-position: center center;
  }

  .research-hero-overlay,
  .projects-hero-overlay {
    padding: 3.4rem 0;
  }

  .research-hero-content h1,
  .projects-hero-content h1 {
    font-size: 2.2rem;
  }

  .research-hero-content .lead,
  .projects-hero-content .lead {
    font-size: 1rem;
    max-width: 100%;
  }
}

/* ===== RESEARCH HERO IMAGE BANNER ===== */

.research-hero {
  position: relative;
  min-height: 68vh;
  background:
    linear-gradient(
      rgba(10,20,30,0.55),
      rgba(10,20,30,0.68)
    ),
    url("images/research-banner.png");

  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  display: flex;
  align-items: center;
}

.research-hero-overlay {
  width: 100%;
  padding: 5rem 0;
}

.research-hero-content {
  color: #fff;
  max-width: 650px;
  margin-left: 4rem;
}

.research-hero-content .kicker {
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  color: rgba(255,255,255,0.86);
}

.research-hero-content h1 {
  margin: 0 0 1rem;
  line-height: 1.05;
  font-size: clamp(2.7rem, 5vw, 4.8rem);
  color: #fff;
}

.research-hero-content .lead {
  font-size: 1.1rem;
  max-width: 560px;
  color: rgba(255,255,255,0.93);
  margin: 0;
}

/* ===== PROJECTS HERO IMAGE BANNER ===== */

.projects-hero {
  position: relative;
  min-height: 68vh;
  background:
    linear-gradient(rgba(10,20,30,0.30), rgba(10,20,30,0.48)),
    url("images/projects-banner.jpg");
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  display: flex;
  align-items: center;
}

.projects-hero-overlay {
  width: 100%;
  padding: 5rem 0;
}

.projects-hero-content {
  color: #fff;
  max-width: 650px;
  margin-left: 4rem;
}

.projects-hero-content .kicker {
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  color: rgba(255,255,255,0.86);
}

.projects-hero-content h1 {
  margin: 0 0 1rem;
  line-height: 1.05;
  font-size: clamp(2.7rem, 5vw, 4.8rem);
  color: #fff;
}

.projects-hero-content .lead {
  font-size: 1.1rem;
  max-width: 560px;
  color: rgba(255,255,255,0.93);
  margin: 0;
}

/* ===== PROJECTS PAGE LAYOUT ===== */

.projects-list {
  display: grid;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 1.6rem;
  box-shadow: var(--shadow);
}

.project-card h3 {
  margin: 0 0 0.75rem;
  color: var(--text);
}

.project-card p {
  margin: 0;
  color: var(--text);
}

.project-type {
  display: inline-block;
  margin-bottom: 0.9rem;
  padding: 0.38rem 0.75rem;
  border-radius: 999px;
  background: #eef4f7;
  border: 1px solid #d8e4ea;
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 600;
}

@media (max-width: 768px) {
  .projects-hero {
    min-height: 48vh;
    background-position: center center;
  }

  .projects-hero-overlay {
    padding: 3.2rem 0;
  }

  .projects-hero-content h1 {
    font-size: 2.2rem;
  }

  .projects-hero-content .lead {
    font-size: 1rem;
  }
}

/* ===== TEACHING HERO IMAGE BANNER ===== */

.teaching-hero {
  position: relative;
  min-height: 62vh;
  background:
    linear-gradient(
      rgba(10,20,30,0.55),
      rgba(10,20,30,0.68)
    ),
    url("images/teaching-banner.jpeg");

  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  display: flex;
  align-items: center;
}

.teaching-hero-overlay {
  width: 100%;
  padding: 4.5rem 0;
}

.teaching-hero-content {
  color: #fff;
  max-width: 650px;
  margin-left: 4rem;

  padding: 1.5rem 1.75rem;
  border-radius: 18px;

  background: rgba(8,16,24,0.24);
  backdrop-filter: blur(3px);

  position: relative;
  z-index: 2;
}

.teaching-hero-content .kicker {
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  color: rgba(255,255,255,0.96);

  text-shadow: 0 2px 8px rgba(0,0,0,0.45);
}

.teaching-hero-content h1 {
  margin: 0 0 1rem;
  line-height: 1.05;
  font-size: clamp(2.7rem, 5vw, 4.8rem);
  color: #fff;

  text-shadow: 0 3px 12px rgba(0,0,0,0.45);
}

.teaching-hero-content .lead {
  font-size: 1.1rem;
  max-width: 560px;
  color: rgba(255,255,255,0.93);
  margin: 0;

  text-shadow: 0 2px 8px rgba(0,0,0,0.40);
}


/* ===== MOBILE ===== */

@media (max-width: 768px) {
  .teaching-hero {
    min-height: 52vh;
    background-position: center center;
  }

  .teaching-hero-overlay {
    padding: 3.4rem 0;
  }

  .teaching-hero-content {
    margin-left: 0;
    padding: 1.25rem;
    max-width: 100%;
  }

  .teaching-hero-content h1 {
    font-size: 2.2rem;
  }

  .teaching-hero-content .lead {
    font-size: 1rem;
    max-width: 100%;
  }
}

/* ===== PUBLICATIONS HERO ===== */

.publications-hero {
  position: relative;
  min-height: 42vh;

  background:
    linear-gradient(
      135deg,
      #061826 0%,
      #0b2d42 45%,
      #1a5a70 100%
    );

  display: flex;
  align-items: center;
}

.publications-hero .container {
  padding: 4rem 0;
}

.publications-hero h1 {
  color: #fff;
  font-size: clamp(2.6rem, 5vw, 4.5rem);
  line-height: 1.08;
  margin: 0;
}


/* ===== MOBILE ===== */

@media (max-width: 768px) {
  .publications-hero {
    min-height: 32vh;
  }

  .publications-hero .container {
    padding: 3rem 0;
  }

  .publications-hero h1 {
    font-size: 2.2rem;
  }
}

/* ===== CONTACT PAGE LAYOUT ===== */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
  align-items: stretch;
}

.contact-grid .card {
  height: 100%;
}


/* ===== CONTACT ICON STYLING ===== */

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid #edf1f5;
}

.contact-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.contact-icon {
  width: 34px;
  height: 34px;

  display: flex;
  align-items: center;
  justify-content: center;

  border-radius: 50%;
  background: #eef4f7;

  font-size: 0.95rem;
  color: var(--accent);

  flex-shrink: 0;
}

.contact-item a {
  font-weight: 500;
  color: var(--accent);
}


/* ===== MOBILE ===== */

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