:root {
  --bg: #eef7f3;
  --surface: #ffffff;
  --surface-2: #ecf8f4;
  --text: #183934;
  --muted: #5f7d77;
  --green: #2c7a6b;
  --green-dark: #1f5a4e;
  --green-soft: #d7eee7;
  --accent: #f29f67;
  --border: #d5e7e1;
  --shadow-sm: 0 6px 18px rgba(25, 70, 60, 0.08);
  --shadow-md: 0 14px 30px rgba(25, 70, 60, 0.14);
  --radius-lg: 18px;
  --radius-md: 12px;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  font-family: "Poppins", system-ui, sans-serif;
  background:
    radial-gradient(circle at 20% 0%, rgba(44, 122, 107, 0.08), transparent 30%),
    radial-gradient(circle at 80% 0%, rgba(242, 159, 103, 0.08), transparent 30%),
    linear-gradient(180deg, #f8fcfb 0%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.6;
}

a {
  text-decoration: none;
}

.container {
  width: min(calc(100% - 1.5rem), var(--max-width));
  margin: 0 auto;
}

.site-header {
  position: relative;
  padding: 4rem 0 3rem;
  background-image: url("images/header.jpg");
  background-size: cover;
  background-position: center 75%;
  background-repeat: no-repeat;
  color: white;
  text-align: center;
  overflow: hidden;
}

.header-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(
      135deg,
      rgba(20, 90, 80, 0.86),
      rgba(44, 122, 107, 0.74),
      rgba(242, 159, 103, 0.42)
    );
}

.header-content {
  position: relative;
  z-index: 1;
}

.eyebrow {
  margin: 0 0 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
  font-weight: 700;
  opacity: 0.88;
}

.site-header h1 {
  margin: 0;
  font-size: 2.2rem;
  line-height: 1.1;
}

.subtitle {
  margin: 0.8rem auto 0;
  max-width: 34rem;
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.92);
}

.unit-section {
  margin-top: 1.25rem;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.section-heading {
  margin-bottom: 0.9rem;
}

.section-heading h2 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--green-dark);
}

.link-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
}

.project-card {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  padding: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: 0 2px 8px rgba(25, 70, 60, 0.03);
  transition:
    transform 180ms ease,
    box-shadow 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease;
}

.project-card h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}

.project-button {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1rem;
  border: 1px solid rgba(44, 122, 107, 0.25);
  border-radius: 999px;
  background: var(--green-soft);
  color: var(--green-dark);
  font-size: 0.86rem;
  font-weight: 600;
  transition:
    background-color 180ms ease,
    border-color 180ms ease,
    color 180ms ease,
    transform 180ms ease,
    box-shadow 180ms ease;
}

.project-button:active {
  transform: translateY(1px);
}

.project-button:focus-visible {
  outline: 3px solid rgba(44, 122, 107, 0.18);
  outline-offset: 3px;
}

.site-footer {
  padding: 2rem 0 2.5rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.95rem;
}

@media (min-width: 700px) {
  .site-header {
    padding: 5rem 0 4rem;
  }

  .site-header h1 {
    font-size: 3rem;
  }

  .unit-section {
    margin-top: 1.5rem;
    padding: 1.2rem;
  }

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

@media (min-width: 980px) {
  .site-header h1 {
    font-size: 3.5rem;
  }

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

@media (hover: hover) and (pointer: fine) {
  .project-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: #c4ddd5;
    background: #fcfffd;
  }

  .project-button:hover {
    background: #d3efe7;
    border-color: rgba(44, 122, 107, 0.42);
    color: var(--green);
    transform: translateY(-1px);
    box-shadow: 0 6px 14px rgba(25, 70, 60, 0.08);
  }
}