:root {
  --page-bg: #f3f4f6;
  --page-fg: #1f2933;
  --accent: #2563eb;
  --accent-soft: #e5edff;
  --border-soft: #e5e7eb;
  --header-bg: #f9fafb;
  --font-base: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
               Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: "Georgia", "Times New Roman", serif;
  --radius-lg: 14px;
  --shadow-soft: 0 10px 30px rgba(15, 23, 42, 0.08);
  --line-height-base: 1.6;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-base);
  background: radial-gradient(circle at top left, #e0ecff 0, #f3f4f6 40%, #eef2ff 100%);
  color: var(--page-fg);
  line-height: var(--line-height-base);
  padding: 1.25rem;
}

.page {
  max-width: 900px;
  margin: 0 auto;
  background-color: #ffffff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: clamp(1.5rem, 3vw, 2.5rem);
  border: 1px solid #e5e7eb;
}

@media (min-width: 768px) {
  body {
    padding: 2.5rem;
  }
  .page {
    padding: 2.5rem 3rem;
  }
}

/* Header */

header {
  border-bottom: 1px solid var(--border-soft);
  padding-bottom: 1.5rem;
  margin-bottom: 1.5rem;
  background: linear-gradient(to bottom, var(--header-bg), #ffffff);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  margin: -1.5rem -1.5rem 1.5rem;
  padding: 1.5rem 1.5rem 1.75rem;
}

@media (min-width: 768px) {
  header {
    margin: -2.5rem -2.5rem 2rem;
    padding: 2rem 2.5rem 2.25rem;
  }
}

.header-top {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.header-meta {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.95rem;
  color: #4b5563;
}

@media (min-width: 640px) {
  .header-top {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }
  .header-meta {
    text-align: right;
  }
}

.date {
  font-size: 0.95rem;
  color: #6b7280;
}

h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 2.7vw, 2rem);
  margin: 0.3rem 0 0.4rem;
  color: #111827;
}

.subtitle {
  font-size: 0.95rem;
  color: #4b5563;
  margin: 0;
}

.school-name {
  font-weight: 600;
}

/* Links */

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.13em;
}

a:hover {
  text-decoration-thickness: 2px;
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* Main content */

main {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  font-size: 1rem;
}

section {
  border-left: 3px solid transparent;
  padding-left: 0.75rem;
}

section:focus-within {
  border-left-color: var(--accent);
}

h2 {
  font-size: 1.05rem;
  margin: 0 0 0.35rem;
  color: #111827;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  font-weight: 600;
}

p {
  margin: 0.25rem 0 0.5rem;
}

.intro {
  border-radius: 0.75rem;
  padding: 0.75rem 0.9rem;
  background: var(--accent-soft);
  border-left: 4px solid var(--accent);
}

.signature {
  margin-top: 0.75rem;
}

.signature strong {
  display: inline-block;
  margin-bottom: 0.1rem;
}

.footer-note {
  margin-top: 1.5rem;
  font-size: 0.85rem;
  color: #6b7280;
  border-top: 1px dashed #e5e7eb;
  padding-top: 0.75rem;
}