:root {
  --color-bg: #f4f5f7;
  --color-surface: #ffffff;
  --color-border: #dde1e6;
  --color-text: #1f2430;
  --color-muted: #6b7280;
  --color-primary: #1d4ed8;
  --color-primary-dark: #1e3a8a;
  --color-danger: #b91c1c;
  --color-ok-bg: #dcfce7;
  --color-ok-text: #166534;
  --color-void-bg: #fee2e2;
  --color-void-text: #991b1b;
  --radius: 8px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

.container-narrow { max-width: 480px; }

/* Nav */
.app-nav {
  background: var(--color-primary-dark);
  color: white;
  position: sticky;
  top: 0;
  z-index: 10;
}
.app-nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.brand {
  color: white;
  font-weight: 700;
  font-size: 1.2rem;
  margin-right: auto;
}
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}
.nav-links a, .nav-links .link-button {
  color: white;
  opacity: 0.9;
}
.nav-links a:hover, .nav-links .link-button:hover { opacity: 1; text-decoration: underline; }
.nav-user { opacity: 0.75; font-size: 0.9rem; }
.link-button {
  background: none;
  border: none;
  font: inherit;
  cursor: pointer;
  padding: 0;
}

@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
    padding-top: 0.75rem;
  }
  .nav-links.open { display: flex; }
}

/* Auth */
.auth-body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(160deg, var(--color-primary-dark), #0f172a);
}
.auth-card {
  background: var(--color-surface);
  padding: 2.5rem 2rem;
  border-radius: var(--radius);
  width: 100%;
  max-width: 360px;
  margin: 1rem;
  box-shadow: 0 10px 40px rgba(0,0,0,0.25);
}
.auth-card h1 { margin-bottom: 0.25rem; }

/* Forms */
.stack-form { display: flex; flex-direction: column; gap: 1rem; }
label { display: flex; flex-direction: column; gap: 0.35rem; font-size: 0.9rem; font-weight: 600; }
input, select, textarea, button {
  font: inherit;
}
input[type=text], input[type=password], input[type=date], input[type=number], select, textarea {
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  color: var(--color-text);
  width: 100%;
}
textarea { resize: vertical; }
.field-checkbox { flex-direction: row; align-items: center; gap: 0.5rem; font-weight: 500; }
.field-checkbox input { width: auto; }

fieldset { border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1rem 1.25rem 1.25rem; margin: 0 0 1.25rem; background: var(--color-surface); }
legend { padding: 0 0.5rem; font-weight: 700; }
.field-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; }
.field-full { grid-column: 1 / -1; }

.type-picker { max-width: 420px; margin-bottom: 1.25rem; }

.btn {
  display: inline-block;
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  font-weight: 600;
  text-align: center;
}
.btn-primary { background: var(--color-primary); color: white; }
.btn-primary:hover { background: var(--color-primary-dark); text-decoration: none; }
.btn-secondary { background: var(--color-surface); color: var(--color-text); border-color: var(--color-border); }
.btn-secondary:hover { border-color: var(--color-primary); text-decoration: none; }
.btn-danger { background: var(--color-danger); color: white; }
.btn-link { background: none; color: var(--color-primary); border: none; }
.btn-block { width: 100%; }
.btn-sm { padding: 0.3rem 0.6rem; font-size: 0.85rem; }

.alert { padding: 0.75rem 1rem; border-radius: var(--radius); margin-bottom: 1rem; }
.alert-error { background: var(--color-void-bg); color: var(--color-void-text); }

.muted { color: var(--color-muted); }

/* Dashboard */
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 1rem; margin: 1.25rem 0; }
.stat-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1.25rem; text-align: center; }
.stat-number { font-size: 2rem; font-weight: 700; color: var(--color-primary-dark); }
.stat-label { color: var(--color-muted); font-size: 0.9rem; margin-top: 0.25rem; }

.section-header { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin: 1.5rem 0 0.75rem; flex-wrap: wrap; }
.quick-actions { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-bottom: 1rem; }

/* Tables */
.table-scroll { overflow-x: auto; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius); }
.data-table { width: 100%; border-collapse: collapse; min-width: 640px; }
.data-table th, .data-table td { text-align: left; padding: 0.65rem 0.9rem; border-bottom: 1px solid var(--color-border); white-space: nowrap; }
.data-table tbody tr:hover { background: #f8fafc; cursor: pointer; }
.data-table th { background: #f8fafc; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.03em; color: var(--color-muted); }

.badge { display: inline-block; padding: 0.15rem 0.6rem; border-radius: 999px; font-size: 0.78rem; font-weight: 700; }
.badge-ok { background: var(--color-ok-bg); color: var(--color-ok-text); }
.badge-void { background: var(--color-void-bg); color: var(--color-void-text); }

.filter-form { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-bottom: 1rem; }
.filter-form input, .filter-form select { width: auto; flex: 1 1 160px; }

.actions-cell { display: flex; flex-direction: column; gap: 0.4rem; white-space: normal; }
.inline-form { display: inline-flex; gap: 0.4rem; align-items: center; margin: 0; }
.reset-pass-form input { width: 130px; padding: 0.3rem 0.5rem; }

.course-input-table { width: 100%; border-collapse: collapse; min-width: 480px; }
.course-input-table th, .course-input-table td { padding: 0.4rem; border-bottom: 1px solid var(--color-border); }
.course-input-table input { padding: 0.35rem 0.5rem; }

@media (max-width: 640px) {
  .data-table thead { display: none; }
  .data-table, .data-table tbody, .data-table tr, .data-table td { display: block; width: 100%; }
  .data-table tr { border-bottom: 2px solid var(--color-border); padding: 0.5rem 0; }
  .data-table td { border: none; padding: 0.3rem 0.9rem; white-space: normal; }
  .data-table td::before { content: attr(data-label) ": "; font-weight: 700; color: var(--color-muted); }
}

/* Letter sheet (screen preview mirrors the printed page) */
.action-bar { display: flex; gap: 0.6rem; flex-wrap: wrap; }

.letter-sheet {
  background: white;
  max-width: 820px;
  margin: 1.5rem auto 3rem;
  padding: 3rem 3.5rem;
  box-shadow: 0 0 0 1px var(--color-border), 0 8px 30px rgba(0,0,0,0.08);
  color: #111;
}
.letter-sheet.is-voided { position: relative; }
.letter-sheet.is-voided::after {
  content: "VOIDED";
  position: absolute;
  top: 45%;
  left: 50%;
  transform: translate(-50%, -50%) rotate(-25deg);
  font-size: 5rem;
  font-weight: 900;
  color: rgba(200, 0, 0, 0.15);
  pointer-events: none;
}

.letterhead { display: flex; align-items: center; gap: 1rem; }
.letterhead-logo { max-height: 70px; }
.letterhead-text h2 { margin: 0; font-size: 1.6rem; }
.letterhead-text .subtitle { margin: 0.1rem 0; color: #444; font-size: 0.95rem; }
.letterhead-text .contact { margin: 0.1rem 0; color: #555; font-size: 0.85rem; }
.letterhead-rule { border: none; border-top: 2px solid #222; margin: 0.75rem 0 1.25rem; }

.letter-meta { display: flex; justify-content: space-between; font-size: 0.95rem; margin-bottom: 1.5rem; }
.letter-title { text-align: center; font-size: 1.5rem; margin: 0 0 1.5rem; }
.letter-body p { margin: 0 0 1rem; text-align: justify; }
.detail-table { border-collapse: collapse; margin: 1rem 0; width: 100%; max-width: 520px; }
.detail-table td, .detail-table th { padding: 0.35rem 0.75rem; border: 1px solid #ccc; }
.detail-table.course-table { max-width: 100%; }
.letter-signature { margin-top: 3.5rem; }

@page {
  size: A4;
  margin: 0.6in;
}

@media print {
  .no-print { display: none !important; }
  body { background: white; }
  /* @page margin already provides the page border, so the sheet itself
     should not add its own padding on top of it (that was pushing
     short letters onto a second page). */
  .letter-sheet { box-shadow: none; margin: 0; padding: 0; max-width: 100%; }
  .letter-body p { margin: 0 0 0.7rem; }
  .letter-title { margin-bottom: 1rem; }
  .letter-meta { margin-bottom: 1rem; }
  .letterhead-rule { margin: 0.5rem 0 0.9rem; }
  .letter-signature { margin-top: 2.5rem; }
}