/* weightedgpacalc.com — student-facing, mobile-first */
:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --ink: #0f172a;
  --muted: #5b6575;
  --line: #e4e9f2;
  --brand: #4f46e5;
  --brand-dark: #3730a3;
  --brand-soft: #eef2ff;
  --accent: #0d9488;
  --accent-soft: #f0fdfa;
  --warn-bg: #fffbeb;
  --warn-border: #fde68a;
  --warn-ink: #92400e;
  --ok: #047857;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgba(15,23,42,.04), 0 12px 28px rgba(15,23,42,.06);
  --max: 1040px;
  --font: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--brand); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--brand-dark); }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: -9999px; top: 0; background: var(--brand); color: #fff;
  padding: .5rem 1rem; z-index: 100;
}
.skip-link:focus { left: 0; }
.wrap { width: min(100% - 1.5rem, var(--max)); margin-inline: auto; }

.site-header {
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 40;
}
.nav {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: .5rem 1rem; padding: .7rem 0;
}
.logo {
  font-weight: 700; color: var(--ink); text-decoration: none;
  font-size: .98rem; letter-spacing: -.02em;
}
.logo span { color: var(--brand); }
.nav-links {
  display: flex; flex-wrap: wrap; gap: .15rem .85rem;
  list-style: none; margin: 0; padding: 0;
}
.nav-links a {
  color: var(--muted); text-decoration: none; font-size: .9rem;
  padding: .35rem .15rem; min-height: 40px;
  display: inline-flex; align-items: center;
}
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--brand); font-weight: 600; }

.hero { padding: 1.15rem 0 .5rem; }
.hero h1 {
  margin: 0 0 .4rem;
  font-size: clamp(1.4rem, 4.2vw, 1.9rem);
  line-height: 1.22; letter-spacing: -.025em;
}
.lede {
  color: var(--muted); margin: 0 0 .65rem; max-width: 62ch;
  font-size: 1rem; line-height: 1.5;
}
.badge-row { display: flex; flex-wrap: wrap; gap: .35rem; margin: 0 0 .55rem; }
.badge {
  display: inline-block; font-size: .7rem; font-weight: 650;
  padding: .2rem .5rem; border-radius: 999px;
  background: var(--brand-soft); color: var(--brand-dark); border: 1px solid #c7d2fe;
}
.badge.soft {
  background: var(--accent-soft); color: #115e59; border-color: #99f6e4;
}
.badge.warn {
  background: var(--warn-bg); color: var(--warn-ink); border-color: var(--warn-border);
}

.tool-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
  padding-bottom: 1.25rem;
}
@media (min-width: 900px) {
  .tool-grid { grid-template-columns: 1.35fr .9fr; align-items: start; }
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1rem 1rem 1.1rem;
}
.card h2 {
  margin: 0 0 .75rem;
  font-size: 1.05rem;
  letter-spacing: -.015em;
}
.controls {
  display: flex; flex-wrap: wrap; gap: .65rem 1.25rem;
  margin-bottom: .85rem;
  padding-bottom: .85rem;
  border-bottom: 1px solid var(--line);
}
.seg {
  display: flex; flex-wrap: wrap; gap: .35rem; align-items: center;
}
.seg-label {
  font-size: .78rem; font-weight: 650; color: var(--muted);
  text-transform: uppercase; letter-spacing: .04em; width: 100%;
}
.seg label.chip {
  display: inline-flex; align-items: center; gap: .35rem;
  border: 1px solid var(--line); border-radius: 999px;
  padding: .35rem .7rem; font-size: .88rem; cursor: pointer;
  background: #fff; min-height: 40px;
}
.seg label.chip:has(input:checked) {
  border-color: #a5b4fc; background: var(--brand-soft); color: var(--brand-dark); font-weight: 600;
}
.seg input { accent-color: var(--brand); }

.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 0 -.15rem; }
table.courses {
  width: 100%; border-collapse: collapse; min-width: 560px; font-size: .92rem;
}
table.courses th {
  text-align: left; font-size: .72rem; text-transform: uppercase; letter-spacing: .04em;
  color: var(--muted); font-weight: 650; padding: .35rem .4rem .5rem;
  border-bottom: 1px solid var(--line);
}
table.courses td { padding: .35rem .35rem; vertical-align: middle; }
.inp {
  width: 100%; border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: .55rem .6rem; font: inherit; background: #fff; color: var(--ink);
  min-height: 42px;
}
.inp:focus { outline: 2px solid #c7d2fe; outline-offset: 1px; border-color: #a5b4fc; }
.inp:disabled { opacity: .55; background: #f8fafc; }
.inp.name { min-width: 7rem; }
.inp.letter, .inp.type { min-width: 5.5rem; }
.inp.credits, .inp.pct { min-width: 4.5rem; max-width: 6rem; }
.btn-icon {
  border: 1px solid var(--line); background: #fff; border-radius: 8px;
  width: 40px; height: 40px; font-size: 1.25rem; line-height: 1; cursor: pointer; color: var(--muted);
}
.btn-icon:hover { color: #b91c1c; border-color: #fecaca; }

.prior {
  display: grid; gap: .65rem; grid-template-columns: 1fr 1fr;
  margin: .85rem 0 .35rem;
}
.prior label { display: flex; flex-direction: column; gap: .3rem; font-size: .86rem; color: var(--muted); }
.actions {
  display: flex; flex-wrap: wrap; gap: .45rem; margin-top: .85rem;
}
.btn {
  appearance: none; border: 1px solid transparent; border-radius: var(--radius-sm);
  padding: .65rem 1rem; font: inherit; font-weight: 650; cursor: pointer;
  min-height: 44px; display: inline-flex; align-items: center; justify-content: center;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-secondary { background: #fff; border-color: var(--line); color: var(--ink); }
.btn-secondary:hover { border-color: #c7d2fe; background: var(--brand-soft); }
.btn-ghost { background: transparent; color: var(--muted); border-color: transparent; }
.btn-ghost:hover { color: var(--ink); background: #f1f5f9; }

.results { position: sticky; top: 4.2rem; }
.results .big {
  font-size: clamp(2.2rem, 6vw, 2.85rem);
  font-weight: 750; letter-spacing: -.04em; line-height: 1.05;
  color: var(--brand-dark); margin: .15rem 0 .35rem;
}
.results .metric-label {
  font-size: .75rem; text-transform: uppercase; letter-spacing: .05em;
  color: var(--muted); font-weight: 650;
}
.metrics {
  display: grid; gap: .75rem; grid-template-columns: 1fr 1fr;
  margin: .85rem 0;
}
.metric {
  background: #f8fafc; border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: .7rem .75rem;
}
.metric .val { font-size: 1.35rem; font-weight: 700; letter-spacing: -.02em; }
.compare {
  display: flex; gap: .65rem; flex-wrap: wrap;
  background: var(--accent-soft); border: 1px solid #99f6e4;
  border-radius: var(--radius-sm); padding: .7rem .8rem; font-size: .9rem;
}
.compare strong { color: #115e59; }
.disclaimer {
  margin: .85rem 0 0;
  font-size: .82rem; color: var(--warn-ink);
  background: var(--warn-bg); border: 1px solid var(--warn-border);
  border-radius: var(--radius-sm); padding: .65rem .75rem; line-height: 1.45;
}
#emptyHint {
  font-size: .88rem; color: #b91c1c; margin: .5rem 0 0;
}
details.detail {
  margin-top: .85rem; border-top: 1px solid var(--line); padding-top: .65rem;
}
details.detail summary {
  cursor: pointer; font-weight: 650; font-size: .92rem; color: var(--ink);
  min-height: 40px; display: flex; align-items: center;
}
.detail table {
  width: 100%; border-collapse: collapse; font-size: .85rem; margin-top: .5rem;
}
.detail th, .detail td {
  text-align: left; padding: .4rem .35rem; border-bottom: 1px solid var(--line);
}
.detail th { color: var(--muted); font-size: .7rem; text-transform: uppercase; letter-spacing: .03em; }

.content { padding: 1.25rem 0 2rem; }
.content section {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.1rem 1.15rem; margin-bottom: 1rem;
  box-shadow: 0 1px 2px rgba(15,23,42,.03);
}
.content h2 {
  margin: 0 0 .55rem; font-size: 1.2rem; letter-spacing: -.02em;
}
.content h3 { margin: 1rem 0 .35rem; font-size: 1.02rem; }
.content p, .content li { color: #334155; }
.content ol, .content ul { padding-left: 1.2rem; }
.steps { display: grid; gap: .65rem; }
@media (min-width: 700px) {
  .steps { grid-template-columns: repeat(3, 1fr); }
}
.step {
  background: #f8fafc; border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: .75rem .8rem;
}
.step .n {
  display: inline-flex; width: 1.6rem; height: 1.6rem; border-radius: 999px;
  align-items: center; justify-content: center;
  background: var(--brand-soft); color: var(--brand-dark); font-weight: 700; font-size: .8rem;
  margin-bottom: .35rem;
}
.faq details {
  border-bottom: 1px solid var(--line); padding: .55rem 0;
}
.faq summary {
  cursor: pointer; font-weight: 650; min-height: 40px;
  display: flex; align-items: center;
}
.faq p { margin: .4rem 0 .2rem; font-size: .95rem; }

.site-footer {
  border-top: 1px solid var(--line); background: #fff;
  padding: 1.25rem 0 1.75rem; color: var(--muted); font-size: .88rem;
}
.site-footer nav { display: flex; flex-wrap: wrap; gap: .5rem 1rem; margin-bottom: .5rem; }
.site-footer a { color: var(--muted); text-decoration: none; }
.site-footer a:hover { color: var(--brand); }

#toast {
  position: fixed; bottom: 1.1rem; left: 50%; transform: translateX(-50%);
  background: #0f172a; color: #fff; padding: .65rem 1rem; border-radius: 999px;
  font-size: .88rem; z-index: 80; box-shadow: var(--shadow);
}

.legal { padding: 1.5rem 0 2.5rem; max-width: 720px; }
.legal h1 { font-size: 1.6rem; margin: 0 0 .75rem; }
.legal h2 { font-size: 1.1rem; margin: 1.25rem 0 .4rem; }
.legal p, .legal li { color: #334155; }

@media print {
  .site-header, .site-footer, .actions, .skip-link, .badge-row, #toast, .btn-icon { display: none !important; }
  body { background: #fff; }
  .card, .content section { box-shadow: none; border-color: #ccc; }
  .results { position: static; }
}