/* MyGPA — Stylesheet | Always light mode */

/* ── TOKENS ── */
:root {
  color-scheme: light only;

  --c-primary:      #1e3a5f;
  --c-primary-mid:  #2a5298;
  --c-primary-lite: #edf2f9;
  --c-accent:       #2ecc71;
  --c-accent-dark:  #27ae60;
  --c-warning:      #f39c12;
  --c-danger:       #e74c3c;

  --c-bg:           #ffffff;
  --c-bg-soft:      #f7f9fc;
  --c-bg-muted:     #eef1f6;
  --c-text:         #0f172a;
  --c-text-muted:   #64748b;
  --c-text-subtle:  #94a3b8;
  --c-border:       #e2e8f0;
  --c-border-mid:   #cbd5e1;

  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;

  --max-w:     840px;
  --radius:    14px;
  --radius-sm: 9px;
  --shadow-xs: 0 1px 3px rgba(15,23,42,.06);
  --shadow:    0 4px 20px rgba(15,23,42,.08);
  --shadow-md: 0 8px 32px rgba(15,23,42,.11);

  --t: .16s ease;
}

/* ── RESET ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  background: var(--c-bg);
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}

@media (prefers-color-scheme: dark) {
  html, body { background: #fff !important; color: #0f172a !important; }
  :root { color-scheme: light only; }
}

/* ── SKIP LINK ── */
.skip-link {
  position: absolute; top: -100%; left: 1rem;
  background: var(--c-primary); color: #fff;
  padding: .5rem 1rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  text-decoration: none; z-index: 9999; font-size: .875rem; font-weight: 600;
}
.skip-link:focus { top: 0; }

/* ── HEADER ── */
.site-header {
  background: var(--c-primary);
  color: #fff;
  position: sticky; top: 0; z-index: 100;
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.header-inner {
  max-width: var(--max-w); margin: 0 auto;
  padding: 0 1.5rem;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  min-height: 58px;
}
.site-logo {
  font-size: 1.2rem; font-weight: 800; color: #fff;
  text-decoration: none; white-space: nowrap; letter-spacing: -.03em;
}
.site-logo span { color: var(--c-accent); }

.site-nav { display: flex; gap: .15rem; flex-wrap: wrap; align-items: center; }
.site-nav a {
  color: rgba(255,255,255,.72);
  text-decoration: none; font-size: .8rem; font-weight: 500;
  padding: .3rem .6rem; border-radius: 6px;
  transition: background var(--t), color var(--t);
  white-space: nowrap;
}
.site-nav a:hover, .site-nav a[aria-current="page"] {
  background: rgba(255,255,255,.12); color: #fff;
}

/* ── MAIN ── */
main { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem 4rem; }

/* ── HERO ── */
.hero { text-align: center; padding: 3rem 0 1.75rem; }
.hero h1 {
  font-size: clamp(1.9rem, 4.5vw, 2.65rem);
  font-weight: 800; color: var(--c-primary);
  line-height: 1.12; margin-bottom: .6rem;
  letter-spacing: -.03em;
}
.hero p {
  font-size: 1.05rem; color: var(--c-text-muted);
  max-width: 540px; margin: 0 auto; line-height: 1.6;
}

/* ── CALCULATOR CARD ── */
.calc-card {
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden; margin-bottom: 2rem;
}

/* Tabs */
.calc-tabs {
  display: flex;
  background: var(--c-bg-soft);
  border-bottom: 1px solid var(--c-border);
  padding: 0 .75rem; gap: .2rem;
}
.tab-btn {
  flex: 1; padding: .8rem .5rem;
  background: none; border: none;
  border-bottom: 2.5px solid transparent; margin-bottom: -1px;
  font-size: .82rem; font-weight: 600; color: var(--c-text-muted);
  cursor: pointer; font-family: var(--font-sans);
  transition: color var(--t), border-color var(--t);
  min-height: 46px; letter-spacing: .005em;
}
.tab-btn:hover { color: var(--c-primary); }
.tab-btn.active { color: var(--c-primary); border-bottom-color: var(--c-accent); }

.tab-panel { display: none; padding: 1.75rem; }
.tab-panel.active { display: block; }

/* Course table */
.course-table-wrap { overflow-x: auto; }
.course-table { width: 100%; border-collapse: collapse; font-size: .9rem; }
.course-table th {
  text-align: left; padding: .45rem .5rem .6rem;
  font-size: .7rem; font-weight: 700; color: var(--c-text-subtle);
  border-bottom: 1px solid var(--c-border);
  text-transform: uppercase; letter-spacing: .07em;
}
.course-table td { padding: .35rem .3rem; vertical-align: middle; }
.course-table tbody tr:hover { background: var(--c-bg-soft); }

.course-table input,
.course-table select {
  width: 100%; padding: .48rem .6rem;
  font-size: .92rem;
  border: 1.5px solid var(--c-border);
  border-radius: var(--radius-sm);
  background: var(--c-bg); color: var(--c-text);
  font-family: var(--font-sans); min-height: 40px;
  transition: border-color var(--t), box-shadow var(--t);
}
.course-table input:focus,
.course-table select:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: 0 0 0 3px rgba(30,58,95,.1);
}
.course-table input[type="number"] { width: 70px; }
.course-name-input { min-width: 120px; }

.btn-remove {
  background: none; border: 1.5px solid var(--c-border);
  border-radius: var(--radius-sm); color: var(--c-text-subtle);
  font-size: 1rem; cursor: pointer;
  width: 34px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  transition: background var(--t), color var(--t), border-color var(--t);
  font-family: var(--font-sans);
}
.btn-remove:hover { background: #fff0ef; color: var(--c-danger); border-color: var(--c-danger); }

.calc-actions { display: flex; gap: .75rem; margin-top: 1.25rem; flex-wrap: wrap; }

/* ── BUTTONS ── */
.btn {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .58rem 1.2rem; border-radius: var(--radius-sm);
  font-size: .875rem; font-weight: 600; cursor: pointer; border: none;
  transition: background var(--t), box-shadow var(--t), transform .1s;
  text-decoration: none; min-height: 40px;
  font-family: var(--font-sans); letter-spacing: .01em;
}
.btn:active { transform: scale(.98); }

.btn-primary { background: var(--c-primary); color: #fff; box-shadow: var(--shadow-xs); }
.btn-primary:hover { background: #162d4a; box-shadow: var(--shadow); }

.btn-secondary {
  background: var(--c-bg); color: var(--c-text);
  border: 1.5px solid var(--c-border-mid);
}
.btn-secondary:hover { background: var(--c-bg-soft); border-color: var(--c-primary); color: var(--c-primary); }

/* ── GPA RESULT ── */
.gpa-result {
  margin-top: 1.5rem;
  border-radius: var(--radius);
  background: var(--c-bg-soft);
  border: 1.5px solid var(--c-border);
  padding: 1.5rem 1.75rem;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  align-items: center;
  transition: border-color .25s, background .25s;
  position: relative;
  overflow: hidden;
}
/* left accent stripe */
.gpa-result::before {
  content: '';
  position: absolute; left: 0; top: 0; bottom: 0; width: 4px;
  background: var(--c-border-mid);
  border-radius: var(--radius) 0 0 var(--radius);
  transition: background .25s;
}
.gpa-result.result-great { border-color: #bbf7d0; background: linear-gradient(120deg,#f0fdf6,#f7fffe); }
.gpa-result.result-great::before { background: var(--c-accent); }
.gpa-result.result-good  { border-color: #fde68a; background: linear-gradient(120deg,#fffbeb,#fefce8); }
.gpa-result.result-good::before  { background: var(--c-warning); }
.gpa-result.result-low   { border-color: #fecaca; background: linear-gradient(120deg,#fef2f2,#fff5f5); }
.gpa-result.result-low::before   { background: var(--c-danger); }

/* circular ring around the GPA number */
.gpa-ring-wrap {
  position: relative; width: 90px; height: 90px; flex-shrink: 0;
}
.gpa-ring-wrap::before {
  content: '';
  position: absolute; inset: 0; border-radius: 50%;
  background: conic-gradient(
    var(--ring-color, var(--c-border-mid)) var(--ring-pct, 0%),
    var(--c-border) var(--ring-pct, 0%)
  );
}
.gpa-ring-wrap::after {
  content: '';
  position: absolute; inset: 10px; border-radius: 50%;
  background: #f0fdf6;
}
.gpa-result.result-good  .gpa-ring-wrap::after { background: #fffcf0; }
.gpa-result.result-low   .gpa-ring-wrap::after { background: #fff5f5; }

.gpa-ring-wrap .gpa-number {
  position: absolute; inset: 0; z-index: 1;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
}

/* fallback: gpa-number without ring (old HTML / cumulative result) */
.gpa-number {
  font-size: 3rem; font-weight: 800; line-height: 1;
  color: var(--c-primary); letter-spacing: -.04em;
}
.gpa-result.result-great .gpa-number { color: #15803d; }
.gpa-result.result-good  .gpa-number { color: #b45309; }
.gpa-result.result-low   .gpa-number { color: #dc2626; }

.gpa-meta { display: flex; flex-direction: column; gap: .25rem; }
.gpa-label { font-size: .72rem; font-weight: 700; color: var(--c-text-subtle); text-transform: uppercase; letter-spacing: .07em; }
.gpa-letter { font-size: 1.35rem; font-weight: 800; color: var(--c-primary); line-height: 1.1; }
.gpa-credits { font-size: .82rem; color: var(--c-text-muted); }

/* ── FORM INPUTS ── */
.calc-form { display: flex; flex-direction: column; gap: 1.25rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-group { display: flex; flex-direction: column; gap: .38rem; }
.form-group label {
  font-size: .78rem; font-weight: 700; color: var(--c-text-muted);
  text-transform: uppercase; letter-spacing: .05em;
}
.form-group input {
  padding: .58rem .875rem; font-size: .97rem;
  border: 1.5px solid var(--c-border); border-radius: var(--radius-sm);
  background: var(--c-bg); color: var(--c-text);
  font-family: var(--font-sans); min-height: 44px;
  transition: border-color var(--t), box-shadow var(--t);
}
.form-group input:focus {
  outline: none; border-color: var(--c-primary);
  box-shadow: 0 0 0 3px rgba(30,58,95,.1);
}

.form-divider {
  text-align: center; color: var(--c-text-subtle);
  font-size: .7rem; font-weight: 700;
  letter-spacing: .09em; text-transform: uppercase;
  position: relative;
}
.form-divider::before, .form-divider::after {
  content: ''; position: absolute; top: 50%;
  width: 38%; height: 1px; background: var(--c-border);
}
.form-divider::before { left: 0; }
.form-divider::after  { right: 0; }

/* ── AD SLOTS ── */
.ad-slot {
  min-height: 90px; background: var(--c-bg-soft);
  display: flex; align-items: center; justify-content: center;
  border: 1px dashed var(--c-border-mid); border-radius: var(--radius-sm);
  color: var(--c-text-subtle); font-size: 10px;
  letter-spacing: .05em; text-transform: uppercase;
  margin: 1.75rem 0;
}
.ad-slot--in-content { min-height: 280px; }
@media (max-width: 600px) {
  .ad-slot           { min-height: 50px; }
  .ad-slot--in-content { min-height: 250px; }
}

/* ── SECTION HEADINGS ── */
.section-title { font-size: 1.4rem; font-weight: 800; color: var(--c-primary); margin: 2.5rem 0 1.25rem; letter-spacing: -.025em; }
.section-title--sm { font-size: 1.1rem; font-weight: 700; color: var(--c-primary); margin: 1.75rem 0 .875rem; }

/* ── TOOL CARDS ── */
.tools-grid {
  display: grid; grid-template-columns: repeat(auto-fill,minmax(200px,1fr));
  gap: 1rem; margin-bottom: 2rem;
}
.tool-card {
  background: var(--c-bg);
  border: 1.5px solid var(--c-border); border-radius: var(--radius);
  padding: 1.25rem 1.2rem 1.1rem;
  text-decoration: none; color: var(--c-text);
  display: flex; flex-direction: column; gap: .3rem;
  transition: box-shadow var(--t), transform var(--t), border-color var(--t);
}
.tool-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); border-color: var(--c-primary); }
.tool-card-icon  { font-size: 1.4rem; margin-bottom: .1rem; }
.tool-card-title { font-weight: 700; font-size: .93rem; color: var(--c-primary); }
.tool-card-desc  { font-size: .815rem; color: var(--c-text-muted); line-height: 1.45; }

/* ── GPA SCALE TABLE ── */
.gpa-scale-table {
  width: 100%; border-collapse: collapse; font-size: .875rem;
  margin-bottom: 1.5rem; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-xs);
}
.gpa-scale-table th {
  background: var(--c-primary); color: #fff;
  padding: .7rem 1rem; text-align: left;
  font-size: .72rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .07em;
}
.gpa-scale-table td { padding: .55rem 1rem; border-bottom: 1px solid var(--c-border); color: var(--c-text); }
.gpa-scale-table tbody tr:last-child td { border-bottom: none; }
.gpa-scale-table tr:nth-child(even) td { background: var(--c-bg-soft); }

.gpa-badge {
  display: inline-flex; align-items: center;
  padding: .18rem .65rem; border-radius: 20px;
  font-size: .7rem; font-weight: 700; color: #fff; letter-spacing: .02em;
}
.badge-great { background: #16a34a; }
.badge-good  { background: #d97706; }
.badge-avg   { background: #ea580c; }
.badge-low   { background: #dc2626; }

/* ── FAQ ── */
.faq-list { display: flex; flex-direction: column; gap: .4rem; margin-bottom: 2rem; }
.faq-item {
  border: 1.5px solid var(--c-border); border-radius: var(--radius);
  overflow: hidden; transition: border-color var(--t);
}
.faq-item:hover { border-color: var(--c-border-mid); }
.faq-item[open] { border-color: var(--c-primary); }

.faq-item summary {
  padding: .95rem 1.25rem;
  font-weight: 600; cursor: pointer; list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  font-size: .93rem; color: var(--c-text);
  background: var(--c-bg);
  transition: background var(--t);
  min-height: 50px; user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: '+'; font-size: 1.1rem; font-weight: 400;
  color: var(--c-text-muted); flex-shrink: 0;
  width: 22px; text-align: center;
}
.faq-item[open] summary { background: var(--c-primary-lite); color: var(--c-primary); }
.faq-item[open] summary::after { content: '−'; color: var(--c-primary); }
.faq-item summary:hover { background: var(--c-bg-soft); }
.faq-item[open] summary:hover { background: var(--c-primary-lite); }

.faq-body {
  padding: 1rem 1.25rem 1.2rem;
  font-size: .88rem; line-height: 1.75;
  border-top: 1px solid var(--c-border); color: var(--c-text);
}
.faq-body p { margin-bottom: .7rem; }
.faq-body p:last-child { margin-bottom: 0; }
.faq-section { margin-bottom: 2rem; }

/* ── CONTENT ── */
.content-article h2 { font-size: 1.3rem; color: var(--c-primary); margin: 2.25rem 0 .875rem; font-weight: 800; letter-spacing: -.02em; }
.content-article h3 { font-size: 1.02rem; color: var(--c-primary); margin: 1.75rem 0 .5rem; font-weight: 700; }
.content-article p  { margin-bottom: 1rem; font-size: .93rem; line-height: 1.75; color: var(--c-text); }
.content-article ul, .content-article ol { padding-left: 1.5rem; margin-bottom: 1rem; }
.content-article li { margin-bottom: .45rem; font-size: .93rem; line-height: 1.65; }
.content-article strong { color: var(--c-primary); font-weight: 700; }

.info-box {
  background: var(--c-bg-soft);
  border-left: 3px solid var(--c-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: .95rem 1.2rem; margin: 1.5rem 0;
  font-size: .88rem; line-height: 1.65;
}
.info-box.accent  { border-left-color: var(--c-accent); }
.info-box.warning { border-left-color: var(--c-warning); }

.tips-list { display: flex; flex-direction: column; gap: .75rem; margin-bottom: 2rem; }
.tip-item {
  display: flex; gap: .875rem; align-items: flex-start;
  background: var(--c-bg-soft); border: 1px solid var(--c-border);
  border-radius: var(--radius); padding: .95rem 1.1rem;
  font-size: .88rem; line-height: 1.65;
  transition: border-color var(--t);
}
.tip-item:hover { border-color: var(--c-border-mid); }
.tip-num {
  background: var(--c-primary); color: #fff; border-radius: 50%;
  width: 26px; height: 26px; display: flex; align-items: center; justify-content: center;
  font-size: .75rem; font-weight: 800; flex-shrink: 0; margin-top: .1rem;
}

.related-links { display: flex; flex-wrap: wrap; gap: .45rem; margin: 1.75rem 0; }
.related-link {
  background: var(--c-bg-soft); border: 1.5px solid var(--c-border);
  border-radius: 999px; padding: .32rem .95rem;
  font-size: .81rem; color: var(--c-primary); text-decoration: none; font-weight: 600;
  transition: background var(--t), border-color var(--t), color var(--t);
}
.related-link:hover { background: var(--c-primary); color: #fff; border-color: var(--c-primary); }

.cta-box {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-mid) 100%);
  color: #fff; border-radius: var(--radius);
  padding: 2.25rem 2rem; text-align: center; margin: 2.5rem 0;
  box-shadow: var(--shadow-md);
}
.cta-box h2 { color: #fff; font-size: 1.35rem; margin-bottom: .5rem; font-weight: 800; letter-spacing: -.02em; }
.cta-box p  { opacity: .86; font-size: .88rem; margin-bottom: 1.5rem; }

.btn-cta {
  display: inline-flex; align-items: center; gap: .4rem;
  background: var(--c-accent); color: #fff;
  padding: .78rem 1.75rem; border-radius: var(--radius-sm);
  font-weight: 700; text-decoration: none; font-size: .975rem;
  transition: background var(--t), box-shadow var(--t), transform .1s;
  box-shadow: 0 4px 14px rgba(46,204,113,.35);
}
.btn-cta:hover { background: var(--c-accent-dark); box-shadow: 0 6px 20px rgba(46,204,113,.45); transform: translateY(-1px); }
.btn-cta:active { transform: scale(.98); }

.compact-calc {
  background: var(--c-bg-soft); border: 1.5px solid var(--c-border);
  border-radius: var(--radius); padding: 1.5rem; margin: 1.75rem 0;
}
.compact-calc h3 { font-size: 1rem; color: var(--c-primary); margin-bottom: 1rem; font-weight: 700; }

/* ── COMPARISON TABLE ── */
.comparison-table {
  width: 100%; border-collapse: collapse; font-size: .875rem;
  margin-bottom: 1.75rem; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-xs);
}
.comparison-table th {
  background: var(--c-bg-soft); color: var(--c-primary);
  padding: .65rem 1rem; text-align: left;
  border-bottom: 2px solid var(--c-border);
  font-size: .75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .06em;
}
.comparison-table td { padding: .55rem 1rem; border-bottom: 1px solid var(--c-border); color: var(--c-text); }
.comparison-table tr:last-child td { border-bottom: none; }
.comparison-table .highlight { font-weight: 700; color: var(--c-accent-dark); }

/* ── QUICK ANSWER ── */
.quick-answer {
  background: #f0fdf6;
  border-left: 3px solid var(--c-accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1rem 1.3rem; margin: 0 0 1.75rem;
  font-size: .92rem; line-height: 1.72; color: var(--c-text);
}
.quick-answer-label {
  display: block; font-size: .68rem; font-weight: 800;
  text-transform: uppercase; letter-spacing: .1em; color: #059669;
  margin-bottom: .35rem;
}
.quick-answer p { margin: 0; }

/* ── KEY INSIGHT ── */
.key-insight {
  background: #eff6ff;
  border-left: 3px solid #3b82f6;
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1rem 1.2rem; margin: 1.5rem 0;
  font-size: .88rem; line-height: 1.7;
}

/* ── FOOTER ── */
.site-footer {
  background: var(--c-primary); color: rgba(255,255,255,.7);
  padding: 3rem 1.5rem 1.75rem; margin-top: 4rem;
}
.footer-inner { max-width: var(--max-w); margin: 0 auto; }
.footer-grid {
  display: grid; grid-template-columns: repeat(auto-fill,minmax(175px,1fr));
  gap: 2rem 1.5rem; margin-bottom: 2.5rem;
}
.footer-col h3 {
  color: #fff; font-size: .72rem; margin-bottom: .875rem;
  text-transform: uppercase; letter-spacing: .09em; font-weight: 700;
}
.footer-col a {
  display: block; color: rgba(255,255,255,.6); text-decoration: none;
  font-size: .815rem; margin-bottom: .4rem; transition: color var(--t); line-height: 1.45;
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding-top: 1.5rem;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: .75rem; font-size: .78rem; color: rgba(255,255,255,.45);
}
.footer-bottom a { color: rgba(255,255,255,.55); text-decoration: none; transition: color var(--t); }
.footer-bottom a:hover { color: #fff; }

/* ── MISC ── */
.breadcrumb { font-size: .78rem; color: var(--c-text-subtle); margin-bottom: 1rem; }
.breadcrumb a { color: var(--c-text-muted); text-decoration: none; transition: color var(--t); }
.breadcrumb a:hover { color: var(--c-primary); }
.breadcrumb span { color: var(--c-text-subtle); margin: 0 .3rem; }

.page-intro { font-size: .97rem; color: var(--c-text-muted); margin-bottom: 1.75rem; max-width: 680px; line-height: 1.75; }
.divider { height: 1px; background: var(--c-border); margin: 2.5rem 0; }

/* ── FOCUS ── */
:focus-visible { outline: 2px solid var(--c-primary); outline-offset: 2px; border-radius: 3px; }

/* ── PERFECT GPA BADGE ── */
.perfect-gpa-badge {
  display: inline-flex; align-items: center; gap: .4rem;
  margin-top: .75rem; padding: .42rem .95rem;
  background: linear-gradient(135deg,#f6d365,#fda085);
  color: #7c3a00; font-weight: 700; font-size: .9rem;
  border-radius: 999px; box-shadow: 0 4px 16px rgba(253,160,133,.4);
  opacity: 0; transform: scale(.7) translateY(8px);
  transition: opacity .35s ease, transform .35s cubic-bezier(.34,1.56,.64,1);
  letter-spacing: .01em;
}
.perfect-gpa-badge--show { opacity: 1; transform: scale(1) translateY(0); }

/* ── RESPONSIVE ── */
@media (max-width: 680px) {
  main { padding: 0 1rem 3rem; }
  .header-inner { padding: 0 1rem; }
  .site-footer  { padding: 2.5rem 1rem 1.5rem; }
}
@media (max-width: 640px) {
  .header-inner  { flex-direction: column; padding: .5rem 1rem; min-height: auto; gap: .4rem; }
  .site-nav      { gap: .08rem; justify-content: center; }
  .site-nav a    { font-size: .74rem; padding: .26rem .5rem; }
  .form-row      { grid-template-columns: 1fr; }
  .tools-grid    { grid-template-columns: 1fr 1fr; }
  .footer-grid   { grid-template-columns: 1fr 1fr; }
  .tab-btn       { font-size: .79rem; }
  .tab-panel     { padding: 1.25rem 1rem; }
  .gpa-result    { padding: 1.1rem 1.25rem; gap: 1rem; }
  .hero          { padding: 2rem 0 1.5rem; }
  .gpa-number    { font-size: 1.5rem; }
  .gpa-ring-wrap { width: 76px; height: 76px; }
}
@media (max-width: 400px) {
  .tools-grid  { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .site-nav a  { font-size: .7rem; padding: .22rem .38rem; }
}