/* gpucheck marketing site — single stylesheet, no dependencies */

:root {
  --bg: #0b0f14;
  --bg-raised: #11161d;
  --bg-terminal: #0d1117;
  --border: #1f2733;
  --border-bright: #2d3a4a;
  --text: #d7dee8;
  --text-dim: #8b98a9;
  --text-faint: #5c6878;
  --green: #4ade80;
  --green-dim: #22c55e;
  --amber: #fbbf24;
  --orange: #f97316;
  --blue: #60a5fa;
  --red: #f87171;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --maxw: 60rem;
  --radius: 10px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4.5rem;
}

body {
  margin: 0;
  background:
    radial-gradient(1100px 520px at 50% -120px, rgba(74, 222, 128, 0.07), transparent 65%),
    radial-gradient(900px 500px at 85% 28%, rgba(96, 165, 250, 0.045), transparent 60%),
    var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

::selection { background: rgba(74, 222, 128, 0.25); }

a { color: var(--green); text-decoration: none; transition: color 0.15s ease; }
a:hover { text-decoration: underline; }

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

code, pre, .mono { font-family: var(--mono); }

code {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.1em 0.35em;
  font-size: 0.9em;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 15, 20, 0.86);
  backdrop-filter: blur(12px) saturate(1.3);
  -webkit-backdrop-filter: blur(12px) saturate(1.3);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.7rem 1.25rem;
}

.logo {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  white-space: nowrap;
}
.logo:hover { text-decoration: none; }
.logo .prompt { color: var(--green); }

.nav-links {
  display: flex;
  gap: 1.25rem;
  margin-left: auto;
  align-items: center;
}

.nav-links a {
  color: var(--text-dim);
  font-size: 0.92rem;
}
.nav-links a:hover { color: var(--text); text-decoration: none; }

/* ---------- buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0.55rem 1.25rem;
  border-radius: 7px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.15s ease, box-shadow 0.2s ease,
              background-color 0.15s ease, border-color 0.15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn:active { transform: translateY(0) scale(0.98); }

.btn-primary {
  background: linear-gradient(180deg, #2fd371, var(--green-dim));
  color: #04120a;
  box-shadow: 0 2px 14px rgba(34, 197, 94, 0.22);
}
.btn-primary:hover {
  background: linear-gradient(180deg, #4ade80, #2fd371);
  box-shadow: 0 6px 26px rgba(74, 222, 128, 0.35);
}

.btn-ghost {
  border-color: var(--border-bright);
  color: var(--text);
}
.btn-ghost:hover {
  border-color: var(--text-faint);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.35);
}

.nav .btn { min-height: 2.25rem; padding: 0.35rem 0.95rem; font-size: 0.88rem; }

/* ---------- hero ---------- */

.hero {
  padding: 4.75rem 0 3rem;
  text-align: center;
}

.hero > * { animation: heroIn 0.7s ease both; }
.hero > :nth-child(2) { animation-delay: 0.08s; }
.hero > :nth-child(3) { animation-delay: 0.16s; }
.hero > :nth-child(4) { animation-delay: 0.22s; }
.hero > :nth-child(5) { animation-delay: 0.3s; }

@keyframes heroIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}

.hero h1 {
  font-size: clamp(2.1rem, 6.5vw, 3.3rem);
  line-height: 1.08;
  margin: 0 0 1.1rem;
  letter-spacing: -0.028em;
  font-weight: 750;
}

.hero h1 .accent {
  color: var(--green);
  text-shadow: 0 0 32px rgba(74, 222, 128, 0.35);
}

.hero .sub {
  font-size: clamp(1rem, 2.6vw, 1.2rem);
  color: var(--text-dim);
  max-width: 42rem;
  margin: 0 auto 2rem;
}

.hero-ctas {
  display: flex;
  gap: 0.9rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 1.1rem;
}

.hero-note {
  color: var(--text-faint);
  font-size: 0.85rem;
  font-family: var(--mono);
}

/* ---------- terminal ---------- */

.terminal {
  background: var(--bg-terminal);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 2.75rem auto 0;
  max-width: 46rem;
  text-align: left;
  box-shadow:
    0 0 0 1px rgba(74, 222, 128, 0.05),
    0 24px 70px rgba(0, 0, 0, 0.55),
    0 0 110px rgba(74, 222, 128, 0.08);
}

.term-bar {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.9rem;
  background: linear-gradient(180deg, #161d27, var(--bg-raised));
  border-bottom: 1px solid var(--border);
}

.term-bar .dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--border-bright);
}
.term-bar .dot.r { background: #ff5f57; }
.term-bar .dot.y { background: #febc2e; }
.term-bar .dot.g { background: #28c840; }

.term-title {
  margin-left: 0.5rem;
  color: var(--text-faint);
  font-family: var(--mono);
  font-size: 0.78rem;
}

.term-replay {
  margin-left: auto;
  background: none;
  border: 1px solid var(--border-bright);
  color: var(--text-dim);
  border-radius: 5px;
  font-family: var(--mono);
  font-size: 0.72rem;
  padding: 0.3rem 0.65rem;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.term-replay:hover { color: var(--green); border-color: var(--green-dim); }

.term-body {
  margin: 0;
  padding: 1rem 1.1rem 1.2rem;
  font-family: var(--mono);
  font-size: clamp(0.66rem, 2.8vw, 0.82rem);
  line-height: 1.55;
  height: 24em;
  overflow-x: auto;
  overflow-y: hidden;
  white-space: pre;
}

.term-body .t-cmd { color: var(--text); }
.term-body .t-prompt { color: var(--green); }
.term-body .t-dim { color: var(--text-faint); }
.term-body .t-out { color: var(--text-dim); }
.term-body .t-warn { color: var(--amber); }
.term-body .t-ok { color: var(--green); }
.term-body .t-link { color: var(--blue); }

.term-body .t-grade {
  color: var(--green);
  font-weight: 700;
  animation: gradeIn 0.9s ease both;
  text-shadow: 0 0 20px rgba(74, 222, 128, 0.45);
}

@keyframes gradeIn {
  0% { opacity: 0; filter: brightness(2.2); }
  40% { opacity: 1; filter: brightness(1.6); }
  100% { opacity: 1; filter: brightness(1); }
}

.cursor {
  display: inline-block;
  width: 0.55em;
  height: 1.1em;
  background: var(--green);
  vertical-align: text-bottom;
  animation: blink 1.06s steps(1) infinite;
}

@keyframes blink { 50% { opacity: 0; } }

/* ---------- sections ---------- */

section { padding: 4.5rem 0; }

.section-kicker {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--green);
  margin: 0 0 0.6rem;
}
.section-kicker::before { content: "// "; color: var(--text-faint); }

section h2 {
  font-size: clamp(1.55rem, 4.5vw, 2.1rem);
  margin: 0 0 0.75rem;
  letter-spacing: -0.02em;
  font-weight: 720;
}

.section-sub {
  color: var(--text-dim);
  max-width: 44rem;
  margin: 0 0 2.25rem;
}

/* ---------- how it works ---------- */

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.1rem;
}

.step {
  background: linear-gradient(180deg, #131a23, var(--bg-raised));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.35rem;
  transition: border-color 0.2s ease, box-shadow 0.25s ease;
}
.step:hover {
  border-color: var(--border-bright);
  box-shadow: 0 10px 34px rgba(0, 0, 0, 0.35);
}

.step .num {
  font-family: var(--mono);
  color: var(--green);
  font-size: 0.85rem;
  display: block;
  margin-bottom: 0.6rem;
}

.step h3 { margin: 0 0 0.5rem; font-size: 1.05rem; }
.step p { margin: 0; color: var(--text-dim); font-size: 0.93rem; }
.step code { font-size: 0.82em; }

/* ---------- telemetry graph ---------- */

.graph-card {
  background: var(--bg-terminal);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.25rem 0.75rem;
  overflow-x: auto;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.02), 0 14px 44px rgba(0, 0, 0, 0.35);
}

.graph-card svg { display: block; width: 100%; height: auto; min-width: 560px; }

.graph-legend {
  display: flex;
  gap: 1.4rem;
  flex-wrap: wrap;
  padding: 0.4rem 0.25rem 0.5rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-dim);
}

.graph-legend .key {
  display: inline-block;
  width: 1.1em;
  height: 3px;
  border-radius: 2px;
  vertical-align: middle;
  margin-right: 0.45em;
}

.graph-hint {
  display: none;
  color: var(--text-faint);
  font-family: var(--mono);
  font-size: 0.72rem;
  padding: 0.3rem 0.25rem 0.4rem;
}

/* line-draw animation */
.g-line {
  fill: none;
  stroke-width: 2.25;
  stroke-linejoin: round;
  stroke-linecap: round;
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
}
.g-line.l1 { filter: drop-shadow(0 0 5px rgba(249, 115, 22, 0.45)); }
.g-line.l2 { filter: drop-shadow(0 0 5px rgba(96, 165, 250, 0.45)); }
.g-line.l3 { filter: drop-shadow(0 0 5px rgba(74, 222, 128, 0.45)); }

.graph-drawn .g-line {
  transition: stroke-dashoffset 2.1s cubic-bezier(0.45, 0, 0.3, 1);
  stroke-dashoffset: 0;
}
.graph-drawn .g-line.l2 { transition-delay: 0.3s; }
.graph-drawn .g-line.l3 { transition-delay: 0.6s; }

.g-anno { opacity: 0; }
.graph-drawn .g-anno {
  transition: opacity 0.9s ease 2.2s;
  opacity: 1;
}

@media (prefers-reduced-motion: reduce) {
  .g-line, .graph-drawn .g-line { stroke-dashoffset: 0; transition: none; }
  .g-anno, .graph-drawn .g-anno { opacity: 1; transition: none; }
}

/* ---------- certificate ---------- */

.cert-grid {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 2rem;
  align-items: start;
}

.cert-grid h3 { margin: 0 0 0.9rem; font-size: 1.02rem; }
.cert-grid h3 + .proof-list { margin-top: 0; }

.proof-list { list-style: none; padding: 0; margin: 0 0 1.6rem; }

.proof-list li {
  position: relative;
  padding: 0 0 0.85rem 1.9rem;
  color: var(--text-dim);
  font-size: 0.95rem;
}
.proof-list li strong { color: var(--text); }

.proof-list li::before {
  position: absolute;
  left: 0;
  top: 0.05rem;
  font-family: var(--mono);
  font-weight: 700;
}
.proof-list.yes li::before { content: "✓"; color: var(--green); }
.proof-list.no li::before { content: "✗"; color: var(--red); }

.cert-tagline {
  border-left: 3px solid var(--green);
  padding: 0.7rem 1.1rem;
  margin: 1.6rem 0 0;
  background: linear-gradient(90deg, rgba(74, 222, 128, 0.07), var(--bg-raised) 55%);
  border-radius: 0 7px 7px 0;
  font-size: 1.02rem;
}
.cert-tagline strong { color: var(--green); }

/* sample certificate card */

.cert-card {
  background: linear-gradient(168deg, #141d2b 0%, #0d1117 65%);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius);
  padding: 1.5rem 1.5rem 1.25rem;
  font-family: var(--mono);
  font-size: 0.82rem;
  position: relative;
  overflow: hidden;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.4);
}

.cert-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(420px 180px at 80% 0%, rgba(74, 222, 128, 0.07), transparent 70%);
  pointer-events: none;
}

.cert-card::after {
  content: "SAMPLE";
  position: absolute;
  top: 1.4rem;
  right: -2.6rem;
  transform: rotate(38deg);
  background: var(--border);
  color: var(--text-faint);
  font-size: 0.68rem;
  letter-spacing: 0.25em;
  padding: 0.25rem 3rem;
}

.cert-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-bottom: 1px dashed var(--border-bright);
  padding-bottom: 0.8rem;
  margin-bottom: 0.9rem;
}

.cert-head .cert-title {
  color: var(--text);
  font-weight: 700;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
}

.cert-head .cert-id { color: var(--text-faint); font-size: 0.72rem; }

.cert-row {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.22rem 0;
}
.cert-row .k { color: var(--text-faint); }
.cert-row .v { color: var(--text); text-align: right; }

.cert-grade-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 0.9rem 0;
  padding: 0.8rem 1rem;
  background: rgba(74, 222, 128, 0.06);
  border: 1px solid rgba(74, 222, 128, 0.25);
  border-radius: 8px;
}

.cert-grade {
  font-size: 2.1rem;
  font-weight: 700;
  color: var(--green);
  line-height: 1;
  text-shadow: 0 0 24px rgba(74, 222, 128, 0.4);
}

.cert-grade-note { color: var(--text-dim); font-size: 0.78rem; }

.cert-sig {
  border-top: 1px dashed var(--border-bright);
  margin-top: 0.9rem;
  padding-top: 0.8rem;
  color: var(--text-faint);
  font-size: 0.72rem;
  line-height: 1.7;
  word-break: break-all;
}
.cert-sig .ok { color: var(--green); }

/* ---------- pricing ---------- */

.pricing {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  max-width: 46rem;
}

.price-card {
  background: linear-gradient(180deg, #131a23, var(--bg-raised));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem 1.5rem;
  display: flex;
  flex-direction: column;
  transition: border-color 0.2s ease, box-shadow 0.25s ease;
}
.price-card:hover { border-color: var(--border-bright); }

.price-card.featured {
  border-color: rgba(74, 222, 128, 0.45);
  box-shadow: 0 0 44px rgba(74, 222, 128, 0.07);
}
.price-card.featured:hover {
  border-color: rgba(74, 222, 128, 0.7);
  box-shadow: 0 0 54px rgba(74, 222, 128, 0.12);
}

.price-card h3 { margin: 0 0 0.25rem; font-size: 1.05rem; }

.price {
  font-size: 2.2rem;
  font-weight: 750;
  margin: 0.4rem 0 1rem;
  letter-spacing: -0.02em;
}
.price .per { font-size: 0.85rem; font-weight: 400; color: var(--text-faint); }

.price-card ul {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
  color: var(--text-dim);
  font-size: 0.92rem;
  flex: 1;
}
.price-card li { padding: 0.25rem 0 0.25rem 1.5rem; position: relative; }
.price-card li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--green);
  font-family: var(--mono);
}

.price-foot {
  margin-top: 0.9rem;
  color: var(--text-faint);
  font-size: 0.8rem;
}

/* ---------- install ---------- */

.cmd-block { max-width: 46rem; }

.cmd-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--bg-terminal);
  border: 1px solid var(--border-bright);
  border-radius: 8px;
  padding: 0.8rem 1rem;
  margin-bottom: 0.9rem;
  font-family: var(--mono);
  font-size: 0.88rem;
  overflow-x: auto;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.cmd-row:hover {
  border-color: var(--text-faint);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.3);
}

.cmd-row .prompt { color: var(--green); user-select: none; }
.cmd-row code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
  color: var(--text);
  white-space: nowrap;
}

.cmd-label {
  font-size: 0.82rem;
  color: var(--text-faint);
  margin: 1.1rem 0 0.4rem;
  font-family: var(--mono);
}

.copy-btn {
  margin-left: auto;
  flex-shrink: 0;
  background: none;
  border: 1px solid var(--border-bright);
  color: var(--text-dim);
  border-radius: 5px;
  font-family: var(--mono);
  font-size: 0.72rem;
  padding: 0.38rem 0.7rem;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease, transform 0.12s ease;
}
.copy-btn:hover { color: var(--text); border-color: var(--text-faint); }
.copy-btn:active { transform: scale(0.94); }
.copy-btn.copied { color: var(--green); border-color: var(--green-dim); }

/* ---------- FAQ ---------- */

.faq { max-width: 46rem; }

.faq details {
  border-bottom: 1px solid var(--border);
  padding: 0.35rem 0;
}

.faq summary {
  cursor: pointer;
  padding: 0.85rem 0;
  font-weight: 600;
  list-style: none;
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  transition: color 0.15s ease;
}
.faq summary:hover { color: var(--green); }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
  content: ">";
  font-family: var(--mono);
  color: var(--green);
  transition: transform 0.18s ease;
}
.faq details[open] summary::before { transform: rotate(90deg); }

.faq .a {
  color: var(--text-dim);
  font-size: 0.94rem;
  padding: 0 0 1rem 1.45rem;
  margin: 0;
}

/* ---------- footer ---------- */

footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 0 3rem;
  color: var(--text-faint);
  font-size: 0.85rem;
}

.foot-grid {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
}

.foot-links { display: flex; gap: 1.4rem; flex-wrap: wrap; }
.foot-links a { color: var(--text-dim); padding: 0.2rem 0; }
.foot-links a:hover { color: var(--text); }

footer .fine { margin-top: 1.2rem; max-width: 44rem; }

/* ---------- legal pages ---------- */

.legal {
  max-width: 44rem;
  margin: 0 auto;
  padding: 3rem 1.25rem 4rem;
}

.legal h1 { font-size: 1.9rem; letter-spacing: -0.02em; margin-bottom: 0.3rem; }
.legal .updated { color: var(--text-faint); font-size: 0.85rem; margin-bottom: 2rem; }
.legal h2 { font-size: 1.2rem; margin-top: 2.2rem; }
.legal p, .legal li { color: var(--text-dim); font-size: 0.95rem; }
.legal li { margin-bottom: 0.4rem; }
.legal strong { color: var(--text); }

/* ---------- reveal on scroll ---------- */

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.65s cubic-bezier(0.25, 0.1, 0.25, 1),
              transform 0.65s cubic-bezier(0.25, 0.1, 0.25, 1);
}
.reveal.shown { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .reveal.shown { opacity: 1; transform: none; transition: none; }
  .cursor { animation: none; }
  .hero > * { animation: none; }
  .term-body .t-grade { animation: none; }
  .btn, .btn:hover, .btn:active { transform: none; }
}

/* ---------- responsive ---------- */

@media (max-width: 760px) {
  .nav-links { gap: 0.9rem; }
  .nav-links a:not(.btn) { display: none; }

  .hero { padding-top: 3rem; }

  .hero-ctas {
    flex-direction: column;
    align-items: stretch;
    max-width: 21rem;
    margin-left: auto;
    margin-right: auto;
  }
  .hero-ctas .btn { min-height: 3rem; font-size: 1rem; }

  .steps { grid-template-columns: 1fr; }
  .cert-grid { grid-template-columns: 1fr; }
  .pricing { grid-template-columns: 1fr; }
  section { padding: 3.25rem 0; }

  .term-body { height: 25em; }

  .graph-card { padding: 1rem 1rem 0.6rem; }
  .graph-hint { display: block; }

  .faq summary { padding: 1rem 0; }

  .price-card .btn { min-height: 3rem; }

  .cert-card { font-size: 0.78rem; }
}

/* nav CTA: beat .nav-links a specificity so button text stays dark */
.nav-links a.btn-primary,
.nav-links a.btn-primary:hover { color: #04120a; }