/* LinkFlow site — follows system light/dark */
:root {
  color-scheme: light dark;
  --font: "Segoe UI", "IBM Plex Sans", "Helvetica Neue", sans-serif;
  --radius: 14px;
  --shadow: 0 1px 2px rgb(0 0 0 / 6%), 0 16px 40px rgb(0 0 0 / 8%);

  --bg: #f3f7f6;
  --bg-elev: #ffffff;
  --ink: #0f1c1a;
  --muted: #5b6b68;
  --line: #d5e0dd;
  --accent: #0f766e;
  --accent-strong: #115e59;
  --accent-soft: #ccfbf1;
  --warn-bg: #fff7ed;
  --warn-line: #fed7aa;
  --hero-glow: rgb(20 184 166 / 35%);
  --btn-primary-ink: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1211;
    --bg-elev: #121a19;
    --ink: #e8f0ee;
    --muted: #9aaca7;
    --line: #243230;
    --accent: #2dd4bf;
    --accent-strong: #5eead4;
    --accent-soft: rgb(45 212 191 / 14%);
    --warn-bg: rgb(120 53 15 / 28%);
    --warn-line: rgb(251 146 60 / 35%);
    --hero-glow: rgb(45 212 191 / 18%);
    --shadow: 0 1px 2px rgb(0 0 0 / 35%), 0 18px 48px rgb(0 0 0 / 35%);
    --btn-primary-ink: #042f2e;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: var(--font);
  background:
    radial-gradient(90% 55% at 8% -10%, var(--hero-glow), transparent 55%),
    radial-gradient(70% 40% at 100% 0%, rgb(15 118 110 / 12%), transparent 45%),
    var(--bg);
  color: var(--ink);
  line-height: 1.55;
}

a { color: var(--accent); }
a:hover { color: var(--accent-strong); }

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 18px 72px;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 36px;
}

.nav:has(.nav-links-only):not(:has(.brand)) {
  justify-content: flex-end;
  margin-bottom: 48px;
}

.nav-links-only {
  margin-left: auto;
}

.hero {
  text-align: left;
  margin-bottom: 36px;
}

.hero .hero-logo {
  width: 88px;
  height: 88px;
  border-radius: 22px;
  box-shadow: var(--shadow);
  display: block;
  margin-bottom: 20px;
}

.brand-name {
  margin: 0 0 10px;
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 750;
  letter-spacing: -0.04em;
  line-height: 1.05;
}

.tagline {
  margin: 0 0 14px;
  font-size: clamp(1.2rem, 2.8vw, 1.45rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--muted);
  line-height: 1.35;
}

.hero .lead {
  margin: 0 0 22px;
}

.hero .lead strong {
  color: var(--ink);
  font-weight: 700;
}

.hero .actions {
  margin: 0;
}

.cta-note {
  margin: 12px 0 0;
  font-size: 0.88rem;
  color: var(--muted);
  max-width: 36rem;
}

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

code {
  font-size: 0.9em;
  padding: 0.1em 0.35em;
  border-radius: 6px;
  background: var(--accent-soft);
}

.features h2 {
  margin-bottom: 14px;
}

.feature-list.flat {
  gap: 10px;
}

.feature-list.flat li {
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--line);
  border-radius: 0;
  padding: 10px 0;
}

.feature-list.flat li:last-child {
  border-bottom: 0;
}

.audience {
  margin: 16px 0 0 !important;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 0.95rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  overflow: hidden;
  flex-shrink: 0;
  box-shadow: 0 0 0 1px var(--line), var(--shadow);
  background: linear-gradient(145deg, #14b8a6, #0f766e);
}

.brand-mark img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.brand-text strong {
  display: block;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.brand-text span {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 8px 10px;
  border-radius: 999px;
}

.nav-links a:hover {
  color: var(--ink);
  background: var(--accent-soft);
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(1.85rem, 5vw, 2.55rem);
  letter-spacing: -0.035em;
  line-height: 1.15;
}

.lead {
  margin: 0 0 22px;
  color: var(--muted);
  font-size: 1.08rem;
  max-width: 38rem;
}

.card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
  margin-bottom: 14px;
  box-shadow: var(--shadow);
}

.card h2 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.card p {
  margin: 0 0 12px;
  color: var(--muted);
}

.card p:last-child { margin-bottom: 0; }

.card.highlight {
  background: linear-gradient(180deg, var(--accent-soft), var(--bg-elev));
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
}

.card.warn {
  background: var(--warn-bg);
  border-color: var(--warn-line);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none !important;
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 11px 16px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 80ms ease, background 120ms ease, border-color 120ms ease;
}

.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--accent);
  color: var(--btn-primary-ink) !important;
}

.btn-primary:hover {
  background: var(--accent-strong);
}

.btn-secondary {
  background: transparent;
  color: var(--ink) !important;
  border-color: var(--line);
}

.btn-secondary:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, var(--line));
  background: var(--accent-soft);
}

.tips,
.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.tips li,
.feature-list li {
  background: color-mix(in srgb, var(--bg) 70%, var(--bg-elev));
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 0.95rem;
}

.tips strong,
.feature-list strong {
  color: var(--ink);
}

.meta {
  color: var(--muted);
  font-size: 0.95rem;
}

.site-footer {
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  justify-content: space-between;
}

.site-footer a {
  text-decoration: none;
  font-weight: 600;
}

.logo-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 18px;
}

.logo-row img.hero-logo {
  width: 72px;
  height: 72px;
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 999px;
  padding: 5px 10px;
  margin-bottom: 14px;
}

.reasons {
  display: grid;
  gap: 8px;
  margin: 12px 0 14px;
}

.reason {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: color-mix(in srgb, var(--bg) 55%, var(--bg-elev));
  cursor: pointer;
}

.reason:has(input:checked) {
  border-color: var(--accent);
  background: var(--accent-soft);
}

label.field {
  display: block;
  margin-bottom: 8px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

textarea,
input[type="email"] {
  width: 100%;
  font: inherit;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  margin-bottom: 12px;
  background: var(--bg-elev);
}

textarea {
  min-height: 96px;
  resize: vertical;
}

textarea:focus,
input[type="email"]:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 30%, transparent);
}

@media (max-width: 560px) {
  .nav {
    flex-direction: column;
    align-items: flex-start;
  }
}