:root {
  --ink: #15202b;
  --ink-soft: #3d4f5f;
  --paper: #eef3f6;
  --paper-elev: #f7fafb;
  --line: rgba(21, 32, 43, 0.12);
  --teal: #0b7a78;
  --teal-deep: #065e5c;
  --amber: #c9852d;
  --glow: rgba(11, 122, 120, 0.18);
  --shadow: 0 24px 60px rgba(21, 32, 43, 0.08);
  --font-display: "Fraunces", "Songti SC", "Noto Serif SC", serif;
  --font-body: "IBM Plex Sans", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  --max: 1080px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  background: var(--paper);
  overflow-x: hidden;
}

.atmosphere {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(900px 520px at 12% -10%, rgba(11, 122, 120, 0.16), transparent 60%),
    radial-gradient(700px 420px at 88% 8%, rgba(201, 133, 45, 0.12), transparent 55%),
    linear-gradient(180deg, #e8eef2 0%, var(--paper) 42%, #e6edf1 100%);
}

.grid-layer {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.35;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 78%);
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.topbar {
  max-width: var(--max);
  margin: 0 auto;
  padding: 28px 40px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  animation: rise 0.7s var(--ease) both;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 600;
}

.brand-mark {
  width: 12px;
  height: 12px;
  border-radius: 2px;
  background: linear-gradient(135deg, var(--teal), #1aa6a2);
  box-shadow: 0 0 0 4px var(--glow);
}

.brand-text {
  font-family: var(--font-display);
  font-size: 1.15rem;
  letter-spacing: 0.04em;
}

.nav {
  display: flex;
  gap: 28px;
}

.nav a {
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 0.95rem;
  transition: color 160ms ease;
}

.nav a:hover {
  color: var(--teal-deep);
}

.hero {
  max-width: var(--max);
  margin: 0 auto;
  padding: 88px 40px 72px;
  min-height: min(78vh, 720px);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--teal-deep);
  font-size: 0.82rem;
  animation: rise 0.75s var(--ease) 0.05s both;
}

.brand-hero {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(4.2rem, 9vw, 7.2rem);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--ink);
  animation: rise 0.8s var(--ease) 0.1s both;
}

.lede {
  margin: 22px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 2.6vw, 2.15rem);
  font-weight: 500;
  color: var(--ink);
  animation: rise 0.8s var(--ease) 0.18s both;
}

.support {
  margin: 18px 0 0;
  max-width: 34em;
  color: var(--ink-soft);
  font-size: 1.05rem;
  animation: rise 0.8s var(--ease) 0.26s both;
}

.cta-row {
  margin-top: 36px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  animation: rise 0.8s var(--ease) 0.34s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 10px;
  font-weight: 550;
  font-size: 0.95rem;
  text-decoration: none;
  transition: transform 160ms var(--ease), background 160ms ease, color 160ms ease, border-color 160ms ease;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--ink);
  color: #f4f8fa;
}

.btn-primary:hover {
  background: var(--teal-deep);
}

.btn-ghost {
  border: 1px solid var(--line);
  background: rgba(247, 250, 251, 0.65);
  color: var(--ink);
  backdrop-filter: blur(6px);
}

.btn-ghost:hover {
  border-color: rgba(11, 122, 120, 0.45);
  color: var(--teal-deep);
}

.notes,
.about {
  max-width: var(--max);
  margin: 0 auto;
  padding: 24px 40px 72px;
}

.section-head {
  margin-bottom: 28px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}

.section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.85rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.section-head p {
  margin: 8px 0 0;
  color: var(--ink-soft);
}

.note-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.note {
  padding: 26px 28px;
  border: 1px solid transparent;
  border-radius: 16px;
  background: linear-gradient(var(--paper-elev), var(--paper-elev)) padding-box,
    linear-gradient(135deg, rgba(11, 122, 120, 0.28), rgba(201, 133, 45, 0.18), rgba(21, 32, 43, 0.08)) border-box;
  box-shadow: var(--shadow);
  transition: transform 220ms var(--ease), box-shadow 220ms ease;
}

.note:hover {
  transform: translateY(-3px);
  box-shadow: 0 28px 70px rgba(21, 32, 43, 0.11);
}

.note time {
  display: block;
  margin-bottom: 10px;
  color: var(--teal-deep);
  font-size: 0.78rem;
}

.note h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.3;
}

.note p {
  margin: 12px 0 0;
  color: var(--ink-soft);
  max-width: 58ch;
}

.tag {
  display: inline-block;
  margin-top: 16px;
  padding: 4px 8px;
  border-radius: 6px;
  background: rgba(11, 122, 120, 0.08);
  color: var(--teal-deep);
  font-size: 0.74rem;
}

.about-body {
  max-width: 46em;
}

.about-body p {
  margin: 0 0 14px;
  color: var(--ink-soft);
}

.site-footer {
  margin-top: 24px;
  border-top: 1px solid var(--line);
  background: rgba(247, 250, 251, 0.72);
  backdrop-filter: blur(8px);
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 28px 40px 36px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  align-items: baseline;
  justify-content: space-between;
}

.footer-brand {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.footer-icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.86rem;
}

.footer-icp a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}

.footer-icp a:hover {
  color: var(--teal-deep);
  border-bottom-color: rgba(11, 122, 120, 0.45);
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 720px) {
  .topbar,
  .hero,
  .notes,
  .about,
  .footer-inner {
    padding-left: 22px;
    padding-right: 22px;
  }

  .hero {
    padding-top: 56px;
    min-height: auto;
  }

  .brand-hero {
    font-size: clamp(3.2rem, 18vw, 4.6rem);
  }

  .nav {
    gap: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}