:root {
  color-scheme: light;
  --bg: #fbfdfb;
  --surface: #ffffff;
  --surface-muted: #eef6f1;
  --ink: #17211e;
  --muted: #52645d;
  --brand: #0f5c4f;
  --brand-strong: #0b3f37;
  --accent: #b86f00;
  --line: #d7e3dc;
  --shadow: 0 18px 45px rgba(15, 61, 53, 0.12);
  --radius: 8px;
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  font-size: 16px;
  line-height: 1.7;
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--brand);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

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

a:focus-visible,
button:focus-visible {
  outline: 3px solid #f2b84b;
  outline-offset: 3px;
}

code {
  overflow-wrap: anywhere;
  border-radius: 6px;
  background: #f0f5f2;
  padding: 0.08rem 0.28rem;
  font-family: "Cascadia Mono", Consolas, monospace;
  font-size: 0.92em;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: 0.5rem;
  z-index: 50;
  transform: translateY(-160%);
  background: var(--brand-strong);
  color: #fff;
  padding: 0.6rem 0.8rem;
  border-radius: 6px;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(215, 227, 220, 0.95);
  background: rgba(251, 253, 251, 0.96);
  backdrop-filter: blur(12px);
}

.nav-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
}

.brand-link img {
  border-radius: 8px;
  box-shadow: 0 8px 18px rgba(15, 61, 53, 0.16);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.9rem;
  font-size: 0.95rem;
}

.nav-links a {
  color: var(--ink);
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--brand);
  text-decoration: underline;
}

.hero {
  min-height: 72vh;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--line);
  background-color: #f7fbf8;
  background-image: url("echotime-logo-horizontal-1600x512.png");
  background-repeat: no-repeat;
  background-position: calc(100% + 210px) 50%;
  background-size: min(940px, 84vw) auto;
}

.hero-inner {
  width: min(var(--max), calc(100% - 2.5rem));
  margin: 0 auto;
  padding: 5rem 0 5.5rem;
}

.eyebrow {
  margin: 0 0 0.65rem;
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.25;
  margin: 0 0 0.8rem;
  letter-spacing: 0;
}

h1 {
  max-width: 760px;
  font-size: clamp(2.3rem, 7vw, 4.8rem);
  font-weight: 800;
}

h2 {
  font-size: clamp(1.75rem, 4vw, 2.55rem);
}

h3 {
  font-size: 1.18rem;
}

p {
  margin: 0 0 1rem;
}

.hero-lead {
  max-width: 720px;
  color: var(--muted);
  font-size: clamp(1.06rem, 2vw, 1.26rem);
}

.hero-actions,
.link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.6rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  border-radius: 8px;
  padding: 0.72rem 1.05rem;
  font-weight: 700;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button.primary {
  background: var(--brand);
  color: #fff;
  box-shadow: 0 10px 24px rgba(15, 92, 79, 0.2);
}

.button.primary:hover {
  background: var(--brand-strong);
  color: #fff;
}

.button.secondary {
  border: 1px solid var(--brand);
  background: rgba(255, 255, 255, 0.72);
  color: var(--brand-strong);
}

.button.compact {
  min-height: 42px;
  margin-top: 0.7rem;
}

.download-note {
  max-width: 680px;
  margin-top: 1rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.notice-band {
  border-bottom: 1px solid var(--line);
  background: var(--brand-strong);
  color: #fff;
  padding: 2rem 1.25rem;
}

.notice-band p {
  color: rgba(255, 255, 255, 0.9);
}

.content-narrow {
  max-width: 860px;
  margin: 0 auto;
}

.section {
  padding: 5rem 1.25rem;
}

.section.tinted {
  border-block: 1px solid var(--line);
  background: var(--surface-muted);
}

.compact-section {
  padding-block: 3.5rem;
}

.section-heading,
.download-grid,
.feature-grid,
.facts-grid,
.split-layout,
.table-wrap,
.link-row {
  width: min(var(--max), 100%);
  margin-inline: auto;
}

.section-heading {
  margin-bottom: 2rem;
}

.section-heading p {
  max-width: 760px;
  color: var(--muted);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.download-panel {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 1rem;
  align-items: start;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}

.download-panel.muted {
  box-shadow: none;
}

.download-panel img {
  border-radius: 8px;
}

.download-panel p {
  margin-bottom: 0.45rem;
  color: var(--muted);
}

.hash {
  display: inline-block;
  max-width: 100%;
}

.feature-grid,
.facts-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.facts-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.tile {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.25rem;
}

.tile p {
  color: var(--muted);
}

.split-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  gap: 2rem;
  align-items: start;
}

.split-layout p {
  color: var(--muted);
}

.check-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  margin-bottom: 0.7rem;
  border-left: 4px solid var(--brand);
  background: var(--surface);
  padding: 0.8rem 1rem;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
}

caption {
  padding: 0.85rem 1rem;
  color: var(--muted);
  text-align: left;
}

th,
td {
  border-top: 1px solid var(--line);
  padding: 0.9rem 1rem;
  text-align: left;
  vertical-align: top;
}

th {
  background: #f0f6f3;
  color: var(--brand-strong);
}

.text-link {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: 0.55rem 0.8rem;
  font-weight: 700;
  text-decoration: none;
}

.document-page {
  padding: 4rem 1.25rem;
}

.document {
  width: min(880px, 100%);
  margin: 0 auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: clamp(1.25rem, 4vw, 3rem);
}

.document h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
}

.document h2 {
  margin-top: 2rem;
  font-size: 1.45rem;
}

.document h3 {
  margin-top: 1.35rem;
}

.document ul {
  padding-left: 1.35rem;
}

.doc-meta {
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #111c19;
  color: #fff;
  padding: 2rem 1.25rem;
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1rem;
  width: min(var(--max), 100%);
  margin: 0 auto;
}

.site-footer p {
  margin-bottom: 0.35rem;
  color: rgba(255, 255, 255, 0.78);
}

.site-footer a {
  color: #d7fff0;
}

@media (max-width: 860px) {
  .nav-shell {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    justify-content: flex-start;
  }

  .hero {
    min-height: auto;
    background-position: 100% 1.5rem;
    background-size: min(620px, 125vw) auto;
  }

  .hero-inner {
    padding: 4rem 0 4.5rem;
  }

  .download-grid,
  .feature-grid,
  .facts-grid,
  .split-layout,
  .footer-inner {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .nav-shell,
  .hero-inner {
    width: min(100% - 1.5rem, var(--max));
  }

  .section,
  .document-page,
  .notice-band {
    padding-inline: 0.75rem;
  }

  .download-panel {
    grid-template-columns: 1fr;
  }

  .download-panel img {
    width: 72px;
    height: 72px;
  }

  .button,
  .text-link {
    width: 100%;
  }

  table {
    min-width: 560px;
  }
}

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

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