/* ixosnsfr — 浅色软件官网单页 */
:root {
  --bg: #f6f9fc;
  --surface: #ffffff;
  --text: #0f172a;
  --text-body: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #eff6ff;
  --shadow: 0 18px 48px rgba(15, 23, 42, 0.06);
  --radius: 16px;
  --wrap: 72rem;
  --header-h: 4.25rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-body);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
  font-size: 1rem;
}

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

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: 0 0 8px 0;
}

.skip-link:focus {
  left: 0;
}

.wrap {
  width: min(var(--wrap), calc(100% - 2.4rem));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: inherit;
  text-decoration: none !important;
}

.brand:hover {
  text-decoration: none !important;
}

.brand__title {
  display: block;
  font-size: 1.02rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1.2;
}

.brand__sub {
  display: block;
  font-size: 0.76rem;
  color: var(--muted);
  line-height: 1.2;
}

.site-nav {
  display: none;
  gap: 1.35rem;
  font-size: 0.9rem;
}

.site-nav a {
  color: var(--text-body);
  text-decoration: none;
  font-weight: 500;
}

.site-nav a:hover {
  color: var(--accent);
  text-decoration: none;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.62rem 1.15rem;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  line-height: 1.2;
  border-radius: 10px;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none !important;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.btn--primary {
  color: #fff !important;
  background: var(--accent);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.22);
}

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

.btn--secondary {
  color: var(--accent) !important;
  background: var(--surface);
  border-color: #bfdbfe;
}

.btn--secondary:hover {
  background: var(--accent-soft);
}

.btn--text {
  color: var(--accent) !important;
  background: transparent;
  padding-inline: 0.35rem;
}

.menu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

.mobile-nav {
  display: none;
  flex-direction: column;
  gap: 0.15rem;
  padding: 0.5rem 0 1rem;
  border-top: 1px solid var(--line);
}

.mobile-nav.is-open {
  display: flex;
}

.mobile-nav a {
  padding: 0.55rem 0;
  color: var(--text-body);
  text-decoration: none;
  font-weight: 500;
}

@media (min-width: 960px) {
  .site-nav {
    display: flex;
  }
  .menu-btn {
    display: none;
  }
}

.section {
  padding: 5rem 0;
}

.section__eyebrow {
  display: inline-block;
  margin: 0 0 1rem;
  padding: 0.35rem 0.8rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid #bfdbfe;
  border-radius: 999px;
}

.section h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.65rem, 3.2vw, 2.35rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--text);
}

.section__sub {
  margin: 0 0 1.5rem;
  max-width: 42rem;
  font-size: 1.05rem;
  color: var(--muted);
}

.section__sub--center {
  margin-inline: auto;
  text-align: center;
}

.section-head--center {
  margin-bottom: 0.25rem;
}

.section-head--center .section__sub {
  margin-bottom: 0;
}

.prose p {
  margin: 0 0 1.1rem;
  max-width: 44rem;
}

.prose .highlight {
  margin: 1.5rem 0 0;
  padding: 1rem 1.15rem;
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 10px 10px 0;
  color: var(--text);
}

.hero {
  padding: 4.5rem 0 5rem;
  background: linear-gradient(180deg, #ffffff 0%, var(--bg) 100%);
}

.hero__grid {
  display: grid;
  gap: 2.5rem;
  align-items: start;
}

.hero h1 {
  margin: 0 0 1.15rem;
  font-size: clamp(2rem, 4.5vw, 3.15rem);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.03em;
  color: var(--text);
}

.hero__lead {
  margin: 0 0 1.1rem;
  max-width: 36rem;
  font-size: 1.08rem;
}

.hero__note {
  margin: 0 0 1.6rem;
  max-width: 36rem;
  padding: 0.85rem 1rem;
  font-size: 0.88rem;
  color: var(--muted);
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 1.5rem;
}

.hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.hero__tags li {
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.visual {
  margin: 0;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
  overflow: hidden;
}

.visual img {
  display: block;
  width: 100%;
  height: auto;
}

.visual--hero {
  padding: 0.65rem;
}

@media (min-width: 960px) {
  .hero__grid {
    grid-template-columns: 0.95fr 1.05fr;
    gap: 3rem;
  }
}

.intro-block .prose p,
.intro-block .section__sub {
  max-width: 52rem;
}

.intro-block .visual--wide {
  margin-top: 2.5rem;
}

.feature-band {
  padding: 2rem 0 0;
}

.feature-lines {
  display: grid;
  gap: 0.75rem;
  margin: 2rem 0 0;
  padding: 0;
  list-style: none;
}

.feature-lines li {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.65rem;
  padding: 1rem 1.1rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
}

.feature-lines strong {
  color: var(--text);
  min-width: 5.5rem;
}

.platforms-visual {
  margin: 2rem 0 2.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
  overflow: hidden;
  padding: 0.65rem;
}

.platforms-visual img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius) - 4px);
}

.platform-list {
  display: grid;
  gap: 1.5rem;
}

.platform-item {
  padding: 1.75rem 1.85rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.04);
}

.platform-item h3 {
  margin: 0 0 0.75rem;
  font-size: 1.2rem;
  color: var(--text);
}

.platform-item p {
  margin: 0 0 1rem;
}

.platform-item__tags {
  margin: 0 0 1.15rem;
  font-size: 0.88rem;
  color: var(--muted);
}

@media (min-width: 900px) {
  .platform-list {
    grid-template-columns: repeat(3, 1fr);
  }
}

.official-zone {
  padding: 2.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  box-shadow: var(--shadow);
}

.official-zone__head {
  max-width: 44rem;
}

.official-zone .visual--banner {
  margin: 2rem 0;
  padding: 0.65rem;
}

.official-zone__actions {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.link-flow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.link-flow a {
  font-weight: 600;
}

.official-zone .hint {
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.tutorial-zone {
  display: grid;
  gap: 1.5rem;
}

.tutorial-featured {
  padding: 2rem;
  background: linear-gradient(135deg, #ffffff 0%, #eff6ff 100%);
  border: 1px solid #bfdbfe;
  border-radius: var(--radius);
}

.tutorial-featured h3 {
  margin: 0.35rem 0 0.85rem;
  font-size: 1.35rem;
  color: var(--text);
}

.tutorial-meta {
  margin: 0;
  font-size: 0.86rem;
  color: var(--muted);
}

.tutorial-more {
  padding: 1.75rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.tutorial-more h4 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
}

.tutorial-more p {
  margin: 0 0 1.15rem;
  font-size: 0.92rem;
  color: var(--muted);
}

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

@media (min-width: 900px) {
  .tutorial-zone {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: start;
  }
}

.faq-grid {
  display: grid;
  gap: 0.75rem;
  max-width: 48rem;
}

.faq-grid details {
  padding: 1rem 1.15rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
}

.faq-grid summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--text);
}

.faq-grid p {
  margin: 0.75rem 0 0;
}

.site-footer {
  padding: 3rem 0 2.5rem;
  background: #fff;
  border-top: 1px solid var(--line);
}

.site-footer__disclaimer {
  margin: 0 0 1.5rem;
  max-width: 52rem;
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.7;
}

.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  list-style: none;
  padding: 0;
  margin: 0 0 1rem;
  font-size: 0.88rem;
}

.site-footer__copy {
  margin: 0;
  font-size: 0.82rem;
  color: var(--muted);
}