:root {
  color-scheme: light;
  --ink: #14171f;
  --muted: #657080;
  --soft: #f6f9fc;
  --line: rgba(28, 34, 45, 0.1);
  --blue: #1677ff;
  --mint: #38b98f;
  --orange: #ff9820;
  --violet: #7b6fd4;
  --glass: rgba(255, 255, 255, 0.72);
  --shadow: 0 24px 80px rgba(51, 70, 96, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    linear-gradient(115deg, rgba(226, 241, 255, 0.78), rgba(255, 255, 255, 0) 38%),
    linear-gradient(245deg, rgba(239, 235, 255, 0.78), rgba(255, 255, 255, 0) 42%),
    #ffffff;
  color: var(--ink);
  font-family:
    -apple-system,
    BlinkMacSystemFont,
    "SF Pro Text",
    "PingFang SC",
    "Hiragino Sans GB",
    "Microsoft YaHei",
    sans-serif;
  letter-spacing: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px clamp(22px, 5vw, 72px);
  background: rgba(255, 255, 255, 0.7);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 17px;
  font-weight: 700;
}

.brand-mark {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  color: #fff;
  background: var(--ink);
  border-radius: 8px;
  font-size: 16px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
}

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

.hero {
  position: relative;
  display: grid;
  min-height: 88vh;
  align-items: center;
  padding: 124px clamp(22px, 5vw, 72px) 96px;
  overflow: hidden;
}

.hero-scene {
  position: absolute;
  inset: 88px clamp(14px, 4vw, 56px) 36px;
  z-index: 0;
  display: flex;
  align-items: flex-end;
  justify-content: flex-end;
  opacity: 0.9;
}

.mock-window {
  width: min(800px, 58vw);
  aspect-ratio: 1.42;
  border: 1px solid rgba(255, 255, 255, 0.88);
  border-radius: 24px;
  background: rgba(244, 248, 252, 0.68);
  box-shadow: var(--shadow);
  backdrop-filter: blur(24px);
  transform: translateX(24%) rotate(-1.5deg);
}

.mock-titlebar {
  display: flex;
  gap: 8px;
  height: 42px;
  align-items: center;
  padding: 0 18px;
  border-bottom: 1px solid rgba(28, 34, 45, 0.08);
  background: rgba(255, 255, 255, 0.62);
  border-radius: 24px 24px 0 0;
}

.mock-titlebar span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.mock-titlebar span:nth-child(1) {
  background: #ff5f57;
}

.mock-titlebar span:nth-child(2) {
  background: #ffbd2e;
}

.mock-titlebar span:nth-child(3) {
  background: #28c840;
}

.mock-app {
  padding: 26px;
}

.mock-app-top,
.mock-board,
.mock-column-head {
  display: flex;
}

.mock-app-top {
  align-items: center;
  justify-content: space-between;
  gap: 22px;
}

.mock-title,
.mock-subtitle {
  margin: 0;
}

.mock-title {
  font-size: 26px;
  font-weight: 800;
}

.mock-subtitle {
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
}

.mock-search,
.mock-composer,
.mock-column,
.mock-card,
.mock-empty {
  border: 1px solid rgba(255, 255, 255, 0.72);
  background: rgba(255, 255, 255, 0.58);
  backdrop-filter: blur(16px);
}

.mock-search {
  width: 210px;
  padding: 12px 18px;
  border-radius: 8px;
  color: #7b8491;
  font-size: 14px;
}

.mock-composer {
  margin: 24px 0 18px;
  padding: 18px 22px;
  border-radius: 8px;
  color: #7c848f;
  font-size: 20px;
  font-weight: 700;
}

.mock-board {
  gap: 14px;
}

.mock-column {
  flex: 1;
  min-height: 300px;
  padding: 14px;
  border-radius: 16px;
}

.mock-column.blue {
  background: rgba(206, 229, 255, 0.72);
}

.mock-column.orange {
  background: rgba(255, 235, 214, 0.74);
}

.mock-column.green {
  background: rgba(211, 244, 235, 0.74);
}

.mock-column.violet {
  background: rgba(229, 224, 250, 0.74);
}

.mock-column-head {
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  font-size: 15px;
  font-weight: 800;
}

.mock-column-head strong {
  display: grid;
  min-width: 24px;
  height: 24px;
  place-items: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.44);
  color: var(--blue);
  font-size: 12px;
}

.mock-column.orange strong {
  color: var(--orange);
}

.mock-column.green strong {
  color: var(--mint);
}

.mock-column.violet strong {
  color: var(--violet);
}

.mock-card,
.mock-empty {
  margin-top: 10px;
  padding: 16px;
  border-radius: 8px;
  color: #3e4652;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.35;
}

.mock-card.active {
  box-shadow: 0 16px 36px rgba(255, 152, 32, 0.15);
}

.mock-card.thin {
  color: #657080;
  font-weight: 650;
}

.mock-empty {
  display: grid;
  min-height: 106px;
  place-items: center;
  color: #5f8d7a;
}

.hero-copy {
  position: relative;
  z-index: 1;
  max-width: 520px;
  padding-top: 24px;
}

.hero h1,
.section h2,
.download-band h2 {
  margin: 0;
  font-family:
    "SF Pro Display",
    -apple-system,
    BlinkMacSystemFont,
    "PingFang SC",
    sans-serif;
  font-weight: 800;
  letter-spacing: 0;
}

.hero h1 {
  font-size: clamp(60px, 8.2vw, 118px);
  line-height: 0.95;
}

.hero-line {
  max-width: 470px;
  margin: 24px 0 0;
  font-size: clamp(26px, 3.2vw, 40px);
  line-height: 1.08;
  font-weight: 800;
}

.hero-text {
  max-width: 500px;
  margin: 24px 0 0;
  color: #3f4956;
  font-size: clamp(17px, 1.5vw, 20px);
  line-height: 1.75;
}

.hero-actions,
.download-band {
  display: flex;
  align-items: center;
  gap: 18px;
}

.hero-actions {
  margin-top: 34px;
  flex-wrap: wrap;
}

.primary-button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 0 24px;
  border-radius: 8px;
  background: var(--blue);
  color: #fff;
  font-size: 15px;
  font-weight: 800;
  box-shadow: 0 16px 32px rgba(22, 119, 255, 0.24);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.primary-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 20px 40px rgba(22, 119, 255, 0.28);
}

.text-link {
  color: #2f3b4a;
  font-size: 15px;
  font-weight: 750;
}

.text-link:hover {
  color: var(--blue);
}

.section {
  max-width: 1180px;
  margin: 0 auto;
  padding: 104px clamp(22px, 5vw, 48px);
}

.intro,
.sync,
.principles,
.download-band {
  border-top: 1px solid var(--line);
}

.intro,
.sync {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(38px, 7vw, 96px);
  align-items: center;
}

.section-copy h2,
.principle h2,
.download-band h2 {
  font-size: clamp(34px, 5vw, 64px);
  line-height: 1.06;
}

.section-copy p,
.principle p,
.download-band p {
  margin: 22px 0 0;
  color: #4d5867;
  font-size: 18px;
  line-height: 1.8;
}

.quiet-list {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.quiet-list article {
  display: grid;
  grid-template-columns: 48px 120px minmax(0, 1fr);
  gap: 20px;
  align-items: baseline;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
}

.quiet-list span {
  color: var(--blue);
  font-size: 13px;
  font-weight: 800;
}

.quiet-list h3 {
  margin: 0;
  font-size: 21px;
}

.quiet-list p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.sync-visual {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 80px 0.68fr;
  align-items: center;
  min-height: 330px;
  padding: 32px;
  border: 1px solid rgba(255, 255, 255, 0.78);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(222, 239, 255, 0.86), rgba(231, 248, 239, 0.78)),
    rgba(255, 255, 255, 0.72);
  box-shadow: 0 24px 70px rgba(77, 102, 135, 0.12);
}

.device {
  display: grid;
  place-items: center;
  color: rgba(20, 23, 31, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.8);
  background: rgba(255, 255, 255, 0.62);
  box-shadow: 0 18px 52px rgba(66, 84, 111, 0.14);
  font-weight: 800;
}

.device.mac {
  height: 190px;
  border-radius: 8px;
}

.device.phone {
  height: 246px;
  border-radius: 28px;
}

.sync-line {
  height: 2px;
  background: linear-gradient(90deg, var(--blue), var(--mint));
}

.principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.8fr);
  gap: clamp(40px, 7vw, 100px);
  align-items: start;
}

.principle-grid {
  display: grid;
  gap: 14px;
}

.principle-grid p {
  margin: 0;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  color: #2f3b4a;
  font-size: 18px;
  font-weight: 750;
}

.download-band {
  max-width: 1180px;
  margin: 0 auto 42px;
  padding: 72px clamp(22px, 5vw, 48px);
  justify-content: space-between;
}

.download-band p {
  max-width: 620px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 28px clamp(22px, 5vw, 72px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 920px) {
  .site-header {
    position: sticky;
  }

  .nav-links {
    gap: 16px;
  }

  .hero {
    min-height: auto;
    padding-top: 72px;
  }

  .hero-scene {
    position: relative;
    inset: auto;
    order: 2;
    margin-top: 42px;
    justify-content: center;
  }

  .mock-window {
    width: min(680px, 100%);
    transform: none;
  }

  .hero-copy {
    max-width: 100%;
  }

  .intro,
  .sync,
  .principles {
    grid-template-columns: 1fr;
  }

  .sync-visual {
    order: 2;
  }

  .quiet-list article {
    grid-template-columns: 42px 1fr;
  }

  .quiet-list p {
    grid-column: 2;
  }

  .download-band {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 640px) {
  .site-header {
    padding: 14px 18px;
  }

  .nav-links a:nth-child(2) {
    display: none;
  }

  .hero {
    padding: 54px 18px 68px;
  }

  .mock-app {
    padding: 18px;
  }

  .mock-app-top {
    align-items: flex-start;
    flex-direction: column;
  }

  .mock-search {
    width: 100%;
  }

  .mock-board {
    display: grid;
    grid-template-columns: 1fr;
  }

  .mock-column {
    min-height: 150px;
  }

  .mock-column:nth-child(n + 3) {
    display: none;
  }

  .section {
    padding: 76px 18px;
  }

  .sync-visual {
    grid-template-columns: 1fr;
    gap: 22px;
    min-height: auto;
  }

  .sync-line {
    width: 2px;
    height: 54px;
    justify-self: center;
  }

  .device.mac,
  .device.phone {
    height: 150px;
    border-radius: 8px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    padding: 24px 18px;
  }
}

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

  .primary-button,
  .section,
  .download-band {
    transition: none;
  }

}