:root {
  color-scheme: light dark;
  --bg: #f5f5f7;
  --bg-elevated: #ffffff;
  --text: #1d1d1f;
  --text-2: #6e6e73;
  --hairline: rgba(0, 0, 0, 0.08);
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --nav-bg: rgba(251, 251, 253, 0.72);
  --card-shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 8px 28px rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 2px 6px rgba(0, 0, 0, 0.06), 0 18px 44px rgba(0, 0, 0, 0.1);
  --grad-a: #0a84ff;
  --grad-b: #30d158;
  --radius-lg: 20px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-elevated: #1c1c1e;
    --text: #f5f5f7;
    --text-2: #a1a1a6;
    --hairline: rgba(255, 255, 255, 0.12);
    --accent: #2997ff;
    --accent-hover: #409cff;
    --nav-bg: rgba(22, 22, 23, 0.72);
    --card-shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 28px rgba(0, 0, 0, 0.35);
    --card-shadow-hover: 0 2px 6px rgba(0, 0, 0, 0.35), 0 18px 44px rgba(0, 0, 0, 0.5);
  }
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 17px;
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 100;
  padding: 10px 18px;
  background: var(--accent);
  color: #fff;
  border-radius: 999px;
  font-size: 14px;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 12px;
}

/* ---------- Nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--nav-bg);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--hairline);
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 32px);
  height: 56px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.brand-mark {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.brand-mark.small {
  width: 22px;
  height: 22px;
  border-radius: 5.5px;
}

.nav-links {
  display: flex;
  gap: 26px;
  margin-left: auto;
  font-size: 14px;
  color: var(--text-2);
}

.nav-links a {
  transition: color 0.2s ease;
}

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

.nav-cta {
  font-size: 14px;
  font-weight: 500;
  color: #fff;
  background: var(--accent);
  padding: 6px 16px;
  border-radius: 999px;
  transition: background 0.2s ease;
}

.nav-cta:hover {
  background: var(--accent-hover);
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .nav-cta {
    margin-left: auto;
  }
}

/* ---------- Hero ---------- */

.hero {
  max-width: 1080px;
  margin: 0 auto;
  padding: clamp(88px, 14vw, 168px) clamp(20px, 4vw, 32px) clamp(72px, 10vw, 120px);
  text-align: center;
}

.hero-eyebrow {
  font-size: clamp(13px, 1.6vw, 15px);
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--text-2);
  text-transform: uppercase;
  margin-bottom: clamp(16px, 2.5vw, 24px);
}

.hero-title {
  font-size: clamp(42px, 8.4vw, 88px);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -0.022em;
}

.hero-title .grad {
  background: linear-gradient(94deg, var(--grad-a) 8%, var(--grad-b) 92%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  max-width: 640px;
  margin: clamp(20px, 3vw, 30px) auto 0;
  font-size: clamp(18px, 2.4vw, 23px);
  line-height: 1.5;
  color: var(--text-2);
  font-weight: 400;
}

.hero-actions {
  margin-top: clamp(30px, 4vw, 44px);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  font-size: 17px;
  font-weight: 500;
  padding: 13px 28px;
  border-radius: 999px;
  transition: background 0.2s ease, transform 0.2s ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

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

.btn-ghost {
  color: var(--accent);
  padding: 13px 10px;
}

.btn-ghost:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.hero-note {
  margin-top: clamp(36px, 5vw, 56px);
  font-size: 12.5px;
  color: var(--text-2);
  opacity: 0.75;
}

.br-desktop {
  display: none;
}

@media (min-width: 641px) {
  .br-desktop {
    display: inline;
  }
}

/* ---------- Sections ---------- */

.section {
  max-width: 1080px;
  margin: 0 auto;
  padding: clamp(64px, 9vw, 110px) clamp(20px, 4vw, 32px);
}

.section-head {
  text-align: center;
  margin-bottom: clamp(40px, 6vw, 64px);
}

.section-head h2 {
  font-size: clamp(30px, 4.6vw, 52px);
  font-weight: 700;
  letter-spacing: -0.018em;
  line-height: 1.15;
}

.section-head p {
  margin-top: 12px;
  font-size: clamp(16px, 2vw, 19px);
  color: var(--text-2);
}

.grid {
  display: grid;
  gap: clamp(14px, 2vw, 20px);
}

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

@media (max-width: 640px) {
  .services {
    grid-template-columns: 1fr;
  }
}

/* ---------- Cards ---------- */

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  box-shadow: var(--card-shadow);
  transition: transform 0.3s cubic-bezier(0.2, 0.7, 0.3, 1), box-shadow 0.3s ease;
}

.icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(10, 132, 255, 0.12), rgba(48, 209, 88, 0.12));
  flex-shrink: 0;
}

.icon svg {
  width: 24px;
  height: 24px;
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.feature {
  padding: clamp(24px, 3vw, 32px);
}

.feature:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
}

.feature h3 {
  margin-top: 18px;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.feature p {
  margin-top: 8px;
  font-size: 15.5px;
  color: var(--text-2);
}

/* ---------- Entry cards ---------- */

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

@media (max-width: 640px) {
  .entries {
    grid-template-columns: 1fr;
  }
}

.entry {
  position: relative;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: clamp(20px, 2.6vw, 26px) clamp(22px, 3vw, 28px);
}

.entry:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
}

.entry .arrow {
  width: 18px;
  height: 18px;
  margin-left: auto;
  fill: none;
  stroke: var(--text-2);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 0.25s ease, stroke 0.25s ease;
  flex-shrink: 0;
}

.entry:hover .arrow {
  transform: translate(2px, -2px);
  stroke: var(--accent);
}

.entry-body h3 {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.entry-body p {
  margin-top: 3px;
  font-size: 14px;
  color: var(--text-2);
}

.entry .host {
  position: absolute;
  right: clamp(22px, 3vw, 28px);
  bottom: 10px;
  font-size: 11px;
  letter-spacing: 0.02em;
  color: var(--text-2);
  opacity: 0.65;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 420px) {
  .entry .host {
    display: none;
  }
}

/* ---------- Footer ---------- */

.footer {
  border-top: 1px solid var(--hairline);
  margin-top: clamp(24px, 4vw, 48px);
}

.footer-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: clamp(32px, 5vw, 48px) clamp(20px, 4vw, 32px);
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 15px;
  font-weight: 600;
}

.footer-links {
  display: flex;
  gap: 22px;
  margin-left: auto;
  font-size: 13.5px;
  color: var(--text-2);
  flex-wrap: wrap;
}

.footer-links a {
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--text);
}

.footer-copy {
  width: 100%;
  font-size: 12.5px;
  color: var(--text-2);
  opacity: 0.7;
}

@media (max-width: 640px) {
  .footer-links {
    margin-left: 0;
  }
}

/* ---------- Reveal on scroll ---------- */

.js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.2, 0.7, 0.3, 1);
}

.js .reveal.in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .js .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

@media print {
  .js .reveal {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}