@import url("../fonts/inter.css");

:root {
  --ease: cubic-bezier(0.16, 1, 0.3, 1);

  /* 亮色现代极简 tokens */
  --brand: #000000;
  --brand-hover: #27272a;
  --brand-on: #ffffff;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.08);

  --text-primary: #101112;
  --text-strong: #18181b;
  --text-secondary: #71717a;
  --text-muted: #9f9fa9;

  --surface-page: #f9fafb;
  --surface-card: #ffffff;
  --surface-muted: #f4f4f5;
  --surface-section: #f8f9fa;

  --border-subtle: rgba(0, 0, 0, 0.06);
  --border-default: #e4e4e7;
  --border-soft: rgba(228, 228, 231, 0.55);
  --focus-ring: #a1a1aa;

  --shadow-card: 0 0 0 1px rgba(0, 0, 0, 0.03), 0 2px 4px rgba(0, 0, 0, 0.05), 0 12px 24px rgba(0, 0, 0, 0.05);
  --shadow-floating: 0 20px 40px -15px rgba(0, 0, 0, 0.08), 0 8px 16px -8px rgba(0, 0, 0, 0.05);
  --shadow-button: 0 20px 60px -30px rgba(0, 0, 0, 0.12);
  --shadow-hover: 0 20px 60px -10px rgba(0, 0, 0, 0.08);

  --radius-xs: 0.55rem;
  --radius-sm: 0.65rem;
  --radius-md: 0.85rem;
  --radius-lg: 1rem;
  --radius-xl: 16px;
  --radius-pill: 9999px;

  --font-family-base: "Inter", "PingFang SC", "Microsoft YaHei", "Noto Serif SC", "Helvetica Neue", Arial, sans-serif;
  --font-size-base: 16px;
  --control-height-base: 44px;

  --container-max: 80rem;
  --container-padding: 1.25rem;
  --section-padding-y: clamp(4rem, 8vw, 6rem);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text-primary);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  letter-spacing: -0.015em;
  line-height: 1.6;
  background: linear-gradient(180deg, #ffffff 0%, #fafafa 100%);
  position: relative;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 50% at 0% -20%, rgba(99, 102, 241, 0.08), transparent 50%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(139, 92, 246, 0.06), transparent 45%),
    radial-gradient(ellipse 50% 30% at 100% 100%, rgba(244, 63, 94, 0.05), transparent 50%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.42;
  background-image: radial-gradient(circle at 1px 1px, rgba(0, 0, 0, 0.06) 1px, transparent 0);
  background-size: 18px 18px;
}

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

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

button {
  font-family: inherit;
  letter-spacing: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

.page-wrap {
  position: relative;
  z-index: 1;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.section-title {
  margin: 0 0 1rem;
  color: var(--text-strong);
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  text-align: center;
}

.section-subtitle {
  margin: 0 auto 3rem;
  max-width: 36rem;
  color: var(--text-secondary);
  font-size: 1rem;
  text-align: center;
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--accent);
  font-size: 0.9375rem;
  font-weight: 600;
  transition: gap 0.2s var(--ease), color 0.2s var(--ease);
}

.link-arrow:hover {
  gap: 0.55rem;
  color: var(--accent-hover);
}

.link-arrow:focus-visible {
  outline: none;
  border-radius: 4px;
  box-shadow: 0 0 0 2px #fff, 0 0 0 4px var(--focus-ring);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: var(--control-height-base);
  padding: 0.65rem 1.5rem;
  border-radius: var(--radius-pill);
  font-size: 0.9375rem;
  font-weight: 600;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), box-shadow 0.2s var(--ease), transform 0.15s var(--ease);
}

.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px #fff, 0 0 0 4px var(--focus-ring);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--brand);
  color: var(--brand-on);
  box-shadow: var(--shadow-button);
}

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

.btn-accent {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 12px 32px -12px rgba(37, 99, 235, 0.45);
}

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

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border-default);
}

.btn-ghost:hover {
  background: var(--surface-muted);
  color: var(--text-strong);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}