/* 不囿成建 Unframed — 与 ai.bycjdesign.com 风格一致：Inter、gray-50、blue-600 */

:root {
  --color-bg: #f8fafc;
  --color-card: #fff;
  --color-text: #111827;
  --color-muted: #6b7280;
  --color-gray-500: #6b7280;
  --color-blue-600: #2563eb;
  --color-blue-700: #1d4ed8;
  --color-purple-600: #9333ea;
  --color-border: #e5e7eb;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 顶部导航：与 AI 站 Navbar 一致 */
.header {
  background: var(--color-card);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav {
  max-width: 72rem;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}

.logo-box {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 0.75rem;
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.logo-text-wrap {
  line-height: 1.25;
}

.logo-name {
  font-weight: 800;
  font-size: 1.125rem;
  letter-spacing: -0.025em;
  color: var(--color-text);
  display: block;
}

.logo-slogan-zh {
  font-size: 0.75rem;
  color: var(--color-gray-500);
  display: block;
}

.logo-slogan-en {
  font-size: 0.6875rem;
  color: var(--color-gray-500);
  display: block;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.25rem;
}

.nav-links a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.2s;
}

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

/* Hero：与 AI 站 HomeScreen 一致 */
.hero {
  max-width: 48rem;
  margin: 0 auto;
  padding: 4rem 1.5rem 5rem;
  text-align: center;
}

.hero-title {
  font-size: clamp(1.875rem, 5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
  line-height: 1.25;
  color: var(--color-text);
}

.hero-intro {
  color: var(--color-gray-500);
  font-size: 1.125rem;
  margin-bottom: 1.75rem;
  line-height: 1.6;
}

/* 主按钮：与 AI 站渐变按钮一致 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem 2rem;
  background: linear-gradient(to right, var(--color-blue-600), var(--color-purple-600));
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.125rem;
  border-radius: 9999px;
  box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  transition: box-shadow 0.2s, transform 0.15s;
}

.btn:hover {
  box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  transform: translateY(-1px);
}

/* 页脚 */
.footer {
  margin-top: auto;
  padding: 1.5rem;
  text-align: center;
  color: var(--color-muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--color-border);
  background: var(--color-card);
}

.footer a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s;
}

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

/* 响应式：手机 */
@media (max-width: 640px) {
  .nav {
    flex-direction: column;
    align-items: flex-start;
  }

  .nav-links {
    width: 100%;
    justify-content: flex-start;
    gap: 1rem;
  }

  .logo-slogan-en {
    display: none;
  }

  .hero {
    padding: 3rem 1.25rem 4rem;
  }

  .hero-intro {
    font-size: 1rem;
  }

  .btn {
    width: 100%;
    max-width: 20rem;
  }
}