:root {
  --bg: #f4f7fb;
  --text: #1f2a37;
  --muted: #5b6472;
  --primary: #1a73e8;
  --primary-deep: #1558b0;
  --card: #ffffff;
  --border: #dce3ee;
  --shadow: 0 10px 30px rgba(18, 53, 95, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
  scroll-behavior: smooth;
}

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

.container {
  width: min(1120px, calc(100% - 2.4rem));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  background: rgba(244, 247, 251, 0.88);
  border-bottom: 1px solid rgba(220, 227, 238, 0.7);
}

.nav-wrap {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-weight: 800;
  font-size: 1.05rem;
  color: #0f3f85;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-link {
  color: var(--muted);
  font-weight: 500;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  transition: all 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary);
  background: rgba(26, 115, 232, 0.1);
}

.hero {
  padding: 4.2rem 0 3rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 2rem;
  align-items: center;
}

.hero-tag {
  display: inline-block;
  margin: 0;
  color: var(--primary);
  font-weight: 700;
  background: rgba(26, 115, 232, 0.1);
  border: 1px solid rgba(26, 115, 232, 0.2);
  border-radius: 999px;
  padding: 0.35rem 0.8rem;
}

.hero h1 {
  margin: 1rem 0 0.8rem;
  font-size: clamp(1.8rem, 4vw, 2.7rem);
  line-height: 1.25;
}

.hero-desc {
  color: var(--muted);
  line-height: 1.75;
  font-size: 1rem;
  margin-bottom: 1.5rem;
}

.hero-actions {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  padding: 0.68rem 1.2rem;
  border: 1px solid transparent;
  font-weight: 600;
  transition: all 0.2s ease;
}

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

.btn-primary:hover {
  background: var(--primary-deep);
  transform: translateY(-1px);
}

.btn-ghost {
  border-color: var(--border);
  color: #2c3f57;
  background: #fff;
}

.btn-ghost:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.hero-card {
  background: linear-gradient(135deg, #ffffff, #f5f9ff);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.4rem 1.3rem;
  box-shadow: var(--shadow);
}

.hero-card h2 {
  margin-top: 0;
  margin-bottom: 0.8rem;
  font-size: 1.2rem;
}

.hero-card ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
  line-height: 1.8;
}

.features,
.contact {
  padding: 3rem 0;
}

.features h2,
.contact h2 {
  margin: 0;
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.section-desc {
  color: var(--muted);
  margin: 0.6rem 0 1.6rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.feature-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.2rem;
  box-shadow: 0 5px 20px rgba(18, 53, 95, 0.05);
}

.feature-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 1.2rem;
  align-items: start;
}

.contact-meta {
  color: #20456f;
  font-weight: 600;
}

.contact-form {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
  box-shadow: var(--shadow);
  display: grid;
  gap: 0.8rem;
}

.contact-form label {
  font-size: 0.93rem;
  display: grid;
  gap: 0.4rem;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid #cdd8e7;
  border-radius: 10px;
  padding: 0.65rem 0.75rem;
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.14);
}

.form-hint {
  min-height: 1.2em;
  margin: 0;
  color: #166534;
  font-size: 0.9rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 1rem;
  background: #f2f6fc;
}

.footer-wrap {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  color: #41526a;
}

.footer-wrap a {
  color: var(--primary);
  font-weight: 600;
}

@media (max-width: 900px) {
  .hero-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .nav-wrap {
    min-height: 64px;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.55rem 0;
  }

  .main-nav {
    width: 100%;
    overflow-x: auto;
  }
}