:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-soft: #eef1f5;
  --text: #101319;
  --muted: #626b78;
  --line: rgba(16, 19, 25, 0.12);
  --accent: #0f6fff;
  --accent-strong: #084fc4;
  --shadow: 0 18px 45px rgba(18, 24, 33, 0.1);
  --radius: 10px;
}

body.dark {
  --bg: #0e1116;
  --surface: #171b22;
  --surface-soft: #202630;
  --text: #f3f6fb;
  --muted: #a8b0bd;
  --line: rgba(243, 246, 251, 0.14);
  --accent: #65a6ff;
  --accent-strong: #8abbff;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.32);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background-color 0.45s ease, color 0.45s ease;
}

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

a {
  color: inherit;
}

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(247, 248, 251, 0.82);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
  transition: background-color 0.45s ease, border-color 0.45s ease;
}

body.dark .header {
  background: rgba(14, 17, 22, 0.82);
}

.header-inner {
  max-width: 1120px;
  min-height: 72px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 18px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  text-decoration: none;
  font-weight: 800;
  white-space: nowrap;
}

.logo img {
  width: 72px;
  height: 48px;
  object-fit: contain;
  transition: opacity 0.25s ease;
}

.logo-text {
  display: grid;
  gap: 1px;
  font-weight: 900;
  line-height: 1.05;
}

.logo-text small {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}
.nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 15px;
  transition: background-color 0.3s ease, color 0.3s ease;
}

.nav a:hover,
.nav a.active {
  color: var(--text);
  background: var(--surface-soft);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn {
  min-width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  font-size: 14px;
  box-shadow: 0 8px 22px rgba(18, 24, 33, 0.06);
  transition: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.hamburger {
  display: none;
}

.page-title {
  max-width: 1120px;
  margin: 0 auto;
  padding: 122px 20px 34px;
}

.page-title h1 {
  margin: 0;
  font-size: clamp(34px, 6vw, 64px);
  line-height: 1.05;
}

.page-title p {
  max-width: 720px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.section {
  max-width: 1120px;
  margin: 0 auto;
  padding: 48px 20px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: background-color 0.45s ease, color 0.45s ease, border-color 0.45s ease, box-shadow 0.45s ease;
}

.divider {
  max-width: 1120px;
  height: 1px;
  background: var(--line);
  margin: 28px auto;
  transition: background-color 0.45s ease;
}

.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.show {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 768px) {
  .header-inner {
    min-height: 66px;
    padding: 0 14px;
  }


  .logo-text {
    max-width: 128px;
    font-size: 13px;
  }

  .logo-text small {
    font-size: 11px;
  }

  .hamburger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .nav {
    position: absolute;
    top: 72px;
    left: 14px;
    right: 14px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    margin: 0;
    padding: 10px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
  }

  .nav.active {
    display: flex;
  }

  .nav a {
    padding: 11px 12px;
  }

  .page-title {
    padding-top: 72px;
  }
}