:root {
  --primary: #4FAF9F;
  --primary-soft: #5BB8A8;
  --primary-dark: #409688;

  --background: #edf6f4;
  --surface: #f2f2f2;
  --surface-soft: #f7f7f7;

  --text: #1f2a2e;
  --muted: #5f6b70;

  --accent: #f4b400;
  --accent-dark: #d99d00;

  --secondary: #4c6ef5;
  --secondary-dark: #3d5fe0;

  --danger: #e45757;
  --danger-dark: #cc4747;

  --chat-bg: #d7ccb8;
  --message: #8fd3c7;

  --border: #d7dfdc;
  --shadow: 0 10px 30px rgba(20, 40, 45, 0.08);

  --radius: 18px;
  --radius-sm: 12px;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

a {
  color: var(--secondary-dark);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

.container {
  width: min(100% - 32px, var(--max-width));
  margin: 0 auto;
}

.page-shell {
  min-height: 100vh;
  padding: 36px 0 60px;
}

.brand-top {
  text-align: center;
  margin-bottom: 26px;
}

.brand-logo {
  width: 100px;
  height: 100px;
  margin: 0 auto 12px;
  border-radius: 22px;
  background: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.brand-logo img {
  width: 100%;
  height: auto;
}

.brand-title {
  margin: 0;
  color: white;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
}

.brand-subtitle {
  color: rgba(255, 255, 255, 0.92);
  max-width: 760px;
  margin: 10px auto 0;
}

.hero-card,
.card,
.section-card,
.toc,
.footer-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-card,
.card,
.toc,
.footer-box {
  padding: 28px;
}

.toc {
  margin-top: 20px;
}

.section-card {
  overflow: hidden;
  margin-bottom: 22px;
}

.buttons,
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-block;
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: white;
  color: var(--text);
  font-weight: bold;
  transition: 0.2s ease;
  text-decoration: none;
}

.btn:hover {
  transform: translateY(-1px);
  text-decoration: none;
}

.btn-primary {
  background: var(--secondary);
  color: white;
  border-color: var(--secondary);
}

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

.btn-accent {
  background: var(--primary-soft);
  color: white;
  border-color: var(--primary-soft);
}

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

.lead,
.subtitle {
  color: var(--muted);
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.2;
}

h2 {
  font-size: 1.6rem;
  margin-bottom: 10px;
}

p {
  margin-top: 0;
}

section {
  margin: 26px 0;
}

.grid {
  display: grid;
  gap: 20px;
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.feature {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
}

.feature-accent {
  background: #fff7de;
  border: 1px solid #f2df9e;
}

.feature-soft {
  background: #eef8f6;
  border: 1px solid #cfe7e1;
}

.toc h2 {
  margin-bottom: 12px;
  font-size: 1.2rem;
}

.toc-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.toc-list a {
  display: block;
  padding: 10px 12px;
  background: #ffffff;
  border-radius: 12px;
  color: var(--text);
  border: 1px solid var(--border);
}

.section-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 0;
}

.section-content {
  padding: 28px;
}

.section-media {
  background: #eef8f6;
  border-left: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  padding: 20px;
}

.section-media img {
  width: 100%;
  max-width: 420px;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: white;
}

.step {
  display: inline-block;
  margin-bottom: 12px;
  background: var(--accent);
  color: #1f1f1f;
  font-weight: bold;
  font-size: 0.9rem;
  padding: 6px 10px;
  border-radius: 999px;
}

.tip {
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: 14px;
  background: #eef8f6;
  border: 1px solid #cfe7e1;
  color: var(--text);
}

.tip-danger {
  background: #ffeaea;
  border-color: #f2c4c4;
}

.highlight {
  font-weight: bold;
  color: var(--secondary-dark);
}

.footer-box {
  text-align: center;
}

.muted {
  color: var(--muted);
}

.center {
  text-align: center;
}

ul {
  margin: 14px 0 0;
  padding-left: 20px;
}

li + li {
  margin-top: 8px;
}

footer.site-footer {
  text-align: center;
  color: rgba(255, 255, 255, 0.92);
  padding: 10px 0 0;
}

@media (max-width: 860px) {
  .section-grid {
    grid-template-columns: 1fr;
  }

  .section-media {
    border-left: none;
    border-top: 1px solid var(--border);
    min-height: auto;
  }

  .grid-3 {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .page-shell {
    padding-top: 24px;
  }

  .hero-card,
  .card,
  .toc,
  .footer-box,
  .section-content,
  .section-media {
    padding: 18px;
  }

  h2 {
    font-size: 1.35rem;
  }

  .brand-logo {
    width: 72px;
    height: 72px;
    border-radius: 18px;
  }

  .brand-logo img {
    width: 100px;
  }
}