/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-primary: #1a73e8;
  --color-primary-dark: #1557b0;
  --color-text: #1a1a2e;
  --color-text-muted: #555;
  --color-border: #e0e0e0;
  --color-accent-bg: #f0f4ff;
  --radius: 12px;
  --max-width: 1100px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

a:hover {
  text-decoration: underline;
}

/* ===== Header ===== */
header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

header nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 24px;
}

.nav-links a {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  transition: all 0.2s;
  text-decoration: none;
}

.btn:hover {
  text-decoration: none;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

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

/* ===== Hero ===== */
.hero {
  padding: 100px 0 80px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1px;
  margin-bottom: 20px;
}

.hero .subtitle {
  font-size: 1.2rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 36px;
}

.cta-group {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Features ===== */
.features {
  padding: 80px 0;
  background: var(--color-surface);
}

.features h2,
.how-it-works h2,
.about h2,
.contact h2 {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 48px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 28px;
}

.feature-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: box-shadow 0.2s;
}

.feature-card:hover {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* ===== How It Works ===== */
.how-it-works {
  padding: 80px 0;
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
  text-align: center;
}

.step-number {
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.step h3 {
  margin-bottom: 8px;
}

.step p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* ===== About ===== */
.about {
  padding: 80px 0;
  background: var(--color-accent-bg);
}

.about p {
  max-width: 700px;
  margin: 0 auto 16px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

/* ===== Contact ===== */
.contact {
  padding: 80px 0;
  text-align: center;
}

.contact p {
  color: var(--color-text-muted);
  margin-bottom: 24px;
  font-size: 1.1rem;
}

/* ===== Footer ===== */
footer {
  background: var(--color-text);
  color: #ccc;
  padding: 48px 0 24px;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-brand .logo {
  color: #fff;
  margin-bottom: 8px;
}

.footer-brand p {
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  color: #ccc;
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid #333;
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .nav-links {
    display: none;
  }

  .hero {
    padding: 60px 0 50px;
  }

  .features,
  .how-it-works,
  .about,
  .contact {
    padding: 50px 0;
  }
}