:root {
  --bg: #ffffff;
  --fg: #111111;
  --muted: #666666;
  --border: #e5e5e5;
  --green: #25D366;
  --green-dark: #1DA851;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: 'Inter', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* HERO */
.hero {
  padding: 72px 24px 64px;
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  max-width: 560px;
}

.hero-kicker {
  font-family: 'Manrope', sans-serif;
  font-weight: 600;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 20px;
}

.hero-headline {
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  font-size: 28px;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--fg);
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 17px;
  color: var(--muted);
  line-height: 1.55;
  margin-bottom: 32px;
}

.hero-promise {
  margin-top: 14px;
  font-size: 14px;
  font-weight: 400;
  color: var(--muted);
  line-height: 1.55;
  text-align: center;
}

/* SHARED BUTTON */
.btn-primary {
  display: inline-block;
  background: var(--green);
  color: #ffffff;
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.01em;
  text-decoration: none;
  padding: 14px 28px;
  border-radius: 4px;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease;
}

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

/* PROBLEM */
.problem {
  padding: 64px 24px;
  border-bottom: 1px solid var(--border);
}

.problem-inner { max-width: 560px; }

.problem-label {
  font-family: 'Manrope', sans-serif;
  font-weight: 600;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 24px;
}

.problem-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.problem-list li {
  font-family: 'Manrope', sans-serif;
  font-weight: 500;
  font-size: 17px;
  color: var(--fg);
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}

.problem-list li:first-child { border-top: 1px solid var(--border); }

.problem-closing {
  margin-top: 28px;
  font-size: 15px;
  color: var(--muted);
  line-height: 1.6;
}

/* HOW IT WORKS */
.how {
  padding: 64px 24px;
  border-bottom: 1px solid var(--border);
}

.how-inner { max-width: 560px; }

.how-label {
  font-family: 'Manrope', sans-serif;
  font-weight: 600;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 32px;
}

.steps { display: flex; flex-direction: column; gap: 0; }

.step {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 0 16px;
  align-items: start;
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
}

.step:first-child { border-top: 1px solid var(--border); }

.step-num {
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  font-size: 14px;
  color: var(--muted);
  padding-top: 2px;
}

.step-text {
  font-size: 16px;
  color: var(--fg);
  line-height: 1.5;
}

/* PROMISE */
.promise {
  padding: 80px 24px;
  background: var(--fg);
  color: #ffffff;
}

.promise-inner { max-width: 560px; }

.promise-main {
  font-family: 'Manrope', sans-serif;
  font-weight: 800;
  font-size: 26px;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.promise-sub {
  font-size: 17px;
  color: rgba(255,255,255,0.65);
  line-height: 1.55;
}

/* INVITATION */
.invitation {
  padding: 56px 24px;
  border-bottom: 1px solid var(--border);
}

.invitation-inner { max-width: 560px; }

.invitation-text {
  font-family: 'Manrope', sans-serif;
  font-weight: 500;
  font-size: 18px;
  color: var(--fg);
  line-height: 1.5;
}

/* FORM */
.form-section {
  padding: 56px 24px 72px;
}

.form-inner { max-width: 480px; }

.signup-form {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.form-title {
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 24px;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
}

.form-field label {
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.form-field input {
  border: none;
  outline: none;
  font-family: 'Manrope', sans-serif;
  font-size: 16px;
  font-weight: 500;
  color: var(--fg);
  background: transparent;
  padding: 4px 0;
  width: 100%;
}

.form-field input::placeholder { color: #bbbbbb; }

.btn-submit {
  display: block;
  width: 100%;
  background: var(--green);
  color: #ffffff;
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.01em;
  text-decoration: none;
  padding: 16px 28px;
  border-radius: 4px;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease;
  margin-top: 8px;
}

.btn-submit:hover { background: var(--green-dark); }

/* FOOTER */
footer {
  padding: 32px 24px;
  border-top: 1px solid var(--border);
}

.footer-copy {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* DESKTOP */
@media (min-width: 768px) {
  .hero-headline { font-size: 38px; }
  .promise-main { font-size: 34px; }
  .hero, .problem, .how, .form-section {
    padding: 96px 48px;
  }
  .invitation { padding: 72px 48px; }
  .promise { padding: 96px 48px; }
}