/* ========================================
   English Learning — Base Styles
   ======================================== */

:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --surface-soft: #f0f3f7;

  --text: #172033;
  --text-soft: #667085;
  --text-light: #98a2b3;

  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --primary-soft: #eef2ff;

  --border: #e4e7ec;

  --success: #12b76a;

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --shadow-sm: 0 4px 14px rgba(16, 24, 40, 0.06);
  --shadow-md: 0 12px 30px rgba(16, 24, 40, 0.08);

  --container: 1120px;
}


/* ========================================
   Reset
   ======================================== */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family:
    Inter,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Arial,
    sans-serif;

  background: var(--bg);
  color: var(--text);

  line-height: 1.6;
  min-height: 100vh;
}

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

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


/* ========================================
   Container
   ======================================== */

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


/* ========================================
   Header
   ======================================== */

.site-header {
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--border);

  position: sticky;
  top: 0;
  z-index: 100;

  backdrop-filter: blur(12px);
}

.header-inner {
  min-height: 68px;

  display: flex;
  align-items: center;
  justify-content: space-between;

  gap: 20px;
}

.logo {
  font-size: 18px;
  font-weight: 750;
  letter-spacing: -0.3px;
}

.header-login {
  color: var(--primary);
  font-size: 14px;
  font-weight: 650;

  padding: 8px 12px;
  border-radius: var(--radius-sm);

  transition:
    background 0.2s ease,
    color 0.2s ease;
}

.header-login:hover {
  background: var(--primary-soft);
}


/* ========================================
   Hero
   ======================================== */

.hero {
  padding: 72px 0 76px;

  background:
    radial-gradient(
      circle at 80% 20%,
      rgba(79, 70, 229, 0.10),
      transparent 34%
    ),
    linear-gradient(
      180deg,
      #ffffff 0%,
      var(--bg) 100%
    );
}

.hero-content {
  max-width: 780px;
  text-align: center;
  margin-inline: auto;
}

.eyebrow {
  display: inline-block;

  color: var(--primary);

  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.4px;

  margin-bottom: 14px;
}

.hero h1 {
  font-size: clamp(36px, 8vw, 64px);
  line-height: 1.08;
  letter-spacing: -1.8px;
  font-weight: 800;

  margin-bottom: 22px;
}

.hero p {
  max-width: 650px;
  margin: 0 auto;

  color: var(--text-soft);

  font-size: 17px;
  line-height: 1.7;
}


/* ========================================
   Buttons
   ======================================== */

.hero-actions {
  display: flex;
  flex-direction: column;

  gap: 12px;

  margin-top: 32px;
}

.btn {
  min-height: 50px;

  display: inline-flex;
  align-items: center;
  justify-content: center;

  padding: 0 22px;

  border-radius: 13px;

  font-size: 15px;
  font-weight: 700;

  border: 1px solid transparent;

  transition:
    transform 0.2s ease,
    background 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

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

  box-shadow: 0 8px 20px rgba(79, 70, 229, 0.20);
}

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

.btn-secondary {
  background: var(--surface);
  color: var(--text);

  border-color: var(--border);
}

.btn-secondary:hover {
  background: var(--surface-soft);
}


/* ========================================
   Intro Section
   ======================================== */

.intro-section {
  padding: 76px 0;
  background: var(--bg);
}

.section-heading {
  max-width: 680px;
  margin-bottom: 36px;
}

.section-heading h2 {
  font-size: clamp(28px, 6vw, 42px);
  line-height: 1.15;
  letter-spacing: -0.8px;

  margin-bottom: 14px;
}

.section-heading p {
  color: var(--text-soft);
  font-size: 16px;
}


/* ========================================
   Feature Cards
   ======================================== */

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

  gap: 16px;
}

.feature-card {
  background: var(--surface);

  border: 1px solid var(--border);
  border-radius: var(--radius-md);

  padding: 26px;

  box-shadow: var(--shadow-sm);

  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.feature-number {
  width: 40px;
  height: 40px;

  display: flex;
  align-items: center;
  justify-content: center;

  margin-bottom: 20px;

  border-radius: 11px;

  background: var(--primary-soft);
  color: var(--primary);

  font-size: 13px;
  font-weight: 800;
}

.feature-card h3 {
  font-size: 19px;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--text-soft);
  font-size: 15px;
  line-height: 1.65;
}


/* ========================================
   Guest Section
   ======================================== */

.guest-section {
  padding: 20px 0 80px;
}

.guest-card {
  display: flex;
  flex-direction: column;

  gap: 28px;

  padding: 30px;

  background: var(--primary);
  color: #ffffff;

  border-radius: var(--radius-lg);

  box-shadow: var(--shadow-md);
}

.guest-card .eyebrow {
  color: #ffffff;
  opacity: 0.85;
}

.guest-card h2 {
  font-size: clamp(26px, 6vw, 38px);
  line-height: 1.15;
  letter-spacing: -0.6px;

  margin-bottom: 12px;
}

.guest-card p {
  max-width: 620px;

  color: rgba(255, 255, 255, 0.82);

  font-size: 15px;
}

.guest-card .btn {
  background: #ffffff;
  color: var(--primary);

  width: 100%;
}

.guest-card .btn:hover {
  background: #f8f9ff;
}


/* ========================================
   Footer
   ======================================== */

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

.footer-inner {
  min-height: 72px;

  display: flex;
  align-items: center;
  justify-content: center;

  text-align: center;
}

.footer-inner p {
  color: var(--text-light);
  font-size: 13px;
}


/* ========================================
   Tablet
   ======================================== */

@media (min-width: 640px) {

  .container {
    width: min(100% - 48px, var(--container));
  }

  .hero {
    padding: 100px 0 110px;
  }

  .hero-actions {
    flex-direction: row;
    justify-content: center;
  }

  .hero-actions .btn {
    min-width: 170px;
  }

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

  .guest-card {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;

    padding: 42px;
  }

  .guest-card .btn {
    width: auto;
    min-width: 180px;
    flex-shrink: 0;
  }
}


/* ========================================
   Desktop
   ======================================== */

@media (min-width: 900px) {

  .container {
    width: min(100% - 64px, var(--container));
  }

  .header-inner {
    min-height: 74px;
  }

  .hero h1 {
    max-width: 850px;
    margin-inline: auto;
  }

  .feature-card {
    padding: 30px;
  }

  .guest-card {
    padding: 48px;
  }
}


/* ========================================
   Reduced Motion
   ======================================== */

@media (prefers-reduced-motion: reduce) {

  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition: none !important;
  }
  }