:root {
  --primary-color: #2D5C7F;
  --secondary-color: #4A90E2;
  --accent-color: #B3D0D9;
  --light-color: #F5F5F5;
  --dark-color: #1D2A3C;
  --gradient-primary: linear-gradient(135deg, #2D5C7F 0%, #4A90E2 100%);
  --hover-color: #245070;
  --background-color: #F0F6FA;
  --text-color: #2C3E50;
  --border-color: rgba(45, 92, 127, 0.2);
  --divider-color: rgba(45, 92, 127, 0.15);
  --shadow-color: rgba(45, 92, 127, 0.12);
  --highlight-color: #F2D57F;
  --main-font: 'Merriweather', serif;
  --alt-font: 'Open Sans', sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--alt-font);
  color: var(--text-color);
  background-color: var(--background-color);
  line-height: 1.8;
}

h1, h2, h3, h4 {
  font-family: var(--main-font);
  font-weight: 700;
  color: var(--dark-color);
}

.container { max-width: 1200px; margin: 0 auto; }

/* ===== HEADER ===== */
header {
  background: linear-gradient(135deg, var(--primary-color) 0%, #1D2A3C 100%);
  color: var(--light-color);
  padding: 1.2rem 0;
  position: relative;
  z-index: 1000;
  box-shadow: 0 3px 15px var(--shadow-color);
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  padding: 8px;
  background: rgba(255,255,255,0.1);
  border-radius: 8px;
}
.hamburger .line {
  width: 28px; height: 3px;
  background-color: var(--light-color);
  margin: 3px 0;
  transition: 0.3s;
  border-radius: 2px;
}
#menu-toggle { display: none; }
#menu-toggle:checked ~ .mobile-nav { max-height: 500px; opacity: 1; }

.mobile-nav {
  position: absolute; top: 100%; left: 0; right: 0;
  background: linear-gradient(135deg, var(--primary-color) 0%, #1D2A3C 100%);
  max-height: 0; overflow: hidden; opacity: 0;
  transition: all 0.4s ease;
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
  z-index: 1000;
}
.mobile-nav ul { padding: 2rem; margin: 0; list-style: none; }
.mobile-nav li { margin: 0.8rem 0; }
.mobile-nav a {
  display: block; padding: 1rem 1.5rem;
  color: var(--light-color); text-decoration: none;
  border-radius: 12px; transition: all 0.3s ease;
  font-size: 1rem; font-weight: 500;
  border: 2px solid transparent;
}
.mobile-nav a:hover {
  background-color: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.3);
  transform: translateX(8px);
}

.navigation a {
  color: var(--light-color);
  text-decoration: none;
  padding: 0.5rem 0.9rem;
  border-radius: 8px;
  transition: all 0.3s ease;
  font-family: var(--alt-font);
  font-weight: 500;
  font-size: 0.92rem;
}
.navigation a:hover { background: rgba(255,255,255,0.15); }

/* ===== HERO ===== */
.hero {
  position: relative;
  overflow: hidden;
}
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(29,42,60,0.82) 0%, rgba(45,92,127,0.75) 100%);
}

/* ===== PATTERN ===== */
.pattern-bg {
  background-image:
    radial-gradient(circle at 20% 35%, rgba(45,92,127,0.07) 0%, transparent 55%),
    radial-gradient(circle at 80% 65%, rgba(74,144,226,0.06) 0%, transparent 55%),
    linear-gradient(60deg, rgba(242,213,127,0.04) 25%, transparent 25%),
    linear-gradient(-60deg, rgba(179,208,217,0.04) 25%, transparent 25%);
  background-size: 170px 170px, 210px 210px, 40px 40px, 40px 40px;
}

/* ===== BUTTONS ===== */
button, .btn {
  transition: all 0.35s ease;
  position: relative; overflow: hidden;
  background: var(--gradient-primary);
  color: white; border: none;
  padding: 1rem 2.5rem;
  border-radius: 50px;
  font-weight: 600;
  font-family: var(--alt-font);
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 0.92rem;
  text-decoration: none;
  display: inline-block;
  text-align: center;
}
button:hover, .btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(45,92,127,0.35);
}

/* ===== LESSON BLOCK ===== */
.lesson-block {
  background: white;
  border-radius: 20px;
  padding: 2.5rem;
  box-shadow: 0 6px 22px var(--shadow-color);
  border-left: 5px solid var(--secondary-color);
  margin-bottom: 2rem;
}
.lesson-block h3 {
  color: var(--primary-color);
  font-size: 1.3rem;
  margin-bottom: 1rem;
}
.lesson-block p { color: var(--text-color); margin-bottom: 0.8rem; }
.lesson-block ul {
  list-style: none; padding: 0; margin: 0.5rem 0;
}
.lesson-block ul li {
  padding: 0.4rem 0 0.4rem 1.8rem;
  position: relative;
  color: var(--text-color);
}
.lesson-block ul li::before {
  content: '✓';
  position: absolute; left: 0;
  color: var(--secondary-color);
  font-weight: 700;
}

/* ===== FEATURE CARDS ===== */
.feature-card {
  background: white;
  border-radius: 20px;
  padding: 2.2rem;
  box-shadow: 0 6px 20px var(--shadow-color);
  text-align: center;
  border-top: 4px solid var(--secondary-color);
  transition: all 0.35s ease;
}
.feature-card:hover {
  transform: translateY(-7px);
  box-shadow: 0 16px 35px var(--shadow-color);
}
.feature-icon {
  font-size: 2.8rem;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0 auto 1.2rem auto;
  width: 100%;
}

/* ===== TESTIMONIALS ===== */
.testimonial {
  background: white;
  padding: 2.2rem;
  border-radius: 18px;
  box-shadow: 0 6px 18px var(--shadow-color);
  border-top: 4px solid var(--primary-color);
  transition: all 0.35s ease;
}
.testimonial:hover {
  transform: translateY(-5px);
  box-shadow: 0 14px 32px var(--shadow-color);
}

/* ===== FAQ ===== */
.faq-item {
  background: white;
  padding: 2rem;
  margin: 1.2rem 0;
  border-radius: 16px;
  box-shadow: 0 4px 16px var(--shadow-color);
  border-left: 4px solid var(--accent-color);
}
.faq-item h3 { color: var(--primary-color); margin-bottom: 0.8rem; font-size: 1.05rem; }

/* ===== FORMS ===== */
input, textarea {
  transition: all 0.3s ease;
  font-family: var(--alt-font);
  border: 2px solid var(--border-color);
  border-radius: 10px;
  padding: 0.9rem 1.1rem;
  background: white;
  color: var(--text-color);
  font-size: 0.97rem;
  width: 100%;
  box-sizing: border-box;
}
input:focus, textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(45,92,127,0.1);
}

/* ===== CONTACT ===== */
#contact .contact-wrapper {
  max-width: 80%;
  margin: 0 auto;
}
@media (max-width: 768px) {
  #contact .contact-wrapper { max-width: 100%; }
}

/* ===== INFO BOX ===== */
.info-box {
  background: linear-gradient(135deg, var(--primary-color), #1D2A3C);
  color: white;
  border-radius: 18px;
  padding: 2rem 2.5rem;
  margin: 1.5rem 0;
}
.info-box h4 { color: var(--highlight-color); margin-bottom: 0.7rem; }
.info-box p { color: rgba(255,255,255,0.88); margin: 0; }

/* ===== FOOTER ===== */
footer {
  background-color: var(--dark-color);
  color: var(--light-color);
}
footer a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color 0.3s;
}
footer a:hover { color: var(--highlight-color); }
footer img[alt="logo"],
header img[alt="logo"] { filter: brightness(0) invert(1); }

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--light-color); }
::-webkit-scrollbar-thumb { background: var(--gradient-primary); border-radius: 5px; }

/* ===== FOCUS ===== */
a:focus, button:focus, input:focus, textarea:focus {
  outline: 3px solid var(--highlight-color);
  outline-offset: 3px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hamburger { display: flex; }
  .navigation { display: none; }
  .container { padding: 0 1.2rem; }
  .lesson-block { padding: 1.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

@media (prefers-contrast: high) {
  :root {
    --text-color: #000;
    --background-color: #fff;
    --primary-color: #003366;
    --secondary-color: #0055aa;
  }
}