@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;600;700&display=swap');

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

html,
body {
  height: 100%;
}

body {
  font-family: "IBM Plex Sans", sans-serif;
  background: #f5f2eb;
  padding: 24px 6%;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding-bottom: 110px;
  color: #2d2a26;
}

/* ========================= LOADER ========================= */
#loader {
  position: fixed;
  inset: 0;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 99999;
  transition: opacity 180ms ease, visibility 180ms ease;
  opacity: 1;
  visibility: visible;
  pointer-events: all;
}

#loader.loaded {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.spinner {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 6px solid rgba(6, 168, 124, .18);
  border-top-color: #06a87c;
  animation: spin 900ms linear infinite;
  box-shadow: 0 6px 18px rgba(6, 168, 124, .12);
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

body.no-scroll {
  overflow: hidden;
  touch-action: none;
}

/* ----------------- HEADER ----------------- */
.header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 32px;
  position: relative;
  z-index: 1100;
}

/* Hide header completely on mobile (≤767px) */
@media (max-width: 767px) {
  .header {
    display: none;
  }
}

.title-group {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 700;
  color: #2d2a26;
  margin-bottom: 6px;
  letter-spacing: -0.5px;
}

h2 {
  font-size: clamp(1rem, 2.5vw, 1.4rem);
  font-weight: 400;
  color: #4e4a45;
}

/* BACK BUTTON */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: clamp(4px, 1vw, 8px);
  text-decoration: none;
  background: #F4320B;
  color: #fff;
  border-radius: 14px;
  padding: clamp(8px, 1.2vw, 14px) clamp(12px, 2vw, 22px);
  font-size: clamp(.9rem, 1.5vw, 1.2rem);
  font-weight: 600;
  box-shadow: 0 3px 6px rgba(244, 50, 11, .2);
  transition: background .18s ease, transform .18s ease, box-shadow .18s ease;
}

.back-btn:hover {
  background: #f54d2b;
  box-shadow: 0 5px 10px rgba(244, 50, 11, .25);
}

.back-btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 4px rgba(244, 50, 11, .2);
}

/* MAIN CONTENT */
.studyguide-main {
  flex: 1;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

/* HERO SECTION */
.hero-section-sg {
  display: flex;
  flex-direction: column;
  gap: 32px;
  margin: 20px 0 60px;
  padding: 0;
  align-items: center;
  text-align: center;
}

/* Add generous top spacing on mobile when header is hidden */
@media (max-width: 767px) {
  .hero-section-sg {
    margin-top: 40px;     /* Creates nice breathing room from top of screen */
    gap: 40px;            /* Slightly more space between hero elements */
  }
}

.hero-content {
  flex: 1;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 700;
  color: #2d2a26;
  margin-bottom: 16px;
  letter-spacing: -1px;
  line-height: 1.1;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  color: #4e4a45;
  margin-bottom: 28px;
  line-height: 1.5;
  max-width: 700px;
}

.telegram-btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: #229ED9;
  color: #fff;
  padding: 16px 28px;
  border-radius: 16px;
  font-weight: 600;
  font-size: 1.15rem;
  text-decoration: none;
  box-shadow: 0 6px 16px rgba(34, 158, 217, .25);
  transition: all .2s ease;
}

.telegram-btn:hover {
  background: #1a8cc7;
  transform: translateY(-3px);
  box-shadow: 0 10px 20px rgba(34, 158, 217, .3);
}

.telegram-icon {
  width: 28px;
  height: 28px;
}

.hero-image {
  flex: 1;
  max-width: 500px;
  width: 100%;
}

.hero-image img {
  width: 100%;
  border-radius: 20px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, .1);
}

/* SECTION TITLES */
.section-title {
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 700;
  color: #2d2a26;
  text-align: center;
  margin: 60px 0 32px;
  letter-spacing: -0.6px;
}

/* BENEFITS */
.benefits-section {
  padding: 0;
  margin-bottom: 40px;
}

.benefits-list {
  list-style: none;
  display: grid;
  gap: 18px;
  max-width: 900px;
  margin: 0 auto;
}

.benefits-list li {
  background: #fff;
  padding: 20px 24px;
  border-radius: 16px;
  font-size: 1.15rem;
  font-weight: 500;
  box-shadow: 0 6px 16px rgba(0, 0, 0, .06);
  display: flex;
  align-items: center;
  gap: 16px;
  line-height: 1.4;
}

.benefits-list li::before {
  content: "✓";
  color: #06a87c;
  font-weight: bold;
  font-size: 1.6rem;
  flex-shrink: 0;
}

/* MENTORS */
.mentors-section {
  padding: 0 0 60px;
}

.mentors-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  max-width: 1100px;
  margin: 0 auto;
}

.mentor-card {
  background: #fff;
  border-radius: 20px;
  padding: 28px 24px;
  text-align: center;
  box-shadow: 0 8px 20px rgba(0, 0, 0, .08);
  transition: transform .24s ease, box-shadow .24s ease;
}

.mentor-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, .12);
}

.mentor-img {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 18px;
  border: 5px solid #f5f2eb;
}

.mentor-card h3 {
  font-size: 1.4rem;
  margin: 8px 0 6px;
  color: #2d2a26;
  font-weight: 700;
}

.mentor-role {
  font-size: 1rem;
  color: #06a87c;
  font-weight: 600;
  margin-bottom: 10px;
}

.mentor-bio {
  font-size: 1rem;
  color: #4e4a45;
  line-height: 1.45;
}

/* MOBILE FOOTER */
.bottom-nav {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  bottom: 18px;
  display: flex;
  gap: 14px;
  align-items: flex-end;
  z-index: 1100;
  padding: 8px;
  pointer-events: auto;
  -webkit-tap-highlight-color: transparent;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 58px;
  height: 58px;
  border-radius: 12px;
  background: linear-gradient(135deg, #2fd8ab, #06a87c);
  box-shadow: 0 8px 20px rgba(0, 0, 0, .12);
  border: 1px solid rgba(0, 0, 0, .04);
  text-decoration: none;
  transition: transform .16s ease, box-shadow .16s ease;
}

.nav-btn img {
  width: 26px;
  height: 26px;
}

.nav-btn:active {
  transform: scale(.95);
}

.nav-btn:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, .14);
}

.nav-btn.center {
  width: 76px;
  height: 76px;
  border-radius: 18px;
  background: linear-gradient(135deg, #f9734b, #ffab25);
  box-shadow: 0 14px 36px rgba(255, 120, 50, .22);
  margin-bottom: 6px;
}

.nav-btn.center img {
  width: 34px;
  height: 34px;
  filter: brightness(0) invert(1);
}

@media (min-width: 768px) {
  .bottom-nav {
    display: none;
  }
}

/* DESKTOP: HERO LAYOUT */
@media (min-width: 768px) {
  .hero-section-sg {
    flex-direction: row;
    text-align: left;
    align-items: center;
    gap: 5%;
    padding: 0 6%;
    margin-top: 20px; /* Keep normal spacing when header is visible */
  }

  .hero-content {
    max-width: 50%;
  }

  .hero-image {
    max-width: 45%;
  }

  .hero-subtitle {
    margin-bottom: 32px;
  }
}

/* RIGHT-SIDE FIXED AD (DESKTOP ONLY) */
.rightside-ad {
  display: none;
}

@media (min-width: 1024px) {
  .rightside-ad {
    display: block;
    position: fixed;
    top: 100px;
    right: 0;
    width: 180px;
    padding: 12px;
    background: #ffffff;
    border-left: 2px solid #eee;
    box-shadow: -4px 0 12px rgba(0, 0, 0, .08);
    border-radius: 12px 0 0 12px;
    z-index: 999;
    text-align: center;
  }

  .rightside-ad p {
    margin: 12px 0 0;
    font-size: 13px;
    color: #666;
  }
}

/* LINKS */
a {
  text-decoration: none !important;
}