/* =====================================================
   GIA SU GIOI 247 – Project 3
   Style: Modern, Energetic, Blue + Orange
   Mobile-first Responsive CSS
   ===================================================== */

/* ---- CSS Variables ---- */
:root {
  --primary: #4a90e2;
  --primary-dark: #2575cc;
  --primary-light: #74aee8;
  --accent: #f39c12;
  --accent-dark: #d68910;
  --accent-light: #f5b633;

  --green: #27ae60;
  --purple: #8e44ad;
  --red: #e74c3c;
  --teal: #16a085;
  --blue: #2980b9;

  --text-dark: #1a202c;
  --text-medium: #4a5568;
  --text-light: #718096;
  --text-muted: #a0aec0;

  --bg-white: #ffffff;
  --bg-light: #f8fafc;
  --bg-gray: #edf2f7;
  --bg-section: #f0f7ff;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.16);
  --shadow-blue: 0 8px 32px rgba(74, 144, 226, 0.25);
  --shadow-orange: 0 8px 32px rgba(243, 156, 18, 0.3);

  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;

  --transition: all 0.3s ease;
  --transition-fast: all 0.2s ease;

  --container-max: 1200px;
  --section-padding: 80px 0;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text-dark);
  background: var(--bg-white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Montserrat', sans-serif;
  line-height: 1.3;
  font-weight: 700;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition-fast);
}

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

ul {
  list-style: none;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

input, select, textarea {
  font-family: 'Inter', sans-serif;
}

/* ---- Container ---- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---- Utility Classes ---- */
.accent-blue { color: var(--primary); }
.accent-orange { color: var(--accent); }
.text-orange { color: var(--accent); }
.text-blue { color: var(--primary); }
.bg-light { background-color: var(--bg-light); }
.bg-section { background-color: var(--bg-section); }

.section {
  padding: var(--section-padding);
}

/* ---- Section Header ---- */
.section-header {
  text-align: center;
  max-width: 740px;
  margin: 0 auto 52px;
}

.section-tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--primary);
  background: rgba(74, 144, 226, 0.1);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
}

.section-tag.light {
  color: var(--accent);
  background: rgba(243, 156, 18, 0.15);
}

.section-header h2 {
  font-size: clamp(1.7rem, 3.5vw, 2.4rem);
  margin-bottom: 16px;
  color: var(--text-dark);
}

.section-header p {
  font-size: 1.05rem;
  color: var(--text-medium);
  line-height: 1.8;
}

/* ---- Buttons ---- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  padding: 14px 28px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  box-shadow: var(--shadow-blue);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(74, 144, 226, 0.35);
  color: #fff;
}

.btn-primary.btn-lg {
  padding: 16px 32px;
  font-size: 1rem;
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: transparent;
  color: #fff;
  padding: 14px 28px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  border: 2px solid rgba(255, 255, 255, 0.6);
  transition: var(--transition);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #fff;
  color: #fff;
}

.btn-outline.btn-lg {
  padding: 16px 32px;
  font-size: 1rem;
}

/* Pulse animation for hero CTA */
.pulse-animation {
  animation: pulse 2.5s infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 8px 32px rgba(74, 144, 226, 0.3); }
  50% { box-shadow: 0 8px 40px rgba(74, 144, 226, 0.6), 0 0 0 10px rgba(74, 144, 226, 0.1); }
}

/* ---- Fixed CTA Button ---- */
.fixed-cta {
  position: fixed;
  bottom: 28px;
  right: 28px;
  display: flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
  color: #fff;
  padding: 14px 22px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: var(--shadow-orange);
  z-index: 900;
  transition: var(--transition);
  transform: scale(1);
}

.fixed-cta:hover {
  transform: scale(1.05);
  color: #fff;
}

/* ---- Back to Top Button ---- */
.back-to-top {
  position: fixed;
  bottom: 90px;
  right: 28px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 900;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  font-size: 0.9rem;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-3px);
}

/* =====================================================
   NAVIGATION
   ===================================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 18px 0;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
  padding: 12px 0;
}

.navbar.scrolled .logo {
  color: var(--text-dark);
}

.navbar.scrolled .nav-link {
  color: var(--text-medium);
}

.navbar.scrolled .nav-link:hover {
  color: var(--primary);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: 'Montserrat', sans-serif;
  font-size: 1.25rem;
  color: #fff;
  font-weight: 600;
}

.logo i {
  font-size: 1.4rem;
  color: var(--accent);
}

.logo strong {
  font-weight: 800;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  color: rgba(255, 255, 255, 0.9);
  font-weight: 500;
  font-size: 0.9rem;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: var(--transition-fast);
}

.nav-link:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.15);
}

.btn-nav {
  display: inline-flex;
  align-items: center;
  background: var(--accent);
  color: #fff !important;
  padding: 10px 22px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.88rem;
  transition: var(--transition);
}

.btn-nav:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 32px;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: var(--transition-fast);
}

.navbar.scrolled .hamburger span {
  background: var(--text-dark);
}

.hamburger.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger.active span:nth-child(2) {
  opacity: 0;
}
.hamburger.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* =====================================================
   HERO SECTION
   ===================================================== */
.hero {
  position: relative;
  min-height: 100vh;
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 40%, var(--primary) 100%);
  display: flex;
  align-items: center;
  padding: 100px 0 60px;
  overflow: hidden;
}

/* Animated background particles */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(255,255,255,0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(243, 156, 18, 0.08) 0%, transparent 50%);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

/* Hero Badge */
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(243, 156, 18, 0.2);
  border: 1px solid rgba(243, 156, 18, 0.4);
  color: var(--accent-light);
  padding: 8px 18px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-badge i {
  color: var(--accent);
}

/* Hero Heading */
.hero-text h1 {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  color: #fff;
  margin-bottom: 20px;
  line-height: 1.2;
}

.hero-sub {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 28px;
  line-height: 1.8;
}

/* Hero Bullets */
.hero-bullets {
  margin-bottom: 36px;
}

.hero-bullets li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.95rem;
  margin-bottom: 12px;
}

.hero-bullets li i {
  color: var(--accent);
  font-size: 1rem;
  margin-top: 3px;
  flex-shrink: 0;
}

/* Hero CTA Group */
.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 40px;
}

/* Hero Stats */
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.hero-stat {
  text-align: center;
  padding: 0 12px;
}

.hero-stat strong {
  display: block;
  font-size: 1.5rem;
  font-weight: 800;
  color: #fff;
  font-family: 'Montserrat', sans-serif;
}

.hero-stat span {
  display: block;
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.7);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.hero-stat-divider {
  width: 1px;
  height: 36px;
  background: rgba(255, 255, 255, 0.2);
}

/* Hero Image */
.hero-image {
  position: relative;
}

.hero-img-wrapper {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.hero-img-wrapper img {
  width: 100%;
  height: 480px;
  object-fit: cover;
  display: block;
  border-radius: var(--radius-xl);
}

/* Floating Badges on hero image */
.float-badge {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  color: var(--text-dark);
  padding: 10px 18px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  box-shadow: var(--shadow-md);
  animation: float 3s ease-in-out infinite;
}

.float-badge.float-top-right {
  top: 24px;
  right: -14px;
  animation-delay: 0s;
}

.float-badge.float-bottom-left {
  bottom: 24px;
  left: -14px;
  animation-delay: 1.5s;
}

.text-orange { color: var(--accent); }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* Hero Wave */
.hero-wave {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
}

.hero-wave svg {
  width: 100%;
  height: 80px;
  display: block;
}

/* =====================================================
   PAIN POINTS
   ===================================================== */
.pain-points {
  background: var(--bg-white);
}

.pain-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.pain-card {
  background: #fff;
  border: 1px solid #e8edf5;
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.pain-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-light) 100%);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.pain-card:hover {
  border-color: transparent;
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.pain-card:hover::before {
  transform: scaleX(1);
}

.pain-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, rgba(243, 156, 18, 0.12) 0%, rgba(243, 156, 18, 0.05) 100%);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.4rem;
  color: var(--accent);
}

.pain-card h3 {
  font-size: 1.05rem;
  margin-bottom: 10px;
  color: var(--text-dark);
}

.pain-card p {
  font-size: 0.9rem;
  color: var(--text-medium);
  line-height: 1.7;
}

/* =====================================================
   SOLUTIONS / DIFFERENTIATORS
   ===================================================== */
.solutions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.solution-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid #e8edf5;
}

.solution-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-6px);
  border-color: transparent;
}

.solution-icon {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin: 0 auto 20px;
}

.icon-blue { background: rgba(74, 144, 226, 0.12); color: var(--primary); }
.icon-orange { background: rgba(243, 156, 18, 0.12); color: var(--accent); }
.icon-green { background: rgba(39, 174, 96, 0.12); color: var(--green); }
.icon-purple { background: rgba(142, 68, 173, 0.12); color: var(--purple); }
.icon-red { background: rgba(231, 76, 60, 0.12); color: var(--red); }
.icon-teal { background: rgba(22, 160, 133, 0.12); color: var(--teal); }

.solution-card h3 {
  font-size: 1.05rem;
  margin-bottom: 12px;
  color: var(--text-dark);
}

.solution-card p {
  font-size: 0.88rem;
  color: var(--text-medium);
  line-height: 1.7;
}

/* =====================================================
   BENEFITS
   ===================================================== */
.benefits {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  padding: var(--section-padding);
}

.benefits .section-tag {
  color: var(--accent-light);
  background: rgba(255, 255, 255, 0.1);
}

.benefits-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.benefits-text h2 {
  color: #fff;
  font-size: clamp(1.7rem, 3vw, 2.2rem);
  margin-bottom: 28px;
}

.benefits-list {
  margin-bottom: 36px;
}

.benefits-list li {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.95rem;
  margin-bottom: 20px;
  line-height: 1.6;
}

.benefit-icon {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: var(--accent-light);
  flex-shrink: 0;
}

/* Benefits Visual */
.benefits-visual {
  position: relative;
}

.benefits-visual img {
  border-radius: var(--radius-xl);
  width: 100%;
  height: 400px;
  object-fit: cover;
  box-shadow: var(--shadow-lg);
}

.score-badge {
  position: absolute;
  top: -20px;
  right: 20px;
  background: var(--accent);
  color: #fff;
  padding: 16px 20px;
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: var(--shadow-orange);
}

.score-number {
  font-size: 2rem;
  font-weight: 900;
  font-family: 'Montserrat', sans-serif;
  line-height: 1;
}

.score-label {
  font-size: 0.72rem;
  margin-top: 4px;
  line-height: 1.4;
  opacity: 0.9;
}

.stats-card-float {
  position: absolute;
  bottom: -16px;
  left: 20px;
  background: #fff;
  padding: 16px 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
}

.stats-row {
  display: flex;
  gap: 24px;
}

.mini-stat {
  text-align: center;
}

.mini-stat strong {
  display: block;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  font-family: 'Montserrat', sans-serif;
}

.mini-stat span {
  font-size: 0.72rem;
  color: var(--text-medium);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* =====================================================
   TEACHERS
   ===================================================== */
.teachers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 28px;
}

.teacher-card {
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid #e8edf5;
}

.teacher-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-6px);
  border-color: transparent;
}

.teacher-img-wrap {
  position: relative;
}

.teacher-img-wrap img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.teacher-subject-badge {
  position: absolute;
  bottom: 14px;
  left: 14px;
  background: var(--primary);
  color: #fff;
  padding: 5px 14px;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 600;
}

.teacher-subject-badge.orange { background: var(--accent); }
.teacher-subject-badge.green { background: var(--green); }
.teacher-subject-badge.purple { background: var(--purple); }

.teacher-body {
  padding: 24px;
}

.teacher-body h3 {
  font-size: 1.05rem;
  margin-bottom: 4px;
  color: var(--text-dark);
}

.teacher-degree {
  font-size: 0.82rem;
  color: var(--text-medium);
  margin-bottom: 12px;
}

.teacher-rating {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.stars {
  color: var(--accent);
  font-size: 0.85rem;
  letter-spacing: 1px;
}

.rating-num {
  font-weight: 700;
  color: var(--text-dark);
  font-size: 0.9rem;
}

.review-count {
  font-size: 0.78rem;
  color: var(--text-light);
}

.teacher-highlights {
  margin-bottom: 20px;
}

.teacher-highlights li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-medium);
  margin-bottom: 8px;
}

.teacher-highlights li i {
  color: var(--green);
  font-size: 0.8rem;
  margin-top: 3px;
  flex-shrink: 0;
}

.btn-teacher {
  display: block;
  text-align: center;
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
  padding: 10px 20px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.85rem;
  transition: var(--transition);
}

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

/* =====================================================
   SUBJECTS
   ===================================================== */
.subjects {
  background: var(--bg-white);
}

.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 20px;
}

.subject-card {
  background: #fff;
  border: 1px solid #e8edf5;
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  transition: var(--transition);
  cursor: default;
}

.subject-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

.subject-icon {
  width: 60px;
  height: 60px;
  background: rgba(74, 144, 226, 0.1);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--primary);
  margin: 0 auto 16px;
  transition: var(--transition);
}

.subject-card:hover .subject-icon {
  background: var(--primary);
  color: #fff;
}

.subject-icon.orange { background: rgba(243,156,18,0.1); color: var(--accent); }
.subject-card:hover .subject-icon.orange { background: var(--accent); color: #fff; }

.subject-icon.green { background: rgba(39,174,96,0.1); color: var(--green); }
.subject-card:hover .subject-icon.green { background: var(--green); color: #fff; }

.subject-icon.purple { background: rgba(142,68,173,0.1); color: var(--purple); }
.subject-card:hover .subject-icon.purple { background: var(--purple); color: #fff; }

.subject-icon.red { background: rgba(231,76,60,0.1); color: var(--red); }
.subject-card:hover .subject-icon.red { background: var(--red); color: #fff; }

.subject-icon.teal { background: rgba(22,160,133,0.1); color: var(--teal); }
.subject-card:hover .subject-icon.teal { background: var(--teal); color: #fff; }

.subject-icon.blue { background: rgba(41,128,185,0.1); color: var(--blue); }
.subject-card:hover .subject-icon.blue { background: var(--blue); color: #fff; }

.subject-card h4 {
  font-size: 0.95rem;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.subject-card p {
  font-size: 0.8rem;
  color: var(--text-medium);
  margin-bottom: 14px;
  line-height: 1.6;
}

.subject-level {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 600;
}

.level-basic { background: rgba(39,174,96,0.1); color: var(--green); }
.level-advanced { background: rgba(74,144,226,0.1); color: var(--primary); }
.level-exam { background: rgba(231,76,60,0.1); color: var(--red); }

/* =====================================================
   TESTIMONIALS
   ===================================================== */
.testimonials-wrapper {
  overflow: hidden;
  border-radius: var(--radius-lg);
  margin-bottom: 28px;
}

.testimonials-track {
  display: flex;
  gap: 24px;
  transition: transform 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.testimonial-card {
  width: calc(33.333% - 16px);
  min-width: 0;
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  border: 1px solid #e8edf5;
  transition: var(--transition);
  flex-shrink: 0;
}

.testimonial-card:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(74, 144, 226, 0.2);
}

.testi-stars {
  font-size: 1rem;
  color: var(--accent);
  margin-bottom: 14px;
  letter-spacing: 2px;
}

.testi-text {
  font-size: 0.9rem;
  color: var(--text-medium);
  line-height: 1.8;
  font-style: italic;
  margin-bottom: 20px;
  position: relative;
}

.testi-text::before {
  content: '"';
  font-size: 3rem;
  color: rgba(74, 144, 226, 0.15);
  position: absolute;
  top: -12px;
  left: -8px;
  font-family: Georgia, serif;
  line-height: 1;
}

.testi-author {
  display: flex;
  align-items: center;
  gap: 14px;
}

.testi-author img {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid rgba(74, 144, 226, 0.2);
}

.testi-info strong {
  display: block;
  font-size: 0.88rem;
  color: var(--text-dark);
}

.testi-info span {
  font-size: 0.78rem;
  color: var(--text-light);
}

/* Slider Controls */
.slider-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 8px;
}

.slider-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 2px solid var(--primary);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  transition: var(--transition-fast);
}

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

.slider-dots {
  display: flex;
  gap: 8px;
}

.slider-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(74, 144, 226, 0.25);
  transition: var(--transition-fast);
  cursor: pointer;
}

.slider-dot.active {
  background: var(--primary);
  width: 28px;
  border-radius: var(--radius-full);
}

/* =====================================================
   HOW IT WORKS
   ===================================================== */
.how-it-works {
  background: linear-gradient(135deg, #f0f7ff 0%, var(--bg-light) 100%);
}

.steps-container {
  display: flex;
  align-items: flex-start;
  gap: 0;
  justify-content: center;
  margin-bottom: 48px;
  flex-wrap: wrap;
  gap: 8px;
}

.step-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  flex: 1;
  min-width: 200px;
  max-width: 250px;
  border: 1px solid #e8edf5;
  transition: var(--transition);
  position: relative;
}

.step-card:hover {
  box-shadow: var(--shadow-blue);
  border-color: rgba(74, 144, 226, 0.2);
  transform: translateY(-4px);
}

.step-number {
  font-size: 3rem;
  font-weight: 900;
  font-family: 'Montserrat', sans-serif;
  color: rgba(74, 144, 226, 0.1);
  line-height: 1;
  margin-bottom: 8px;
}

.step-icon-wrap {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #fff;
  margin: 0 auto 16px;
  box-shadow: var(--shadow-blue);
}

.step-card h3 {
  font-size: 1rem;
  margin-bottom: 10px;
  color: var(--text-dark);
}

.step-card p {
  font-size: 0.85rem;
  color: var(--text-medium);
  line-height: 1.7;
}

.step-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--primary-light);
  padding: 0 4px;
  margin-top: 80px;
  flex-shrink: 0;
}

.steps-cta {
  text-align: center;
}

/* =====================================================
   PRICING
   ===================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  margin-bottom: 28px;
}

.pricing-card {
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid #e8edf5;
  transition: var(--transition);
  position: relative;
}

.pricing-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-6px);
  border-color: transparent;
}

.pricing-card.featured-price {
  border: 2px solid var(--primary);
  transform: scale(1.02);
  box-shadow: var(--shadow-blue);
}

.pricing-card.featured-price:hover {
  transform: scale(1.02) translateY(-6px);
  box-shadow: 0 20px 56px rgba(74, 144, 226, 0.2);
}

.price-popular-badge {
  background: var(--accent);
  color: #fff;
  text-align: center;
  padding: 8px 16px;
  font-size: 0.82rem;
  font-weight: 700;
}

.pricing-header {
  padding: 28px 28px 24px;
  color: #fff;
}

.pricing-header.level-basic {
  background: linear-gradient(135deg, #718096 0%, #4a5568 100%);
}

.pricing-header.level-advanced {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
}

.pricing-header.level-exam {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
}

.pricing-header h3 {
  font-size: 1.2rem;
  margin-bottom: 10px;
  color: #fff;
}

.price-display {
  margin-bottom: 8px;
}

.price-amount {
  font-size: 1.9rem;
  font-weight: 900;
  font-family: 'Montserrat', sans-serif;
}

.price-unit {
  font-size: 0.9rem;
  opacity: 0.85;
  margin-left: 4px;
}

.price-desc {
  font-size: 0.82rem;
  opacity: 0.85;
}

.pricing-list {
  padding: 24px 28px;
}

.pricing-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-medium);
  padding: 8px 0;
  border-bottom: 1px solid #f0f4f8;
}

.pricing-list li:last-child { border-bottom: none; }

.pricing-list li i {
  color: var(--green);
  font-size: 0.85rem;
  flex-shrink: 0;
}

.pricing-list li.disabled {
  opacity: 0.4;
}

.pricing-list li.disabled i {
  color: var(--text-muted);
}

.btn-price {
  display: block;
  text-align: center;
  margin: 0 28px 28px;
  padding: 13px 24px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.9rem;
  border: 2px solid var(--primary);
  color: var(--primary);
  transition: var(--transition);
}

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

.btn-price.featured-btn {
  border-color: var(--primary);
}

.pricing-note {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-medium);
  padding: 20px;
  background: rgba(74, 144, 226, 0.05);
  border-radius: var(--radius);
  border: 1px solid rgba(74, 144, 226, 0.15);
}

.pricing-note i {
  color: var(--primary);
  margin-right: 6px;
}

.pricing-note a {
  color: var(--primary);
  font-weight: 600;
}

.pricing-note a:hover {
  color: var(--primary-dark);
}

/* =====================================================
   FAQ
   ===================================================== */
.faq {
  background: var(--bg-white);
}

.faq-wrapper {
  max-width: 780px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid #e8edf5;
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  background: #fff;
  transition: var(--transition);
}

.faq-item:hover, .faq-item.active {
  border-color: rgba(74, 144, 226, 0.3);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 20px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-dark);
  text-align: left;
  background: none;
  cursor: pointer;
  gap: 16px;
  transition: var(--transition-fast);
}

.faq-question:hover {
  color: var(--primary);
}

.faq-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: rgba(74, 144, 226, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  color: var(--primary);
  flex-shrink: 0;
  transition: var(--transition-fast);
}

.faq-item.active .faq-icon {
  background: var(--primary);
  color: #fff;
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.2s ease;
}

.faq-answer.open {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 24px 20px;
  font-size: 0.88rem;
  color: var(--text-medium);
  line-height: 1.8;
}

.faq-answer strong {
  color: var(--text-dark);
}

/* =====================================================
   CONTACT
   ===================================================== */
.contact {
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 40%, var(--primary) 100%);
  color: #fff;
  padding: var(--section-padding);
}

.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: flex-start;
}

.contact-info h2 {
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  color: #fff;
  margin-bottom: 16px;
}

.contact-info p {
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 36px;
  font-size: 1rem;
  line-height: 1.8;
}

.contact-channels {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 32px;
}

.contact-channel {
  display: flex;
  align-items: center;
  gap: 14px;
  background: rgba(255, 255, 255, 0.1);
  padding: 16px 20px;
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: var(--transition);
  color: #fff;
}

.contact-channel:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateX(4px);
  color: #fff;
}

.channel-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.channel-icon.green { background: rgba(39, 174, 96, 0.3); color: #2ecc71; }
.channel-icon.blue-fb { background: rgba(59, 89, 152, 0.4); color: #fff; }

.channel-info strong {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 2px;
}

.channel-info span {
  font-size: 0.8rem;
  opacity: 0.8;
}

.trust-badges {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.8);
}

.trust-item i {
  color: var(--accent-light);
}

/* Contact Form */
.contact-form-wrap {
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-lg);
}

.contact-form-wrap h3 {
  font-size: 1.25rem;
  color: var(--text-dark);
  margin-bottom: 28px;
  text-align: center;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-dark);
}

.required {
  color: var(--red);
}

.form-group input,
.form-group select,
.form-group textarea {
  padding: 12px 16px;
  border: 2px solid #e8edf5;
  border-radius: var(--radius);
  font-size: 0.9rem;
  color: var(--text-dark);
  background: #fff;
  transition: var(--transition-fast);
  outline: none;
  width: 100%;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.form-group input.error,
.form-group select.error,
.form-group textarea.error {
  border-color: var(--red);
}

.form-error {
  font-size: 0.78rem;
  color: var(--red);
  display: block;
  min-height: 16px;
}

.form-group textarea {
  resize: vertical;
  min-height: 90px;
}

.btn-submit {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 16px 28px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 700;
  font-family: 'Montserrat', sans-serif;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-submit:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-blue);
}

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

.btn-submit.loading {
  opacity: 0.8;
  cursor: not-allowed;
  pointer-events: none;
}

/* Form Success */
.form-success {
  text-align: center;
  padding: 40px 24px;
  animation: fadeIn 0.5s ease;
}

.form-success i {
  font-size: 3rem;
  color: var(--green);
  margin-bottom: 16px;
  display: block;
}

.form-success h4 {
  font-size: 1.3rem;
  color: var(--text-dark);
  margin-bottom: 10px;
}

.form-success p {
  font-size: 0.9rem;
  color: var(--text-medium);
  line-height: 1.7;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* =====================================================
   FOOTER
   ===================================================== */
.site-footer {
  background: #0f1e35;
  color: rgba(255, 255, 255, 0.8);
  padding: 64px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand .logo-white {
  color: #fff;
  margin-bottom: 16px;
  display: inline-flex;
}

.footer-brand p {
  font-size: 0.88rem;
  line-height: 1.8;
  margin-bottom: 24px;
  color: rgba(255, 255, 255, 0.7);
}

.social-links {
  display: flex;
  gap: 12px;
}

.social-link {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  transition: var(--transition-fast);
}

.social-link:hover {
  background: var(--primary);
  color: #fff;
}

.footer-col h4 {
  font-size: 0.88rem;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 18px;
}

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul li a {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.65);
  transition: var(--transition-fast);
}

.footer-col ul li a:hover {
  color: var(--accent-light);
  padding-left: 4px;
}

/* Contact list in footer */
.contact-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.65);
  margin-bottom: 12px;
}

.contact-list li i {
  color: var(--accent);
  margin-top: 3px;
  width: 14px;
  flex-shrink: 0;
}

.contact-list li a {
  color: rgba(255, 255, 255, 0.65);
}

.contact-list li a:hover {
  color: var(--accent-light);
}

/* Footer Bottom */
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.5);
}

/* =====================================================
   RESPONSIVE STYLES
   ===================================================== */

/* Large tablets */
@media (max-width: 1024px) {
  :root {
    --section-padding: 64px 0;
  }

  .hero-content {
    gap: 40px;
  }

  .benefits-inner {
    gap: 40px;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

/* Tablets */
@media (max-width: 768px) {
  :root {
    --section-padding: 52px 0;
  }

  /* Navbar */
  .hamburger {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    bottom: 0;
    width: 280px;
    background: #fff;
    flex-direction: column;
    align-items: flex-start;
    padding: 80px 28px 40px;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.15);
    transition: right 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    z-index: 999;
  }

  .nav-links.open {
    right: 0;
  }

  .nav-link {
    color: var(--text-dark);
    font-size: 1rem;
    width: 100%;
    padding: 12px 0;
  }

  .btn-nav {
    width: 100%;
    text-align: center;
    justify-content: center;
    margin-top: 16px;
  }

  /* Hero */
  .hero-content {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .hero-text {
    order: 2;
  }

  .hero-image {
    order: 1;
  }

  .hero-cta-group {
    justify-content: center;
  }

  .hero-bullets li {
    text-align: left;
  }

  .hero-stats {
    justify-content: center;
  }

  .hero-img-wrapper img {
    height: 300px;
  }

  .float-badge.float-top-right {
    right: 14px;
  }

  .float-badge.float-bottom-left {
    left: 14px;
  }

  /* Section layouts */
  .benefits-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .contact-wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .contact-form-wrap {
    padding: 28px 24px;
  }

  /* Steps */
  .steps-container {
    flex-direction: column;
    align-items: center;
  }

  .step-card {
    max-width: 100%;
    width: 100%;
  }

  .step-arrow {
    transform: rotate(90deg);
    margin-top: 0;
  }

  /* Testimonials */
  .testimonial-card {
    width: calc(100% - 8px);
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }
}

/* Mobile */
@media (max-width: 480px) {
  :root {
    --section-padding: 40px 0;
  }

  .container {
    padding: 0 16px;
  }

  /* Forms */
  .form-row {
    grid-template-columns: 1fr;
  }

  /* Pricing */
  .pricing-grid {
    grid-template-columns: 1fr;
  }

  .pricing-card.featured-price {
    transform: none;
  }

  .pricing-card.featured-price:hover {
    transform: translateY(-6px);
  }

  /* Subjects */
  .subjects-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Teachers grid */
  .teachers-grid {
    grid-template-columns: 1fr;
  }

  /* Pain grid */
  .pain-grid {
    grid-template-columns: 1fr;
  }

  /* Solutions grid */
  .solutions-grid {
    grid-template-columns: 1fr;
  }

  /* Hero */
  .hero-badge {
    font-size: 0.75rem;
    padding: 6px 14px;
  }

  .hero-stat strong {
    font-size: 1.2rem;
  }

  /* Fixed CTA */
  .fixed-cta span {
    display: none;
  }

  .fixed-cta {
    width: 52px;
    height: 52px;
    padding: 0;
    justify-content: center;
    border-radius: 50%;
  }

  .fixed-cta i {
    margin: 0;
  }

  /* Back to top */
  .back-to-top {
    bottom: 80px;
    right: 16px;
  }
}

/* Extra small mobile */
@media (max-width: 360px) {
  .subjects-grid {
    grid-template-columns: 1fr;
  }

  .hero-cta-group {
    flex-direction: column;
  }

  .btn-outline.btn-lg,
  .btn-primary.btn-lg {
    width: 100%;
    justify-content: center;
  }
}