/* ==========================================================================
   MATH COURSES BY MAHMOUD IBRAHIM - PREMIUM DESIGN SYSTEM
   ========================================================================== */

:root {
  /* HSL Palette - Rich Mathematical Dark Theme */
  --bg-primary: hsl(222, 47%, 7%);
  --bg-secondary: hsl(222, 42%, 11%);
  --bg-tertiary: hsl(222, 35%, 15%);
  --bg-glass: rgba(15, 23, 42, 0.78);
  --bg-glass-hover: rgba(30, 41, 59, 0.85);

  /* Primary Accent Tones */
  --accent-cyan: hsl(192, 95%, 50%);
  --accent-blue: hsl(212, 95%, 55%);
  --accent-gold: hsl(42, 95%, 60%);
  --accent-indigo: hsl(240, 85%, 65%);

  /* Theme Accents for Courses */
  --sat-primary: hsl(188, 86%, 45%);
  --sat-glow: rgba(6, 182, 212, 0.35);
  
  --calc-primary: hsl(42, 95%, 58%);
  --calc-glow: rgba(245, 158, 11, 0.35);
  
  --act-primary: hsl(205, 90%, 52%);
  --act-glow: rgba(14, 165, 233, 0.35);

  /* Typography */
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-math: 'Fira Code', monospace;

  /* Colors */
  --text-main: hsl(210, 25%, 98%);
  --text-muted: hsl(215, 18%, 72%);
  --text-dark: hsl(222, 47%, 11%);
  --border-light: rgba(255, 255, 255, 0.12);
  --border-glow: rgba(56, 189, 248, 0.4);

  /* Layout & Transitions */
  --container-max: 1240px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ==========================================================================
   RESET & BASE STYLES
   ========================================================================== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  background-image: 
    radial-gradient(circle at 15% 10%, rgba(2, 132, 199, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 85% 30%, rgba(99, 102, 241, 0.1) 0%, transparent 45%),
    radial-gradient(circle at 50% 85%, rgba(245, 158, 11, 0.08) 0%, transparent 50%);
}

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

ul {
  list-style: none;
}

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

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

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

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

/* ==========================================================================
   BACKGROUND CANVAS
   ========================================================================== */
.math-canvas-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
  opacity: 0.85;
}

/* ==========================================================================
   NAVIGATION BAR
   ========================================================================== */
.navbar-wrapper {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(11, 17, 32, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  transition: var(--transition-fast);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo-icon {
  width: 44px;
  height: 44px;
  filter: drop-shadow(0 0 10px rgba(56, 189, 248, 0.5));
  transition: transform 0.3s ease;
}

.brand-logo:hover .logo-icon {
  transform: rotate(-6deg) scale(1.05);
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #fff 0%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-instructor {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--accent-gold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 6px 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-blue));
  transition: width var(--transition-fast);
}

.nav-link:hover {
  color: var(--text-main);
}

.nav-link:hover::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition-smooth);
  white-space: nowrap;
}

.btn-login {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-main);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.btn-login:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--accent-cyan);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(56, 189, 248, 0.25);
}

.btn-dashboard {
  background: linear-gradient(135deg, #0284c7 0%, #4f46e5 100%);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 0 20px rgba(14, 165, 233, 0.4);
}

.btn-dashboard:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79, 70, 229, 0.6);
}

.user-greeting {
  font-size: 0.82rem;
  font-weight: 500;
  opacity: 0.9;
  background: rgba(255, 255, 255, 0.18);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  margin-left: 4px;
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 32px;
  height: 28px;
  padding: 4px;
}

.hamburger-line {
  width: 100%;
  height: 2.5px;
  background-color: var(--text-main);
  border-radius: 2px;
  transition: var(--transition-fast);
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero-section {
  padding: 100px 0 80px;
  position: relative;
  overflow: hidden;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  max-width: 900px;
  position: relative;
  z-index: 2;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.28);
  padding: 8px 18px;
  border-radius: var(--radius-full);
  margin-bottom: 28px;
  font-family: var(--font-math);
  font-size: 0.85rem;
  color: var(--accent-cyan);
  box-shadow: 0 0 20px rgba(56, 189, 248, 0.15);
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-cyan);
  box-shadow: 0 0 10px var(--accent-cyan);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(2.8rem, 6vw, 4.2rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}

.gradient-text {
  background: linear-gradient(135deg, #38bdf8 0%, #818cf8 50%, #f59e0b 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--text-muted);
  max-width: 760px;
  margin-bottom: 40px;
  line-height: 1.7;
}

.hero-subtitle strong {
  color: var(--text-main);
  font-weight: 600;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 64px;
  flex-wrap: wrap;
  justify-content: center;
}

.btn-primary {
  background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  color: #ffffff;
  padding: 16px 36px;
  font-size: 1.05rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-glow:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(37, 99, 235, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-main);
  border: 1px solid var(--border-light);
  padding: 16px 32px;
  font-size: 1.05rem;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-3px);
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  width: 100%;
  flex-wrap: wrap;
}

.stat-card {
  background: rgba(15, 23, 42, 0.65);
  border: 1px solid var(--border-light);
  padding: 16px 28px;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 170px;
  backdrop-filter: blur(8px);
  transition: var(--transition-fast);
}

.stat-card:hover {
  border-color: var(--border-glow);
  transform: translateY(-2px);
}

.stat-value {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent-cyan);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ==========================================================================
   OUR COURSES SECTION (IMAGE TOPICS: DIGITAL SAT, AP CALCULUS, ACT)
   ========================================================================== */
.courses-section {
  padding: 100px 0;
  position: relative;
}

.section-badge {
  display: inline-block;
  font-family: var(--font-math);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent-cyan);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(2.2rem, 4vw, 3.2rem);
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text-main);
}

.section-subtitle {
  font-size: 1.12rem;
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 56px;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 32px;
  align-items: stretch;
}

/* Course Cards with 3D Tilt Support */
.course-card {
  background: var(--bg-glass);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease-out, box-shadow 0.25s ease-out, border-color 0.25s;
  position: relative;
  will-change: transform;
}

.course-card:hover {
  border-color: rgba(255, 255, 255, 0.28);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
}

.card-image-wrapper {
  position: relative;
  width: 100%;
  height: 220px;
  overflow: hidden;
}

.course-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.course-card:hover .course-image {
  transform: scale(1.08);
}

.card-badge {
  position: absolute;
  top: 16px;
  right: 16px;
  background: rgba(15, 23, 42, 0.88);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-family: var(--font-math);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--text-main);
  z-index: 2;
}

.card-content {
  padding: 32px 28px 28px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.course-icon-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.course-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.course-level {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
}

.course-title {
  font-family: var(--font-heading);
  font-size: 1.65rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-main);
}

.course-description {
  font-size: 0.96rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  line-height: 1.65;
  flex-grow: 1;
}

.course-highlights {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 20px;
}

.course-highlights li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-main);
}

.check-icon {
  flex-shrink: 0;
}

.card-footer {
  margin-top: auto;
}

.btn-course {
  width: 100%;
  justify-content: center;
  padding: 14px;
  font-weight: 600;
  border-radius: 12px;
}

/* Card Themes */
.theme-sat {
  border-top: 4px solid var(--sat-primary);
}
.theme-sat .course-icon {
  color: var(--sat-primary);
  box-shadow: 0 0 20px var(--sat-glow);
}
.theme-sat .check-icon { color: var(--sat-primary); }
.btn-sat {
  background: linear-gradient(135deg, #0891b2 0%, #0284c7 100%);
  color: #fff;
}
.btn-sat:hover {
  box-shadow: 0 8px 25px var(--sat-glow);
}

.theme-calc {
  border-top: 4px solid var(--calc-primary);
}
.theme-calc .course-icon {
  color: var(--calc-primary);
  box-shadow: 0 0 20px var(--calc-glow);
}
.theme-calc .check-icon { color: var(--calc-primary); }
.btn-calc {
  background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
  color: #fff;
}
.btn-calc:hover {
  box-shadow: 0 8px 25px var(--calc-glow);
}

.theme-act {
  border-top: 4px solid var(--act-primary);
}
.theme-act .course-icon {
  color: var(--act-primary);
  box-shadow: 0 0 20px var(--act-glow);
}
.theme-act .check-icon { color: var(--act-primary); }
.btn-act {
  background: linear-gradient(135deg, #0284c7 0%, #1e40af 100%);
  color: #fff;
}
.btn-act:hover {
  box-shadow: 0 8px 25px var(--act-glow);
}

/* ==========================================================================
   INTERACTIVE MATH VISUALIZER SECTION
   ========================================================================== */
.visualizer-section {
  padding: 80px 0 100px;
}

.visualizer-card {
  background: linear-gradient(145deg, rgba(30, 41, 59, 0.75) 0%, rgba(15, 23, 42, 0.85) 100%);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 48px;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.45);
}

.visualizer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
  margin-bottom: 40px;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 32px;
}

.formula-display {
  background: rgba(11, 17, 32, 0.9);
  border: 1px solid var(--border-glow);
  padding: 16px 28px;
  border-radius: var(--radius-md);
  font-family: var(--font-math);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--accent-cyan);
  box-shadow: 0 0 25px rgba(56, 189, 248, 0.2);
}

.visualizer-content {
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  gap: 48px;
  align-items: center;
}

.visualizer-controls {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.slider-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.slider-label {
  display: flex;
  justify-content: space-between;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-main);
}

.slider-value {
  font-family: var(--font-math);
  color: var(--accent-gold);
  background: rgba(255, 255, 255, 0.08);
  padding: 2px 10px;
  border-radius: 6px;
}

.math-slider {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 4px;
  outline: none;
  -webkit-appearance: none;
  accent-color: var(--accent-cyan);
  cursor: pointer;
}

.math-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 12px var(--accent-cyan);
  cursor: pointer;
  transition: transform 0.15s;
}

.math-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.visualizer-tips {
  background: rgba(56, 189, 248, 0.08);
  border-left: 4px solid var(--accent-cyan);
  padding: 18px;
  border-radius: 8px;
  margin-top: 10px;
}

.visualizer-tips h4 {
  font-size: 0.95rem;
  margin-bottom: 6px;
  color: var(--text-main);
}

.visualizer-tips p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.visualizer-canvas-wrapper {
  background: rgba(11, 17, 32, 0.9);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: inset 0 0 30px rgba(0, 0, 0, 0.6);
}

#graph-canvas {
  width: 100%;
  height: auto;
  max-width: 560px;
}

/* ==========================================================================
   ABOUT THE INSTRUCTOR SECTION
   ========================================================================== */
.about-section {
  padding: 100px 0;
  position: relative;
  background: rgba(15, 23, 42, 0.4);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.about-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.3fr;
  gap: 64px;
  align-items: center;
}

.instructor-portrait-card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
}

.portrait-glow {
  position: absolute;
  top: -20%;
  left: -20%;
  width: 140%;
  height: 140%;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.25) 0%, transparent 60%);
  z-index: 1;
  pointer-events: none;
}

.instructor-image {
  width: 100%;
  height: auto;
  position: relative;
  z-index: 2;
}

.portrait-badge {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(0deg, rgba(11, 17, 32, 0.95) 0%, rgba(11, 17, 32, 0.6) 80%, transparent 100%);
  padding: 32px 24px 20px;
  z-index: 3;
  display: flex;
  flex-direction: column;
}

.badge-title {
  font-family: var(--font-heading);
  font-size: 1.45rem;
  font-weight: 800;
  color: #fff;
}

.badge-subtitle {
  font-size: 0.9rem;
  color: var(--accent-gold);
  font-weight: 500;
}

.bio-content {
  margin-bottom: 40px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.bio-lead {
  font-size: 1.15rem;
  color: var(--text-main);
  line-height: 1.7;
}

.bio-tagline {
  margin-top: 8px;
  padding-left: 16px;
  border-left: 3px solid var(--accent-gold);
  color: var(--accent-gold);
  font-weight: 500;
  font-size: 1.05rem;
}

.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.pillar-card {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 20px 16px;
  border-radius: 14px;
  text-align: center;
  transition: var(--transition-fast);
}

.pillar-card:hover {
  background: rgba(255, 255, 255, 0.08);
  transform: translateY(-3px);
}

.pillar-icon {
  font-size: 1.8rem;
  margin-bottom: 12px;
}

.pillar-card h4 {
  font-size: 0.98rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-main);
}

.pillar-card p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ==========================================================================
   TESTIMONIALS SECTION
   ========================================================================== */
.testimonials-section {
  padding: 100px 0;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}

.testimonial-card {
  background: var(--bg-glass);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
  transition: var(--transition-fast);
}

.testimonial-card:hover {
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-4px);
}

.stars {
  color: var(--accent-gold);
  font-size: 1.25rem;
  letter-spacing: 2px;
}

.quote {
  font-size: 1.02rem;
  color: var(--text-main);
  font-style: italic;
  line-height: 1.65;
}

.student-info {
  display: flex;
  align-items: center;
  gap: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 16px;
}

.avatar-circle {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  color: #fff;
  flex-shrink: 0;
}

.student-info strong {
  display: block;
  font-size: 0.95rem;
  color: var(--text-main);
}

.student-info span {
  font-size: 0.82rem;
  color: var(--accent-cyan);
}

/* ==========================================================================
   FAQ SECTION
   ========================================================================== */
.faq-section {
  padding: 80px 0 100px;
}

.faq-container {
  max-width: 860px;
}

.faq-accordion {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-glass);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item.active {
  border-color: var(--border-glow);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 28px;
  text-align: left;
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  gap: 16px;
}

.faq-chevron {
  flex-shrink: 0;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  color: var(--accent-cyan);
}

.faq-item.active .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-answer p {
  padding: 0 28px 24px;
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.7;
}

/* ==========================================================================
   CALL TO ACTION BANNER
   ========================================================================== */
.cta-section {
  padding: 60px 0 100px;
}

.cta-box {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.25) 0%, rgba(79, 70, 229, 0.25) 100%);
  border: 1px solid rgba(56, 189, 248, 0.4);
  border-radius: var(--radius-lg);
  padding: 64px 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(12px);
}

.cta-glow {
  position: absolute;
  top: -50%;
  left: 20%;
  width: 60%;
  height: 100%;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.3) 0%, transparent 70%);
  pointer-events: none;
}

.cta-box h2 {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 16px;
  position: relative;
  z-index: 2;
}

.cta-box p {
  font-size: 1.12rem;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 36px;
  position: relative;
  z-index: 2;
}

.cta-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  position: relative;
  z-index: 2;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.footer {
  background: rgba(11, 17, 32, 0.95);
  border-top: 1px solid var(--border-light);
  padding: 80px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 64px;
}

.footer-logo {
  display: flex;
  flex-direction: column;
  margin-bottom: 20px;
}

.footer-bio {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
  max-width: 320px;
}

.footer-col h4 {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--text-main);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  color: var(--text-muted);
  font-size: 0.92rem;
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--accent-cyan);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-bottom-links {
  display: flex;
  gap: 24px;
}

/* ==========================================================================
   RESPONSIVE DESIGN
   ========================================================================== */
@media (max-width: 992px) {
  .visualizer-content {
    grid-template-columns: 1fr;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .navbar {
    height: 70px;
  }
  .nav-links {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: rgba(11, 17, 32, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 32px 24px;
    border-bottom: 1px solid var(--border-light);
    transform: translateY(-150%);
    transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  }
  .nav-links.mobile-open {
    transform: translateY(0);
  }
  .mobile-menu-toggle {
    display: flex;
  }
  .hero-section {
    padding: 60px 0 60px;
  }
  .philosophy-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}