/* =============================================
   PROFESSIONAL LANDING PAGE STYLES
   Modern, polished design with depth & motion
   ============================================= */

/* Root Variables - Professional Color Palette */
:root {
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-accent: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --gradient-premium: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);
  
  --blur-sm: blur(8px);
  --blur-md: blur(16px);
}

/* Landing Page Container */
.landing-page {
  background: linear-gradient(180deg, #f8f9fd 0%, #ffffff 100%);
  min-height: 100vh;
}

/* =============================================
   NAVIGATION - Glassmorphism Style
   ============================================= */
.landing-nav {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.3);
  padding: 20px 0;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: all 0.3s ease;
}

.landing-nav.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.landing-nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 26px;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: transform 0.3s ease;
  text-decoration: none;
  cursor: pointer;
}

.nav-brand:hover {
  transform: scale(1.05);
}

.logo-icon {
  font-size: 36px;
  filter: drop-shadow(0 2px 8px rgba(102, 126, 234, 0.3));
  animation: float 3s ease-in-out infinite;
}

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

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

.nav-link {
  text-decoration: none;
  color: #4C566A;
  font-weight: 600;
  font-size: 15px;
  position: relative;
  transition: color 0.3s ease;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width 0.3s ease;
}

.nav-link:hover {
  color: #667eea;
}

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

/* Login button style */
.nav-login {
  background: var(--gradient-primary, linear-gradient(135deg, #667eea 0%, #764ba2 100%));
  color: white !important;
  padding: 8px 20px;
  border-radius: 8px;
  margin-left: 8px;
}

.nav-login::after {
  display: none;
}

.nav-login:hover {
  color: white !important;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-cta {
  padding: 12px 28px;
  background: var(--gradient-primary);
  color: white;
  text-decoration: none;
  border-radius: 12px;
  font-weight: 700;
  font-size: 15px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 16px rgba(102, 126, 234, 0.3);
  position: relative;
  overflow: hidden;
}

.btn-cta::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: left 0.5s ease;
}

.btn-cta:hover::before {
  left: 100%;
}

.btn-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(102, 126, 234, 0.4);
}

.btn-cta:active {
  transform: translateY(0) scale(0.98);
}

/* =============================================
   HERO SECTION - Premium Design
   ============================================= */
.hero {
  padding: 120px 32px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -20%;
  width: 60%;
  height: 60%;
  background: radial-gradient(circle, rgba(102, 126, 234, 0.1) 0%, transparent 70%);
  animation: pulse 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  right: -20%;
  width: 50%;
  height: 50%;
  background: radial-gradient(circle, rgba(136, 192, 208, 0.1) 0%, transparent 70%);
  animation: pulse 8s ease-in-out infinite reverse;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.1); opacity: 0.8; }
}

.hero .container {
  max-width: 1000px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 64px;
  font-weight: 900;
  line-height: 1.1;
  color: #2E3440;
  margin-bottom: 28px;
  letter-spacing: -1px;
}

.hero-title .highlight {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  position: relative;
  display: inline-block;
}

.hero-title .highlight::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-accent);
  border-radius: 2px;
  opacity: 0.5;
}

.hero-subtitle {
  font-size: 22px;
  color: #6B7280;
  line-height: 1.7;
  margin-bottom: 48px;
  max-width: 750px;
  margin-left: auto;
  margin-right: auto;
  font-weight: 400;
}

.hero-cta {
  margin-bottom: 80px;
}

.btn-primary-large {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  padding: 22px 48px;
  background: var(--gradient-primary);
  color: white;
  text-decoration: none;
  border-radius: 16px;
  font-size: 22px;
  font-weight: 800;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 8px 32px rgba(102, 126, 234, 0.35);
  position: relative;
  overflow: hidden;
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-primary-large::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  transform: translate(-50%, -50%);
  transition: width 0.6s ease, height 0.6s ease;
}

.btn-primary-large:hover::before {
  width: 400px;
  height: 400px;
}

.btn-primary-large:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 16px 48px rgba(102, 126, 234, 0.45);
}

.btn-primary-large:active {
  transform: translateY(-2px) scale(0.98);
}

.btn-icon {
  font-size: 28px;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(4px); }
}

.cta-note {
  margin-top: 20px;
  color: #9CA3AF;
  font-size: 15px;
  font-weight: 500;
}

/* Hero Stats - Glass Cards */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  max-width: 800px;
  margin: 0 auto;
}

.stat {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 20px;
  padding: 32px 24px;
  text-align: center;
  transition: all 0.3s ease;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
}

.stat:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
  background: rgba(255, 255, 255, 0.8);
}

.stat-value {
  font-size: 48px;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
  line-height: 1;
}

.stat-label {
  font-size: 14px;
  color: #6B7280;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
}

/* =============================================
   SECTIONS - Enhanced Design
   ============================================= */
.languages-section,
.features-section,
.social-proof-section,
.popular-verbs-section {
  padding: 100px 32px;
  position: relative;
}

.languages-section {
  background: white;
}

.features-section {
  background: linear-gradient(180deg, #ffffff 0%, #f8f9fd 100%);
}

.section-title {
  font-size: 48px;
  font-weight: 900;
  text-align: center;
  margin-bottom: 20px;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.5px;
}

.section-subtitle {
  text-align: center;
  font-size: 20px;
  color: #6B7280;
  margin-bottom: 64px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  font-weight: 400;
  line-height: 1.6;
}

/* Language Cards - Premium Glassmorphism */
.language-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
  max-width: 1200px;
  margin: 0 auto;
}

.language-card {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 2px solid rgba(255, 255, 255, 0.5);
  border-radius: 24px;
  padding: 40px 32px;
  text-align: center;
  text-decoration: none;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.05);
  position: relative;
  overflow: hidden;
}

.language-card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, transparent, rgba(102, 126, 234, 0.1), transparent);
  transform: rotate(45deg);
  transition: all 0.6s ease;
}

.language-card:hover::before {
  left: 100%;
  top: 100%;
}

.language-card:hover {
  transform: translateY(-12px) scale(1.02);
  box-shadow: 0 16px 48px rgba(102, 126, 234, 0.15);
  border-color: rgba(102, 126, 234, 0.3);
  background: rgba(255, 255, 255, 0.9);
}

.language-flag {
  font-size: 64px;
  margin-bottom: 20px;
  display: inline-block;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.1));
  transition: transform 0.4s ease;
}

.language-card:hover .language-flag {
  transform: scale(1.1) rotate(5deg);
}

.language-name {
  font-size: 26px;
  font-weight: 800;
  color: #2E3440;
  margin-bottom: 12px;
}

.language-verbs {
  font-size: 15px;
  color: #6B7280;
  font-weight: 600;
}

/* Feature Cards - Modern Design */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 40px;
  max-width: 1200px;
  margin: 0 auto;
}

.feature-card {
  background: white;
  border-radius: 24px;
  padding: 48px 36px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  transition: all 0.4s ease;
  border: 2px solid transparent;
  position: relative;
  overflow: hidden;
}

.feature-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.feature-card:hover::after {
  transform: scaleX(1);
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.1);
  border-color: rgba(102, 126, 234, 0.2);
}

.feature-icon {
  font-size: 56px;
  margin-bottom: 24px;
  display: inline-block;
  filter: drop-shadow(0 4px 12px rgba(102, 126, 234, 0.2));
}

.feature-title {
  font-size: 24px;
  font-weight: 800;
  color: #2E3440;
  margin-bottom: 16px;
}

.feature-description {
  font-size: 16px;
  color: #6B7280;
  line-height: 1.7;
  font-weight: 400;
}

/* CTA Section - Premium Gradient */
.cta-section {
  padding: 120px 32px;
  background: var(--gradient-primary);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -10%;
  width: 120%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  animation: rotate 20s linear infinite;
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.cta-section .container {
  position: relative;
  z-index: 1;
}

.cta-title {
  font-size: 52px;
  font-weight: 900;
  color: white;
  margin-bottom: 24px;
  letter-spacing: -0.5px;
}

.cta-subtitle {
  font-size: 22px;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 48px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.btn-cta-large {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  padding: 22px 48px;
  background: white;
  color: #667eea;
  text-decoration: none;
  border-radius: 16px;
  font-size: 20px;
  font-weight: 800;
  transition: all 0.4s ease;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.btn-cta-large:hover {
  transform: translateY(-6px) scale(1.05);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.3);
}

/* =============================================
   DARK MODE OVERRIDES
   ============================================= */
[data-theme="dark"] .landing-page {
  background: linear-gradient(180deg, #0f0f1a 0%, #1a1a2e 100%);
}

[data-theme="dark"] .landing-nav {
  background: rgba(15, 15, 26, 0.95);
  border-bottom: 1px solid #3d3d5c;
}

[data-theme="dark"] .hero {
  background: linear-gradient(180deg, #1a1a2e 0%, #252542 100%);
}

[data-theme="dark"] .hero-title {
  background: linear-gradient(135deg, #88C0D0 0%, #81A1C1 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

[data-theme="dark"] .hero-subtitle {
  color: #D8DEE9;
}

[data-theme="dark"] .section-title {
  color: #ECEFF4;
}

[data-theme="dark"] .section-subtitle {
  color: #D8DEE9;
}

[data-theme="dark"] .language-card {
  background: #1a1a2e;
  border: 1px solid #3d3d5c;
}

[data-theme="dark"] .language-card:hover {
  border-color: #88C0D0;
  box-shadow: 0 12px 40px rgba(136, 192, 208, 0.15);
}

[data-theme="dark"] .language-name {
  color: #ECEFF4;
}

[data-theme="dark"] .language-verbs {
  color: #7a849e;
}

[data-theme="dark"] .feature-card {
  background: #1a1a2e;
  border: 1px solid #3d3d5c;
}

[data-theme="dark"] .feature-title {
  color: #ECEFF4;
}

[data-theme="dark"] .feature-description {
  color: #D8DEE9;
}

[data-theme="dark"] .mode-card {
  background: #1a1a2e;
  border: 1px solid #3d3d5c;
}

[data-theme="dark"] .mode-card:hover {
  border-color: #88C0D0;
}

[data-theme="dark"] .mode-title {
  color: #ECEFF4;
}

[data-theme="dark"] .mode-description {
  color: #D8DEE9;
}

[data-theme="dark"] .testimonials-section {
  background: linear-gradient(180deg, #0f0f1a 0%, #1a1a2e 100%);
}

[data-theme="dark"] .testimonial-card {
  background: #1a1a2e;
  border: 1px solid #3d3d5c;
}

[data-theme="dark"] .testimonial-text {
  color: #D8DEE9;
}

[data-theme="dark"] .testimonial-author {
  color: #ECEFF4;
}

[data-theme="dark"] .landing-footer {
  background: #0a0a14;
  border-top: 1px solid #3d3d5c;
}

[data-theme="dark"] .footer-link {
  color: #7a849e;
}

[data-theme="dark"] .footer-link:hover {
  color: #88C0D0;
}

[data-theme="dark"] .languages-section,
[data-theme="dark"] .features-section,
[data-theme="dark"] .training-modes {
  background: transparent;
}

[data-theme="dark"] .popular-verbs-section {
  background: #1a1a2e;
}

[data-theme="dark"] .verb-link {
  background: #252542;
  border: 1px solid #3d3d5c;
  color: #ECEFF4;
}

[data-theme="dark"] .verb-link:hover {
  border-color: #88C0D0;
  color: #88C0D0;
}

/* Responsive Design */
@media (max-width: 768px) {
  .landing-nav .container {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
  }

  .landing-nav .nav-brand {
    grid-column: 2;
    justify-self: center;
  }

  .landing-nav .nav-links {
    grid-column: 3;
    justify-self: end;
  }

  .hero-title {
    font-size: 40px;
  }
  
  .hero-subtitle {
    font-size: 18px;
  }
  
  .btn-primary-large {
    padding: 18px 36px;
    font-size: 18px;
  }
  
  .hero-stats {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .section-title {
    font-size: 36px;
  }
  
  .nav-links {
    gap: 16px;
  }
  
  .nav-link {
    font-size: 14px;
  }
}