/* ==========================================================================
   S-Learning Web Design System
   Monochrome Aesthetic • Responsive • High Performance • SEO Optimized
   ========================================================================== */

:root, [data-theme="dark"] {
  --font-family: 'Nunito', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --max-width: 1200px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --whatsapp-green: #25D366;
  --whatsapp-dark: #128C7E;

  /* Dark Theme */
  --bg-primary: #0A0A0A;
  --bg-secondary: #141414;
  --bg-card: #191919;
  --bg-card-hover: #222222;
  --border-color: #282828;
  --border-subtle: #1F1F1F;
  --border-hover: #444444;
  --text-primary: #FFFFFF;
  --text-secondary: #A0A0A0;
  --text-muted: #666666;
  --brand-white: #FFFFFF;
  --brand-black: #000000;
  --navbar-bg: rgba(10, 10, 10, 0.85);
  --footer-bg: #050505;
  --mockup-bg: #191919;
  --mockup-tile-bg: #141414;
  --mockup-tile-badge-bg: #282828;
  --mockup-tile-badge-text: #CCCCCC;
  --mockup-dot-bg: #333333;
  --badge-bg: #2A2A2A;
  --badge-text: #FFFFFF;
  --feature-highlight-bg: linear-gradient(180deg, #222222 0%, #171717 100%);
  --feature-highlight-border: #666666;
  --feature-icon-bg: #000000;
  --card-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
  --mockup-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
  --btn-primary-bg: #FFFFFF;
  --btn-primary-text: #000000;
  --btn-primary-shadow: rgba(255, 255, 255, 0.15);
}

[data-theme="light"] {
  /* Light Theme */
  --bg-primary: #F8F9FA;
  --bg-secondary: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F1F3F5;
  --border-color: #E2E8F0;
  --border-subtle: #EDF2F7;
  --border-hover: #94A3B8;
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  --brand-white: #0F172A;
  --brand-black: #FFFFFF;
  --navbar-bg: rgba(248, 249, 250, 0.92);
  --footer-bg: #F1F5F9;
  --mockup-bg: #FFFFFF;
  --mockup-tile-bg: #F8FAFC;
  --mockup-tile-badge-bg: #E2E8F0;
  --mockup-tile-badge-text: #334155;
  --mockup-dot-bg: #CBD5E1;
  --badge-bg: #E2E8F0;
  --badge-text: #0F172A;
  --feature-highlight-bg: linear-gradient(180deg, #FFFFFF 0%, #F8FAFC 100%);
  --feature-highlight-border: #94A3B8;
  --feature-icon-bg: #F1F5F9;
  --card-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
  --mockup-shadow: 0 20px 40px rgba(15, 23, 42, 0.08);
  --btn-primary-bg: #0F172A;
  --btn-primary-text: #FFFFFF;
  --btn-primary-shadow: rgba(15, 23, 42, 0.2);
}

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

html {
  scroll-behavior: smooth;
  color-scheme: dark;
}

html[data-theme="light"] {
  color-scheme: light;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color 0.25s cubic-bezier(0.16, 1, 0.3, 1),
              color 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

a {
  color: inherit;
  text-decoration: none;
}

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

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

/* Navigation Header */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--navbar-bg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.5px;
}

.brand-logo img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--text-primary);
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
  padding: 0;
  flex-shrink: 0;
}

.theme-toggle-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: rotate(15deg) scale(1.05);
}

.theme-toggle-btn svg {
  width: 19px;
  height: 19px;
  stroke: currentColor;
}

/* Dark mode: show sun icon */
[data-theme="dark"] .icon-moon,
:root:not([data-theme="light"]) .icon-moon {
  display: none !important;
}
[data-theme="dark"] .icon-sun,
:root:not([data-theme="light"]) .icon-sun {
  display: block !important;
}

/* Light mode: show moon icon */
[data-theme="light"] .icon-sun {
  display: none !important;
}
[data-theme="light"] .icon-moon {
  display: block !important;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 24px;
  cursor: pointer;
  padding: 8px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-text);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--btn-primary-shadow);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

.btn-whatsapp {
  background: var(--whatsapp-green);
  color: #FFFFFF;
}

.btn-whatsapp:hover {
  background: var(--whatsapp-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 211, 102, 0.3);
}

/* App Store Buttons */
.store-buttons-wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
}

.store-btn {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 12px 22px;
  border-radius: var(--radius-md);
  color: var(--text-primary);
  transition: var(--transition);
}

.store-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-3px);
  box-shadow: var(--card-shadow);
}

.store-btn svg {
  width: 26px;
  height: 26px;
  fill: currentColor;
}

.store-btn-text {
  display: flex;
  flex-direction: column;
  text-align: left;
}

.store-btn-text .small {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-secondary);
}

.store-btn-text .big {
  font-size: 16px;
  font-weight: 800;
  line-height: 1.2;
}

/* Hero Section */
.hero {
  padding: 80px 0 60px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 60px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 1px;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-primary);
  box-shadow: 0 0 8px var(--border-hover);
}

.hero-title {
  font-size: 52px;
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -1.5px;
  margin-bottom: 20px;
}

.hero-title span {
  display: block;
  font-style: italic;
  color: var(--text-secondary);
}

.hero-description {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
}

/* Mockup Card in Hero */
.hero-mockup-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--mockup-shadow);
  position: relative;
}

.mockup-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 20px;
}

.mockup-dots {
  display: flex;
  gap: 6px;
}

.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--mockup-dot-bg);
}

.mockup-tile {
  background: var(--mockup-tile-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 14px;
  transition: var(--transition);
}

.mockup-tile:hover {
  border-color: var(--border-hover);
  transform: translateX(4px);
}

.mockup-tile-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.mockup-tile-title {
  font-size: 14px;
  font-weight: 800;
  color: var(--text-primary);
}

.mockup-tile-badge {
  font-size: 10px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  background: var(--mockup-tile-badge-bg);
  color: var(--mockup-tile-badge-text);
}

.mockup-tile-desc {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Section Common */
.section {
  padding: 90px 0;
  border-top: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px;
}

.section-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.section-title {
  font-size: 38px;
  font-weight: 900;
  letter-spacing: -1px;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-6px);
  box-shadow: var(--card-shadow);
}

.feature-card.highlighted {
  border-color: var(--feature-highlight-border);
  background: var(--feature-highlight-bg);
}

.feature-icon-wrap {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-md);
  background: var(--feature-icon-bg);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.feature-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: var(--badge-bg);
  color: var(--badge-text);
  margin-bottom: 14px;
  align-self: flex-start;
}

.feature-title {
  font-size: 19px;
  font-weight: 800;
  margin-bottom: 12px;
}

.feature-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  flex-grow: 1;
}

/* Stats Section */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.stat-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 20px;
  text-align: center;
  transition: var(--transition);
}

.stat-box:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.stat-value {
  font-size: 38px;
  font-weight: 900;
  letter-spacing: -1px;
  margin-bottom: 6px;
}

.stat-label {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.stat-sub {
  font-size: 12px;
  color: var(--text-secondary);
}

/* FAQ Accordion */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

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

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 22px 26px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-family: inherit;
}

.faq-icon {
  font-size: 20px;
  font-weight: 300;
  transition: transform 0.3s ease;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  padding: 0 26px 22px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  display: block;
}

/* Contact Cards Grid */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  transition: var(--transition);
}

.contact-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-5px);
}

.contact-card h3 {
  font-size: 19px;
  font-weight: 800;
  margin-bottom: 10px;
}

.contact-card p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.6;
}

/* Legal Section on Landing Page */
.legal-preview-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.legal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.legal-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.legal-card h4 {
  font-size: 17px;
  font-weight: 800;
  margin-bottom: 10px;
}

.legal-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

.legal-card .link-arrow {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Footer */
.footer {
  background: var(--footer-bg);
  border-top: 1px solid var(--border-color);
  padding: 70px 0 40px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 50px;
}

.footer-brand p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 14px;
  line-height: 1.6;
  max-width: 320px;
}

.footer-col h5 {
  font-size: 14px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  font-size: 14px;
  color: var(--text-secondary);
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--text-primary);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 32px;
  border-top: 1px solid var(--border-subtle);
  font-size: 13px;
  color: var(--text-muted);
}

/* Floating WhatsApp Button */
.floating-whatsapp {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 999;
  background: var(--whatsapp-green);
  color: #FFFFFF;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 22px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 800;
  box-shadow: 0 8px 30px rgba(37, 211, 102, 0.4);
  transition: var(--transition);
}

.floating-whatsapp:hover {
  background: var(--whatsapp-dark);
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 12px 36px rgba(37, 211, 102, 0.5);
}

/* Standalone Legal Document Page Styles */
.legal-page-header {
  padding: 50px 0 30px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.legal-back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 20px;
  transition: var(--transition);
}

.legal-back-link:hover {
  color: var(--text-primary);
}

.legal-tabs {
  display: flex;
  gap: 10px;
  margin-top: 24px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.legal-tab {
  padding: 10px 20px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 700;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  transition: var(--transition);
  white-space: nowrap;
}

.legal-tab.active {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  border-color: var(--btn-primary-bg);
}

.legal-tab:hover:not(.active) {
  background: var(--bg-card-hover);
  color: var(--text-primary);
}

.legal-content-wrap {
  max-width: 860px;
  margin: 50px auto 100px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
}

.legal-doc-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 36px;
  flex-wrap: wrap;
  gap: 16px;
}

.legal-doc-meta .date {
  font-size: 13px;
  color: var(--text-secondary);
}

.legal-section-block {
  margin-bottom: 36px;
}

.legal-section-block h3 {
  font-size: 20px;
  font-weight: 800;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.legal-section-block p, .legal-section-block li {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 12px;
}

.legal-section-block ul {
  padding-left: 24px;
  margin-bottom: 16px;
}

/* Mobile Responsiveness */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .contact-grid, .legal-preview-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links, .nav-cta .btn {
    display: none;
  }
  .nav-toggle {
    display: block;
  }
  .hero-title {
    font-size: 38px;
  }
  .section-title {
    font-size: 30px;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .stats-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .legal-content-wrap {
    padding: 24px 20px;
    margin: 30px 16px 60px;
  }
  .floating-whatsapp span {
    display: none;
  }
  .floating-whatsapp {
    padding: 14px;
    border-radius: 50%;
  }
}