/* ===== CSS Variables ===== */
:root {
  --color-primary: #dfe0e1;
  --color-bg-light: #eff1f1;
  --color-text-dark: #1c1c1c;
  --color-gray-medium: #8f8f90;
  --color-gray-dark: #747374;
  --color-gray: #7c7c7c;
  --color-gray-teal: #6c7474;
  --color-white: #ffffff;
  --color-black: #0a0a0a;
  --color-accent: #1c1c1c;
  --color-border: #e0e0e0;
  --font-heading: 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;
  --max-width: 1200px;
  --section-padding: 100px 0;
  --transition: 0.3s ease;
  --radius: 12px;
  --radius-lg: 20px;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--color-text-dark);
  background-color: var(--color-white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

ul, ol {
  list-style: none;
}

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

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

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text-dark);
}

h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.5rem); }

p {
  color: var(--color-gray-dark);
  font-size: 1.05rem;
}

.section-label {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-gray-medium);
  margin-bottom: 12px;
}

.section-title {
  margin-bottom: 20px;
}

.section-desc {
  max-width: 680px;
  margin: 0 auto 48px;
  font-size: 1.1rem;
  color: var(--color-gray);
}

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

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  font-family: var(--font-body);
}

.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: #333;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(28, 28, 28, 0.2);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-text-dark);
  border: 2px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-text-dark);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 10px 24px;
  font-size: 0.9rem;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  transition: all var(--transition);
}

.header.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-text-dark);
}

.logo img {
  width: 32px;
  height: 32px;
}

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

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

.nav-links a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text-dark);
  border-radius: 8px;
  transition: all var(--transition);
}

.nav-links a:hover {
  color: var(--color-text-dark);
  background-color: var(--color-bg-light);
}

.nav-links a i {
  font-size: 0.85rem;
  width: 18px;
  text-align: center;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Language Switcher */
.lang-switcher {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-gray-dark);
  background: transparent;
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn:hover {
  border-color: var(--color-gray-medium);
  color: var(--color-text-dark);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 160px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.1);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition);
  z-index: 100;
  overflow: hidden;
}

.lang-dropdown.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-dropdown a {
  display: block;
  padding: 10px 16px;
  font-size: 0.9rem;
  color: var(--color-gray-dark);
  transition: all var(--transition);
}

.lang-dropdown a:hover,
.lang-dropdown a.current {
  background-color: var(--color-bg-light);
  color: var(--color-text-dark);
}

.lang-dropdown a.current {
  font-weight: 600;
}

/* Mobile Menu */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-dark);
  border-radius: 2px;
  transition: all var(--transition);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero Section ===== */
.hero {
  padding: 160px 0 100px;
  background: linear-gradient(180deg, var(--color-bg-light) 0%, var(--color-white) 100%);
  text-align: center;
  overflow: hidden;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 50px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text-dark);
  margin-bottom: 32px;
}

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

.hero h1 {
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--color-text-dark), var(--color-gray-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  max-width: 640px;
  margin: 0 auto 40px;
  font-size: 1.15rem;
  color: var(--color-gray);
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 64px;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 60px;
  padding-top: 48px;
  border-top: 1px solid var(--color-border);
  max-width: 600px;
  margin: 0 auto;
}

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

.hero-stat .number {
  display: block;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--color-text-dark);
  line-height: 1.2;
}

.hero-stat .label {
  font-size: 0.88rem;
  color: var(--color-gray-medium);
  margin-top: 4px;
}

/* ===== Speed Comparison ===== */
.speed-section {
  padding: var(--section-padding);
  background: var(--color-white);
}

.speed-compare {
  display: flex;
  gap: 32px;
  max-width: 800px;
  margin: 0 auto;
}

.speed-bar {
  flex: 1;
  background: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 36px;
  text-align: center;
  transition: all var(--transition);
}

.speed-bar:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.06);
}

.speed-bar .icon {
  font-size: 2rem;
  margin-bottom: 16px;
  color: var(--color-gray-medium);
}

.speed-bar.highlight .icon {
  color: var(--color-text-dark);
}

.speed-bar h3 {
  margin-bottom: 8px;
}

.speed-value {
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--color-text-dark);
  line-height: 1;
  margin: 16px 0 8px;
}

.speed-bar.highlight {
  background: var(--color-text-dark);
}

.speed-bar.highlight h3,
.speed-bar.highlight .speed-value,
.speed-bar.highlight p {
  color: var(--color-white);
}

.speed-bar.highlight p {
  color: rgba(255, 255, 255, 0.6);
}

.speed-unit {
  font-size: 0.9rem;
  color: var(--color-gray-medium);
}

/* ===== Features Section ===== */
.features-section {
  padding: var(--section-padding);
  background: var(--color-bg-light);
}

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

.feature-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: all var(--transition);
  border: 1px solid transparent;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.06);
  border-color: var(--color-border);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: var(--color-bg-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: var(--color-text-dark);
  margin-bottom: 20px;
}

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 1.15rem;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--color-gray);
  line-height: 1.7;
}

/* ===== Translate Section ===== */
.translate-section {
  padding: var(--section-padding);
  background: var(--color-white);
}

.translate-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.translate-visual {
  background: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 48px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.translate-visual .bubble {
  padding: 16px 24px;
  border-radius: 16px;
  font-size: 1rem;
  line-height: 1.6;
  max-width: 85%;
}

.translate-visual .bubble.source {
  background: var(--color-text-dark);
  color: var(--color-white);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}

.translate-visual .bubble.target {
  background: var(--color-white);
  color: var(--color-text-dark);
  align-self: flex-end;
  border-bottom-right-radius: 4px;
  border: 1px solid var(--color-border);
}

.translate-text h2 {
  margin-bottom: 20px;
}

.translate-text p {
  margin-bottom: 32px;
  font-size: 1.08rem;
  line-height: 1.8;
}

/* ===== Ask Section ===== */
.ask-section {
  padding: var(--section-padding);
  background: var(--color-bg-light);
}

.ask-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.ask-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  text-align: center;
  transition: all var(--transition);
  border: 1px solid transparent;
}

.ask-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.06);
  border-color: var(--color-border);
}

.ask-card .icon-wrapper {
  width: 64px;
  height: 64px;
  margin: 0 auto 24px;
  border-radius: 50%;
  background: var(--color-bg-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--color-text-dark);
}

.ask-card h3 {
  margin-bottom: 12px;
}

.ask-card p {
  font-size: 0.95rem;
  color: var(--color-gray);
  line-height: 1.7;
}

/* ===== Privacy Section ===== */
.privacy-section {
  padding: var(--section-padding);
  background: var(--color-text-dark);
  color: var(--color-white);
}

.privacy-section .section-label {
  color: rgba(255, 255, 255, 0.5);
}

.privacy-section .section-title {
  color: var(--color-white);
}

.privacy-section .section-desc {
  color: rgba(255, 255, 255, 0.6);
}

.privacy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.privacy-card {
  background: rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.08);
  transition: all var(--transition);
}

.privacy-card:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-4px);
}

.privacy-card .icon-wrapper {
  width: 60px;
  height: 60px;
  margin: 0 auto 20px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: var(--color-white);
}

.privacy-card h3 {
  color: var(--color-white);
  margin-bottom: 10px;
}

.privacy-card p {
  color: rgba(255, 255, 255, 0.55);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ===== Testimonials Section ===== */
.testimonials-section {
  padding: var(--section-padding);
  background: var(--color-white);
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: all var(--transition);
}

.testimonial-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.06);
}

.testimonial-quote {
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--color-text-dark);
  margin-bottom: 24px;
  font-style: italic;
}

.testimonial-quote::before {
  content: '\201c';
  font-size: 2rem;
  color: var(--color-gray-medium);
  line-height: 0;
  vertical-align: -0.3em;
  margin-right: 4px;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.testimonial-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text-dark);
}

.testimonial-info .name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-text-dark);
}

.testimonial-info .role {
  font-size: 0.85rem;
  color: var(--color-gray-medium);
}

/* ===== CTA Section ===== */
.cta-section {
  padding: var(--section-padding);
  background: var(--color-bg-light);
  text-align: center;
}

.cta-section h2 {
  margin-bottom: 16px;
}

.cta-section p {
  max-width: 540px;
  margin: 0 auto 40px;
  font-size: 1.1rem;
}

/* ===== FAQ Section ===== */
.faq-section {
  padding: var(--section-padding);
  background: var(--color-white);
}

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

.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-item:first-child {
  border-top: 1px solid var(--color-border);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0;
  cursor: pointer;
  width: 100%;
  background: none;
  border: none;
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text-dark);
  text-align: left;
  transition: color var(--transition);
}

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

.faq-question i {
  font-size: 0.85rem;
  transition: transform var(--transition);
  color: var(--color-gray-medium);
  flex-shrink: 0;
  margin-left: 16px;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.faq-answer-inner {
  padding: 0 0 24px;
  font-size: 0.98rem;
  color: var(--color-gray);
  line-height: 1.8;
}

/* ===== Footer ===== */
.footer {
  padding: 64px 0 0;
  background: var(--color-text-dark);
  color: rgba(255, 255, 255, 0.7);
}

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

.footer-brand .logo {
  color: var(--color-white);
  margin-bottom: 16px;
}

.footer-brand p {
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.92rem;
  line-height: 1.7;
}

.footer-col h4 {
  color: var(--color-white);
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 20px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.footer-col a {
  display: block;
  padding: 6px 0;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 24px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.4);
}

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

.footer-bottom-links a {
  color: rgba(255, 255, 255, 0.4);
  font-size: 0.85rem;
}

.footer-bottom-links a:hover {
  color: var(--color-white);
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-text-dark);
  color: var(--color-white);
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
  z-index: 999;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: #333;
  transform: translateY(-2px);
}

/* ===== Mobile Nav ===== */
.mobile-nav {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-white);
  z-index: 999;
  padding: 24px;
  flex-direction: column;
  gap: 8px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
}

.mobile-nav.active {
  opacity: 1;
  visibility: visible;
}

.mobile-nav a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--color-gray-dark);
  border-radius: 10px;
  transition: all var(--transition);
}

.mobile-nav a:hover {
  background: var(--color-bg-light);
  color: var(--color-text-dark);
}

.mobile-nav .lang-mobile {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

.mobile-nav .lang-mobile a {
  font-size: 0.95rem;
  color: var(--color-gray);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .features-grid,
  .privacy-grid,
  .ask-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 36px;
  }

  .translate-content {
    gap: 48px;
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding: 72px 0;
  }

  .nav-links,
  .header-actions .btn {
    display: none;
  }

  .menu-toggle,
  .mobile-nav {
    display: flex;
  }

  .hero {
    padding: 130px 0 72px;
  }

  .hero-buttons {
    flex-direction: column;
    margin-bottom: 48px;
  }

  .hero-stats {
    gap: 32px;
    flex-wrap: wrap;
  }

  .features-grid,
  .privacy-grid,
  .ask-grid,
  .testimonials-grid {
    grid-template-columns: 1fr;
  }

  .speed-compare {
    flex-direction: column;
  }

  .translate-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  h1 {
    font-size: 1.8rem;
  }

  .hero-desc {
    font-size: 1rem;
  }
}