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

:root {
  --blue: #0969da;
  --blue-hover: #0550ae;
  --blue-light: #ddf4ff;
  --blue-dark: #0a3069;

  --gray-50: #f6f8fa;
  --gray-100: #eef1f5;
  --gray-200: #d0d7de;
  --gray-300: #afb8c1;
  --gray-500: #656d76;
  --gray-700: #424a53;
  --gray-900: #1f2328;

  --green: #1a7f37;
  --green-bg: #e6ffec;
  --green-hl: #abf2bc;

  --red: #cf222e;
  --red-bg: #ffebe9;
  --red-hl: #ffc1ba;

  --purple: #7c3aed;
  --purple-bg: #f5f0ff;
  --purple-hl: #e4d4ff;

  --amber: #9a6700;
  --amber-bg: #fff8c5;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.1);
  --shadow-xl: 0 16px 48px rgba(0,0,0,0.12);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-900);
  background: #fff;
  -webkit-font-smoothing: antialiased;
}

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

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

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-weight: 600;
  font-size: 0.9375rem;
  padding: 10px 24px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--blue);
  color: #fff;
  cursor: pointer;
  transition: background 150ms ease, transform 80ms ease, box-shadow 150ms ease;
  text-decoration: none;
}

.btn:hover {
  background: var(--blue-hover);
}

.btn:active {
  transform: scale(0.98);
}

.btn-outline {
  background: transparent;
  color: var(--gray-700);
  border: 1.5px solid var(--gray-200);
}

.btn-outline:hover {
  background: var(--gray-50);
  border-color: var(--gray-300);
}

.btn-sm {
  padding: 6px 16px;
  font-size: 0.8125rem;
}

.btn-lg {
  padding: 14px 32px;
  font-size: 1rem;
  border-radius: var(--radius-md);
}

.btn-block {
  width: 100%;
}

.btn-disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

/* ===== Nav ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--gray-100);
}

.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 32px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-logo-img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.nav-logo-text {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--gray-900);
}

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

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-500);
  transition: color 150ms;
}

.nav-links a:hover {
  color: var(--gray-900);
}

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

.lang-switch {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-sm);
  color: var(--gray-500);
  transition: color 150ms, border-color 150ms;
  letter-spacing: 0.03em;
}

.lang-switch:hover {
  color: var(--gray-900);
  border-color: var(--gray-300);
}

/* ===== Hero ===== */
.hero {
  padding: 140px 32px 80px;
  text-align: center;
  background: linear-gradient(180deg, #fff 0%, var(--gray-50) 100%);
}

.hero-inner {
  max-width: 720px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  padding: 4px 14px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--blue);
  background: var(--blue-light);
  border-radius: 100px;
  margin-bottom: 24px;
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--gray-900);
  margin-bottom: 20px;
}

.hero-title-accent {
  background: linear-gradient(135deg, var(--blue) 0%, #6366f1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.1875rem;
  line-height: 1.7;
  color: var(--gray-500);
  max-width: 560px;
  margin: 0 auto 32px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-note {
  font-size: 0.8125rem;
  color: var(--gray-300);
  margin-top: 16px;
}

/* ===== App Preview ===== */
.hero-preview {
  max-width: 960px;
  margin: 64px auto 0;
}

.preview-window {
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  background: #fff;
}

.preview-titlebar {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  background: var(--gray-50);
  border-bottom: 1px solid var(--gray-200);
  gap: 8px;
}

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

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.dot-red { background: #ff5f57; }
.dot-yellow { background: #febc2e; }
.dot-green { background: #28c840; }

.preview-title {
  flex: 1;
  text-align: center;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--gray-500);
  margin-right: 44px; /* offset for dots */
}

.preview-content {
  background: #fff;
}

.preview-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 16px;
  background: var(--gray-50);
  border-bottom: 1px solid var(--gray-100);
  font-size: 0.75rem;
}

.preview-btn-new {
  padding: 3px 10px;
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: 4px;
  font-weight: 500;
  color: var(--gray-500);
}

.preview-toggle {
  display: flex;
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: 6px;
  overflow: hidden;
}

.preview-toggle span {
  padding: 3px 12px;
  color: var(--gray-500);
  font-weight: 500;
}

.preview-toggle-active {
  background: var(--blue) !important;
  color: #fff !important;
}

.preview-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--gray-300);
}

.preview-nav-count {
  font-size: 0.6875rem;
  color: var(--gray-500);
  font-weight: 500;
}

.preview-diff {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.preview-panel {
  font-size: 0.8125rem;
  font-family: 'Inter', sans-serif;
  line-height: 1.7;
}

.preview-panel:first-child {
  border-right: 1px solid var(--gray-200);
}

.preview-panel-header {
  padding: 6px 16px;
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--gray-500);
  background: var(--gray-50);
  border-bottom: 1px solid var(--gray-100);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.preview-line {
  padding: 2px 16px;
  color: var(--gray-700);
}

.preview-line-removed {
  background: var(--red-bg);
}

.preview-line-added {
  background: var(--green-bg);
}

.preview-line-moved {
  background: var(--purple-bg);
}

.hl-removed {
  background: var(--red-hl);
  color: var(--red);
  border-radius: 2px;
  padding: 0 2px;
  text-decoration: line-through;
  font-weight: 500;
}

.hl-added {
  background: var(--green-hl);
  color: var(--green);
  border-radius: 2px;
  padding: 0 2px;
  text-decoration: underline;
  font-weight: 500;
}

.hl-moved {
  background: var(--purple-hl);
  color: var(--purple);
  border-radius: 2px;
  padding: 1px 6px;
  font-size: 0.6875rem;
  font-weight: 600;
}

/* ===== Sections ===== */
.section-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 32px;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 1.0625rem;
  color: var(--gray-500);
}

/* ===== Features ===== */
.features {
  padding: 100px 32px;
  background: #fff;
}

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

.feature-card {
  padding: 32px;
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-lg);
  transition: border-color 200ms, box-shadow 200ms;
}

.feature-card:hover {
  border-color: var(--gray-200);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.feature-icon-blue { background: var(--blue-light); color: var(--blue); }
.feature-icon-green { background: var(--green-bg); color: var(--green); }
.feature-icon-purple { background: var(--purple-bg); color: var(--purple); }
.feature-icon-amber { background: var(--amber-bg); color: var(--amber); }
.feature-icon-red { background: var(--red-bg); color: var(--red); }
.feature-icon-teal { background: #e0f7fa; color: #00796b; }

.feature-title {
  font-size: 1.0625rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-desc {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--gray-500);
}

/* ===== Comparison Table ===== */
.comparison {
  padding: 100px 32px;
  background: var(--gray-50);
}

.comparison-table-wrap {
  max-width: 720px;
  margin: 0 auto;
  background: #fff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.comparison-table thead th {
  padding: 20px 24px;
  font-weight: 600;
  text-align: center;
  background: var(--gray-50);
  border-bottom: 1px solid var(--gray-200);
  font-size: 0.9375rem;
}

.comparison-table thead th:first-child {
  text-align: left;
}

.table-logo {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  display: inline-block;
  vertical-align: middle;
  margin-right: 6px;
}

.comparison-table tbody td {
  padding: 14px 24px;
  border-bottom: 1px solid var(--gray-100);
  text-align: center;
  color: var(--gray-700);
}

.comparison-table tbody td:first-child {
  text-align: left;
  font-weight: 500;
}

.comparison-table tbody tr:last-child td {
  border-bottom: none;
}

.check {
  color: var(--green);
  font-size: 1.25rem;
  font-weight: 700;
}

.check-no {
  color: var(--gray-300);
  font-size: 1.25rem;
}

.comparison-price-row td {
  padding-top: 20px !important;
  padding-bottom: 20px !important;
  background: var(--gray-50);
}

.price-delta {
  color: var(--blue);
  font-size: 1rem;
}

.price-other {
  color: var(--gray-500);
  font-size: 1rem;
}

/* ===== Pricing ===== */
.pricing {
  padding: 100px 32px;
  background: #fff;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 960px;
  margin: 0 auto;
}

.pricing-card {
  position: relative;
  padding: 36px 32px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
}

.pricing-card-featured {
  border-color: var(--blue);
  box-shadow: 0 0 0 1px var(--blue), var(--shadow-lg);
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 2px 14px;
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--blue);
  color: #fff;
  border-radius: 100px;
  white-space: nowrap;
}

.pricing-name {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.pricing-price {
  margin-bottom: 12px;
}

.pricing-amount {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.pricing-period {
  font-size: 1rem;
  color: var(--gray-500);
  font-weight: 400;
}

.pricing-desc {
  font-size: 0.875rem;
  color: var(--gray-500);
  margin-bottom: 24px;
}

.pricing-features {
  list-style: none;
  flex: 1;
  margin-bottom: 28px;
}

.pricing-features li {
  padding: 6px 0;
  font-size: 0.875rem;
  color: var(--gray-700);
  position: relative;
  padding-left: 22px;
}

.pricing-features li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--green);
  font-weight: 700;
  font-size: 0.875rem;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--gray-100);
  padding: 32px;
}

.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer-logo {
  width: 24px;
  height: 24px;
  border-radius: 6px;
}

.footer-name {
  font-weight: 700;
  font-size: 0.9375rem;
}

.footer-copy {
  font-size: 0.8125rem;
  color: var(--gray-300);
}

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

.footer-links a {
  font-size: 0.8125rem;
  color: var(--gray-500);
  transition: color 150ms;
}

.footer-links a:hover {
  color: var(--gray-900);
}

/* ===== Download Page ===== */
.download {
  padding: 140px 32px 80px;
  background: linear-gradient(180deg, #fff 0%, var(--gray-50) 100%);
  text-align: center;
}

.download-inner {
  max-width: 960px;
  margin: 0 auto;
}

.download-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.download-subtitle {
  font-size: 1.0625rem;
  color: var(--gray-500);
  margin-bottom: 48px;
}

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

.download-card {
  padding: 32px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  background: #fff;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.download-card-active {
  border-color: var(--blue);
  box-shadow: 0 0 0 1px var(--blue), var(--shadow-lg);
}

.download-card-soon {
  opacity: 0.55;
}

.download-os {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
}

.download-os svg {
  color: var(--gray-700);
}

.download-meta {
  font-size: 0.875rem;
  color: var(--gray-500);
  line-height: 1.6;
}

.download-meta strong {
  color: var(--gray-700);
}

.download-meta ul {
  list-style: none;
  margin-top: 4px;
}

.download-meta li {
  padding: 2px 0;
  padding-left: 18px;
  position: relative;
}

.download-meta li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--green);
  font-weight: 700;
  font-size: 0.8125rem;
}

.download-beta-note {
  padding-top: 16px;
  border-top: 1px solid var(--gray-100);
  font-size: 0.875rem;
  color: var(--gray-500);
}

.download-beta-link {
  display: inline-block;
  margin-top: 4px;
  font-weight: 600;
  color: var(--blue);
  font-size: 0.875rem;
}

.download-beta-link:hover {
  text-decoration: underline;
}

/* ===== Legal Pages ===== */
.legal {
  padding: 140px 32px 80px;
  background: #fff;
}

.legal-inner {
  max-width: 720px;
  margin: 0 auto;
}

.legal-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 40px;
}

.legal h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-top: 36px;
  margin-bottom: 12px;
  color: var(--gray-900);
}

.legal h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
  color: var(--gray-900);
}

.legal h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-top: 16px;
  margin-bottom: 4px;
  color: var(--gray-700);
}

.legal p {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--gray-500);
  margin-bottom: 12px;
}

.legal a {
  color: var(--blue);
}

.legal a:hover {
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .hero-title {
    font-size: 2.5rem;
  }

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
  }

  .download-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
  }

  .nav-links {
    display: none;
  }
}

@media (max-width: 640px) {
  .hero {
    padding: 120px 20px 60px;
  }

  .hero-title {
    font-size: 2rem;
  }

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

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

  .preview-diff {
    grid-template-columns: 1fr;
  }

  .preview-panel:first-child {
    border-right: none;
    border-bottom: 1px solid var(--gray-200);
  }

  .section-title {
    font-size: 1.75rem;
  }

  .comparison-table {
    font-size: 0.8125rem;
  }

  .comparison-table thead th,
  .comparison-table tbody td {
    padding: 10px 12px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 16px;
  }
}