/* ===================================================================
   Twinkle Tray CN — Global Stylesheet
   Color palette extracted from the official logo (purple / lavender)
   =================================================================== */

:root {
  /* Brand colors */
  --c-primary: #8B5CF6;
  --c-primary-deep: #6D28D9;
  --c-primary-light: #A78BFA;
  --c-lavender: #DDD6FE;
  --c-lavender-soft: #EDE9FE;
  --c-bg: #FBFAFF;
  --c-bg-alt: #F5F2FF;

  /* Neutrals */
  --c-text: #1E1B4B;
  --c-text-muted: #4B5563;
  --c-text-soft: #6B7280;
  --c-border: #E5E7EB;
  --c-border-strong: #D1D5DB;
  --c-white: #FFFFFF;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(30, 27, 75, 0.05);
  --shadow-md: 0 4px 16px rgba(139, 92, 246, 0.08);
  --shadow-lg: 0 12px 40px rgba(139, 92, 246, 0.12);
  --shadow-xl: 0 24px 60px rgba(109, 40, 217, 0.18);

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

  /* Layout */
  --container: 1200px;
  --nav-height: 68px;

  /* Type */
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", Consolas, Monaco, monospace;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-base);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--c-primary-deep); text-decoration: none; transition: color .2s ease; }
a:hover { color: var(--c-primary); }
button { font-family: inherit; cursor: pointer; }

/* ---------- Typography ---------- */
h1, h2, h3, h4 {
  margin: 0 0 .5em;
  line-height: 1.3;
  font-weight: 700;
  color: var(--c-text);
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(2rem, 4.5vw, 3rem); }
h2 { font-size: clamp(1.6rem, 3vw, 2.25rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }
p  { margin: 0 0 1em; }

/* ---------- Layout ---------- */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.section { padding: 80px 0; }
.section--alt { background: var(--c-bg-alt); }
.section-head { text-align: center; margin-bottom: 56px; }
.section-head .eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--c-primary-deep);
  padding: 6px 14px;
  background: var(--c-lavender-soft);
  border-radius: 999px;
  margin-bottom: 16px;
}
.section-head p {
  max-width: 640px;
  margin: 12px auto 0;
  color: var(--c-text-muted);
  font-size: 17px;
}

/* ---------- Navigation ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--c-border);
}
.nav-inner {
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--c-text);
}
.brand img { width: 32px; height: 32px; }
.nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
  padding: 0; margin: 0;
}
.nav-links a {
  display: inline-block;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  color: var(--c-text-muted);
  font-size: 15px;
  font-weight: 500;
  transition: all .2s;
}
.nav-links a:hover, .nav-links a.active {
  color: var(--c-primary-deep);
  background: var(--c-lavender-soft);
}
.nav-cta {
  background: var(--c-primary);
  color: #fff !important;
  padding: 9px 18px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: background .2s;
}
.nav-cta:hover { background: var(--c-primary-deep); color: #fff !important; }
.nav-toggle { display: none; background: transparent; border: 0; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--c-text); margin: 5px 0; transition: .3s; }
@media (max-width: 880px) {
  .nav-links { display: none; position: absolute; top: var(--nav-height); left:0; right:0; background:#fff; flex-direction: column; padding: 12px 24px; border-bottom: 1px solid var(--c-border); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 16px;
  border: 1px solid transparent;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease, color .2s ease;
  text-decoration: none;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn--primary {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-deep) 100%);
  color: #fff;
  box-shadow: 0 8px 24px -8px rgba(139, 92, 246, 0.5);
}
.btn--primary:hover { box-shadow: 0 12px 32px -8px rgba(139, 92, 246, 0.7); color: #fff; }
.btn--ghost {
  background: #fff;
  color: var(--c-primary-deep);
  border-color: var(--c-lavender);
}
.btn--ghost:hover { background: var(--c-lavender-soft); color: var(--c-primary-deep); }
.btn--lg { padding: 16px 34px; font-size: 17px; }
.btn .arrow { transition: transform .2s; }
.btn:hover .arrow { transform: translateX(3px); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 96px 0 80px;
  background:
    radial-gradient(circle at 15% 20%, rgba(167, 139, 250, 0.18) 0%, transparent 45%),
    radial-gradient(circle at 85% 70%, rgba(109, 40, 217, 0.12) 0%, transparent 45%),
    linear-gradient(180deg, var(--c-bg) 0%, var(--c-bg-alt) 100%);
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 64px;
  align-items: center;
}
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.4rem); margin-bottom: 20px; }
.hero h1 .accent {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-deep) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .lead {
  font-size: 18px;
  color: var(--c-text-muted);
  max-width: 540px;
  margin-bottom: 32px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 28px; }
.hero-meta { display: flex; gap: 28px; flex-wrap: wrap; font-size: 14px; color: var(--c-text-soft); }
.hero-meta strong { color: var(--c-text); display: block; font-size: 18px; }
.hero-visual {
  position: relative;
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 22px;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--c-lavender);
}
.hero-visual::before {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: calc(var(--radius-xl) + 3px);
  background: linear-gradient(135deg, var(--c-primary-light), var(--c-primary-deep));
  z-index: -1;
  opacity: .25;
}
.hero-visual-img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--c-lavender);
}
@media (max-width: 880px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
}

/* ---------- Stats bar ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 48px;
}
.stat {
  text-align: center;
  padding: 28px 16px;
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  transition: transform .2s, box-shadow .2s;
}
.stat:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.stat-num {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-deep) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.stat-label { font-size: 14px; color: var(--c-text-muted); margin-top: 4px; }
@media (max-width: 720px) { .stats { grid-template-columns: repeat(2, 1fr); } }

/* ---------- Use case cards ---------- */
.usecases {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.usecase {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.usecase:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-lavender);
}
.usecase-icon {
  width: 48px; height: 48px;
  background: var(--c-lavender-soft);
  border-radius: var(--radius-md);
  display: grid; place-items: center;
  margin-bottom: 18px;
  color: var(--c-primary-deep);
}
.usecase h3 { font-size: 18px; margin-bottom: 8px; }
.usecase p { font-size: 14.5px; color: var(--c-text-muted); margin: 0; }
@media (max-width: 980px) { .usecases { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .usecases { grid-template-columns: 1fr; } }

/* ---------- Advantage grid ---------- */
.advantages {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.adv {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  border: 1px solid var(--c-border);
  position: relative;
  overflow: hidden;
  transition: transform .2s;
}
.adv:hover { transform: translateY(-2px); }
.adv::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 4px; height: 100%;
  background: linear-gradient(180deg, var(--c-primary) 0%, var(--c-primary-deep) 100%);
}
.adv-icon {
  width: 44px; height: 44px;
  display: grid; place-items: center;
  color: var(--c-primary-deep);
  background: var(--c-lavender-soft);
  border-radius: var(--radius-md);
  margin-bottom: 18px;
}
.adv h3 { font-size: 18px; }
.adv p { font-size: 14.5px; color: var(--c-text-muted); margin: 0; }
@media (max-width: 980px) { .advantages { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .advantages { grid-template-columns: 1fr; } }

/* ---------- Requirement table ---------- */
.req-wrap {
  max-width: 760px;
  margin: 0 auto;
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.req-row {
  display: grid;
  grid-template-columns: 200px 1fr;
  padding: 18px 28px;
  border-bottom: 1px solid var(--c-border);
  font-size: 15px;
}
.req-row:last-child { border-bottom: 0; }
.req-row > div:first-child { color: var(--c-text-muted); font-weight: 500; }
.req-row > div:last-child { color: var(--c-text); }
@media (max-width: 600px) {
  .req-row { grid-template-columns: 1fr; gap: 6px; padding: 16px 20px; }
}

/* ---------- Footer ---------- */
.footer {
  background: #1E1B4B;
  color: #c4b5fd;
  padding: 56px 0 32px;
  margin-top: 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer ul { list-style: none; padding: 0; margin: 0; }
.footer li { margin-bottom: 8px; font-size: 14px; }
.footer a { color: #c4b5fd; }
.footer a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid #3730a3;
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
  color: #a5b4fc;
}
.icp-row {
  width: 100%;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 4px;
  font-size: 12px;
}
.icp-row a {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: #a5b4fc;
  text-decoration: none;
}
.icp-row a:hover { color: #fff; }
.footer-brand p { font-size: 14px; color: #c4b5fd; max-width: 280px; margin-top: 12px; }
@media (max-width: 880px) { .footer-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .footer-grid { grid-template-columns: 1fr; } }

/* ---------- Download modal ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(30, 27, 75, 0.55);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  transition: opacity .25s ease;
  padding: 24px;
}
.modal-overlay.show { display: flex; opacity: 1;   left: 0;
  right: 0;
  top: 0;
  bottom: 0;}
  button { outline: none } 
.modal {
  background: #fff;
  border-radius: var(--radius-xl);
  width: min(720px, 100%);
  max-height: 92vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  transform: translateY(16px);
  transition: transform .25s ease;
}
.modal-overlay.show .modal { transform: translateY(0); }
.modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 28px 32px 12px;
  border-bottom: 1px solid var(--c-border);
}
.modal-head h3 { margin: 0; font-size: 20px; }
.modal-close {
  background: transparent; border: 0; padding: 8px; border-radius: 50%;
  color: var(--c-text-muted);
  transition: background .2s;
}
.modal-close:hover { background: var(--c-lavender-soft); color: var(--c-primary-deep); }
.modal-body { padding: 24px 32px 32px; }
.modal-subtitle { color: var(--c-text-muted); margin-bottom: 24px; font-size: 15px; }
.qr-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 24px;
}
@media (max-width: 600px) { .qr-grid { grid-template-columns: 1fr; } }
.qr-card {
  border: 1px solid var(--c-lavender);
  border-radius: var(--radius-lg);
  padding: 20px;
  text-align: center;
  background: linear-gradient(180deg, var(--c-bg) 0%, #fff 100%);
  transition: border-color .2s, transform .2s;
}
.qr-card:hover { border-color: var(--c-primary); transform: translateY(-2px); }
.qr-img {
  width: 160px; height: 160px;
  margin: 0 auto 14px;
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  padding: 8px;
}
.qr-card h4 { font-size: 16px; margin: 0 0 6px; }
.qr-card p { font-size: 13px; color: var(--c-text-muted); margin: 0 0 12px; }
.qr-tip {
  background: var(--c-lavender-soft);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  font-size: 13px;
  color: var(--c-text-muted);
  display: flex;
  gap: 10px;
  align-items: flex-start;
}
.qr-tip svg { flex-shrink: 0; color: var(--c-primary-deep); margin-top: 1px; }

/* ---------- Generic content blocks ---------- */
.faq { max-width: 760px; margin: 0 auto; }
.faq details {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  transition: border-color .2s, box-shadow .2s;
}
.faq details[open] { border-color: var(--c-lavender); box-shadow: var(--shadow-sm); }
.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 20px 24px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: '';
  width: 12px; height: 12px;
  border-right: 2px solid var(--c-primary-deep);
  border-bottom: 2px solid var(--c-primary-deep);
  transform: rotate(45deg);
  transition: transform .25s;
  margin-right: 4px;
}
.faq details[open] summary::after { transform: rotate(-135deg); }
.faq .answer { padding: 0 24px 20px; color: var(--c-text-muted); font-size: 15px; }
.faq .answer code {
  background: var(--c-lavender-soft);
  color: var(--c-primary-deep);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 13px;
}

/* ---------- Download page ---------- */
.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
@media (max-width: 880px) { .download-grid { grid-template-columns: 1fr; } }
.dl-card {
  background: #fff;
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: border-color .2s, box-shadow .2s;
}
.dl-card:hover { border-color: var(--c-lavender); box-shadow: var(--shadow-md); }
.dl-card.recommended { border-color: var(--c-primary); position: relative; }
.dl-card.recommended::before {
  content: 'Recommended';
  position: absolute;
  top: -12px; left: 24px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-deep));
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .1em;
  padding: 4px 12px;
  border-radius: 999px;
}
.dl-card h3 { margin-bottom: 8px; }
.dl-card .dl-meta {
  list-style: none; padding: 0; margin: 16px 0 24px;
  display: grid; gap: 8px;
  font-size: 14px;
  color: var(--c-text-muted);
}
.dl-card .dl-meta li { display: flex; justify-content: space-between; }
.dl-card .dl-meta strong { color: var(--c-text); font-weight: 600; }
.dl-card .dl-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.checksum {
  margin-top: 24px;
  background: var(--c-bg-alt);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-text-muted);
  word-break: break-all;
}
.checksum-label { font-family: var(--font-base); font-size: 12px; font-weight: 600; color: var(--c-primary-deep); margin-bottom: 4px; letter-spacing: .05em; text-transform: uppercase; }

/* ---------- Misc ---------- */
.text-center { text-align: center; }
.mt-32 { margin-top: 32px; }
.mt-48 { margin-top: 48px; }
.divider { height: 1px; background: var(--c-border); margin: 32px 0; }
.subnav { display: flex; gap: 4px; flex-wrap: wrap; margin-bottom: 32px; }
.subnav a {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  color: var(--c-text-muted);
  font-size: 14px;
  font-weight: 500;
}
.subnav a.active, .subnav a:hover { background: var(--c-lavender-soft); color: var(--c-primary-deep); }

/* Feature comparison table */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--c-border);
  font-size: 14px;
}
.compare-table th, .compare-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid var(--c-border);
}
.compare-table th { background: var(--c-bg-alt); font-weight: 600; color: var(--c-text); }
.compare-table tr:last-child td { border-bottom: 0; }
.compare-table .yes { color: #10B981; font-weight: 600; }
.compare-table .no { color: var(--c-text-soft); }
@media (max-width: 720px) { .compare-table { font-size: 13px; } .compare-table th, .compare-table td { padding: 12px 14px; } }

/* page intro */
.page-intro {
  padding: 64px 0 32px;
  background:
    radial-gradient(circle at 80% 0%, rgba(167, 139, 250, 0.12) 0%, transparent 50%),
    linear-gradient(180deg, var(--c-bg-alt) 0%, var(--c-bg) 100%);
  text-align: center;
}
.page-intro h1 { margin-bottom: 16px; }
.page-intro p { max-width: 640px; margin: 0 auto; color: var(--c-text-muted); font-size: 17px; }

/* Code blocks */
pre {
  background: #1E1B4B;
  color: #c4b5fd;
  border-radius: var(--radius-md);
  padding: 16px 20px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.5;
}
pre code { color: inherit; }