/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Noto Sans SC", sans-serif;
  color: #1a1a2e;
  background: #fff;
  line-height: 1.7;
}
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }

/* ===== Variables ===== */
:root {
  --green:   #25D366;
  --teal:    #128C7E;
  --dark:    #075E54;
  --light:   #DCF8C6;
  --accent:  #34B7F1;
  --gray-bg: #f5f7fa;
  --gray-1:  #6b7280;
  --gray-2:  #374151;
  --radius:  14px;
  --shadow:  0 4px 24px rgba(0,0,0,.10);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.15);
  --transition: .25s ease;
}

/* ===== Layout ===== */
.container { max-width: 1140px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-sm { padding: 56px 0; }

/* ===== Header / Nav ===== */
header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,.07);
  box-shadow: 0 2px 12px rgba(0,0,0,.06);
}
.nav-inner {
  display: flex; align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  max-width: 1140px; margin: 0 auto;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 1.2rem; color: var(--dark);
}
.logo svg { flex-shrink: 0; }
nav { display: flex; align-items: center; gap: 4px; }
nav a {
  padding: 8px 16px; border-radius: 8px;
  font-size: .95rem; font-weight: 500; color: var(--gray-2);
  transition: background var(--transition), color var(--transition);
}
nav a:hover, nav a.active {
  background: var(--gray-bg); color: var(--dark);
}
.nav-cta {
  background: var(--green) !important; color: #fff !important;
  border-radius: 8px; padding: 8px 20px !important;
}
.nav-cta:hover { background: var(--teal) !important; }
.hamburger { display: none; background: none; border: none; cursor: pointer; padding: 4px; }
.mobile-nav {
  display: none; flex-direction: column;
  background: #fff; border-top: 1px solid #eee;
  padding: 12px 20px 16px;
}
.mobile-nav a {
  padding: 11px 0; font-size: 1rem; font-weight: 500;
  color: var(--gray-2); border-bottom: 1px solid #f0f0f0;
  display: block;
}
.mobile-nav a:last-child { border-bottom: none; }
.mobile-nav.open { display: flex; }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, var(--dark) 0%, var(--teal) 55%, #1aaf6d 100%);
  color: #fff; padding: 100px 0 80px; position: relative; overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-inner {
  position: relative; display: grid;
  grid-template-columns: 1fr 1fr; gap: 48px;
  align-items: center; max-width: 1140px; margin: 0 auto; padding: 0 20px;
}
.hero-text h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); font-weight: 800; line-height: 1.25; margin-bottom: 20px; }
.hero-text p { font-size: 1.1rem; opacity: .9; margin-bottom: 32px; max-width: 500px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(255,255,255,.15); border: 1px solid rgba(255,255,255,.25);
  border-radius: 50px; padding: 6px 16px; font-size: .85rem;
  margin-bottom: 20px; backdrop-filter: blur(8px);
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-phone {
  display: flex; justify-content: center; align-items: center;
}
.phone-mockup {
  width: 240px; height: 420px;
  background: rgba(255,255,255,.12);
  border: 2px solid rgba(255,255,255,.25);
  border-radius: 36px;
  display: flex; flex-direction: column;
  overflow: hidden; position: relative;
  backdrop-filter: blur(8px);
}
.phone-chat {
  padding: 16px; flex: 1; display: flex;
  flex-direction: column; gap: 10px; justify-content: flex-end;
}
.msg {
  max-width: 75%; padding: 9px 13px;
  border-radius: 16px; font-size: .82rem; line-height: 1.5;
}
.msg.incoming { background: rgba(255,255,255,.25); align-self: flex-start; }
.msg.outgoing { background: var(--green); align-self: flex-end; }
.phone-bar {
  background: rgba(0,0,0,.2); padding: 12px 16px;
  display: flex; align-items: center; gap: 10px; font-size: .8rem;
}
.phone-avatar {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--green); flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 26px; border-radius: 50px; font-size: .98rem;
  font-weight: 600; cursor: pointer; border: none;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), opacity var(--transition);
  text-decoration: none;
}
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.btn:active { transform: translateY(0); }
.btn-primary { background: var(--green); color: #fff; }
.btn-primary:hover { background: #1ebf5a; }
.btn-white { background: #fff; color: var(--dark); }
.btn-white:hover { background: #f0faf5; }
.btn-outline {
  background: transparent; color: #fff;
  border: 2px solid rgba(255,255,255,.5);
}
.btn-outline:hover { background: rgba(255,255,255,.1); border-color: #fff; }
.btn-dark { background: var(--dark); color: #fff; }
.btn-dark:hover { background: var(--teal); }
.btn-lg { padding: 16px 36px; font-size: 1.05rem; }
.btn-sm { padding: 9px 18px; font-size: .88rem; }
.btn[disabled] { opacity: .7; cursor: not-allowed; transform: none; }
@keyframes spin { to { transform: rotate(360deg); } }
.spin-icon { animation: spin .8s linear infinite; }

/* ===== Section Headings ===== */
.section-head { text-align: center; margin-bottom: 56px; }
.section-head .label {
  display: inline-block; background: #e8fdf0; color: var(--teal);
  font-size: .82rem; font-weight: 700; letter-spacing: .08em;
  text-transform: uppercase; padding: 5px 14px; border-radius: 50px;
  margin-bottom: 12px;
}
.section-head h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); font-weight: 800; color: var(--gray-2); margin-bottom: 14px; }
.section-head p { max-width: 600px; margin: 0 auto; color: var(--gray-1); font-size: 1.05rem; }

/* ===== Feature Cards ===== */
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); gap: 28px; }
.feature-card {
  background: #fff; border: 1.5px solid #e8edf3;
  border-radius: var(--radius); padding: 32px 28px;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #c9f7dc; }
.feature-icon {
  width: 56px; height: 56px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
}
.feature-icon.green { background: #e8fdf0; }
.feature-icon.blue  { background: #e8f4fd; }
.feature-icon.purple{ background: #f3e8fd; }
.feature-icon.orange{ background: #fdf3e8; }
.feature-icon.red   { background: #fde8e8; }
.feature-icon.teal  { background: #e8f9fd; }
.feature-card h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; color: var(--gray-2); }
.feature-card p { font-size: .93rem; color: var(--gray-1); line-height: 1.65; }

/* ===== Stats ===== */
.stats-band { background: linear-gradient(90deg, var(--dark), var(--teal)); color: #fff; padding: 56px 0; }
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 32px; text-align: center; }
.stat-item .num { font-size: 2.6rem; font-weight: 800; line-height: 1.1; }
.stat-item .unit { font-size: 1rem; opacity: .75; margin-top: 4px; }

/* ===== Platform Cards ===== */
.platform-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; }
.platform-card {
  background: #fff; border: 1.5px solid #e8edf3; border-radius: var(--radius);
  padding: 28px 24px; text-align: center;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.platform-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #c9f7dc; }
.platform-card.featured {
  border-color: var(--green); box-shadow: 0 0 0 3px rgba(37,211,102,.12);
}
.platform-icon { width: 64px; height: 64px; margin: 0 auto 16px; }
.platform-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; color: var(--gray-2); }
.platform-card p { font-size: .88rem; color: var(--gray-1); margin-bottom: 18px; }
.badge-featured {
  display: inline-block; background: var(--green); color: #fff;
  font-size: .72rem; font-weight: 700; padding: 3px 10px; border-radius: 50px;
  margin-bottom: 12px; text-transform: uppercase; letter-spacing: .06em;
}

/* ===== Steps ===== */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 28px; counter-reset: step; }
.step-card {
  background: var(--gray-bg); border-radius: var(--radius); padding: 32px 24px;
  text-align: center; position: relative;
}
.step-num {
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--green); color: #fff;
  font-size: 1.2rem; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 16px;
}
.step-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; color: var(--gray-2); }
.step-card p { font-size: .9rem; color: var(--gray-1); }

/* ===== FAQ ===== */
.faq-list { max-width: 820px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  background: #fff; border: 1.5px solid #e8edf3; border-radius: var(--radius);
  overflow: hidden;
}
.faq-q {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 24px; cursor: pointer; font-weight: 600;
  font-size: 1rem; color: var(--gray-2);
  user-select: none; gap: 12px;
  transition: background var(--transition);
}
.faq-q:hover { background: var(--gray-bg); }
.faq-icon {
  flex-shrink: 0; width: 22px; height: 22px;
  border-radius: 50%; background: var(--gray-bg);
  display: flex; align-items: center; justify-content: center;
  transition: transform var(--transition), background var(--transition);
}
.faq-item.open .faq-icon { transform: rotate(45deg); background: var(--green); }
.faq-item.open .faq-icon svg { stroke: #fff; }
.faq-a {
  max-height: 0; overflow: hidden;
  transition: max-height .35s ease, padding .35s ease;
  font-size: .95rem; color: var(--gray-1); line-height: 1.7;
}
.faq-item.open .faq-a { max-height: 600px; }
.faq-a-inner { padding: 0 24px 20px; }

/* ===== CTA Banner ===== */
.cta-banner {
  background: linear-gradient(135deg, var(--dark) 0%, var(--teal) 100%);
  color: #fff; text-align: center; padding: 80px 20px;
}
.cta-banner h2 { font-size: clamp(1.5rem, 3vw, 2.2rem); font-weight: 800; margin-bottom: 16px; }
.cta-banner p { font-size: 1.05rem; opacity: .88; margin-bottom: 32px; max-width: 560px; margin-left: auto; margin-right: auto; }
.cta-actions { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }

/* ===== Download Hero ===== */
.dl-hero {
  background: linear-gradient(135deg, #0a2a24 0%, var(--teal) 60%, #1aaf6d 100%);
  color: #fff; padding: 80px 0 64px;
}
.dl-hero h1 { font-size: clamp(1.8rem, 4vw, 2.7rem); font-weight: 800; margin-bottom: 16px; }
.dl-hero p { font-size: 1.08rem; opacity: .88; max-width: 620px; margin-bottom: 32px; }
.dl-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.dl-tag {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(255,255,255,.15); border: 1px solid rgba(255,255,255,.25);
  border-radius: 50px; padding: 5px 14px; font-size: .84rem;
}

/* ===== Windows Featured Card ===== */
.win-card {
  background: linear-gradient(135deg, #0d1b2a 0%, #1e3a5f 100%);
  border-radius: 24px; overflow: hidden; color: #fff;
  display: grid; grid-template-columns: 1fr 1fr;
  box-shadow: var(--shadow-lg); margin-bottom: 48px;
}
.win-card-content { padding: 48px 40px; }
.win-card-content h2 { font-size: 1.8rem; font-weight: 800; margin-bottom: 12px; }
.win-card-content p { font-size: .98rem; opacity: .8; margin-bottom: 24px; }
.win-meta { display: flex; flex-wrap: wrap; gap: 16px; margin-bottom: 28px; }
.win-meta-item {
  display: flex; align-items: center; gap: 6px;
  font-size: .88rem; opacity: .85;
}
.win-card-visual {
  background: rgba(255,255,255,.06); display: flex;
  align-items: center; justify-content: center; padding: 32px;
}
.win-screen {
  width: 100%; max-width: 300px; background: #1a1a2e;
  border-radius: 12px; overflow: hidden;
  border: 1px solid rgba(255,255,255,.15);
}
.win-screen-bar {
  background: #0d1117; padding: 8px 14px;
  display: flex; align-items: center; gap: 6px;
}
.win-dot { width: 10px; height: 10px; border-radius: 50%; }
.win-screen-body { padding: 16px; }
.win-chat-row {
  display: flex; align-items: flex-end; gap: 8px;
  margin-bottom: 10px;
}
.win-bubble {
  padding: 8px 12px; border-radius: 12px;
  font-size: .78rem; max-width: 70%; line-height: 1.45;
}
.win-bubble.in { background: #2d333b; color: #cdd9e5; }
.win-bubble.out { background: #1b4332; color: #d1fae5; margin-left: auto; }

/* ===== Other Platform Cards (small) ===== */
.other-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.other-card {
  background: #fff; border: 1.5px solid #e8edf3; border-radius: var(--radius);
  padding: 28px 24px; display: flex; flex-direction: column; gap: 14px;
}
.other-card:hover { box-shadow: var(--shadow); border-color: #c9f7dc; }
.other-card-head { display: flex; align-items: center; gap: 14px; }
.other-card-icon { width: 48px; height: 48px; border-radius: 12px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; }
.other-card-icon.win-col { background: #e8f0fe; }
.other-card-icon.mac-col { background: #f5f5f5; }
.other-card-icon.android-col { background: #e8fdf0; }
.other-card-icon.ios-col { background: #fff0f0; }
.other-card h3 { font-size: 1rem; font-weight: 700; color: var(--gray-2); margin-bottom: 2px; }
.other-card p { font-size: .86rem; color: var(--gray-1); }

/* ===== Comparison Table ===== */
.compare-wrap { overflow-x: auto; }
.compare-table {
  width: 100%; border-collapse: collapse;
  font-size: .95rem;
}
.compare-table th, .compare-table td {
  padding: 14px 20px; text-align: left;
  border-bottom: 1px solid #e8edf3;
}
.compare-table thead th {
  background: var(--gray-bg); font-weight: 700;
  color: var(--gray-2); font-size: .88rem;
}
.compare-table thead th:first-child { border-radius: var(--radius) 0 0 0; }
.compare-table thead th:last-child { border-radius: 0 var(--radius) 0 0; }
.compare-table tbody tr:hover { background: #f9fbfc; }
.check { color: var(--green); }
.cross { color: #ef4444; }

/* ===== WhatsApp Web Page ===== */
.web-hero {
  background: linear-gradient(135deg, #043b33 0%, #128C7E 55%, #25D366 100%);
  color: #fff; padding: 80px 0 64px;
}
.web-hero h1 { font-size: clamp(1.8rem, 4vw, 2.7rem); font-weight: 800; margin-bottom: 16px; }
.web-hero p { font-size: 1.08rem; opacity: .9; max-width: 600px; margin-bottom: 32px; }

.qr-section { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.qr-box {
  background: #fff; border-radius: 24px; padding: 40px;
  text-align: center; box-shadow: var(--shadow-lg);
  border: 2px solid #e8edf3;
}
.qr-box h3 { font-size: 1.2rem; font-weight: 700; margin-bottom: 8px; color: var(--gray-2); }
.qr-box p { font-size: .9rem; color: var(--gray-1); margin-bottom: 24px; }
.qr-placeholder {
  width: 180px; height: 180px; margin: 0 auto 20px;
  background: var(--gray-bg); border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  border: 2px dashed #cbd5e1;
}
.qr-steps-list { display: flex; flex-direction: column; gap: 16px; }
.qr-step {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 14px 18px; background: var(--gray-bg); border-radius: 10px;
}
.qr-step-num {
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--green); color: #fff; font-weight: 700;
  font-size: .85rem; display: flex; align-items: center;
  justify-content: center; flex-shrink: 0; margin-top: 1px;
}
.qr-step-text h4 { font-size: .95rem; font-weight: 600; color: var(--gray-2); margin-bottom: 2px; }
.qr-step-text p { font-size: .86rem; color: var(--gray-1); }

/* ===== Info Cards ===== */
.info-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.info-card {
  background: var(--gray-bg); border-radius: var(--radius);
  padding: 28px 24px; border-left: 4px solid var(--green);
}
.info-card h3 { font-size: 1rem; font-weight: 700; color: var(--gray-2); margin-bottom: 8px; }
.info-card p { font-size: .9rem; color: var(--gray-1); line-height: 1.65; }

/* ===== Footer ===== */
footer {
  background: #0d1117; color: #9ca3af; font-size: .9rem;
}
.footer-top {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px; padding: 56px 20px 40px;
  max-width: 1140px; margin: 0 auto;
}
.footer-brand .logo { color: #fff; margin-bottom: 12px; }
.footer-brand p { font-size: .88rem; line-height: 1.7; max-width: 280px; }
.footer-col h4 { color: #e5e7eb; font-size: .95rem; font-weight: 700; margin-bottom: 14px; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul li a { color: #9ca3af; transition: color var(--transition); }
.footer-col ul li a:hover { color: var(--green); }
.footer-bottom {
  border-top: 1px solid #1f2937; padding: 20px;
  max-width: 1140px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 10px;
}
.footer-verify {
  background: #0d2818; border: 1px solid #1e4d32; border-radius: 8px;
  padding: 12px 20px; font-size: .88rem;
  color: #86efac; text-align: center;
  max-width: 1140px; margin: 0 auto;
}
.footer-verify-wrap { padding: 0 20px 20px; max-width: 1140px; margin: 0 auto; }

/* ===== Notice / Alert ===== */
.notice {
  display: flex; align-items: flex-start; gap: 12px;
  background: #fffbeb; border: 1.5px solid #fcd34d;
  border-radius: 10px; padding: 16px 20px;
  font-size: .9rem; color: #78350f;
  margin-bottom: 32px;
}
.notice-green {
  background: #f0fdf4; border-color: #86efac; color: #166534;
}
.notice svg { flex-shrink: 0; margin-top: 2px; }

/* ===== Breadcrumb ===== */
.breadcrumb {
  display: flex; align-items: center; gap: 6px;
  font-size: .85rem; color: rgba(255,255,255,.7);
  margin-bottom: 20px; flex-wrap: wrap;
}
.breadcrumb a { color: rgba(255,255,255,.75); }
.breadcrumb a:hover { color: #fff; }
.breadcrumb span { color: rgba(255,255,255,.4); }

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-phone { display: none; }
  .win-card { grid-template-columns: 1fr; }
  .win-card-visual { display: none; }
  .qr-section { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .section { padding: 56px 0; }
  nav { display: none; }
  .hamburger { display: flex; }
  .footer-top { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

/* ===== Utilities ===== */
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-32 { margin-bottom: 32px; }
.text-sm { font-size: .88rem; }
.text-muted { color: var(--gray-1); }
.fw-bold { font-weight: 700; }
.gap-12 { gap: 12px; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.hidden { display: none !important; }