*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

/* HarmonyOS 字体声明 */
@font-face {
  font-family: 'HarmonyOS Sans SC';
  src: url('fonts/HarmonyOS_Sans_SC_Thin.ttf') format('truetype');
  font-weight: 100;
  font-style: normal;
}
@font-face {
  font-family: 'HarmonyOS Sans SC';
  src: url('fonts/HarmonyOS_Sans_SC_Light.ttf') format('truetype');
  font-weight: 300;
  font-style: normal;
}
@font-face {
  font-family: 'HarmonyOS Sans SC';
  src: url('fonts/HarmonyOS_Sans_SC_Regular.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
}
@font-face {
  font-family: 'HarmonyOS Sans SC';
  src: url('fonts/HarmonyOS_Sans_SC_Medium.ttf') format('truetype');
  font-weight: 500;
  font-style: normal;
}
@font-face {
  font-family: 'HarmonyOS Sans SC';
  src: url('fonts/HarmonyOS_Sans_SC_Bold.ttf') format('truetype');
  font-weight: 700;
  font-style: normal;
}
@font-face {
  font-family: 'HarmonyOS Sans SC';
  src: url('fonts/HarmonyOS_Sans_SC_Black.ttf') format('truetype');
  font-weight: 900;
  font-style: normal;
}

:root {
  --accent: #2563EB;
  --accent-soft: rgba(37,99,235,0.1);
  --accent-border: rgba(37,99,235,0.18);
  --text-1: #0D1117;
  --text-2: #5C6878;
  --text-3: #9BA8B7;
  --glass: rgba(255,255,255,0.68);
  --glass-border: rgba(255,255,255,0.88);
  --glass-shadow: 0 2px 24px rgba(37,99,235,0.06), 0 1px 3px rgba(0,0,0,0.04);
  --radius-lg: 20px;
  --radius-md: 14px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'HarmonyOS Sans SC', sans-serif;
  background: #F2F5FB;
  color: var(--text-1);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── BACKGROUND ── */
body::before {
  content: '';
  position: fixed; inset: 0; z-index: -1;
  background: url('muliu.png') center/cover no-repeat fixed;
  filter: blur(8px);
  transform: scale(1.1);
}
body::after {
  content: '';
  position: fixed; inset: 0; z-index: 0;
  background: rgba(242, 245, 251, 0.35);
  pointer-events: none;
}

/* ── LAYOUT WRAPPER ── */
.wrap {
  position: relative; z-index: 2;
  max-width: 880px;
  margin: 0 auto;
  padding: 0 2.5rem;
}

/* ── NAV ── */
nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 200;
  display: flex; justify-content: center;
  padding: 1rem 2.5rem;
}

.nav-pill {
  display: flex; align-items: center;
  justify-content: space-between;
  width: 100%; max-width: 860px;
  padding: 0.65rem 1.5rem;
  background: rgba(255,255,255,0.35);
  border: 1px solid rgba(255,255,255,0.45);
  border-radius: 100px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(37,99,235,0.07), 0 1px 2px rgba(0,0,0,0.04);
  position: relative;
}

.nav-brand {
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--text-1);
}

.nav-brand em { font-style: normal; color: var(--accent); }

.nav-links {
  display: flex; gap: 1.75rem; list-style: none;
}

.nav-links a {
  color: var(--text-2);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 500;
  transition: color 0.2s;
}

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

.nav-dl {
  background: var(--accent);
  color: white;
  text-decoration: none;
  padding: 0.38rem 1.1rem;
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  transition: opacity 0.2s, transform 0.2s;
  white-space: nowrap;
}

.nav-dl:hover { opacity: 0.88; transform: scale(1.03); }

.nav-menu-btn {
  display: none;
  background: rgba(255,255,255,0.25);
  border: 1px solid rgba(255,255,255,0.35);
  padding: 0.5rem;
  cursor: pointer;
  color: var(--text-1);
  width: 42px;
  height: 42px;
  border-radius: 12px;
  transition: background 0.2s, transform 0.15s;
}

.nav-menu-btn:hover {
  background: rgba(255,255,255,0.4);
}

.nav-menu-btn:active {
  transform: scale(0.96);
}

.nav-menu-btn svg {
  width: 100%;
  height: 100%;
}

.nav-drawer {
  visibility: hidden;
  position: absolute;
  top: 100%;
  left: 50%;
  transform-origin: top center;
  transform: translateX(-50%) scale(0.92) translateY(-6px);
  width: 100%;
  max-width: 420px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,0.7);
  border-radius: 18px;
  margin-top: 0.7rem;
  padding: 0.8rem;
  box-shadow: 0 10px 32px rgba(0,0,0,0.15), 0 2px 8px rgba(0,0,0,0.06);
  overflow: hidden;
  opacity: 0;
  transition: transform 0.22s cubic-bezier(0.18, 0.89, 0.32, 1.28), opacity 0.18s, visibility 0.18s;
}

.nav-drawer.open {
  visibility: visible;
  transform: translateX(-50%) scale(1) translateY(0);
  opacity: 1;
}

.nav-drawer-links {
  list-style: none;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.nav-drawer-links a {
  color: var(--text-2);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.7rem 1rem;
  border-radius: 12px;
  transition: background 0.2s, color 0.2s, transform 0.15s;
  flex: 1;
  min-width: 100px;
  text-align: center;
}

.nav-drawer-links a:hover {
  background: rgba(37,99,235,0.08);
  color: var(--accent);
  transform: translateY(-2px);
}

.nav-drawer-links a:first-child {
  margin-top: 0;
}

@media (max-width: 768px) {
  .nav-links,
  .nav-dl {
    display: none;
  }

  .nav-menu-btn {
    display: block;
  }
}

/* ── HERO ── */
.hero {
  position: relative; z-index: 2;
  min-height: 100vh;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center;
  padding: 8rem 2.5rem 6rem;
}

.hero-chip {
  display: inline-flex; align-items: center; gap: 0.45rem;
  background: var(--accent-soft);
  border: 1px solid var(--accent-border);
  border-radius: 100px;
  padding: 0.3rem 0.9rem;
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.04em;
  margin-bottom: 2.25rem;
  animation: rise 0.7s ease both;
}

.hero-chip-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 1.8s ease infinite;
}

.hero-title {
  font-size: clamp(4rem, 10vw, 7rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--text-1);
  margin-bottom: 0.7rem;
  animation: rise 0.7s 0.08s ease both;
}

.hero-sub {
  font-size: clamp(0.9rem, 2.5vw, 1.05rem);
  font-weight: 300;
  letter-spacing: 0.35em;
  color: var(--text-3);
  margin-bottom: 2rem;
  animation: rise 0.7s 0.15s ease both;
}

.hero-desc {
  max-width: 400px;
  font-size: 0.95rem;
  color: var(--text-2);
  line-height: 1.9;
  margin-bottom: 2.75rem;
  animation: rise 0.7s 0.22s ease both;
}

.hero-actions {
  display: flex; gap: 0.9rem; justify-content: center;
  flex-wrap: wrap;
  animation: rise 0.7s 0.3s ease both;
}

.btn-p {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--accent);
  color: white; text-decoration: none;
  padding: 0.72rem 1.9rem;
  border-radius: 12px;
  font-size: 0.88rem; font-weight: 600;
  font-family: inherit;
  box-shadow: 0 4px 18px rgba(37,99,235,0.28);
  transition: box-shadow 0.22s;
}

.btn-p:hover { box-shadow: 0 8px 28px rgba(37,99,235,0.36); }

.btn-s {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--glass);
  color: var(--text-1); text-decoration: none;
  padding: 0.72rem 1.9rem;
  border-radius: 12px;
  border: 1px solid rgba(0,0,0,0.07);
  font-size: 0.88rem; font-weight: 600;
  font-family: inherit;
  backdrop-filter: blur(10px);
  transition: background 0.22s;
}

.btn-s:hover { background: rgba(255,255,255,0.9); }

/* ── SECTION BASE ── */
section {
  position: relative; z-index: 2;
}

.section-inner {
  max-width: 880px;
  margin: 0 auto;
  padding: 6rem 2.5rem;
}

.sec-head {
  text-align: center;
  margin-bottom: 3rem;
}

.sec-eyebrow {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 0.7rem;
}

.sec-title {
  font-size: clamp(1.7rem, 3.5vw, 2.35rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

.sec-desc {
  font-size: 0.9rem;
  color: var(--text-2);
  max-width: 420px;
  margin: 0 auto;
  line-height: 1.85;
}

/* ── GLASS CARD ── */
.card {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--glass-shadow);
  transition: transform 0.3s cubic-bezier(.34,1.56,.64,1), box-shadow 0.3s;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 40px rgba(37,99,235,0.1), 0 2px 6px rgba(0,0,0,0.04);
}

/* ── STATS BAR ── */
.stats-bar {
  max-width: 880px; margin: 0 auto;
  padding: 0 2.5rem 5rem;
  position: relative; z-index: 2;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--glass-shadow);
}

.stat-cell {
  background: var(--glass);
  text-align: center;
  padding: 1.75rem 1rem;
}

.stat-n {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.05em;
  line-height: 1;
}

.stat-l {
  font-size: 0.76rem;
  color: var(--text-2);
  margin-top: 0.4rem;
  letter-spacing: 0.02em;
}

/* ── FEATURES GRID ── */
.feat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.1rem;
}

.feat-card {
  padding: 1.6rem;
}

.feat-icon {
  width: 46px; height: 46px;
  border-radius: 12px;
  background: var(--accent-soft);
  display: grid; place-items: center;
  margin-bottom: 1.1rem;
}

.feat-icon svg {
  width: 24px;
  height: 24px;
  stroke: var(--accent);
  stroke-width: 2;
  fill: none;
}

.feat-name {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.45rem;
  letter-spacing: -0.01em;
}

.feat-text {
  font-size: 0.8rem;
  color: var(--text-2);
  line-height: 1.75;
}

/* ── TOOLS LIST ── */
.tools-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.tool-card {
  display: flex; align-items: flex-start;
  gap: 1rem;
  padding: 1.4rem 1.5rem;
}

.tool-em {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--accent-soft);
  display: grid;
  place-items: center;
}

.tool-em svg {
  width: 22px;
  height: 22px;
  stroke: var(--accent);
  stroke-width: 2;
  fill: none;
}

.tool-name {
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.tool-desc {
  font-size: 0.77rem;
  color: var(--text-2);
  line-height: 1.7;
}

/* ── TESTS GRID ── */
.tests-card {
  padding: 2.25rem;
}

.tests-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
}

.test-item {
  text-align: center;
  padding: 1.5rem 1rem;
  border-right: 1px solid rgba(0,0,0,0.04);
  border-bottom: 1px solid rgba(0,0,0,0.04);
  transition: background 0.2s;
}

.test-item:hover { background: rgba(37,99,235,0.03); }
.test-item:nth-child(3n) { border-right: none; }
.test-item:nth-child(n+5) { border-bottom: none; }

.test-icon {
  margin-bottom: 0.5rem;
  display: inline-flex;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--accent-soft);
  align-items: center;
  justify-content: center;
}

.test-icon svg {
  width: 22px;
  height: 22px;
  stroke: var(--accent);
  stroke-width: 2;
  fill: none;
}

.test-name {
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.test-note {
  font-size: 0.74rem;
  color: var(--text-2);
}

/* ── DELTA DARK CARD ── */
.delta-card {
  border-radius: 24px;
  padding: 3rem 3rem 2.75rem;
  background:
    radial-gradient(ellipse 60% 80% at 90% 50%, rgba(37,99,235,0.18) 0%, transparent 60%),
    linear-gradient(145deg, #0D1626 0%, #111827 100%);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 8px 40px rgba(0,0,0,0.18);
  color: white;
  position: relative;
  overflow: hidden;
  transition: transform 0.3s;
}

.delta-card:hover { transform: translateY(-4px); }

.delta-card::before {
  content: '';
  position: absolute;
  right: 2.5rem; top: 50%;
  transform: translateY(-50%);
  width: 200px;
  height: 200px;
  background: url('deltaforce.png') center/contain no-repeat;
  opacity: 0.12;
  user-select: none;
  pointer-events: none;
}

.delta-chip {
  display: inline-block;
  background: rgba(37,99,235,0.2);
  border: 1px solid rgba(37,99,235,0.35);
  border-radius: 100px;
  padding: 0.22rem 0.75rem;
  font-size: 0.72rem;
  color: #93C5FD;
  font-weight: 600;
  letter-spacing: 0.07em;
  margin-bottom: 1.2rem;
}

.delta-title {
  font-size: 1.85rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 0.7rem;
}

.delta-desc {
  font-size: 0.86rem;
  color: rgba(255,255,255,0.5);
  max-width: 420px;
  line-height: 1.85;
  margin-bottom: 1.8rem;
}

.delta-tags {
  display: flex; flex-wrap: wrap; gap: 0.6rem;
}

.delta-tag {
  display: flex; align-items: center; gap: 0.5rem;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.65);
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 100px;
  padding: 0.28rem 0.8rem;
}

.delta-tag::before {
  content: '';
  width: 5px; height: 5px;
  border-radius: 50%;
  background: #60A5FA;
}

/* ── OPT GRID ── */
.opt-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.1rem;
}

.opt-card { padding: 1.75rem; }

.opt-icon {
  margin-bottom: 0.9rem;
  display: inline-flex;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: var(--accent-soft);
  align-items: center;
  justify-content: center;
}

.opt-icon svg {
  width: 24px;
  height: 24px;
  stroke: var(--accent);
  stroke-width: 2;
  fill: none;
}

.opt-name { font-size: 0.95rem; font-weight: 700; margin-bottom: 0.45rem; }
.opt-text { font-size: 0.8rem; color: var(--text-2); line-height: 1.75; }

/* ── FOOTER ── */
footer {
  position: relative; z-index: 2;
  text-align: center;
  padding: 4rem 2.5rem 3.5rem;
}

.footer-brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-1);
  margin-bottom: 0.6rem;
}

.footer-brand em { font-style: normal; color: var(--accent); }

.footer-note {
  font-size: 0.8rem;
  color: var(--text-3);
  line-height: 1.9;
}

/* ── DIVIDER ── */
.divider-line {
  width: 40px; height: 1px;
  background: var(--text-3);
  margin: 0 auto 2.5rem;
  opacity: 0.3;
}

/* ── ANIMATIONS ── */
@keyframes rise {
  from { opacity: 0; transform: translateY(22px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.5); opacity: 0.6; }
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.cursor {
  display: inline-block;
  animation: blink 0.8s infinite;
  color: var(--accent);
  font-weight: normal;
  margin-left: 2px;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.in {
  opacity: 1;
  transform: translateY(0);
}

/* ── RESPONSIVE ── */
@media (max-width: 700px) {
  .nav-links { display: none; }
  .feat-grid { grid-template-columns: 1fr 1fr; }
  .tools-grid { grid-template-columns: 1fr; }
  .opt-grid { grid-template-columns: 1fr; }
  .tests-grid { grid-template-columns: repeat(2, 1fr); }
  .tests-grid .test-item:nth-child(2n) { border-right: none; }
  .tests-grid .test-item:nth-child(n+5) { border-bottom: none; }
  .tests-grid .test-item:nth-child(3n) { border-right: 1px solid rgba(0,0,0,0.04); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .delta-card { padding: 2rem; }
  .delta-card::before { display: none; }
}

@media (max-width: 480px) {
  .feat-grid { grid-template-columns: 1fr; }
  .hero-title { letter-spacing: -0.03em; }
}