/* ========== 基础与变量 ========== */
:root {
  --bg-deep: #0f1114;
  --bg-card: #1a1d23;
  --bg-elevated: #22262e;
  --text: #e8eaef;
  --text-muted: #9aa3b2;
  --accent: #01a4ef;
  --accent-hover: #33b8f3;
  --border: rgba(255, 255, 255, 0.08);
  --radius: 14px;
  --radius-sm: 10px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --header-h: 64px;
  --max-w: 1080px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg-deep);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

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

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

code {
  font-size: 0.88em;
  padding: 0.15em 0.4em;
  background: var(--bg-elevated);
  border-radius: 6px;
  color: #c5d4e0;
}

.container {
  width: min(100% - 40px, var(--max-w));
  margin-inline: auto;
}

/* ========== 顶栏 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(15, 17, 20, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: var(--header-h);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text);
  font-weight: 700;
  font-size: 1.1rem;
}

.brand:hover {
  color: var(--text);
}

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--accent), #0066aa);
  box-shadow: 0 0 20px rgba(1, 164, 239, 0.35);
}

.site-nav {
  display: flex;
  gap: 1.75rem;
  margin-left: auto;
}

.site-nav a {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

.site-nav a:hover {
  color: var(--text);
}

.header-cta {
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  border: none;
  background: transparent;
  cursor: pointer;
  border-radius: var(--radius-sm);
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 6px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
  transition: transform 0.25s, opacity 0.2s;
}

.site-header.is-open .nav-toggle span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.site-header.is-open .nav-toggle span:nth-child(2) {
  opacity: 0;
}

.site-header.is-open .nav-toggle span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

@media (max-width: 860px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    flex-direction: column;
    padding: 1.25rem 1.5rem 1.5rem;
    background: rgba(15, 17, 20, 0.97);
    border-bottom: 1px solid var(--border);
    gap: 0;
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s ease, opacity 0.25s ease;
  }

  .site-header.is-open .site-nav {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .site-nav a {
    padding: 0.85rem 0;
    border-bottom: 1px solid var(--border);
  }

  .site-nav a:last-child {
    border-bottom: none;
  }

  .header-cta {
    display: none;
  }
}

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1.15rem;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s;
  text-decoration: none;
}

.btn-sm {
  padding: 0.45rem 0.95rem;
  font-size: 0.88rem;
}

.btn-lg {
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 20px rgba(1, 164, 239, 0.25);
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  box-shadow: 0 6px 28px rgba(1, 164, 239, 0.35);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
}

/* ========== Hero ========== */
.hero {
  position: relative;
  padding: clamp(3rem, 8vw, 5.5rem) 0 clamp(4rem, 10vw, 6rem);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(1, 164, 239, 0.22), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(1, 164, 239, 0.08), transparent 50%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-card {
    order: -1;
    max-width: 280px;
    margin-inline: auto;
  }
}

.eyebrow {
  margin: 0 0 0.75rem;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  text-transform: none;
  color: var(--accent);
  font-weight: 600;
}

.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.hero-lead {
  margin: 0 0 1.75rem;
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 36ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0;
  margin: 0;
  list-style: none;
}

.hero-tags li {
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.hero-card-inner {
  position: relative;
  aspect-ratio: 1;
  border-radius: 24px;
  background: linear-gradient(145deg, var(--bg-card), var(--bg-elevated));
  border: 1px solid var(--border);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
}

.mock-screen {
  position: absolute;
  inset: 12%;
  border-radius: 12px;
  background: linear-gradient(180deg, #0d2a3a 0%, #0a1620 100%);
  border: 1px solid rgba(1, 164, 239, 0.25);
}

.mock-screen::after {
  content: "";
  position: absolute;
  inset: 18%;
  border-radius: 8px;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 4px,
    rgba(1, 164, 239, 0.12) 4px,
    rgba(1, 164, 239, 0.12) 5px
  );
}

.mock-glow {
  position: absolute;
  inset: -20%;
  background: radial-gradient(circle, rgba(1, 164, 239, 0.15), transparent 65%);
  z-index: -1;
}

/* ========== 通用区块 ========== */
.section {
  padding: clamp(3rem, 6vw, 5rem) 0;
}

.section-head {
  text-align: center;
  max-width: 560px;
  margin: 0 auto 2.75rem;
}

.section-head-tight {
  margin-bottom: 1.75rem;
}

.section-head h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.6rem, 3vw, 2rem);
  font-weight: 700;
}

.section-desc {
  margin: 0;
  color: var(--text-muted);
  font-size: 1.02rem;
}

.section-intro {
  background: var(--bg-card);
  border-block: 1px solid var(--border);
}

.intro-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 768px) {
  .intro-grid {
    grid-template-columns: 1fr;
  }
}

.card-intro {
  padding: 1.5rem 1.35rem;
  background: var(--bg-elevated);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.card-intro h3 {
  margin: 0 0 0.65rem;
  font-size: 1.05rem;
  color: var(--accent);
}

.card-intro p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ========== 功能网格 ========== */
.section-features {
  background: var(--bg-deep);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1rem;
}

.feature-item {
  padding: 1.35rem 1.1rem;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: border-color 0.2s, transform 0.2s;
}

.feature-item:hover {
  border-color: rgba(1, 164, 239, 0.35);
  transform: translateY(-2px);
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-bottom: 0.75rem;
  border-radius: 10px;
  background: rgba(1, 164, 239, 0.15);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.95rem;
}

.feature-item h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.feature-item p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ========== 下载区 ========== */
.section-download {
  background: linear-gradient(180deg, var(--bg-card) 0%, var(--bg-deep) 100%);
  border-top: 1px solid var(--border);
}

.download-layout {
  max-width: 720px;
}

.download-panel {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  padding: 2rem;
  background: var(--bg-elevated);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

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

.qr-img {
  display: block;
  width: 200px;
  height: 200px;
  margin: 0 auto;
  border-radius: var(--radius-sm);
  background: #fff;
  padding: 8px;
  object-fit: contain;
}

.qr-caption {
  margin: 0.85rem 0 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.download-actions {
  flex: 1;
  min-width: 220px;
  max-width: 320px;
}

.download-hint {
  margin: 1rem 0 0;
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.download-meta {
  margin: 1rem 0 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

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

/* ========== 使用步骤 ========== */
.section-guide {
  border-top: 1px solid var(--border);
}

.steps {
  margin: 0;
  padding: 0;
  list-style: none;
  max-width: 720px;
  margin-inline: auto;
}

.steps li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
}

.steps li:last-child {
  border-bottom: none;
}

.step-num {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: rgba(1, 164, 239, 0.2);
  color: var(--accent);
  font-weight: 800;
  font-size: 1.1rem;
}

.step-body h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.step-body p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ========== FAQ ========== */
.section-faq {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
}

.faq-list {
  max-width: 720px;
  margin-inline: auto;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 0.65rem;
  overflow: hidden;
  background: var(--bg-elevated);
}

.faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem 1.15rem;
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.2s;
}

.faq-trigger:hover {
  background: rgba(255, 255, 255, 0.04);
}

.faq-icon {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  position: relative;
}

.faq-icon::before,
.faq-icon::after {
  content: "";
  position: absolute;
  background: var(--accent);
  border-radius: 1px;
  transition: transform 0.25s ease;
}

.faq-icon::before {
  width: 12px;
  height: 2px;
  top: 10px;
  left: 5px;
}

.faq-icon::after {
  width: 2px;
  height: 12px;
  top: 5px;
  left: 10px;
}

.faq-item.is-open .faq-icon::after {
  transform: scaleY(0);
}

.faq-panel {
  padding: 0 1.15rem 1.1rem;
}

.faq-panel p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.93rem;
  line-height: 1.65;
}

.faq-item.is-open .faq-trigger {
  background: rgba(1, 164, 239, 0.06);
}

/* ========== 页脚 ========== */
.site-footer {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  margin-bottom: 1rem;
}

.footer-brand strong {
  font-size: 1.1rem;
}

.footer-brand span {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-copy,
.footer-note {
  margin: 0.35rem 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.mock-screen-img {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  height: 130%;          /* 基于父容器高度限定，宽度自动等比缩放 */
  width: auto;
  max-width: 92%;       /* 避免极端比例下超出边界 */
  border-radius: 12px;
  object-fit: contain;  /* 保证完整显示且不变形 */
  border: 1px solid rgba(1, 164, 239, 0.25);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.3);
}