/* =====================================================
 * 音频降噪大师 · 官网样式
 * 设计基调:参考 miidii.tech 的极简光线主题,
 * 融入 App 品牌色「深空蓝 + 电光蓝」做点缀。
 * ===================================================== */

/* ---------- 设计变量 ---------- */
:root {
  /* 中性色 */
  --color-bg: #ffffff;
  --color-bg-soft: #f6f8fc;
  --color-bg-mute: #eef1f7;
  --color-line: #e6e9f1;

  /* 文字 */
  --color-text: #0a1224;
  --color-text-soft: #43506b;
  --color-text-mute: #7d8aa3;

  /* 品牌蓝(取自 logo / 截图渐变) */
  --color-brand: #2563ff;
  --color-brand-soft: #4d8bff;
  --color-brand-deep: #0a1f4d;
  --color-brand-glow: rgba(37, 99, 255, 0.18);

  /* 渐变 */
  --grad-hero: radial-gradient(
      120% 80% at 50% 0%,
      #e6efff 0%,
      #f7faff 45%,
      #ffffff 100%
    );
  --grad-card-dark: linear-gradient(
    160deg,
    #0d1a3a 0%,
    #0a1224 60%,
    #060a18 100%
  );
  --grad-blue: linear-gradient(135deg, #2563ff 0%, #4d8bff 100%);

  /* 间距 / 半径 */
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --radius-xl: 40px;
  --shadow-sm: 0 4px 14px rgba(10, 18, 36, 0.06);
  --shadow-md: 0 18px 60px rgba(10, 18, 36, 0.1);
  --shadow-lg: 0 40px 100px -20px rgba(10, 31, 77, 0.35);

  /* 排版 */
  --font-sans:
    "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* 容器 */
  --container: 1180px;
  --gutter: 24px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
  color: inherit;
}

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

/* ---------- 滚动渐入(IntersectionObserver 触发) ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity 0.7s cubic-bezier(0.2, 0.8, 0.2, 1),
    transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1);
  will-change: opacity, transform;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

[data-reveal][data-reveal-delay="1"].is-visible { transition-delay: 0.08s; }
[data-reveal][data-reveal-delay="2"].is-visible { transition-delay: 0.16s; }
[data-reveal][data-reveal-delay="3"].is-visible { transition-delay: 0.24s; }
[data-reveal][data-reveal-delay="4"].is-visible { transition-delay: 0.32s; }

/* 用户偏好减少动效时关闭装饰动画 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

/* 跳过到主内容(无障碍) */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-text);
  color: #fff;
  padding: 10px 16px;
  border-radius: 0 0 8px 0;
  z-index: 100;
}

.skip-link:focus {
  left: 0;
  color: #fff;
}

/* 焦点环更友好 */
:focus-visible {
  outline: 3px solid var(--color-brand-glow);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---------- 通用容器 / 工具类 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--color-brand);
}

/* ===========================================
 * 导航栏
 * =========================================== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid transparent;
  transition:
    background 0.25s ease,
    border-color 0.25s ease,
    box-shadow 0.25s ease;
}

.nav.is-scrolled {
  background: rgba(255, 255, 255, 0.92);
  border-bottom-color: var(--color-line);
  box-shadow: 0 4px 24px rgba(10, 18, 36, 0.05);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  height: 68px;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.nav-brand img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  box-shadow: 0 6px 18px rgba(10, 31, 77, 0.18);
}

.nav-brand-text {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
}

.nav-brand-zh {
  font-size: 18px;
  color: var(--color-text);
}

.nav-links {
  display: inline-flex;
  align-items: center;
  gap: 32px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-soft);
}

.nav-links a {
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -6px;
  height: 2px;
  border-radius: 2px;
  background: var(--color-brand);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s ease;
}

.nav-links a:hover::after {
  transform: scaleX(1);
}

.nav-cta {
  white-space: nowrap;
}

/* ===========================================
 * 通用按钮 / Store 徽章
 * =========================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition:
    transform 0.18s ease,
    box-shadow 0.25s ease,
    background 0.25s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--grad-blue);
  color: #fff;
  box-shadow: 0 12px 30px -10px var(--color-brand-glow);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 40px -8px rgba(37, 99, 255, 0.45);
  color: #fff;
}

.btn-ghost {
  background: rgba(10, 18, 36, 0.04);
  color: var(--color-text);
}

.btn-ghost:hover {
  background: rgba(10, 18, 36, 0.08);
  color: var(--color-text);
}

.badge-store {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 10px 22px 10px 18px;
  border-radius: 14px;
  background: #0a1224;
  color: #fff;
  min-width: 188px;
  transition:
    transform 0.18s ease,
    box-shadow 0.25s ease;
  box-shadow: 0 14px 34px -16px rgba(10, 18, 36, 0.6);
}

.badge-store:hover {
  transform: translateY(-2px);
  color: #fff;
  box-shadow: 0 22px 46px -16px rgba(10, 18, 36, 0.7);
}

.badge-store span {
  display: inline-flex;
  flex-direction: column;
  line-height: 1.05;
  text-align: left;
}

.badge-store small {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  opacity: 0.8;
}

.badge-store strong {
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.01em;
  margin-top: 2px;
}

/* ===========================================
 * Hero
 * =========================================== */
.hero {
  position: relative;
  padding: 152px 0 96px;
  overflow: hidden;
  background: var(--grad-hero);
  isolation: isolate;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.55;
}

.hero-glow--a {
  width: 520px;
  height: 520px;
  top: -120px;
  left: -100px;
  background: radial-gradient(circle, #c6dbff 0%, transparent 70%);
}

.hero-glow--b {
  width: 460px;
  height: 460px;
  top: 60px;
  right: -120px;
  background: radial-gradient(circle, #d8e4ff 0%, transparent 70%);
}

.hero-wave {
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: min(1200px, 100%);
  height: 240px;
  color: var(--color-brand);
  opacity: 0.18;
}

.hero-wave rect {
  transform-origin: center;
  animation: waveFlex 2.4s ease-in-out infinite;
}

.hero-wave rect:nth-child(odd) {
  animation-delay: -0.4s;
}

.hero-wave rect:nth-child(3n) {
  animation-delay: -0.8s;
}

.hero-wave rect:nth-child(4n) {
  animation-delay: -1.2s;
}

@keyframes waveFlex {
  0%, 100% { transform: scaleY(1); }
  50%       { transform: scaleY(0.45); }
}

.hero-inner {
  position: relative;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero-eyebrow {
  margin-bottom: 22px;
}

.hero-title {
  font-size: clamp(40px, 6.4vw, 76px);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.hero-title-grad {
  background: linear-gradient(120deg, #2563ff 0%, #6aa1ff 50%, #2563ff 100%);
  background-size: 200% 100%;
  -webkit-background-clip: text;
          background-clip: text;
  color: transparent;
  animation: gradShift 6s ease-in-out infinite;
}

@keyframes gradShift {
  0%, 100% { background-position: 0% 50%; }
  50%      { background-position: 100% 50%; }
}

.hero-sub {
  margin-top: 24px;
  max-width: 720px;
  font-size: clamp(16px, 1.4vw, 19px);
  color: var(--color-text-soft);
  line-height: 1.75;
}

.hero-actions {
  margin-top: 40px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}

.hero-trust {
  margin: 56px 0 0;
  padding: 0;
  list-style: none;
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px 56px;
}

.hero-trust li {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.hero-trust strong {
  font-size: 28px;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.hero-trust span {
  font-size: 13px;
  color: var(--color-text-mute);
  letter-spacing: 0.04em;
}

/* ===========================================
 * 响应式 — 手机
 * =========================================== */
.only-md {
  display: inline;
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
  }
  .nav-inner {
    height: 60px;
  }
  .hero {
    padding: 120px 0 72px;
  }
  .only-md {
    display: none;
  }
  .badge-store {
    min-width: 168px;
  }
  .hero-trust {
    gap: 12px 36px;
  }
  .hero-trust strong {
    font-size: 24px;
  }
}

@media (max-width: 480px) {
  .nav-cta {
    padding: 10px 16px;
    font-size: 14px;
  }
}

/* ===========================================
 * Section 通用标题
 * =========================================== */
.section-title {
  margin-top: 16px;
  font-size: clamp(30px, 4.4vw, 52px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.section-sub {
  margin-top: 18px;
  font-size: clamp(15px, 1.2vw, 18px);
  color: var(--color-text-soft);
  line-height: 1.7;
  max-width: 640px;
}

/* ===========================================
 * Features
 * =========================================== */
.features {
  position: relative;
  padding: 120px 0 40px;
}

.features-head {
  max-width: 720px;
  text-align: center;
  margin: 0 auto 80px;
}

.features-head .section-sub {
  margin-left: auto;
  margin-right: auto;
}

.features-list {
  display: flex;
  flex-direction: column;
  gap: 96px;
}

.feature-card {
  display: grid;
  grid-template-columns: minmax(280px, 1fr) minmax(0, 1.05fr);
  align-items: center;
  gap: 80px;
}

.feature-card.is-reverse .feature-media {
  order: 2;
}

.feature-media {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 28px;
}

.feature-media-glow {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: radial-gradient(
    60% 60% at 50% 50%,
    rgba(37, 99, 255, 0.18) 0%,
    transparent 70%
  );
  filter: blur(12px);
}

.feature-media img {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 360px;
  border-radius: var(--radius-lg);
  box-shadow:
    0 30px 60px -20px rgba(10, 31, 77, 0.35),
    0 12px 28px -10px rgba(10, 31, 77, 0.25);
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.feature-card:hover .feature-media img {
  transform: translateY(-6px) scale(1.01);
}

.feature-body .eyebrow {
  margin-bottom: 18px;
}

.feature-title {
  font-size: clamp(28px, 3.4vw, 44px);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.feature-desc {
  margin-top: 22px;
  font-size: clamp(15px, 1.15vw, 17px);
  line-height: 1.8;
  color: var(--color-text-soft);
  max-width: 540px;
}

.feature-list {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 12px;
}

.feature-list li {
  display: inline-flex;
  align-items: center;
  height: 36px;
  padding: 0 16px;
  border-radius: 999px;
  background: var(--color-bg-soft);
  border: 1px solid var(--color-line);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  transition:
    transform 0.2s ease,
    border-color 0.2s ease,
    color 0.2s ease;
}

.feature-list li:hover {
  border-color: var(--color-brand);
  color: var(--color-brand);
  transform: translateY(-1px);
}

.feature-list li span {
  display: inline-block;
}

.feature-list--chip li {
  background: linear-gradient(180deg, #ffffff 0%, #f3f6fc 100%);
}

.feature-link {
  margin-top: 28px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-brand);
}

.feature-link svg {
  transition: transform 0.2s ease;
}

.feature-link:hover svg {
  transform: translateX(3px);
}

/* Features 响应式 */
@media (max-width: 980px) {
  .features {
    padding: 80px 0 24px;
  }
  .features-head {
    margin-bottom: 56px;
  }
  .features-list {
    gap: 72px;
  }
  .feature-card,
  .feature-card.is-reverse {
    grid-template-columns: 1fr;
    gap: 32px;
    text-align: center;
  }
  .feature-card.is-reverse .feature-media {
    order: 0;
  }
  .feature-body {
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  .feature-list {
    justify-content: center;
  }
  .feature-desc {
    margin-left: auto;
    margin-right: auto;
  }
}

/* ===========================================
 * Formats
 * =========================================== */
.formats {
  position: relative;
  padding: 120px 0 100px;
  background:
    linear-gradient(180deg, #ffffff 0%, var(--color-bg-soft) 100%);
}

.formats-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}

.formats-head .section-sub {
  margin-left: auto;
  margin-right: auto;
}

.formats-groups {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 32px;
}

.formats-group {
  background: #fff;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 36px 36px 32px;
  box-shadow: var(--shadow-sm);
}

.formats-group-title {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-text);
  margin-bottom: 22px;
}

.formats-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.formats-dot--audio {
  background: var(--color-brand);
  box-shadow: 0 0 0 4px rgba(37, 99, 255, 0.16);
}

.formats-dot--video {
  background: #14c6a3;
  box-shadow: 0 0 0 4px rgba(20, 198, 163, 0.16);
}

.formats-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(78px, 1fr));
  gap: 10px;
}

.formats-grid li {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 44px;
  border-radius: 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-text);
  background: linear-gradient(180deg, #ffffff 0%, #f3f6fc 100%);
  border: 1px solid var(--color-line);
  transition:
    transform 0.18s ease,
    background 0.25s ease,
    color 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.25s ease;
}

.formats-grid li:hover {
  background: var(--grad-blue);
  border-color: transparent;
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 12px 24px -10px rgba(37, 99, 255, 0.45);
}

.formats-note {
  margin: 40px auto 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 14px;
  color: var(--color-text-mute);
  text-align: center;
}

.formats-note svg {
  flex-shrink: 0;
  color: var(--color-brand);
}

@media (max-width: 860px) {
  .formats {
    padding: 80px 0 72px;
  }
  .formats-groups {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .formats-group {
    padding: 28px 22px;
  }
  .formats-grid {
    grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
  }
}

/* ===========================================
 * Download CTA
 * =========================================== */
.cta {
  position: relative;
  padding: 96px 0;
  isolation: isolate;
}

.cta-inner {
  position: relative;
  background: var(--grad-card-dark);
  border-radius: var(--radius-xl);
  padding: 88px 24px 96px;
  text-align: center;
  overflow: hidden;
  color: #fff;
  box-shadow: var(--shadow-lg);
}

.cta-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  z-index: 0;
}

.cta-orb--a {
  width: 460px;
  height: 460px;
  top: -150px;
  left: -120px;
  background: radial-gradient(circle, rgba(37, 99, 255, 0.55) 0%, transparent 70%);
}

.cta-orb--b {
  width: 380px;
  height: 380px;
  bottom: -160px;
  right: -100px;
  background: radial-gradient(circle, rgba(106, 161, 255, 0.45) 0%, transparent 70%);
}

.cta-eyebrow {
  position: relative;
  z-index: 1;
  color: var(--color-brand-soft);
}

.cta-title {
  position: relative;
  z-index: 1;
  margin-top: 18px;
  font-size: clamp(30px, 4.4vw, 52px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.cta-sub {
  position: relative;
  z-index: 1;
  margin-top: 18px;
  color: rgba(255, 255, 255, 0.72);
  font-size: clamp(14px, 1.1vw, 16px);
}

.cta-actions {
  position: relative;
  z-index: 1;
  margin-top: 40px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}

.badge-store--light {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.badge-store--light:hover {
  background: rgba(255, 255, 255, 0.16);
}

@media (max-width: 720px) {
  .cta {
    padding: 64px 0;
  }
  .cta-inner {
    padding: 60px 20px 64px;
    border-radius: var(--radius-lg);
  }
}

/* ===========================================
 * Footer
 * =========================================== */
.footer {
  background: #0a1224;
  color: rgba(255, 255, 255, 0.72);
  padding-top: 80px;
}

.footer .nav-brand-zh {
  color: #fff;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 2fr;
  gap: 80px;
  padding-bottom: 64px;
}

.footer-tagline {
  margin-top: 20px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.6);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 18px;
}

.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.78);
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 22px 0;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.45);
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-meta {
  letter-spacing: 0.04em;
}

@media (max-width: 860px) {
  .footer {
    padding-top: 56px;
  }
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 48px;
    padding-bottom: 48px;
  }
  .footer-cols {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }
}

@media (max-width: 480px) {
  .footer-cols {
    grid-template-columns: 1fr 1fr;
    row-gap: 32px;
  }
}