/* ========================================
   夸克浏览器下载页 - 深色科技主题
   ======================================== */

/* --- Tokens --- */
:root {
  --bg-primary: #141416;
  --bg-secondary: #1C1C1F;
  --bg-surface: #2A2A2E;
  --color-warm-white: #E8DCC8;
  --color-warm-gray: #A89B8C;
  --color-body: #9A9A9D;
  --color-amber: #F5A623;
  --color-divider: #2E2E32;
  --font-stack: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --radius: 12px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-stack);
  background: var(--bg-primary);
  color: var(--color-body);
  line-height: 1.6;
  overflow-x: hidden;
}

/* --- 隐藏视频控件 --- */
video::-webkit-media-controls,
video::-webkit-media-controls-panel,
video::-webkit-media-controls-play-button,
video::-webkit-media-controls-start-playback-button,
video::-webkit-media-controls-overlay-play-button {
  display: none !important;
  -webkit-appearance: none;
}

video::-moz-range-track { background: transparent; }
video::cue { background: transparent; }

/* --- 淡入动画 --- */
.fade-in {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  border: none;
  cursor: pointer;
  font-family: var(--font-stack);
  font-weight: 600;
  border-radius: 50px;
  transition: transform 0.25s var(--ease-out), box-shadow 0.25s var(--ease-out), background 0.25s;
  text-decoration: none;
  user-select: none;
}

.btn--primary {
  background: var(--color-amber);
  color: #141416;
  padding: 14px 36px;
  font-size: 16px;
}

.btn--primary:hover {
  background: #FFB840;
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(245, 166, 35, 0.3);
}

.btn--primary:active {
  transform: translateY(0);
}

.btn--large {
  padding: 18px 48px;
  font-size: 18px;
}

.btn__icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.btn--large .btn__icon {
  width: 22px;
  height: 22px;
}

/* ========================================
   S1 - Hero
   ======================================== */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero__video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(20, 20, 22, 0.5) 0%,
    rgba(20, 20, 22, 0.7) 60%,
    rgba(20, 20, 22, 0.95) 100%
  );
}

.hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0 24px;
  animation: heroFadeIn 1.2s var(--ease-out) both;
}

@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero__logo {
  width: 160px;
  margin-bottom: 32px;
  filter: brightness(0) invert(1);
}

.hero__title {
  font-size: clamp(48px, 8vw, 80px);
  font-weight: 700;
  color: var(--color-warm-white);
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero__subtitle {
  font-size: clamp(16px, 2.5vw, 20px);
  color: var(--color-warm-gray);
  max-width: 500px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.hero__scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-warm-gray);
  font-size: 13px;
  opacity: 0.6;
  animation: scrollBounce 2s infinite;
}

.hero__scroll-hint svg {
  width: 20px;
  height: 20px;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ========================================
   S2 - 核心卖点
   ======================================== */
.highlights {
  padding: 120px 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.highlights__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

.highlight-card {
  text-align: center;
  padding: 48px 24px;
}

.highlight-card__keyword {
  font-size: clamp(36px, 4vw, 48px);
  font-weight: 700;
  color: var(--color-warm-white);
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  line-height: 1.2;
}

.highlight-card__desc {
  font-size: 15px;
  color: var(--color-body);
  line-height: 1.7;
  max-width: 280px;
  margin: 0 auto;
}

/* ========================================
   S3 - 功能演示
   ======================================== */
.features {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px 120px;
}

.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  padding: 80px 0;
  border-top: 1px solid var(--color-divider);
}

.feature-block:last-child {
  border-bottom: 1px solid var(--color-divider);
}

/* 偶数行反转布局 */
.feature-block:nth-child(even) .feature-block__text {
  order: 2;
}

.feature-block:nth-child(even) .feature-block__media {
  order: 1;
}

.feature-block__label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-amber);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.feature-block__title {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 700;
  color: var(--color-warm-white);
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 20px;
}

.feature-block__desc {
  font-size: 16px;
  color: var(--color-body);
  line-height: 1.7;
  max-width: 420px;
}

.feature-block__media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-secondary);
  aspect-ratio: 16 / 10;
}

.feature-block__video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  pointer-events: none;
}

/* ========================================
   S4 - 产品展示（浏览器模拟框）
   ======================================== */
.showcase {
  padding: 120px 24px 140px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* 琥珀辉光背景 */
.showcase::before {
  content: '';
  position: absolute;
  top: 45%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 500px;
  background: radial-gradient(ellipse, rgba(245, 166, 35, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.showcase__title {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 700;
  color: var(--color-warm-white);
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.showcase__subtitle {
  font-size: 16px;
  color: var(--color-warm-gray);
  margin-bottom: 56px;
}

/* 浏览器窗口框架 */
.showcase__browser {
  max-width: 960px;
  margin: 0 auto;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.06);
  box-shadow:
    0 4px 16px rgba(0, 0, 0, 0.3),
    0 24px 80px rgba(0, 0, 0, 0.4);
  background: #1A1A1D;
}

/* 顶部标题栏 */
.showcase__browser-bar {
  display: flex;
  align-items: center;
  padding: 14px 18px;
  background: #222225;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.showcase__dots {
  display: flex;
  gap: 7px;
  flex-shrink: 0;
  width: 68px;
}

.showcase__dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}

.showcase__dot:nth-child(1) { background: #FF5F57; }
.showcase__dot:nth-child(2) { background: #FEBC2E; }
.showcase__dot:nth-child(3) { background: #28C840; }

.showcase__address-bar {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 20px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.05);
  color: rgba(255, 255, 255, 0.4);
  font-size: 13px;
  letter-spacing: 0.02em;
}

.showcase__lock-icon {
  opacity: 0.5;
  flex-shrink: 0;
}

.showcase__bar-spacer {
  width: 68px;
  flex-shrink: 0;
}

/* 浏览器内容区 */
.showcase__browser-body {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: #0D0D0F;
}

.showcase__video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  pointer-events: none;
}

/* ========================================
   S5 - 底部 CTA
   ======================================== */
.cta {
  padding: 120px 24px 80px;
  text-align: center;
}

.cta__title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  color: var(--color-warm-white);
  letter-spacing: -0.02em;
  margin-bottom: 40px;
}

.cta__version {
  margin-top: 20px;
  font-size: 13px;
  color: var(--color-warm-gray);
  opacity: 0.7;
}

/* ========================================
   响应式
   ======================================== */
@media (max-width: 900px) {
  .highlights__grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .highlight-card {
    padding: 32px 24px;
  }

  .feature-block {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 56px 0;
  }

  /* 移动端统一文字在上、视频在下 */
  .feature-block:nth-child(even) .feature-block__text {
    order: 1;
  }

  .feature-block:nth-child(even) .feature-block__media {
    order: 2;
  }
}

@media (max-width: 480px) {
  .hero__logo {
    width: 120px;
  }

  .btn--primary {
    padding: 12px 28px;
    font-size: 15px;
  }

  .btn--large {
    padding: 14px 36px;
    font-size: 16px;
  }
}