:root {
  --bg: #f2f0ff;
  --bg-soft: #faf9ff;
  --text: #111827;
  --muted: #718096;
  --primary: #6a63f6;
  --primary-2: #8a55ed;
  --line: #e4e7f0;
  --panel: #ffffff;
  --shadow: 0 26px 80px rgba(79, 70, 150, 0.18);
  --radius-lg: 22px;
  --radius-md: 16px;
  --container: 1280px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  background: linear-gradient(180deg, #f8f7ff 0, var(--bg) 42%, #f8f6ff 100%);
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

svg {
  display: block;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid #eef0f6;
  backdrop-filter: blur(16px);
}

.header-inner {
  width: min(var(--container), calc(100% - 48px));
  height: 80px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  width: fit-content;
}

.brand-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: #fff;
  background: linear-gradient(135deg, #6964f5, #8b57ef);
  border-radius: 15px;
  box-shadow: 0 16px 36px rgba(105, 100, 245, 0.32);
}

.brand-mark svg {
  width: 27px;
  fill: none;
  stroke: currentColor;
  stroke-linejoin: round;
  stroke-width: 2.5;
}

.brand-text {
  display: grid;
  line-height: 1.05;
}

.brand-text strong {
  font-size: 25px;
  font-weight: 850;
  letter-spacing: 0;
}

.brand-text small {
  margin-top: 6px;
  color: #697386;
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 1px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: clamp(24px, 3vw, 52px);
  font-size: 16px;
  font-weight: 750;
}

.main-nav a {
  color: #111827;
  transition: color 0.2s ease;
}

.main-nav a:hover,
.main-nav .active {
  color: var(--primary);
}

.header-actions {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 14px;
}

.user-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 0 22px;
  border-radius: 999px;
  background: #f8f9fc;
  font-weight: 800;
}

.user-link svg {
  width: 19px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.2;
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  border-radius: 12px;
  background: #f4f5fb;
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  background: #111827;
  border-radius: 99px;
}

.hero {
  min-height: calc(100vh - 80px);
  padding: 112px 0 34px;
  overflow: hidden;
}

.hero-inner {
  width: min(1100px, calc(100% - 48px));
  margin: 0 auto;
  text-align: center;
}

.eyebrow {
  width: fit-content;
  min-height: 44px;
  margin: 0 auto 42px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 0 21px;
  color: var(--primary);
  background: rgba(106, 99, 246, 0.08);
  border: 1px solid rgba(106, 99, 246, 0.2);
  border-radius: 999px;
  font-size: 16px;
  font-weight: 800;
}

.eyebrow svg {
  width: 21px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2;
}

h1 {
  margin: 0;
  color: #111827;
  font-size: clamp(48px, 7.1vw, 98px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: 0;
}

h1 span {
  color: var(--primary);
}

.hero-copy {
  margin: 36px auto 0;
  color: #718096;
  font-size: clamp(18px, 2vw, 24px);
  font-weight: 750;
  line-height: 1.55;
}

.hero-buttons {
  margin-top: 45px;
  display: flex;
  justify-content: center;
  gap: 24px;
}

.btn {
  min-width: 225px;
  height: 70px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  border-radius: 18px;
  font-size: 21px;
  font-weight: 850;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn svg {
  width: 24px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.4;
}

.btn.primary {
  color: #fff;
  background: linear-gradient(135deg, #6964f5, #8a55ed);
  box-shadow: 0 18px 40px rgba(106, 99, 246, 0.26);
}

.btn.secondary {
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: 0 10px 26px rgba(17, 24, 39, 0.06);
}

.trust {
  margin-top: 58px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  color: #718096;
  font-size: 16px;
  font-weight: 700;
}

.trust strong {
  color: #111827;
}

.avatars {
  display: flex;
  align-items: center;
}

.avatars i {
  width: 35px;
  height: 35px;
  margin-left: -5px;
  display: block;
  border: 3px solid #fff;
  border-radius: 999px;
  background: linear-gradient(135deg, #6863f4, #8a55ed);
}

.avatars i:first-child {
  margin-left: 0;
}

.demo-panel {
  margin: 115px auto 0;
  padding: 26px;
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 26px;
  text-align: left;
  background: var(--panel);
  border: 1px solid #dfe6f0;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.video-preview {
  position: relative;
  min-height: 340px;
  overflow: hidden;
  border-radius: 18px;
  background-color: #e7e3ff;
  background-image:
    linear-gradient(rgba(126, 110, 242, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(126, 110, 242, 0.07) 1px, transparent 1px),
    linear-gradient(135deg, rgba(122, 103, 247, 0.08), rgba(255, 255, 255, 0.2));
  background-size: 20px 20px, 20px 20px, 100% 100%;
}

.play-button {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100px;
  height: 100px;
  display: grid;
  place-items: center;
  padding: 0;
  color: #fff;
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 999px;
  transform: translate(-50%, -50%);
  cursor: pointer;
}

.play-button svg {
  width: 46px;
  fill: none;
  stroke: currentColor;
  stroke-linejoin: round;
  stroke-width: 1.7;
  transform: translateX(3px);
}

.video-bar {
  position: absolute;
  left: 22px;
  right: 22px;
  bottom: 22px;
  min-height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 0 24px;
  color: #fff;
  background: rgba(35, 35, 45, 0.74);
  border-radius: 12px;
  font-size: 15px;
}

.video-bar strong {
  font-size: 17px;
}

.prompt-card {
  display: grid;
  grid-template-rows: 1fr 54px 54px;
  gap: 14px;
}

.prompt-box {
  min-height: 190px;
  padding: 24px;
  background: #fbfcff;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
}

.prompt-box span {
  display: block;
  margin-bottom: 12px;
  color: #718096;
  font-size: 14px;
  font-weight: 750;
}

.prompt-box p {
  margin: 0;
  color: #111827;
  font-size: 18px;
  font-weight: 700;
}

.utility-button,
.generate-button {
  width: 100%;
  height: 54px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border-radius: 12px;
  font-size: 17px;
  font-weight: 850;
  cursor: pointer;
}

.utility-button {
  color: var(--primary);
  background: rgba(106, 99, 246, 0.07);
  border: 1px solid rgba(106, 99, 246, 0.25);
}

.generate-button {
  color: #fff;
  background: linear-gradient(135deg, #6964f5, #8a55ed);
  border: 0;
}

.utility-button svg,
.generate-button svg {
  width: 21px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.2;
}

.site-footer {
  padding: 28px 16px 34px;
  color: #7a8396;
  text-align: center;
  font-size: 14px;
  background: #f8f6ff;
}

.site-footer a:hover {
  color: var(--primary);
}

@media (max-width: 900px) {
  .header-inner {
    width: min(100% - 32px, var(--container));
    height: 72px;
    grid-template-columns: 1fr auto;
  }

  .main-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 82px;
    display: none;
    padding: 18px;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 16px;
    box-shadow: 0 22px 55px rgba(17, 24, 39, 0.12);
  }

  .main-nav.is-open {
    display: flex;
  }

  .main-nav a {
    padding: 14px;
    border-radius: 10px;
  }

  .main-nav a:hover,
  .main-nav .active {
    background: rgba(106, 99, 246, 0.08);
  }

  .user-link {
    display: none;
  }

  .menu-toggle {
    display: block;
  }

  .hero {
    padding-top: 72px;
  }

  .demo-panel {
    margin-top: 72px;
    grid-template-columns: 1fr;
  }

  .prompt-card {
    grid-template-rows: auto 54px 54px;
  }
}

@media (max-width: 640px) {
  .header-inner,
  .hero-inner {
    width: calc(100% - 28px);
  }

  .hero-inner {
    width: calc(100% - 48px);
  }

  .brand-mark {
    width: 42px;
    height: 42px;
    border-radius: 13px;
  }

  .brand-text strong {
    font-size: 21px;
  }

  .brand-text small {
    font-size: 12px;
  }

  .hero {
    padding-top: 52px;
  }

  .eyebrow {
    margin-bottom: 30px;
    font-size: 14px;
  }

  h1 {
    font-size: clamp(36px, 10.5vw, 44px);
    line-height: 1.22;
  }

  h1 span {
    display: block;
  }

  .hero-copy {
    margin-top: 26px;
    font-size: 15px;
    overflow-wrap: anywhere;
  }

  .hero-copy br {
    display: none;
  }

  .hero-buttons {
    margin-top: 34px;
    flex-direction: column;
    gap: 14px;
  }

  .btn {
    width: 100%;
    min-width: 0;
    height: 62px;
    font-size: 18px;
  }

  .trust {
    margin-top: 38px;
    flex-direction: column;
    flex-wrap: wrap;
    overflow-wrap: anywhere;
  }

  .demo-panel {
    margin-top: 58px;
    padding: 16px;
    gap: 16px;
    border-radius: 18px;
  }

  .video-preview {
    min-height: 280px;
  }

  .play-button {
    width: 82px;
    height: 82px;
  }

  .video-bar {
    left: 14px;
    right: 14px;
    bottom: 14px;
    min-height: 52px;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 2px;
    padding: 0 16px;
    font-size: 12px;
  }

  .video-bar strong {
    font-size: 14px;
  }

  .video-bar span {
    white-space: nowrap;
  }

  .prompt-box {
    min-height: 170px;
    padding: 20px;
  }
}