/* Antigravity IDE 主题 - 白底、黑/蓝/橙点缀、现代无衬线 */

:root {
  --color-bg: #fff;
  --color-text: #1a1a1a;
  --color-primary: #1a73e8;
  --color-accent: #ea4335;
  --color-orange: #f29900;
  --color-border: #dadce0;
  --font-sans: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
}

/* 顶部导航 */
.header {
  border-bottom: 1px solid var(--color-border);
  padding: 0.75rem 1.5rem;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 600;
  font-size: 1.125rem;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  background: var(--color-primary);
  color: #fff;
  border-radius: 6px;
  font-weight: 700;
}

.nav {
  display: flex;
  gap: 1.5rem;
}

.nav a {
  color: var(--color-text);
  text-decoration: none;
  font-size: 0.9375rem;
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.icon-btn {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.35rem;
  font-size: 1rem;
  color: var(--color-text);
}

.btn-login {
  padding: 0.5rem 1rem;
  background: var(--color-text);
  color: #fff;
  text-decoration: none;
  border-radius: 6px;
  font-size: 0.9375rem;
  font-weight: 500;
}

.btn-login:hover {
  background: #333;
}

/* 公测横幅 */
.banner {
  background: #e8f0fe;
  padding: 0.5rem 1.5rem;
}

.banner-link {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: var(--color-primary);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
}

.banner-icon {
  font-size: 1rem;
}

.banner-arrow {
  margin-left: 0.25rem;
}

/* 主宣传区 */
.hero {
  max-width: 800px;
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
  text-align: center;
}

.hero-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}

.underline-orange {
  position: relative;
  display: inline-block;
}

.underline-orange::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 2px;
  height: 4px;
  background: var(--color-orange);
  border-radius: 2px;
}

.hero-desc {
  font-size: 1rem;
  color: #5f6368;
  margin: 0 0 2rem;
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--color-text);
  color: #fff;
}

.btn-primary:hover {
  background: #333;
}

.btn-outline {
  background: #fff;
  color: var(--color-text);
  border-color: var(--color-text);
}

.btn-outline:hover {
  background: #f5f5f5;
}

.btn-icon {
  font-size: 1rem;
}

.hero-tagline {
  font-size: 0.875rem;
  color: #5f6368;
  margin: 0;
}

.star {
  color: var(--color-orange);
}

/* 嵌入式视频区域 */
.video-section {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.video-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.video-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0;
}

.video-title-icon {
  font-size: 1.25rem;
}

.video-actions {
  display: flex;
  gap: 0.5rem;
}

.video-btn {
  padding: 0.4rem 0.75rem;
  background: #f1f3f4;
  border: none;
  border-radius: 6px;
  font-size: 0.875rem;
  cursor: pointer;
  color: var(--color-text);
}

.video-btn:hover {
  background: #e8eaed;
}

.video-wrapper {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  background: #000;
  border-radius: 8px;
}

.video-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.video-footer {
  margin-top: 0.5rem;
  font-size: 0.8125rem;
  color: #5f6368;
}

/* 为什么选择 Antigravity IDE */
.why-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
  background: var(--color-bg);
}

.why-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--color-text);
}

.why-subtitle {
  font-size: 1rem;
  color: #5f6368;
  margin: 0 0 2.5rem;
  line-height: 1.5;
}

.why-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: start;
}

.why-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.why-item {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
}

.why-item[open] .why-item-head::after {
  transform: rotate(180deg);
}

.why-item-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
}

.why-item-head::-webkit-details-marker {
  display: none;
}

.why-item-head::after {
  content: "▼";
  margin-left: auto;
  font-size: 0.75rem;
  color: #5f6368;
  transition: transform 0.2s;
}

.why-item-icon {
  font-size: 1.25rem;
}

.why-item-desc {
  margin: 0;
  padding: 0 1.25rem 1.25rem 3.25rem;
  font-size: 0.9375rem;
  color: #5f6368;
  line-height: 1.6;
}

.why-preview {
  position: sticky;
  top: 1rem;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: #f8f9fa;
}

.why-preview-img {
  display: block;
  width: 100%;
  height: auto;
  vertical-align: top;
}

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

  .why-preview {
    position: static;
  }
}

/* 如何开始使用 */
.steps-section {
  max-width: 1000px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
  text-align: center;
}

.steps-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--color-text);
}

.steps-subtitle {
  font-size: 1rem;
  color: var(--color-text);
  margin: 0 0 2.5rem;
  font-weight: 400;
}

.steps-inner {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 0;
  flex-wrap: wrap;
}

.step-card {
  flex: 1;
  min-width: 140px;
  max-width: 220px;
  padding: 1.5rem 1rem;
  text-align: center;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  margin-bottom: 1rem;
  background: #e8eaed;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.125rem;
  border-radius: 50%;
}

.step-title {
  font-size: 1.0625rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--color-text);
}

.step-desc {
  font-size: 0.9375rem;
  color: #5f6368;
  margin: 0;
  line-height: 1.5;
}

.step-arrow {
  display: flex;
  align-items: center;
  padding: 0 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: #dadce0;
  align-self: center;
}

@media (max-width: 700px) {
  .steps-inner {
    flex-direction: column;
    align-items: center;
  }

  .step-arrow {
    transform: rotate(90deg);
    padding: 0.5rem 0;
  }

  .step-card {
    max-width: 100%;
  }
}

/* Antigravity IDE 统计 */
.stats-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
  background: var(--color-bg);
  text-align: center;
}

.stats-title {
  font-size: clamp(1.75rem, 3.5vw, 2.25rem);
  font-weight: 800;
  margin: 0 0 0.5rem;
  color: var(--color-text);
}

.stats-subtitle {
  font-size: 1rem;
  color: #5f6368;
  margin: 0 0 2.5rem;
  line-height: 1.5;
}

.stats-inner {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  align-items: start;
}

.stats-col {
  padding: 0 1rem;
}

.stats-item {
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--color-text);
  margin: 0;
  line-height: 1.5;
}

@media (max-width: 600px) {
  .stats-inner {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

/* 常见问题 */
.faq-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
  background: var(--color-bg);
}

.faq-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--color-text);
  text-align: center;
}

.faq-subtitle {
  font-size: 1rem;
  color: #5f6368;
  margin: 0 0 2rem;
  text-align: center;
  line-height: 1.5;
}

.faq-list {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  overflow: visible;
  background: var(--color-bg);
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
  position: relative;
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-item[open] {
  z-index: 1;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.faq-item[open] .faq-question::after {
  transform: rotate(180deg);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.25rem;
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question::after {
  content: "▼";
  flex-shrink: 0;
  font-size: 0.75rem;
  color: #5f6368;
  transition: transform 0.2s;
}

.faq-answer {
  margin: 0;
  padding: 0 1.25rem 1.25rem 3rem;
  font-size: 0.9375rem;
  color: #5f6368;
  line-height: 1.6;
}

/* 行动号召 */
.cta-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
  background: var(--color-bg);
  text-align: center;
}

.cta-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin: 0 0 0.75rem;
  color: var(--color-text);
}

.cta-desc {
  font-size: 1rem;
  color: var(--color-text);
  margin: 0 0 2rem;
  line-height: 1.5;
}

.cta-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.btn-cta-primary {
  background: var(--color-text);
  color: #fff;
  border-color: transparent;
}

.btn-cta-primary:hover {
  background: #333;
}

.btn-cta-outline {
  background: #fff;
  color: var(--color-text);
  border: 1px solid var(--color-text);
}

.btn-cta-outline:hover {
  background: #f5f5f5;
}

/* 页脚 */
.footer {
  border-top: 2px dashed var(--color-border);
  padding: 1.25rem 1.5rem;
  font-size: 0.875rem;
  color: #5f6368;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-copy {
  margin: 0;
}

.footer-icons {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.footer-icon {
  color: #5f6368;
  transition: color 0.2s;
}

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

@media (max-width: 600px) {
  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
  }

  .nav {
    order: 3;
    width: 100%;
    justify-content: flex-start;
  }
}