/* ===================================
   破甲AI · ArmorBreak AI — Styles
   =================================== */

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

:root {
  /* Brand Colors */
  --color-primary: #2945FF;
  --color-primary-dark: #1a30d9;
  --color-accent: #FF6B2C;
  --color-accent-dark: #e55a1f;
  --color-dark: #0A0E27;
  --color-white: #FFFFFF;
  --color-cloud: #F5F7FA;
  --color-silver: #8993A7;
  
  /* Typography */
  --font-display: 'Space Grotesk', 'Noto Sans SC', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-cn: 'Noto Sans SC', sans-serif;
  
  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 80px;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(10, 14, 39, 0.08);
  --shadow-md: 0 4px 16px rgba(10, 14, 39, 0.1);
  --shadow-lg: 0 8px 24px rgba(10, 14, 39, 0.12);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease-out;
  --transition-slow: 300ms ease-out;
  
  /* Layout */
  --max-width: 1200px;
  --header-height: 72px;
}

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-dark);
  background: var(--color-white);
  overflow-x: hidden;
}

/* === Accessibility === */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
}

/* === Container === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-3xl);
  }
}

/* === Header === */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 100;
  transition: box-shadow var(--transition-base);
}

.header.scrolled {
  box-shadow: var(--shadow-sm);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.header-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.logo-svg {
  height: 36px;
  width: auto;
}

.header-nav {
  display: none;
  gap: var(--space-xl);
}

@media (min-width: 768px) {
  .header-nav {
    display: flex;
  }
}

.header-nav a {
  font-family: var(--font-cn);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-dark);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* Mobile Menu Button */
.header-menu-btn {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 8px;
  background: none;
  border: none;
  cursor: pointer;
}

@media (min-width: 768px) {
  .header-menu-btn {
    display: none;
  }
}

.header-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-dark);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.header-menu-btn.active span:first-child {
  transform: translateY(8px) rotate(45deg);
}

.header-menu-btn.active span:last-child {
  transform: translateY(-8px) rotate(-45deg);
}

/* Mobile Menu */
.mobile-menu {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--color-white);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  transform: translateY(-100%);
  opacity: 0;
  pointer-events: none;
  transition: transform var(--transition-slow), opacity var(--transition-slow);
  z-index: 99;
  box-shadow: var(--shadow-md);
}

.mobile-menu.active {
  transform: translateY(0);
  opacity: 1;
  pointer-events: all;
}

.mobile-menu a {
  font-family: var(--font-cn);
  font-size: 18px;
  font-weight: 500;
  color: var(--color-dark);
  text-decoration: none;
  padding: var(--space-sm) 0;
}

/* === Hero === */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-height);
  overflow: hidden;
}

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

/* Hexagon decorations */
.hex {
  position: absolute;
  border: 1px solid rgba(41, 69, 255, 0.08);
  clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
}

.hex-1 {
  width: 400px;
  height: 400px;
  top: -100px;
  right: -100px;
  background: linear-gradient(135deg, rgba(41, 69, 255, 0.03) 0%, transparent 70%);
}

.hex-2 {
  width: 200px;
  height: 200px;
  bottom: 20%;
  left: -50px;
  background: linear-gradient(45deg, rgba(255, 107, 44, 0.04) 0%, transparent 70%);
}

.hex-3 {
  width: 150px;
  height: 150px;
  top: 30%;
  right: 15%;
  border-color: rgba(41, 69, 255, 0.05);
}

.hero-content {
  position: relative;
  text-align: center;
  padding: var(--space-3xl) 0;
}

@media (min-width: 768px) {
  .hero-content {
    padding: var(--space-4xl) 0;
  }
}

.hero-title {
  font-family: var(--font-cn);
  font-size: 40px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-dark);
  margin-bottom: var(--space-lg);
  animation: fadeInUp 0.8s ease-out;
}

@media (min-width: 768px) {
  .hero-title {
    font-size: 56px;
  }
}

@media (min-width: 1024px) {
  .hero-title {
    font-size: 64px;
  }
}

.hero-subtitle {
  font-family: var(--font-cn);
  font-size: 18px;
  line-height: 1.6;
  color: var(--color-silver);
  max-width: 480px;
  margin: 0 auto var(--space-xl);
  animation: fadeInUp 0.8s ease-out 0.1s both;
}

@media (min-width: 768px) {
  .hero-subtitle {
    font-size: 20px;
  }
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 14px 28px;
  font-family: var(--font-cn);
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn-primary:hover {
  background: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255, 107, 44, 0.3);
}

.btn-cta {
  background: var(--color-accent);
  color: var(--color-white);
  padding: 16px 32px;
  font-size: 17px;
}

.btn-cta:hover {
  background: var(--color-accent-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255, 107, 44, 0.4);
}

.btn-secondary {
  background: var(--color-cloud);
  color: var(--color-silver);
  cursor: not-allowed;
}

.btn-secondary.disabled {
  pointer-events: none;
}

.btn-hint {
  font-size: 12px;
  font-weight: 400;
  opacity: 0.8;
}

/* === Section Common === */
.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

@media (min-width: 768px) {
  .section-header {
    margin-bottom: var(--space-3xl);
  }
}

.section-title {
  font-family: var(--font-cn);
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-dark);
  margin-bottom: var(--space-md);
}

@media (min-width: 768px) {
  .section-title {
    font-size: 40px;
  }
}

.section-subtitle {
  font-family: var(--font-cn);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-silver);
  max-width: 560px;
  margin: 0 auto;
}

@media (min-width: 768px) {
  .section-subtitle {
    font-size: 18px;
  }
}

/* === Features === */
.features {
  padding: var(--space-3xl) 0;
  background: var(--color-cloud);
}

@media (min-width: 768px) {
  .features {
    padding: var(--space-4xl) 0;
  }
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.feature-card {
  background: var(--color-white);
  padding: var(--space-xl);
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  background: rgba(41, 69, 255, 0.08);
  border-radius: 12px;
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
}

.feature-card h3 {
  font-family: var(--font-cn);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: var(--space-sm);
}

.feature-card p {
  font-family: var(--font-cn);
  font-size: 15px;
  line-height: 1.6;
  color: var(--color-silver);
}

/* === Security === */
.security {
  padding: var(--space-3xl) 0;
  background: var(--color-white);
}

@media (min-width: 768px) {
  .security {
    padding: var(--space-4xl) 0;
  }
}

.security-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

@media (min-width: 768px) {
  .security-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-2xl);
  }
}

.security-item {
  text-align: center;
  padding: var(--space-lg);
}

.security-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  background: var(--color-dark);
  border-radius: 50%;
  color: var(--color-white);
  margin-bottom: var(--space-lg);
}

.security-item h4 {
  font-family: var(--font-cn);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: var(--space-sm);
}

.security-item p {
  font-family: var(--font-cn);
  font-size: 15px;
  line-height: 1.6;
  color: var(--color-silver);
}

/* === Download === */
.download {
  padding: var(--space-3xl) 0;
  background: var(--color-dark);
  text-align: center;
}

@media (min-width: 768px) {
  .download {
    padding: var(--space-4xl) 0;
  }
}

.download-content h2 {
  font-family: var(--font-cn);
  font-size: 32px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

@media (min-width: 768px) {
  .download-content h2 {
    font-size: 40px;
  }
}

.download-content > p {
  font-family: var(--font-cn);
  font-size: 16px;
  color: var(--color-silver);
  margin-bottom: var(--space-2xl);
}

.download-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .download-buttons {
    gap: var(--space-lg);
  }
}

.download-buttons .btn {
  animation: none;
  min-width: 160px;
}

/* === Footer === */
.footer {
  padding: var(--space-xl) 0;
  background: var(--color-cloud);
  border-top: 1px solid rgba(10, 14, 39, 0.05);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-lg);
  text-align: center;
}

@media (min-width: 768px) {
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.footer-logo {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-dark);
}

.footer-copyright {
  font-size: 14px;
  color: var(--color-silver);
}

.footer-links {
  display: flex;
  gap: var(--space-lg);
}

.footer-links a {
  font-size: 14px;
  color: var(--color-silver);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.footer-icp a {
  font-size: 13px;
  color: var(--color-silver);
  text-decoration: none;
}

/* === Animations === */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Scroll animations */
[data-animate] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

[data-animate].visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
[data-animate]:nth-child(2) { transition-delay: 0.1s; }
[data-animate]:nth-child(3) { transition-delay: 0.2s; }
[data-animate]:nth-child(4) { transition-delay: 0.3s; }