/* =============================================================================
   Qciot Design System 2.0 - Apple Inspired
   ============================================================================= */

/* 颜色系统 */
:root {
  /* 主色调 - 极具科技感的翡翠绿 */
  --primary-green: #00d084;
  --primary-green-dark: #00a368;
  --primary-green-light: #7ff0c1;
  
  /* 辅助色 - 深邃的午夜青 */
  --primary-teal: #054a49;
  
  /* 强调色 - 活力珊瑚橙 */
  --accent-orange: #ff6b35;
  --accent-orange-light: #ff9d7d;

  /* 中性色 - 极简灰阶 */
  --neutral-black: #0a0a0b;
  --neutral-gray-dark: #3c3c43;
  --neutral-gray: #86868b;
  --neutral-gray-light: #eaeaec;
  --neutral-bg: #f5f5f7;
  --neutral-white: #ffffff;

  /* 阴影 Elevation 系统 */
  --elevation-low: 0 2px 8px rgba(0, 0, 0, 0.04);
  --elevation-mid: 0 12px 24px rgba(0, 0, 0, 0.08);
  --elevation-high: 0 24px 48px rgba(0, 0, 0, 0.12);
  
  /* 功能色 */
  --error: #ff3b30;
  --success: #34c759;
  --warning: #ff9500;
}

/* 字体系统 */
:root {
  --font-display: "Inter", -apple-system, BlinkMacSystemFont, "SF Pro Display", sans-serif;
  --font-text: "Inter", -apple-system, BlinkMacSystemFont, "SF Pro Text", sans-serif;

  /* 字体大小层级 - 响应式基准 */
  --text-hero: clamp(48px, 8vw, 84px);
  --text-h1: clamp(40px, 6vw, 64px);
  --text-h2: clamp(32px, 5vw, 48px);
  --text-h3: clamp(28px, 4vw, 36px);
  --text-h4: 28px;
  --text-h5: 22px;
  --text-body-large: 20px;
  --text-body: 17px;
  --text-small: 14px;
  --text-tiny: 12px;

  /* 字重 */
  --weight-black: 900;
  --weight-bold: 700;
  --weight-semibold: 600;
  --weight-medium: 500;
  --weight-regular: 400;
  --weight-light: 300;

  /* 行高与字间距 */
  --line-height-tight: 1.1;
  --line-height-snug: 1.25;
  --line-height-normal: 1.6;
  --letter-spacing-tight: -0.02em;
  --letter-spacing-heading: -0.015em;
}

/* 间距与圆角 */
:root {
  --spacing-1: 4px; --spacing-2: 8px; --spacing-3: 12px;
  --spacing-4: 16px; --spacing-5: 20px; --spacing-6: 24px;
  --spacing-8: 32px; --spacing-10: 40px; --spacing-12: 48px;
  --spacing-16: 64px; --spacing-20: 80px; --spacing-24: 96px;
  --spacing-32: 128px;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-2xl: 36px;
  --radius-full: 9999px;
}

/* 动画时长与缓动 */
:root {
  --duration-fast: 0.2s;
  --duration-normal: 0.3s;
  --duration-slow: 0.5s;
  --ease-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
}

/* 导航栏专用变量 */
:root {
  --nav-height: 44px;
  --nav-bg: rgba(255, 255, 255, 0.82);
  --nav-backdrop-filter: saturate(180%) blur(20px);
  --nav-text-color: rgba(0, 0, 0, 0.8);
  --nav-text-hover: #000;
  --nav-link-size: 14px;
}

/* =============================================================================
   基础重置与全局样式
   ============================================================================= */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-text);
  font-size: var(--text-body);
  line-height: var(--line-height-normal);
  color: var(--neutral-black);
  background-color: var(--neutral-white);
  overflow-x: hidden;
}

/* 标题样式 */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  line-height: var(--line-height-tight);
  color: var(--neutral-black);
  letter-spacing: var(--letter-spacing-heading);
}

/* 链接样式 */
a {
  color: var(--primary-green);
  text-decoration: none;
  transition: all var(--duration-normal) var(--ease-expo);
}

a:hover {
  color: var(--primary-green-dark);
}

/* Apple-Style Navigation Elements */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  padding: 0;
  display: flex;
  align-items: center;
  transition: all var(--duration-normal) var(--ease-expo);
  background: transparent;
}

.nav.scrolled {
  background: var(--nav-bg);
  backdrop-filter: var(--nav-backdrop-filter);
  -webkit-backdrop-filter: var(--nav-backdrop-filter);
  box-shadow: var(--elevation-low);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 1024px;
  margin: 0 auto;
  padding: 0 22px;
}

.nav-logo img {
  display: block;
  transition: opacity var(--duration-normal);
}

.nav-links-wrapper {
  flex: 1;
  display: flex;
  justify-content: center;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 8px; /* Standard Apple gap */
}

.nav-link {
  font-size: var(--nav-link-size);
  color: var(--neutral-white);
  padding: 0 16px;
  font-weight: var(--weight-medium);
  transition: opacity var(--duration-normal);
  text-decoration: none;
}

.nav.scrolled .nav-link {
  color: var(--nav-text-color);
}

.nav-link:hover {
  opacity: 0.7;
  color: inherit !important;
}

.nav.scrolled .nav-link:hover {
  color: var(--nav-text-hover) !important;
}

.nav-link.active {
  color: var(--primary-green) !important;
  font-weight: var(--weight-semibold);
  opacity: 1;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
}

.nav-lang {
  font-size: 12px;
  color: var(--neutral-white);
  padding: 4px 12px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 12px;
  transition: all var(--duration-normal);
}

.nav.scrolled .nav-lang {
  color: var(--nav-text-color);
  border-color: rgba(0, 0, 0, 0.2);
}

.nav-lang:hover {
  background: var(--primary-green);
  color: var(--neutral-white) !important;
  border-color: var(--primary-green);
}

/* Mobile Menu Toggle */
/* Mobile Menu Toggle - Optimized for Touch */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  position: relative;
  width: 48px; /* Larger touch target */
  height: 48px;
  z-index: 3000;
  -webkit-tap-highlight-color: transparent;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px; /* Thicker lines for visibility */
  background: var(--neutral-white);
  position: absolute;
  left: 13px;
  transition: all 0.3s var(--ease-expo);
  border-radius: 2px;
}

.nav.scrolled .menu-toggle span {
  background: var(--nav-text-color);
}

.menu-toggle span:first-child { top: 18px; }
.menu-toggle span:last-child { bottom: 18px; }

/* Menu Open State */
.menu-toggle.open span {
  background: var(--neutral-black); /* Ensure visibility on white overlay */
}

.menu-toggle.open span:first-child {
  top: 23px;
  transform: rotate(45deg);
}

.menu-toggle.open span:last-child {
  bottom: 23px;
  transform: rotate(-45deg);
}

.mobile-menu-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--neutral-white);
  z-index: 2000;
  display: none;
  padding: 80px 40px;
  flex-direction: column;
  overflow-y: auto;
}

.mobile-menu-overlay.open {
  display: flex;
}

.mobile-link {
  font-size: 28px;
  font-weight: var(--weight-semibold);
  color: var(--neutral-black);
  margin-bottom: 24px;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.5s var(--ease-expo);
  text-decoration: none;
}

.mobile-menu-overlay.open .mobile-link {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1024px) {
  .nav-links-wrapper { display: none; }
  .menu-toggle { display: block; }
  .nav-container { max-width: 100%; }
}

/* 按钮基础 */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 36px;
  font-size: var(--text-body);
  font-weight: var(--weight-semibold);
  color: var(--neutral-white);
  background: var(--primary-green);
  border-radius: var(--radius-full);
  transition: all var(--duration-normal) var(--ease-expo);
  box-shadow: 0 8px 16px rgba(0, 208, 132, 0.2);
  border: 1px solid transparent;
}

.btn-primary:hover {
  background: var(--primary-green-dark);
  color: var(--neutral-white);
  transform: translateY(-3px);
  box-shadow: 0 12px 24px rgba(0, 208, 132, 0.3);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 36px;
  font-size: var(--text-body);
  font-weight: var(--weight-semibold);
  color: var(--neutral-black);
  background: var(--neutral-white);
  border-radius: var(--radius-full);
  transition: all var(--duration-normal) var(--ease-expo);
  border: 1px solid var(--neutral-gray-light);
  box-shadow: var(--elevation-low);
}

.btn-secondary:hover {
  background: var(--neutral-bg);
  transform: translateY(-2px);
  box-shadow: var(--elevation-mid);
}

/* 卡片 */
.card {
  background: var(--neutral-white);
  border-radius: var(--radius-xl);
  padding: var(--spacing-10);
  box-shadow: var(--elevation-low);
  transition: all var(--duration-normal) var(--ease-expo);
  border: 1px solid rgba(0,0,0,0.03);
}

.card:hover {
  box-shadow: var(--elevation-high);
  transform: translateY(-10px);
  border-color: rgba(0, 208, 132, 0.1);
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

/* Section */
.section {
  padding: var(--spacing-24) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-16);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.section-title {
  font-size: var(--text-h2);
  margin-bottom: var(--spacing-4);
}

.section-subtitle {
  font-size: var(--text-body-large);
  color: var(--neutral-gray);
  line-height: var(--line-height-normal);
}

/* Footer CTA */
.footer-cta {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--spacing-6) 0;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid rgba(0, 0, 0, 0.04);
  z-index: 999;
  transform: translateY(100%);
  transition: transform var(--duration-slow) var(--ease-expo);
}

.footer-cta.visible {
  transform: translateY(0);
}

.cta-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

@media (max-width: 768px) {
  .cta-content {
    flex-direction: column;
    gap: var(--spacing-4);
    text-align: center;
  }
}

/* 工具类 */
.glass-panel {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: var(--elevation-mid);
}

/* =============================================================================
   工具类
   ============================================================================= */

.gradient-text {
  background: linear-gradient(
    135deg,
    var(--primary-green),
    var(--primary-green-light)
  );
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.glass-effect {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

/* 动画类 */
.fade-in {
  animation: fadeIn var(--duration-slow) var(--ease-out);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 优化滚动性能 */
.will-animate {
  will-change: transform, opacity;
}

/* Animation Utility Classes for JS Observer */
.opacity-0 {
  opacity: 0;
}

.opacity-100 {
  opacity: 1;
}

.translate-y-10 {
  transform: translateY(40px);
}

.translate-y-0 {
  transform: translateY(0);
}

.transition-all {
  transition-property: all;
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

.duration-1000 {
  transition-duration: 1000ms;
}

.duration-700 {
  transition-duration: 700ms;
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* =============================================================================
   Global Mobile Optimization Overrides
   ============================================================================= */
@media (max-width: 768px) {
  :root {
    /* Reduce Spacing */
    --spacing-32: 64px;
    --spacing-24: 48px;
    --spacing-20: 40px;
    --spacing-16: 32px;
    --spacing-12: 24px;
    
    /* Responsive Typography */
    --text-hero: 40px;
    --text-h1: 32px;
    --text-h2: 26px;
    --text-h3: 22px;
    --text-body-large: 18px;
  }

  /* Adjust Container Padding */
  .container {
    padding: 0 16px;
  }
}