/* ============================================
   QianCheng Tech — Personal Website
   Inspired by antigravity.google aesthetic
   ============================================ */

/* === CSS Variables / Design Tokens === */
:root {
  /* Colors */
  --color-bg: #f8f9fa;
  --color-surface: #ffffff;
  --color-surface-variant: #f1f3f5;
  --color-on-surface: #1a1a2e;
  --color-on-surface-variant: #5f6368;
  --color-primary: #0066ff;
  --color-primary-hover: #0052cc;
  --color-gradient-start: #0066ff;
  --color-gradient-mid: #00b4d8;
  --color-gradient-end: #00d4aa;
  --color-dark: #0f1117;
  --color-dark-surface: #1a1d2e;
  --color-outline: #dadce0;
  --color-outline-variant: rgba(0, 0, 0, 0.08);

  /* Typography */
  --font-sans: 'Google Sans Flex', 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;
  --space-5xl: 128px;

  /* Layout */
  --max-width: 1200px;
  --page-margin: 24px;

  /* Shapes */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 999px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;
}

/* === Dark Theme Tokens === */
[data-theme="dark"] {
  --color-bg: #0b0d13;
  --color-surface: #141722;
  --color-surface-variant: #1c2030;
  --color-on-surface: #f1f3f8;
  --color-on-surface-variant: #9aa0a6;
  --color-primary: #7189ff;
  --color-primary-hover: #5472ff;
  --color-gradient-start: #7189ff;
  --color-gradient-mid: #00d4aa;
  --color-gradient-end: #00b4d8;
  --color-outline: rgba(255, 255, 255, 0.12);
  --color-outline-variant: rgba(255, 255, 255, 0.08);
}

/* === Reset & Base === */
*, *::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-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-on-surface);
  background: var(--color-bg);
  overflow-x: hidden;
}

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

img {
  max-width: 100%;
  height: auto;
}

/* === Utilities === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--page-margin);
}

/* === Reveal Animation === */
.reveal-item {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.reveal-item.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.reveal-item:nth-child(2) { transition-delay: 0.1s; }
.reveal-item:nth-child(3) { transition-delay: 0.2s; }
.reveal-item:nth-child(4) { transition-delay: 0.3s; }
.reveal-item:nth-child(5) { transition-delay: 0.15s; }
.reveal-item:nth-child(6) { transition-delay: 0.25s; }


/* ============================
   HEADER
   ============================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--space-md) 0;
  transition: all var(--duration-normal) var(--ease-out);
}

.header.scrolled {
  background: rgba(248, 249, 250, 0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--color-outline-variant);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--page-margin);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  z-index: 10;
  text-decoration: none;
}

.logo-img {
  height: 38px;
  width: auto;
  display: block;
  object-fit: contain;
  transition: transform var(--duration-normal) var(--ease-out);
}

.logo-link:hover .logo-img {
  transform: scale(1.04);
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-on-surface-variant);
  padding: 8px 16px;
  border-radius: var(--radius-full);
  transition: all var(--duration-fast) ease;
  letter-spacing: 0.01em;
}

.nav-link:hover {
  color: var(--color-on-surface);
  background: var(--color-outline-variant);
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  z-index: 10;
}

/* Theme Toggle Button — Inspired by CTA / Antigravity frosted glass aesthetic */
.theme-toggle {
  position: relative;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--color-outline);
  color: var(--color-on-surface);
  cursor: pointer;
  padding: 0;
  transition: all var(--duration-normal) var(--ease-out);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  outline: none;
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.95);
  border-color: rgba(0, 102, 255, 0.4);
  transform: translateY(-1px) scale(1.05);
  box-shadow: 0 4px 16px rgba(0, 102, 255, 0.18);
  color: var(--color-primary);
}

.theme-toggle:active {
  transform: translateY(0) scale(0.96);
}

.theme-icon {
  width: 18px;
  height: 18px;
  position: absolute;
  transition: transform 0.45s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
  pointer-events: none;
}

/* Light mode state: shows Moon */
.theme-toggle .sun-icon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

.theme-toggle .moon-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* Dark mode state: shows Sun */
[data-theme="dark"] .theme-toggle {
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  color: #f1f3f8;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3), inset 0 0 12px rgba(255, 255, 255, 0.04);
}

[data-theme="dark"] .theme-toggle:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(113, 137, 255, 0.6);
  transform: translateY(-1px) scale(1.05);
  box-shadow: 0 0 20px rgba(113, 137, 255, 0.35), 0 4px 16px rgba(0, 0, 0, 0.4);
  color: #7189ff;
}

[data-theme="dark"] .theme-toggle .sun-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
  color: #ffca3a;
}

[data-theme="dark"] .theme-toggle .moon-icon {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  z-index: 10;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-on-surface);
  border-radius: 2px;
  transition: all var(--duration-normal) var(--ease-out);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}
.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}


/* ============================
   HERO
   ============================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--color-bg);
}

/* 粒子容器通用定位 */
.main-particles-component-section {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 1;
}

/* Hero 粒子底部细腻羽化，保证视口内饱满呼吸同时与下一屏自然融合 */
.hero .main-particles-component-section {
  -webkit-mask-image: linear-gradient(to bottom, #000 82%, rgba(0, 0, 0, 0.4) 94%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 82%, rgba(0, 0, 0, 0.4) 94%, transparent 100%);
}

.main-particles-container,
.main-particles-container canvas {
  width: 100% !important;
  height: 100% !important;
  position: absolute;
  top: 0;
  left: 0;
  display: block;
  outline: none;
}

/* 柔和的底层环境过渡融合，连接下一章节 */
.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: linear-gradient(to bottom, transparent 0%, var(--color-bg) 100%);
  pointer-events: none;
  z-index: 2;
}

.hero-content {
  position: relative;
  z-index: 3;
  text-align: center;
  padding: var(--space-4xl) var(--page-margin);
  max-width: 920px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  background: var(--color-surface);
  border: 1px solid var(--color-outline);
  border-radius: var(--radius-full);
  padding: 6px 18px 6px 12px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-on-surface-variant);
  margin-bottom: var(--space-xl);
  animation: fadeInUp 0.8s var(--ease-out) 0.2s both;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #00d26a;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(0, 210, 106, 0.4); }
  50% { opacity: 0.8; box-shadow: 0 0 0 8px rgba(0, 210, 106, 0); }
}

.hero-title {
  font-size: clamp(40px, 8vw, 80px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-lg);
}

.hero-title .line {
  display: block;
  animation: fadeInUp 0.8s var(--ease-out) both;
}

.hero-title .line-1 { animation-delay: 0.3s; }
.hero-title .line-2 { animation-delay: 0.5s; }

.gradient-text {
  background: linear-gradient(135deg, var(--color-gradient-start), var(--color-gradient-mid), var(--color-gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(14px, 2vw, 18px);
  color: var(--color-on-surface-variant);
  margin-bottom: var(--space-2xl);
  animation: fadeInUp 0.8s var(--ease-out) 0.7s both;
  letter-spacing: 0.02em;
}

.hero-cta {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s var(--ease-out) 0.9s both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Scroll Indicator */
.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  animation: fadeInUp 0.8s var(--ease-out) 1.2s both;
  cursor: pointer;
  z-index: 4;
  display: block;
  text-decoration: none;
}

.scroll-line {
  width: 1px;
  height: 48px;
  background: var(--color-outline);
  position: relative;
  overflow: hidden;
}

.scroll-line::after {
  content: '';
  position: absolute;
  top: -100%;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to bottom, transparent, var(--color-primary));
  animation: scrollDown 2s infinite;
}

@keyframes scrollDown {
  0% { top: -100%; }
  100% { top: 100%; }
}


/* ============================
   BUTTONS
   ============================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  padding: 12px 28px;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--duration-fast) ease;
  text-decoration: none;
  letter-spacing: 0.01em;
}

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

.btn-primary:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0, 102, 255, 0.3);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-on-surface);
  border-color: var(--color-outline);
  backdrop-filter: blur(6px);
}

.btn-secondary:hover {
  background: var(--color-surface-variant);
  transform: translateY(-1px);
}

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

.btn-primary-inverse:hover {
  background: rgba(255, 255, 255, 0.9);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(255, 255, 255, 0.2);
}

.btn-secondary-inverse {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(8px);
}

.btn-secondary-inverse:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: translateY(-1px);
}


/* ============================
   SECTIONS (common)
   ============================ */
.section {
  padding: 80px 0;
  border-top: 1px solid var(--color-outline-variant);
  position: relative;
}

.section-header {
  margin-bottom: var(--space-2xl);
}

.section-header.center {
  text-align: center;
}

.section-label {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--space-md);
}

.section-title {
  font-size: clamp(28px, 5vw, 48px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}


/* ============================
   ABOUT SECTION
   ============================ */
.about-section {
  position: relative;
  padding: 80px 0;
  border-top: 1px solid var(--color-outline-variant);
}

/* 顶部环境流光：与 Hero 底部粒子光环自然交融，消除割裂感 */
.about-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  max-width: 95vw;
  height: 240px;
  background: radial-gradient(ellipse at center top, rgba(0, 180, 216, 0.08) 0%, rgba(0, 102, 255, 0.03) 45%, transparent 75%);
  pointer-events: none;
  z-index: 0;
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  position: relative;
  z-index: 1;
}

.about-card {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  transition: transform var(--duration-normal) var(--ease-out), box-shadow var(--duration-normal) var(--ease-out), border-color var(--duration-normal) var(--ease-out);
  will-change: transform;
  transform: translateZ(0); /* 开启独立 GPU 合成图层，彻底消除滚动与悬停微卡顿 */
  contain: paint;
}

.about-card:hover {
  border-color: rgba(0, 102, 255, 0.35);
  box-shadow: 0 24px 48px -12px rgba(0, 102, 255, 0.14), 0 0 0 1px rgba(0, 102, 255, 0.1);
}

.about-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(0, 102, 255, 0.1), rgba(0, 212, 170, 0.1));
  border: 1px solid rgba(0, 102, 255, 0.15);
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
  transition: transform var(--duration-fast) ease;
}

.about-card:hover .about-icon {
  transform: scale(1.08);
}

.about-icon svg {
  width: 26px;
  height: 26px;
}

.about-card h3 {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-sm);
}

.about-card p {
  color: var(--color-on-surface-variant);
  font-size: 14.5px;
  line-height: 1.75;
}


/* ============================
   FEATURE ROWS (Services)
   ============================ */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  margin-bottom: var(--space-3xl);
}

.feature-row:last-child {
  margin-bottom: 0;
}

.feature-row.reverse .feature-copy {
  order: 2;
}
.feature-row.reverse .feature-media {
  order: 1;
}

.feature-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

.feature-desc {
  color: var(--color-on-surface-variant);
  font-size: 16px;
  line-height: 1.7;
  margin-bottom: var(--space-xl);
  max-width: 480px;
}

/* Feature Card Stack */
.feature-card-stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.stack-card {
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: transform var(--duration-normal) var(--ease-out), box-shadow var(--duration-normal) var(--ease-out), border-color var(--duration-normal) var(--ease-out);
  transform: translateZ(0);
  contain: paint;
  will-change: transform;
}

.stack-card:hover {
  transform: translateY(-3px) scale(1.01);
  border-color: rgba(0, 102, 255, 0.35);
  box-shadow: 0 16px 36px -8px rgba(0, 102, 255, 0.12);
}

.card-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: var(--space-md);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.status-dot.online {
  background: #00d26a;
  box-shadow: 0 0 8px rgba(0, 210, 106, 0.4);
}

.card-body {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.metric {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}

.metric-label {
  color: var(--color-on-surface-variant);
}

.metric-value {
  font-weight: 600;
  font-feature-settings: 'tnum';
}

.metric-value.status-ok {
  color: #00d26a;
}

/* Automation Flow */
.automation-flow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.flow-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  font-size: 13px;
  font-weight: 500;
}

.flow-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  background: var(--color-surface-variant);
  border-radius: var(--radius-md);
}

.flow-arrow {
  color: var(--color-on-surface-variant);
  font-size: 20px;
  margin-bottom: 20px;
}

/* Automation Timeline */
.automation-timeline {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
}

.timeline-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  font-size: 13px;
  transition: all var(--duration-normal) var(--ease-out);
}

.timeline-item:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.timeline-item .time {
  font-weight: 700;
  color: var(--color-primary);
  font-feature-settings: 'tnum';
  min-width: 42px;
}

.timeline-item .event {
  color: var(--color-on-surface-variant);
}


/* ============================
   TECH STACK
   ============================ */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.tech-category {
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
}

.tech-cat-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--space-lg);
  color: var(--color-on-surface);
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.tech-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--color-surface-variant);
  color: var(--color-on-surface-variant);
  border: 1px solid transparent;
  transition: all var(--duration-fast) ease;
}

.tech-tag:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: rgba(0, 102, 255, 0.05);
}


/* ============================
   PROJECTS
   ============================ */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.project-card {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  transition: transform var(--duration-normal) var(--ease-out), box-shadow var(--duration-normal) var(--ease-out), border-color var(--duration-normal) var(--ease-out);
  position: relative;
  overflow: hidden;
  will-change: transform;
  transform: translateZ(0);
  contain: paint;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-gradient-start), var(--color-gradient-mid), var(--color-gradient-end));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration-normal) var(--ease-out);
}

.project-card:hover {
  border-color: rgba(0, 102, 255, 0.35);
  box-shadow: 0 24px 52px -12px rgba(0, 102, 255, 0.14);
}

.project-card:hover::before {
  transform: scaleX(1);
}

.project-number {
  font-size: 48px;
  font-weight: 800;
  color: var(--color-surface-variant);
  line-height: 1;
  margin-bottom: var(--space-md);
  font-feature-settings: 'tnum';
  letter-spacing: -0.04em;
}

.project-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.project-desc {
  color: var(--color-on-surface-variant);
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

.project-tags {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.project-tags span {
  font-size: 12px;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: var(--color-surface-variant);
  color: var(--color-on-surface-variant);
}


/* ============================
   CTA SECTION (Dark)
   ============================ */
.cta-section {
  position: relative;
  padding: 80px 0;
  color: #fff;
  overflow: hidden;
  border-top: 1px solid var(--color-outline-variant);
}

.cta-bg {
  position: absolute;
  inset: 0;
  background: var(--color-dark);
  border-radius: var(--radius-xl);
  margin: 0 var(--page-margin);
  overflow: hidden;
}

.cta-bg .main-particles-component-section {
  position: absolute;
  inset: 0;
  -webkit-mask-image: none;
  mask-image: none;
}

.cta-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: var(--space-4xl) var(--page-margin);
}

.cta-title {
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

.cta-subtitle {
  font-size: 16px;
  color: rgba(255, 255, 255, 0.6);
  max-width: 480px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.7;
}

.cta-buttons {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--space-2xl);
}

.cta-links {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-md);
  font-size: 14px;
}

.cta-links a {
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--duration-fast) ease;
}

.cta-links a:hover {
  color: #fff;
}

.link-sep {
  color: rgba(255, 255, 255, 0.2);
}


/* ============================
   FOOTER
   ============================ */
.footer {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-outline-variant);
}

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

.footer-left {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.footer-logo {
  height: 22px;
  width: auto;
  display: block;
  object-fit: contain;
}

.footer-brand {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-on-surface);
}

.footer-copy {
  font-size: 13px;
  color: var(--color-on-surface-variant);
}


/* ============================
   RESPONSIVE
   ============================ */
@media (max-width: 1024px) {
  .about-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .feature-row {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .feature-row.reverse .feature-copy,
  .feature-row.reverse .feature-media {
    order: unset;
  }

  .feature-desc {
    max-width: 100%;
  }
}

@media (max-width: 767px) {
  :root {
    --page-margin: 16px;
  }

  .nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(248, 249, 250, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-md);
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration-normal) var(--ease-out);
  }

  .nav.open {
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    font-size: 24px;
    padding: 12px 24px;
  }

  .menu-toggle {
    display: flex;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .tech-grid {
    grid-template-columns: 1fr;
  }

  .projects-grid {
    grid-template-columns: 1fr;
  }

  .automation-timeline {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: clamp(32px, 10vw, 56px);
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  .footer-inner {
    flex-direction: column;
    gap: var(--space-md);
    text-align: center;
  }

  .flow-arrow {
    display: none;
  }

  .automation-flow {
    flex-direction: column;
  }

  .cta-bg {
    margin: 0;
    border-radius: 0;
  }
}

/* ============================================
   DARK MODE COMPONENT OVERRIDES
   Inspired by CTA section dark aesthetic
   ============================================ */
body,
.header,
.about-card,
.stack-card,
.project-card,
.tech-category,
.automation-flow,
.timeline-item,
.footer {
  transition: background-color 0.35s ease, border-color 0.35s ease, color 0.35s ease, box-shadow 0.35s ease;
}

[data-theme="dark"] .header.scrolled {
  background: rgba(11, 13, 19, 0.85);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .nav-link {
  color: var(--color-on-surface-variant);
}

[data-theme="dark"] .nav-link:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .about-section::before {
  background: radial-gradient(ellipse at center top, rgba(113, 137, 255, 0.12) 0%, rgba(48, 116, 249, 0.04) 50%, transparent 75%);
}

[data-theme="dark"] .about-card,
[data-theme="dark"] .stack-card,
[data-theme="dark"] .project-card {
  background: rgba(20, 23, 34, 0.75);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 16px 36px -8px rgba(0, 0, 0, 0.5);
}

[data-theme="dark"] .about-card:hover,
[data-theme="dark"] .stack-card:hover,
[data-theme="dark"] .project-card:hover {
  border-color: rgba(113, 137, 255, 0.45);
  box-shadow: 0 24px 52px -12px rgba(113, 137, 255, 0.22), 0 0 0 1px rgba(113, 137, 255, 0.15);
}

[data-theme="dark"] .about-icon {
  background: linear-gradient(135deg, rgba(113, 137, 255, 0.18), rgba(0, 212, 170, 0.12));
  border-color: rgba(113, 137, 255, 0.25);
  color: #7189ff;
}

[data-theme="dark"] .automation-flow,
[data-theme="dark"] .tech-category {
  background: rgba(20, 23, 34, 0.75);
  border-color: rgba(255, 255, 255, 0.08);
  box-shadow: 0 16px 36px -8px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .flow-icon {
  background: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .timeline-item {
  background: rgba(20, 23, 34, 0.65);
  border-color: rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .timeline-item:hover {
  border-color: #7189ff;
  background: rgba(20, 23, 34, 0.95);
  box-shadow: 0 4px 20px rgba(113, 137, 255, 0.15);
}

[data-theme="dark"] .project-number {
  color: rgba(255, 255, 255, 0.12);
}

[data-theme="dark"] .tech-tag,
[data-theme="dark"] .project-tags span {
  background: rgba(255, 255, 255, 0.06);
  color: #9aa0a6;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

[data-theme="dark"] .tech-tag:hover {
  background: rgba(113, 137, 255, 0.15);
  color: #7189ff;
  border-color: rgba(113, 137, 255, 0.4);
}

[data-theme="dark"] .btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.16);
  color: #f1f3f8;
}

[data-theme="dark"] .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(113, 137, 255, 0.4);
  color: #ffffff;
}

[data-theme="dark"] .scroll-line {
  background: rgba(255, 255, 255, 0.15);
}

[data-theme="dark"] .hero-badge {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.12);
  color: #9aa0a6;
}

[data-theme="dark"] .cta-bg {
  border: 1px solid rgba(255, 255, 255, 0.08);
}

@media (max-width: 767px) {
  [data-theme="dark"] .nav {
    background: rgba(11, 13, 19, 0.98);
  }
}