/* ================================
   CSS Variables & Design System
   ================================ */
:root {
  /* Colors - iBest Style (Red Accent) */
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f9fafb;
  --color-bg-card: #ffffff;
  --color-text-primary: #1a1a1a;
  --color-text-secondary: #4a4a4a;
  --color-text-muted: #6b7280;
  --color-accent: #e63946;
  --color-accent-hover: #c1121f;
  --color-accent-secondary: #ff6b6b;
  --color-border: #e5e7eb;
  --color-success: #22c55e;
  
  /* Typography */
  --font-primary: 'Inter', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 5rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-glow: 0 0 40px rgba(230, 57, 70, 0.1);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-primary);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-hover);
}

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

ul, ol {
  list-style: none;
}

/* ================================
   Layout
   ================================ */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

section {
  padding: var(--spacing-2xl) 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-xl);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 60px;
  height: 4px;
  background: var(--color-accent);
  border-radius: 0;
}

/* ================================
   Navigation
   ================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--spacing-sm) 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  border-bottom-color: var(--color-border);
}

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

.nav-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.nav-logo span {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-links a {
  color: var(--color-text-secondary);
  font-weight: 500;
  position: relative;
  padding: var(--spacing-xs) 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-fast);
}

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

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  transition: all var(--transition-fast);
}

/* ================================
   Hero Section
   ================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: 80px;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 80%;
  background: radial-gradient(circle, rgba(230, 57, 70, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -20%;
  width: 60%;
  height: 60%;
  background: radial-gradient(circle, rgba(255, 107, 107, 0.04) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-subtitle {
  color: var(--color-accent);
  font-weight: 500;
  font-size: 1.125rem;
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.hero-subtitle::before {
  content: '';
  display: inline-block;
  width: 40px;
  height: 2px;
  background: var(--color-accent);
}

.hero-title {
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--spacing-md);
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin-bottom: var(--spacing-lg);
}

.hero-stats {
  display: flex;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-xl);
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: var(--spacing-xs);
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

/* ================================
   Buttons
   ================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 1rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 0;
  border: 2px solid var(--color-text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: transparent;
  color: var(--color-text-primary);
}

.btn::after {
  content: '→';
  margin-left: var(--spacing-xs);
  transition: transform var(--transition-fast);
}

.btn:hover::after {
  transform: translateX(4px);
}

.btn-primary {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #ffffff;
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: #ffffff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-text-primary);
  border: 2px solid var(--color-text-primary);
}

.btn-secondary:hover {
  background: var(--color-text-primary);
  color: var(--color-bg-primary);
}

.btn-line {
  background: #06C755;
  border-color: #06C755;
  color: #ffffff;
}

.btn-line::before {
  content: '';
  display: inline-block;
  width: 20px;
  height: 20px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='white'%3E%3Cpath d='M12 2C6.48 2 2 5.92 2 10.67c0 4.28 3.8 7.86 8.93 8.54.35.07.82.23.94.52.11.26.07.67.04.94l-.15.9c-.05.28-.22 1.1.96.6s6.4-3.77 8.73-6.46C23.12 13.82 22 11.87 22 10.67 22 5.92 17.52 2 12 2z'/%3E%3C/svg%3E");
  background-size: contain;
  background-repeat: no-repeat;
  margin-right: 8px;
}

.btn-line::after {
  content: none;
}

.btn-line:hover {
  background: #05a647;
  border-color: #05a647;
  color: #ffffff;
}

/* ================================
   About Section
   ================================ */
.about {
  background: var(--color-bg-secondary);
}

.about-grid {
  display: block;
}

.about-text {
  max-width: 800px;
  margin-bottom: var(--spacing-xl);
}

.about-text p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  font-size: 1.1rem;
}

.about-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  background: var(--color-bg-primary);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.feature-item:hover {
  border-color: var(--color-accent);
  transform: translateX(8px);
}

.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(230, 57, 70, 0.08);
  border-radius: var(--radius-md);
  color: var(--color-accent);
  font-size: 1.5rem;
  flex-shrink: 0;
}

.feature-content h4 {
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.feature-content p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin: 0;
}

/* ================================
   Skills Section
   ================================ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.skill-category {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-fast);
}

.skill-category:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-glow);
}

.skill-category h3 {
  font-size: 1.125rem;
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.skill-category h3 span {
  color: var(--color-accent);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.skill-tag {
  padding: 0.5rem 1rem;
  background: var(--color-bg-primary);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.skill-tag:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ================================
   Portfolio Section
   ================================ */
.portfolio {
  background: var(--color-bg-secondary);
}

.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
}

.portfolio-card {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-normal);
  position: relative;
}

.portfolio-card:hover {
  transform: translateY(-8px);
  border-color: var(--color-accent);
  box-shadow: var(--shadow-glow);
}

.portfolio-image {
  height: 260px;
  background: linear-gradient(135deg, var(--color-bg-secondary), var(--color-bg-card));
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.portfolio-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.portfolio-image::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.05), rgba(167, 139, 250, 0.05));
}

.portfolio-image-placeholder {
  font-size: 3rem;
  color: var(--color-accent);
  opacity: 0.5;
}

.portfolio-content {
  padding: var(--spacing-lg);
}

.portfolio-type {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: var(--spacing-xs);
}

.portfolio-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.portfolio-description {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-md);
}

.portfolio-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-weight: 500;
  color: var(--color-accent);
}

.portfolio-link:hover {
  gap: var(--spacing-sm);
}

/* ================================
   Contact Section
   ================================ */
.contact {
  text-align: center;
}

.contact .section-title {
  display: block;
  text-align: center;
}

.contact .section-title::after {
  left: 50%;
  transform: translateX(-50%);
}

.contact-content {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}

.contact-content p {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

.contact-email {
  margin-bottom: var(--spacing-lg);
}

.contact-email a {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-accent);
  transition: all var(--transition-fast);
}

.contact-email a:hover {
  color: var(--color-accent-hover);
}

.contact-content .hero-cta {
  justify-content: center;
}

.contact-info {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
  margin-top: var(--spacing-xl);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
  flex: 1;
  min-width: 250px;
  max-width: 320px;
}

.contact-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.1), rgba(167, 139, 250, 0.1));
  border-radius: var(--radius-md);
  color: var(--color-accent);
  font-size: 1.25rem;
}

/* ================================
   Footer
   ================================ */
.footer {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer p {
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.footer-heart {
  color: #ef4444;
}

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

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.fade-in-up {
  animation: fadeInUp 0.3s ease forwards;
  opacity: 0;
}

.delay-1 { animation-delay: 0.05s; }
.delay-2 { animation-delay: 0.1s; }
.delay-3 { animation-delay: 0.15s; }
.delay-4 { animation-delay: 0.2s; }
.delay-5 { animation-delay: 0.25s; }

/* ================================
   Responsive Design
   ================================ */
@media (max-width: 992px) {
  .about-features {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .about-features {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-secondary);
    flex-direction: column;
    padding: var(--spacing-md);
    gap: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .hero-stats {
    flex-wrap: wrap;
    gap: var(--spacing-lg);
  }
  
  .hero-cta {
    flex-direction: column;
  }
  
  .hero-cta .btn {
    width: 100%;
  }
  
  .contact-info {
    flex-direction: column;
    align-items: center;
  }
  
  section {
    padding: var(--spacing-xl) 0;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-description {
    font-size: 1rem;
  }
  
  .stat-number {
    font-size: 2rem;
  }
  
  .portfolio-grid {
    grid-template-columns: 1fr;
  }
}