:root {
  /* Light mode colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #f0f2f5;
  --text-primary: #1a1a1a;
  --text-secondary: #555555;
  --text-muted: #999999;
  --border-color: #e5e7eb;
  --code-bg: #f5f5f5;
  --code-text: #d63384;
  --primary-color: #4d4d4d;
  --accent-color: #f25221;
  --accent-hover: #e03f1a;
  --accent-light: rgba(242, 82, 33, 0.1);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Dark mode colors */
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #262626;
    --text-primary: #ffffff;
    --text-secondary: #e5e5e5;
    --text-muted: #999999;
    --border-color: #333333;
    --code-bg: #1a1a1a;
    --code-text: #ff79c6;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  }
}

/* Dark mode toggle (explicit) */
html.dark-mode {
  --bg-primary: #0f0f0f;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #262626;
  --text-primary: #ffffff;
  --text-secondary: #e5e5e5;
  --text-muted: #999999;
  --border-color: #333333;
  --code-bg: #1a1a1a;
  --code-text: #ff79c6;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
}

html.light-mode {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #f0f2f5;
  --text-primary: #1a1a1a;
  --text-secondary: #555555;
  --text-muted: #999999;
  --border-color: #e5e7eb;
  --code-bg: #f5f5f5;
  --code-text: #d63384;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
}

h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-top: 2rem;
}

h3 {
  font-size: 1.5rem;
  font-weight: 700;
}

h4 {
  font-size: 1.25rem;
  font-weight: 600;
}

h5 {
  font-size: 1.1rem;
  font-weight: 600;
}

h6 {
  font-size: 1rem;
  font-weight: 600;
}

p {
  margin-bottom: 1.5rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: var(--transition);
  font-weight: 500;
}

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

/* Code blocks */
pre {
  background-color: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-size: 0.9em;
  line-height: 1.5;
}

code {
  font-family: 'Monaco', 'Courier New', monospace;
  font-size: 0.9em;
  color: var(--code-text);
}

pre code {
  color: inherit;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.875rem 1.75rem;
  border-radius: 8px;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  font-size: 1rem;
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-color) 0%, #ff6a3f 100%);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--accent-hover) 0%, #e03f1a 100%);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--accent-color);
  border: 2px solid var(--accent-color);
}

.btn-secondary:hover {
  background-color: var(--accent-color);
  color: white;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Grid */
.grid {
  display: grid;
  gap: 2rem;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Cards */
.card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  transition: var(--transition);
}

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

/* Responsive images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
}

th, td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  background-color: var(--bg-secondary);
  font-weight: 600;
  color: var(--text-primary);
}

tr:hover {
  background-color: var(--bg-tertiary);
}

/* Blockquotes */
blockquote {
  border-left: 4px solid var(--accent-color);
  padding-left: 1rem;
  margin: 1.5rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

/* Lists */
ul, ol {
  margin: 1rem 0;
  padding-left: 2rem;
}

li {
  margin: 0.5rem 0;
}

/* Responsive utilities */
@media (max-width: 768px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }

  .container {
    padding: 0 1rem;
  }

  .grid {
    gap: 1.5rem;
  }

  .card {
    padding: 1.5rem;
  }
}

/* Contact Modal Styles */
.contact-modal {
  display: none;
  visibility: hidden;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2000;
}

.contact-modal.active {
  display: flex;
  visibility: visible;
  align-items: center;
  justify-content: center;
}

.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  cursor: pointer;
}

.modal-content {
  position: relative;
  background-color: var(--bg-primary);
  border-radius: 12px;
  padding: 2rem;
  max-width: 500px;
  width: 90%;
  box-shadow: var(--shadow-lg);
  z-index: 2001;
  animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
  from {
    transform: translateY(-50px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  transition: var(--transition);
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-close:hover {
  color: var(--accent-color);
}

.modal-content h2 {
  margin-bottom: 1.5rem;
  margin-top: 0;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--text-primary);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 1rem;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.submit-btn {
  width: 100%;
  padding: 0.875rem 1.5rem;
  background-color: var(--accent-color);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.submit-btn:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

@media (max-width: 768px) {
  .modal-content {
    padding: 1.5rem;
    max-width: 100%;
  }

  .modal-content h2 {
    font-size: 1.5rem;
  }
}

/* Message Modal Styles */
.message-modal {
  display: none;
  visibility: hidden;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2000;
}

.message-modal.active {
  display: flex;
  visibility: visible;
  align-items: center;
  justify-content: center;
}

.message-modal .modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  cursor: pointer;
}

.message-modal .modal-content {
  position: relative;
  background-color: var(--bg-primary);
  border-radius: 12px;
  padding: 2rem;
  max-width: 400px;
  width: 90%;
  box-shadow: var(--shadow-lg);
  z-index: 2001;
  animation: slideIn 0.3s ease-out;
  text-align: center;
}

.message-modal .modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  transition: var(--transition);
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.message-modal .modal-close:hover {
  color: var(--accent-color);
}

#message-icon {
  margin: 1rem 0;
  display: flex;
  justify-content: center;
}

#message-icon svg {
  width: 60px;
  height: 60px;
}

.message-modal h2 {
  margin-top: 0;
  margin-bottom: 1rem;
}

.message-modal p {
  margin-bottom: 2rem;
  color: var(--text-secondary);
}

.modal-action-btn {
  padding: 0.75rem 2rem;
  background-color: var(--accent-color);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.modal-action-btn:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}