/* Modern CSS Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

body,
h1,
h2,
h3,
h4,
p,
ul,
ol,
li,
figure,
figcaption,
blockquote,
dl,
dd {
  margin: 0;
  padding: 0;
}

/* Base Variables - Light Mode */
:root {
  /* Light Theme Colors */
  --color-primary: rgb(127, 163, 219);  /* Blue color as requested */
  --color-primary-dark: rgb(87, 123, 179); /* Darker blue for hover states */
  --color-primary-light: rgb(147, 183, 239);
  --color-background: #fafafa;     /* Very light gray */
  --color-surface: #ffffff;        /* White */
  --color-text: #333333;           /* Dark gray for text */
  --color-text-light: #666666;     /* Medium gray for secondary text */
  --color-border: #eeeeee;         /* Light gray for borders */
  --color-accent: #555555;         /* Darker gray for accents */
  
  /* Shared Variables */
  --spacing-xs: 0.25rem;           /* 4px */
  --spacing-sm: 0.5rem;            /* 8px */
  --spacing-md: 1rem;              /* 16px */
  --spacing-lg: 1.5rem;            /* 24px */
  --spacing-xl: 2rem;              /* 32px */
  --spacing-xxl: 3rem;             /* 48px */
  
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-serif: 'EB Garamond', 'Georgia', 'Times New Roman', serif;
  --font-slab: 'Roboto Slab', 'Rockwell', 'Courier New', serif;
  
  --radius-sm: 0.25rem;            /* 4px */
  --radius-md: 0.375rem;           /* 6px */
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
  --shadow-md: 0 2px 4px 0 rgba(0, 0, 0, 0.03);
  
  --max-width: 700px;
  --header-height: 60px;
  --transition: 0.2s ease-in-out;
}

/* Dark Theme Variables */
@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: rgb(127, 163, 219);  /* Keep the blue color as requested */
    --color-primary-dark: rgb(107, 143, 199);
    --color-primary-light: rgb(147, 183, 239);
    --color-background: #121212;     /* Very dark gray */
    --color-surface: #1e1e1e;        /* Dark gray for surfaces */
    --color-text: #e0e0e0;           /* Light gray for text */
    --color-text-light: #a0a0a0;     /* Medium gray for secondary text */
    --color-border: #333333;         /* Darker gray for borders */
    --color-accent: #bbbbbb;         /* Light gray for accents */
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.1);
    --shadow-md: 0 2px 4px 0 rgba(0, 0, 0, 0.15);
  }
}

/* Base Styles */
html {
  font-size: 17px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-background);
  color: var(--color-text);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding-top: var(--header-height);
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-slab);
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary-dark);
  transition: color 0.3s ease;
}

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

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

/* Layout */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 var(--spacing-md);
  z-index: 10;
  box-shadow: var(--shadow-sm);
  transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.header-content {
  width: 100%;
  max-width: var(--max-width);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-container {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

h1 {
  font-size: 1.3rem;
  margin: 0;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 400;
}

h1 img {
  height: 28px;
  transition: transform 0.3s ease;
}

h1:hover img {
  transform: rotate(5deg);
}

.subtitle {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-left: var(--spacing-md);
  transition: color 0.3s ease;
  font-weight: 400;
}

main {
  flex: 1;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-md);
}

footer {
  padding: var(--spacing-md);
  text-align: center;
  color: var(--color-text-light);
  font-size: 0.8rem;
  transition: color 0.3s ease;
}

/* Posts List View */
.post-list {
  list-style-type: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xxl);
}

.post-item {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: background-color 0.3s ease;
}

.post-date {
  display: block;
  padding: var(--spacing-md) var(--spacing-xl);
  font-family: var(--font-slab);
  font-size: 1rem;
  color: var(--color-surface);
  background-color: var(--color-primary);
  font-weight: 400;
  transition: background-color 0.3s ease;
}

.post-date:hover {
  background-color: var(--color-primary-dark);
  color: white;
}

.prompt {
  padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-lg);
  font-family: var(--font-slab);
  font-size: 1.25rem;
  font-weight: 500;
  line-height: 1.4;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-primary-dark);
  transition: color 0.3s ease, border-color 0.3s ease;
}

.reply {
  padding: var(--spacing-xl);
  color: var(--color-text);
  font-family: var(--font-serif);
  font-size: 1.15rem;
  transition: color 0.3s ease;
}

.reply p {
  margin-bottom: var(--spacing-lg);
}

.reply p:last-child {
  margin-bottom: 0;
}

.reply strong {
  color: var(--color-accent);
  transition: color 0.3s ease;
}

.reply h2, .reply h3, .reply h4 {
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  font-family: var(--font-serif);
  font-weight: 600;
}

.reply ul, .reply ol {
  margin-left: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
}

.reply li {
  margin-bottom: var(--spacing-md);
}

/* Single Post View */
#post-detail {
  display: none;
}

.back-button {
  display: inline-block;
  margin-bottom: var(--spacing-xl);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
  background-color: var(--color-background);
  color: var(--color-primary);
  font-size: 0.9rem;
  font-weight: 400;
  transition: background-color var(--transition), color 0.3s ease;
}

.back-button:hover {
  background-color: var(--color-border);
}

.single-post {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.single-post-date {
  padding: var(--spacing-md) var(--spacing-xl);
  font-family: var(--font-slab);
  font-size: 1rem;
  background-color: var(--color-primary);
  color: var(--color-surface);
  margin: 0;
  transition: background-color 0.3s ease, color 0.3s ease;
  font-weight: 400;
}

/* Loading & Error States */
.loading, .error {
  text-align: center;
  padding: var(--spacing-xxl) 0;
  color: var(--color-text-light);
  transition: color 0.3s ease;
}

.loading-icon {
  display: inline-block;
  width: 36px;
  height: 36px;
  margin-bottom: var(--spacing-md);
  animation: spin 1s linear infinite;
  color: var(--color-primary);
  transition: color 0.3s ease;
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* Responsive Adjustments */
@media (max-width: 640px) {
  html {
    font-size: 15px;
  }
  
  .prompt {
    font-size: 1.05rem;
    padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-md);
  }
  
  .reply {
    padding: var(--spacing-lg);
  }
  
  .post-date, .single-post-date {
    padding: var(--spacing-md) var(--spacing-lg);
  }
}