/* ===== VARIABLES GLOBALES ===== */
:root {
  --primary-color: #1da1f2;
  --primary-dark: #1a91da;
  --text-primary: #0f1419;
  --text-secondary: #536471;
  --bg-primary: #ffffff;
  --bg-secondary: #eff3f4;
  --bg-tertiary: #f7f9fa;
  --border-color: #cfd9de;
  
  /* Tema oscuro */
  --dark-bg-primary: #000000;
  --dark-bg-secondary: #16181c;
  --dark-bg-tertiary: #192734;
  --dark-text-primary: #e7e9ea;
  --dark-text-secondary: #71767b;
  --dark-border-color: #2f3336;
}

body.dark {
  --text-primary: var(--dark-text-primary);
  --text-secondary: var(--dark-text-secondary);
  --bg-primary: var(--dark-bg-primary);
  --bg-secondary: var(--dark-bg-secondary);
  --bg-tertiary: var(--dark-bg-tertiary);
  --border-color: var(--dark-border-color);
}

/* ===== ESTILOS BASE ===== */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  margin: 0;
  padding: 0;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* ===== HEADER ===== */
header {
  background: var(--primary-color);
  color: white;
  padding: 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

header h1 {
  margin: 0;
  font-size: 1.8rem;
  font-weight: 800;
  flex: 1;
}

header > #nav {
  flex: 1;
}

/* ===== NAVBAR ===== */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.nav-links,
.nav-auth {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav-link {
  color: inherit;
  text-decoration: none;
  font-weight: 500;
  transition: opacity 0.3s ease;
}

.nav-link:hover {
  opacity: 0.8;
}

/* ===== CONTAINER ===== */
.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 1rem;
}

/* ===== SECTIONS ===== */
section {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  margin-bottom: 1rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

section h2 {
  margin-top: 0;
  color: var(--text-primary);
  font-size: 1.4rem;
}

/* ===== NUEVO POST ===== */
.new-post-section {
  border: 2px solid var(--primary-color);
}

#post-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ===== FEED ===== */
.feed-section {
  padding: 0;
  border: none;
  background: transparent;
}

/* ===== DARK MODE BUTTON ===== */
.dark-btn {
  background: rgba(255, 255, 255, 0.2);
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  transition: background 0.3s ease;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.dark-btn:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* ===== LOADING SCREEN ===== */
#loading {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-primary);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--text-primary);
}
@media (max-width: 768px) {
  header {
    flex-direction: column;
    gap: 1rem;
  }

  header h1 {
    font-size: 1.4rem;
    width: 100%;
  }

  header > #nav {
    width: 100%;
  }

  .navbar {
    flex-direction: column;
    gap: 1rem;
    width: 100%;
  }

  .nav-links,
  .nav-auth {
    width: 100%;
    justify-content: center;
  }

  .container {
    padding: 0.5rem;
  }

  section {
    padding: 1rem;
  }
}