body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background-color: #fff;
  color: #333;
  transition: background-color 0.3s ease, color 0.3s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: #0077cc;
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover {
  text-decoration: underline;
}

/* ===== BOUTON TOGGLE MODE SOMBRE ===== */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  background: #333;
  color: #fff;
  border: none;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  cursor: pointer;
  font-size: 1.5em;
  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
  transition: transform 0.3s ease, background-color 0.3s ease;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-toggle:hover {
  transform: scale(1.1) rotate(15deg);
  background-color: #555;
}

.theme-toggle:active {
  transform: scale(0.95);
}

/* ===== SECTION HERO ===== */
#hero {
  align-items: center;
  background-image: url('bg1.jpeg');
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  color: #333;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 300px;
  overflow: hidden; 
  padding: 100px 20px;
  position: relative;
  text-align: center;
  transition: background-color 0.3s ease;
}

#hero::after {
  content: '';
  position: absolute;
  top: -10px;
  left: -10px;
  right: -10px;
  bottom: -10px;
  background-image: inherit;
  background-size: cover;
  background-position: center;
  filter: blur(5px); 
  z-index: 0;
}

#hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.85);
  z-index: 1;
  transition: background 0.3s ease;
}

#hero * {
  position: relative;
  z-index: 2;
}

#hero h1 {
  font-size: 2.5em;
  font-weight: bold;
  margin: 0;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
  transition: color 0.3s ease, text-shadow 0.3s ease;
}

#hero .subtitle {
  font-size: 1.2em;
  margin-top: 10px;
  color: #555;
  transition: color 0.3s ease;
}

/* ===== DÉFINITIONS COMPARÉES ===== */
#definitions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 30px;
  padding: 40px 20px;
  background-color: #fafafa;
  transition: background-color 0.3s ease;
}

.column {
  flex: 1 1 400px;
  max-width: 500px;
  padding: 20px;
  background-color: #fff;
  border: 1px solid #ddd;
  border-radius: 8px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease, background-color 0.3s ease;
  cursor: pointer;
}

.column:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 24px rgba(0,0,0,0.2);
  border-color: #0077cc;
}

.column h2 {
  font-size: 1.5em;
  margin-bottom: 10px;
  color: #0077cc;
  transition: color 0.3s ease;
}

.column:hover h2 {
  color: #005fa3;
}

.column p {
  margin: 10px 0;
  transition: color 0.3s ease;
}

.word-type {
  font-size: 0.7em;
  font-weight: normal;
  font-style: italic;
  color: #666;
  margin-left: 0.3em;
}

/* Mode sombre */
body.dark-mode .word-type {
  color: #999;
}

/* ===== SECTION IMPORTANCE ===== */
#importance {
  background-color: #f0f8ff;
  padding: 40px 20px;
  text-align: center;
  transition: background-color 0.3s ease;
  flex: 1;
}

#importance h2 {
  font-size: 1.8em;
  margin-bottom: 20px;
  transition: color 0.3s ease;
}

#importance p {
  transition: color 0.3s ease;
}

/* ===== FOOTER ===== */
#footer {
  background-color: #eee;
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
  color: #666;
  transition: background-color 0.3s ease, color 0.3s ease;
}

#footer a {
  color: #555;
  transition: color 0.3s ease;
}

/* ===== MODE SOMBRE ===== */
body.dark-mode {
  background-color: #1a1a1a;
  color: #e0e0e0;
}

body.dark-mode a {
  color: #64b5f6;
}

body.dark-mode .theme-toggle {
  background: #ffd54f;
  color: #333;
}

body.dark-mode #hero::before {
  background: rgba(0, 0, 0, 0.7);
}

body.dark-mode #hero h1 {
  color: #fff;
  text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.8);
}

body.dark-mode #hero .subtitle {
  color: #ccc;
}

body.dark-mode #definitions {
  background-color: #0d0d0d;
}

body.dark-mode .column {
  background-color: #2a2a2a;
  border-color: #444;
  color: #e0e0e0;
}

body.dark-mode .column:hover {
  background-color: #333;
  border-color: #64b5f6;
}

body.dark-mode .column h2 {
  color: #64b5f6;
}

body.dark-mode .column:hover h2 {
  color: #90caf9;
}

body.dark-mode #importance {
  background-color: #1e1e1e;
}

body.dark-mode #importance h2,
body.dark-mode #importance p {
  color: #e0e0e0;
}

body.dark-mode #footer {
  background-color: #0d0d0d;
  color: #999;
}

body.dark-mode #footer a {
  color: #bbb;
}

/* ===== TRANSITIONS GLOBALES ===== */
* {
  transition-property: background-color, color, border-color;
  transition-duration: 0.3s;
  transition-timing-function: ease;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  #hero h1 {
    font-size: 2em;
  }

  .theme-toggle {
    width: 50px;
    height: 50px;
    font-size: 1.2em;
  }
}