:root {
  --primary-color: #005f96;
  --primary-dark: #003b5c;
  --secondary-color: #31708e;
  --success-color: #2d82a4;
  --info-color: #8cc0d4;
  --dark-bg: #00213d;
  --light-bg: #f4f9fb;
  --card-shadow: 0 10px 30px rgba(0, 33, 61, 0.08);
  --hover-shadow: 0 15px 45px rgba(0, 33, 61, 0.15);
  --border-color: #b2d8e5;
}

body {
  font-family: "Poppins", sans-serif;
  background-color: var(--light-bg);
  color: var(--dark-bg);
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* =========================================
   TARJETAS Y CONTENEDORES
   ========================================= */
.card {
  border: 1px solid rgba(178, 216, 229, 0.5);
  border-radius: 16px;
  background: #ffffff;
  transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
  box-shadow: var(--card-shadow) !important;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--hover-shadow) !important;
  border-color: var(--info-color);
}

/* Botones con gradiente refinado */
.btn {
  border-radius: 10px;
  padding: 10px 20px;
  font-weight: 500;
  transition: all 0.3s ease;
  border: none;
  letter-spacing: 0.5px;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--primary-color),
    var(--primary-dark)
  );
  color: white;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 95, 150, 0.3);
  filter: brightness(110%);
}

/* Inputs de Vectores */
.vector-input-group input {
  text-align: center;
  font-family: "Fira Code", monospace;
  font-weight: 600;
  border-radius: 8px;
  border: 2px solid #e9ecef;
  background-color: #fdfdfd;
  transition: all 0.3s ease;
  color: var(--primary-dark);
}

.vector-input-group input:focus {
  border-color: var(--primary-color);
  background-color: #fff;
  box-shadow: 0 0 0 4px rgba(0, 95, 150, 0.1);
  outline: none;
}

/* =========================================
   ZONA DE RESULTADOS Y MATEMÁTICAS
   ========================================= */
.step-box {
  background: white;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 15px;
  border-left: 5px solid var(--info-color);
  transition: all 0.3s ease;
}

.step-box:hover {
  transform: translateX(8px);
  border-left-color: var(--primary-color);
  background: #fafcfe;
}

/* Contenedor de fórmulas */
.math-display {
  overflow-x: auto;
  padding: 15px;
  background: #f8fbfe;
  border-radius: 8px;
  color: var(--primary-dark);
}

/* Scrollbar personalizado estilo "Ice" */
.math-display::-webkit-scrollbar {
  height: 6px;
}
.math-display::-webkit-scrollbar-track {
  background: #f1f1f1;
  border-radius: 10px;
}
.math-display::-webkit-scrollbar-thumb {
  background: var(--info-color);
  border-radius: 10px;
}
.math-display::-webkit-scrollbar-thumb:hover {
  background: var(--secondary-color);
}

.projections-list {
  border-left: 3px dashed var(--border-color);
  padding-left: 20px;
}

/* =========================================
   ANIMACIONES Y LOADER
   ========================================= */
.animate__fadeIn {
  animation: fadeIn 0.6s ease-out forwards;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(15px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

#plot-loader .spinner-border {
  color: var(--primary-color);
  width: 3.5rem;
  height: 3.5rem;
}

/* =========================================
   GRÁFICO PLOTLY
   ========================================= */
#plot-container {
  width: 100%;
  height: 550px;
  min-height: 550px;
  border-radius: 20px;
  box-shadow: var(--card-shadow);
  border: 1px solid var(--border-color);
  background: white;
  display: block;
}

/* Estilo para los títulos de pasos u orden */
h4,
.step-title {
  color: var(--primary-dark);
  font-weight: 700;
  border-bottom: 2px solid var(--light-bg);
  padding-bottom: 10px;
  margin-bottom: 20px;
}
footer {
  background-color: #222;
  color: white;
  text-align: center;
  padding: 15px;
  font-size: 14px;
  margin-top: auto;
}
main {
  flex: 1;
  display: flex;
  flex-direction: column;
}
.math-box {
  overflow-x: auto;
  padding: 10px;
}

/* Solo poner borde en pantallas grandes */
@media (min-width: 768px) {
  .border-md-end {
    border-right: 1px solid var(--border-color);
  }
}