/* ===============================
   Estilos Premium - Herramientas Online
   =============================== */

:root {
  --primary: #2563eb;
  --primary-hover: #1e4fc7;
  --bg: #f4f7fb;
  --text: #1e293b;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --radius: 12px;
  --radius-lg: 18px;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 6px 18px rgba(0, 0, 0, 0.12);
  --transition: 0.25s ease;
  --input-bg: #ffffff;
  --input-border: #cdd5df;
}

/* ------------------------------
   Reset
------------------------------ */
body {
  margin: 0;
  padding: 0;
  font-family: "Inter", sans-serif;
  background: var(--bg);
  color: var(--text);
}

/* ------------------------------
   Header
------------------------------ */
header {
  background: var(--card-bg);
  padding: 22px;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
}

header h1 {
  margin: 0 0 10px 0;
  font-size: 1.7rem;
  text-align: center;
}

nav {
  display: flex;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
}

nav a {
  color: var(--primary);
  text-decoration: none;
  padding: 8px 14px;
  border-radius: var(--radius);
  font-size: 0.95rem;
  transition: var(--transition);
}

nav a:hover {
  background: var(--primary);
  color: #fff;
}

/* ------------------------------
   Main
------------------------------ */
main {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

.intro h2 {
  font-size: 1.9rem;
  margin-bottom: 10px;
  text-align: center;
}

/* ------------------------------
   Tarjetas (grid de herramientas)
------------------------------ */
.tools-grid {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.tool-card {
  background: var(--card-bg);
  padding: 25px 20px;
  border-radius: var(--radius-lg);
  text-align: center;
  font-size: 1.1rem;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.tool-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}

.tool-card svg {
  margin-bottom: 10px;
  stroke-width: 2;
  stroke: var(--primary);
  width: 42px;
  height: 42px;
}

/* ------------------------------
   Contenedores de herramientas
------------------------------ */

.tool-container {
  background: var(--card-bg);
  padding: 30px;
  margin-top: 25px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.tool-container h2 {
  margin-top: 0;
  font-size: 1.6rem;
  text-align: center;
}

.tool-container p {
  text-align: center;
  margin-bottom: 30px;
  color: #475569;
}

/* ------------------------------
   Inputs / Select / Buttons
------------------------------ */

.tool-box {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.input {
  padding: 12px 14px;
  border-radius: var(--radius);
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  font-size: 1rem;
  transition: var(--transition);
}

.input:focus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.btn {
  padding: 12px 18px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
}

.btn:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
}

/* ------------------------------
   Resultado
------------------------------ */

.resultado {
  background: #eef2ff;
  padding: 15px;
  border-radius: var(--radius);
  font-size: 1.1rem;
  border-left: 4px solid var(--primary);
  margin-top: 10px;
  word-break: break-word;
}

/* ------------------------------
   Footer
------------------------------ */

footer {
  margin-top: 45px;
  text-align: center;
  padding: 20px;
  color: #64748b;
  font-size: 0.9rem;
}

/* ------------------------------
   Responsive
------------------------------ */

@media (max-width: 600px) {
  header h1 {
    font-size: 1.4rem;
  }

  nav a {
    font-size: 0.85rem;
  }

  .tool-container {
    padding: 22px;
  }

  .tool-card {
    padding: 20px;
  }
}