/* ==========================================
   VARIABLES DE COLOR - Club de Tenis Madrid Río
   ========================================== */
:root {
  --azul-oscuro: #122955;
  --azul-medio: #1f3f7a;
  --naranja: #ee5915;
  --verde-pelota: #5aa330;
  --gris-oscuro: #1a1a1a;
  --gris-medio: #4a4a4a;
  --gris-claro: #f5f5f5;
  --blanco: #ffffff;
  --sombra: 0 4px 12px rgba(0, 0, 0, 0.1);
  --transicion: all 0.3s ease;
}

/* ==========================================
   RESET BÁSICO
   ========================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  color: var(--gris-oscuro);
  background-color: var(--blanco);
  line-height: 1.6;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

/* ==========================================
   CONTENEDORES Y UTILIDADES
   ========================================== */
.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 0;
}

.section {
  padding: 4rem 0;
}

.section-title {
  font-size: 2.5rem;
  color: var(--azul-oscuro);
  margin-bottom: 2rem;
  text-align: center;
  position: relative;
  padding-bottom: 1rem;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background-color: var(--naranja);
  border-radius: 2px;
}

/* ==========================================
   BOTONES
   ========================================== */
.btn {
  display: inline-block;
  padding: 0.8rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  transition: var(--transicion);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.btn-primary {
  background-color: var(--azul-oscuro);
  color: var(--blanco);
}

.btn-primary:hover {
  background-color: var(--azul-medio);
  transform: translateY(-2px);
  box-shadow: var(--sombra);
}

.btn-secondary {
  background-color: var(--naranja);
  color: var(--gris-oscuro);
}

.btn-secondary:hover {
  background-color: #c94a10;
  transform: translateY(-2px);
  box-shadow: var(--sombra);
}

/* ==========================================
   HERO (portada de inicio)
   ========================================== */
.hero {
  background: linear-gradient(135deg, var(--azul-oscuro) 0%, var(--azul-medio) 100%);
  color: var(--blanco);
  padding: 6rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50px;
  right: -50px;
  width: 200px;
  height: 200px;
  background-color: var(--verde-pelota);
  border-radius: 50%;
  opacity: 0.15;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.hero p {
  font-size: 1.3rem;
  margin-bottom: 2rem;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

/* ==========================================
   TARJETAS (cards)
   ========================================== */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.card {
  background-color: var(--blanco);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--sombra);
  transition: var(--transicion);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.card-img {
  height: 200px;
  background: linear-gradient(135deg, var(--azul-medio), var(--azul-oscuro));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--naranja);
  font-size: 3rem;
}

.card-body {
  padding: 1.5rem;
}

.card-body h3 {
  color: var(--azul-oscuro);
  margin-bottom: 0.8rem;
}

/* ==========================================
   TABLA DE CUOTAS
   ========================================== */
.tabla-cuotas {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  box-shadow: var(--sombra);
  border-radius: 12px;
  overflow: hidden;
}

.tabla-cuotas thead {
  background-color: var(--azul-oscuro);
  color: var(--blanco);
}

.tabla-cuotas th,
.tabla-cuotas td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--gris-claro);
}

.tabla-cuotas tbody tr:nth-child(even) {
  background-color: var(--gris-claro);
}

.tabla-cuotas tbody tr:hover {
  background-color: #e8edf7;
}

/* ==========================================
   FORMULARIO
   ========================================== */
.formulario {
  max-width: 600px;
  margin: 0 auto;
  background-color: var(--blanco);
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: var(--sombra);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--azul-oscuro);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 0.8rem;
  border: 2px solid var(--gris-claro);
  border-radius: 8px;
  font-size: 1rem;
  font-family: inherit;
  transition: var(--transicion);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--azul-medio);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.form-error {
  color: #d9534f;
  font-size: 0.9rem;
  margin-top: 0.3rem;
  display: none;
}

.form-success {
  background-color: #dff0d8;
  color: #3c763d;
  padding: 1rem;
  border-radius: 8px;
  margin-bottom: 1rem;
  display: none;
}