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

:root {
    --azul-marino: #1a2d5a;
    --azul-metal: #2d4a8a;
    --azul-claro: #4a6fb5;
    --azul-suave: #e8eef7;
    --blanco: #ffffff;
    --gris-claro: #f8fafc;
    --gris-borde: #d0d9e4;
    --texto: #1a2d5a;
    --texto-suave: #4a5a7a;
    --texto-gris: #8899aa;
    --exito: #2d8a4a;
    --advertencia: #d4a017;
    --error: #c04040;
    --sombra: 0 4px 16px rgba(15, 35, 80, 0.08);
    --sombra-hover: 0 8px 24px rgba(15, 35, 80, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gris-claro);
    color: var(--texto);
    line-height: 1.6;
    min-height: 100vh;
}

/* ============================================
   HEADER / NAVBAR
   ============================================ */
.navbar {
    background: linear-gradient(145deg, var(--azul-metal), var(--azul-marino));
    color: white;
    padding: 0 24px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: 0 2px 12px rgba(15, 35, 80, 0.2);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 18px;
    font-weight: 600;
    color: white;
    text-decoration: none;
}

.navbar-brand .logo-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.navbar-menu {
    display: flex;
    gap: 8px;
    align-items: center;
}

.navbar-menu a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.2s;
}

.navbar-menu a:hover, .navbar-menu a.active {
    background: rgba(255, 255, 255, 0.15);
    color: white;
}

.navbar-user {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
}

.navbar-user .puntos {
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 14px;
    border-radius: 20px;
    font-weight: 600;
}

/* ============================================
   CONTENEDORES
   ============================================ */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 32px 20px;
}

.auth-container {
    max-width: 440px;
    margin: 60px auto;
    padding: 0 20px;
}

/* ============================================
   TARJETAS
   ============================================ */
.card {
    background: var(--blanco);
    border: 1px solid var(--gris-borde);
    border-radius: 16px;
    padding: 32px;
    box-shadow: var(--sombra);
    transition: all 0.3s;
}

.card:hover {
    box-shadow: var(--sombra-hover);
}

.card-header {
    text-align: center;
    margin-bottom: 28px;
}

.card-header .icon-circle {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: linear-gradient(145deg, var(--azul-metal), var(--azul-marino));
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    color: white;
    margin-bottom: 16px;
    box-shadow: 0 8px 20px rgba(15, 35, 80, 0.25);
}

.card-header h1 {
    font-size: 24px;
    font-weight: 600;
    color: var(--texto);
    margin-bottom: 6px;
}

.card-header p {
    color: var(--texto-gris);
    font-size: 14px;
}

/* ============================================
   FORMULARIOS
   ============================================ */
.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--texto);
    margin-bottom: 6px;
    letter-spacing: 0.3px;
}

.form-group input {
    width: 100%;
    padding: 13px 16px;
    border: 2px solid var(--gris-borde);
    border-radius: 10px;
    font-size: 14px;
    font-family: inherit;
    background: var(--blanco);
    color: var(--texto);
    transition: all 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--azul-metal);
    box-shadow: 0 0 0 4px rgba(45, 74, 138, 0.1);
}

.form-group input::placeholder {
    color: #aabbcc;
}

/* ============================================
   BOTONES
   ============================================ */
.btn {
    display: inline-block;
    padding: 13px 28px;
    border: none;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    font-family: inherit;
    letter-spacing: 0.5px;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    transition: all 0.2s;
}

.btn-primary {
    background: linear-gradient(145deg, var(--azul-metal), var(--azul-marino));
    color: white;
    box-shadow: 0 4px 12px rgba(15, 35, 80, 0.25);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(15, 35, 80, 0.35);
}

.btn-block {
    width: 100%;
}

.btn-outline {
    background: transparent;
    color: var(--azul-marino);
    border: 2px solid var(--azul-marino);
}

.btn-outline:hover {
    background: var(--azul-marino);
    color: white;
}

/* ============================================
   ALERTAS
   ============================================ */
.alert {
    padding: 14px 18px;
    border-radius: 10px;
    font-size: 14px;
    margin-bottom: 20px;
    border-left: 4px solid;
}

.alert-success { background: #e8f5ed; color: #1a5a2e; border-color: var(--exito); }
.alert-error   { background: #fdeaea; color: #8a2020; border-color: var(--error); }
.alert-info    { background: var(--azul-suave); color: var(--azul-marino); border-color: var(--azul-metal); }
.alert-warning { background: #fff8e6; color: #8a6a10; border-color: var(--advertencia); }

/* ============================================
   LINKS AUXILIARES
   ============================================ */
.auth-links {
    text-align: center;
    margin-top: 20px;
    font-size: 13px;
    color: var(--texto-gris);
}

.auth-links a {
    color: var(--azul-metal);
    text-decoration: none;
    font-weight: 600;
}

.auth-links a:hover {
    text-decoration: underline;
}

/* ============================================
   DASHBOARD - STATS
   ============================================ */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--blanco);
    border: 1px solid var(--gris-borde);
    border-radius: 14px;
    padding: 24px;
    text-align: center;
    box-shadow: var(--sombra);
    transition: all 0.3s;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--sombra-hover);
}

.stat-card .stat-icon {
    font-size: 32px;
    margin-bottom: 8px;
}

.stat-card .stat-value {
    font-size: 32px;
    font-weight: 700;
    color: var(--azul-marino);
    line-height: 1.2;
}

.stat-card .stat-label {
    font-size: 12px;
    color: var(--texto-gris);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 4px;
}

/* ============================================
   SECCIONES / TÍTULOS
   ============================================ */
.section-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--texto);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.section-title::before {
    content: '';
    width: 4px;
    height: 24px;
    background: linear-gradient(145deg, var(--azul-metal), var(--azul-marino));
    border-radius: 2px;
}

/* ============================================
   TARJETAS DE TEMAS
   ============================================ */
.temas-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
}

.tema-card {
    background: var(--blanco);
    border: 1px solid var(--gris-borde);
    border-radius: 14px;
    padding: 24px;
    text-decoration: none;
    color: var(--texto);
    transition: all 0.3s;
    display: block;
    position: relative;
    overflow: hidden;
}

.tema-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--azul-metal), var(--azul-claro));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s;
}

.tema-card:hover::before {
    transform: scaleX(1);
}

.tema-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--sombra-hover);
    border-color: var(--azul-metal);
}

.tema-card .tema-icon {
    font-size: 36px;
    margin-bottom: 12px;
}

.tema-card h3 {
    font-size: 17px;
    font-weight: 700;
    color: var(--azul-marino);
    margin-bottom: 8px;
}

.tema-card p {
    font-size: 13px;
    color: var(--texto-suave);
    line-height: 1.5;
}

/* ============================================
   RANKING
   ============================================ */
.ranking-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--blanco);
    border-radius: 14px;
    overflow: hidden;
    box-shadow: var(--sombra);
}

.ranking-table thead {
    background: linear-gradient(145deg, var(--azul-metal), var(--azul-marino));
    color: white;
}

.ranking-table th {
    padding: 16px;
    text-align: left;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.ranking-table td {
    padding: 16px;
    border-bottom: 1px solid var(--gris-borde);
    font-size: 14px;
    color: var(--texto);
}

.ranking-table tbody tr:last-child td {
    border-bottom: none;
}

.ranking-table tbody tr:hover {
    background: var(--azul-suave);
}

.ranking-table tbody tr.mi-fila {
    background: var(--azul-suave);
    font-weight: 600;
}

.rank-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--gris-claro);
    font-weight: 700;
    font-size: 14px;
    color: var(--azul-marino);
}

.rank-badge.top-1 { background: linear-gradient(145deg, #ffd700, #d4a017); color: white; }
.rank-badge.top-2 { background: linear-gradient(145deg, #d0d0d0, #a0a0a0); color: white; }
.rank-badge.top-3 { background: linear-gradient(145deg, #cd7f32, #a05a20); color: white; }

/* ============================================
   PREGUNTAS DE PRÁCTICA
   ============================================ */
.pregunta-card {
    background: var(--blanco);
    border: 1px solid var(--gris-borde);
    border-radius: 14px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--sombra);
}

.pregunta-card .num {
    display: inline-block;
    background: linear-gradient(145deg, var(--azul-metal), var(--azul-marino));
    color: white;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    text-align: center;
    line-height: 32px;
    font-weight: 700;
    font-size: 14px;
    margin-right: 12px;
}

.pregunta-card .pregunta-texto {
    font-size: 16px;
    font-weight: 600;
    color: var(--texto);
    margin-bottom: 18px;
    display: flex;
    align-items: flex-start;
}

.opciones {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.opcion {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    border: 2px solid var(--gris-borde);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 14px;
    background: var(--blanco);
}

.opcion:hover {
    border-color: var(--azul-metal);
    background: var(--azul-suave);
}

.opcion input[type="radio"] {
    accent-color: var(--azul-marino);
    width: 18px;
    height: 18px;
}

.opcion.selected {
    border-color: var(--azul-marino);
    background: var(--azul-suave);
}

/* ============================================
   PROGRESO
   ============================================ */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--gris-claro);
    border-radius: 4px;
    overflow: hidden;
    margin: 10px 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--azul-metal), var(--azul-claro));
    border-radius: 4px;
    transition: width 0.5s;
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 768px) {
    .navbar { padding: 0 16px; }
    .navbar-brand span { display: none; }
    .navbar-menu a { padding: 8px 10px; font-size: 13px; }
    .container { padding: 20px 16px; }
    .card { padding: 24px 20px; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
}