/* V3: bienvenida no intrusiva, botón «?» y manual gráfico */
.vacio-capa .bienv { position: relative; pointer-events: auto; max-width: 30rem; padding: var(--e-4); display: grid; gap: var(--e-2); text-align: left; }
.movil .vacio-capa .bienv { pointer-events: auto; }
.bienv h3 { margin: 0; padding-right: 44px; }
.bienv-sub { margin: 0; color: var(--texto-2); font-size: var(--t-sm); }
.bienv-eti { margin: var(--e-1) 0 0; }
.bienv .ejemplos { display: flex; gap: var(--e-2); flex-wrap: wrap; }
.bienv .ejemplos .btn { flex: 1 1 8rem; min-height: 44px; }
.bienv-btn { width: 100%; min-height: 48px; justify-content: center; }
.bienv-x { position: absolute; top: 6px; right: 6px; width: 44px; height: 44px; font-size: 18px; }
.bienv-q, .btn-ayuda { font-weight: 800; }
.bienv-q { display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; border: 2px solid currentColor; font-size: 13px; margin-right: 6px; }
.btn-ayuda { min-width: 44px; min-height: 44px; font-size: 18px; color: var(--primario); }
.bienv-pista { pointer-events: auto; display: inline-flex; align-items: center; gap: var(--e-2); padding: 4px 4px 4px var(--e-3); border-radius: var(--r-full); background: var(--superficie); box-shadow: var(--sombra-2); font-size: var(--t-sm); color: var(--texto-2); }
.bienv-pista .btn { min-width: 40px; min-height: 40px; font-weight: 800; color: var(--primario); }
.pc-vacio .ejemplos { flex-wrap: wrap; }

/* manual */
.dlg-manual #manCuerpo { padding-bottom: 2rem; }
.man-indice { display: flex; gap: 6px; overflow-x: auto; padding: 4px 16px 8px; -webkit-overflow-scrolling: touch; position: sticky; top: 52px; background: var(--superficie, #fff); z-index: 1; border-bottom: 1px solid var(--borde); }
.man-indice button { flex: none; min-height: 40px; padding: 0 12px; border-radius: 999px; border: 1px solid var(--borde); background: var(--superficie); color: var(--texto-2); font: var(--peso-medio) var(--t-sm) var(--fuente); cursor: pointer; }
.man-indice button[aria-current="true"] { background: var(--primario); border-color: var(--primario); color: var(--sobre-primario); }
.man-sec h2 { margin: .8rem 0 .3rem; font-size: 1.25rem; }
.man-sec h3 { margin: 1rem 0 .3rem; font-size: 1.05rem; }
.man-sec p, .man-sec li { line-height: 1.5; }
.man-intro { color: var(--texto-2); }
.man-fig { margin: .6rem 0 .9rem; }
.man-img { position: relative; max-width: 360px; margin: 0 auto; border-radius: 14px; overflow: hidden; border: 1px solid var(--borde); box-shadow: var(--sombra-1, 0 1px 3px rgba(0,0,0,.12)); }
.man-img img { display: block; width: 100%; height: auto; }
.man-marca { position: absolute; transform: translate(-50%, -50%); width: 24px; height: 24px; border-radius: 50%; display: grid; place-items: center; background: #e5482b; color: #fff; font: 700 13px/1 var(--fuente); border: 2px solid #fff; box-shadow: 0 1px 4px rgba(0,0,0,.35); pointer-events: none; }
.man-leyenda { list-style: none; padding: 0; margin: .5rem auto 0; max-width: 36rem; display: grid; gap: 6px; }
.man-leyenda li { display: grid; grid-template-columns: 26px 1fr; gap: 8px; align-items: start; }
.man-leyenda li > b { width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; background: #e5482b; color: #fff; font-size: 12px; margin-top: 1px; }
.man-fig figcaption { text-align: center; font-size: .85rem; color: var(--texto-2); margin-top: .3rem; }
.man-pasos { padding-left: 1.4em; }
.man-pasos li { margin-bottom: .3rem; }
.man-glosa { display: grid; gap: 8px; margin: .4rem 0; }
.man-glosa > div { display: grid; grid-template-columns: 64px 1fr; gap: 10px; align-items: center; padding: 6px 8px; border: 1px solid var(--borde); border-radius: 10px; }
.man-glosa svg { width: 64px; height: 40px; }
.man-ir { margin-top: .4rem; }
@media (min-width: 900px) { .man-fig.con-leyenda { display: grid; grid-template-columns: 360px 1fr; gap: 1.2rem; align-items: start; } .man-fig.con-leyenda .man-leyenda { margin: 0; } }

/* V4: resistencia de materiales */
.rm-cuerpo { padding-bottom: 2rem; }
.rm-q { font-size: 1.2rem; margin: .7rem 0 .5rem; }
.rm-temas { display: grid; gap: 8px; }
@media (min-width: 700px) { .rm-temas { grid-template-columns: 1fr 1fr; } }
.rm-tema { display: flex; gap: 12px; align-items: center; text-align: left; min-height: 64px; padding: 10px 12px; font: inherit; color: var(--texto); cursor: pointer; border: 1px solid var(--borde); background: var(--superficie); }
.rm-tema:active { transform: scale(.98); }
.rm-tema small { display: block; color: var(--texto-2); font-size: var(--t-sm); margin-top: 2px; }
.rm-ic { flex: none; width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center; font-size: 20px; font-weight: 800; background: var(--primario-suave); color: var(--primario); }
.rm-volver { min-height: 44px; margin-top: 6px; }
.rm-form { display: grid; gap: 8px; }
@media (min-width: 700px) { .rm-form { grid-template-columns: 1fr 1fr; } }
.rm-campo, .rm-op { display: grid; gap: 4px; font-size: var(--t-sm); }
.rm-campo i { color: var(--texto-3); font-style: normal; }
.rm-in { display: flex; align-items: center; border: 1px solid var(--borde-fuerte); border-radius: 10px; background: var(--superficie); padding-right: 10px; }
.rm-in input { flex: 1; min-width: 0; min-height: 44px; border: 0; background: transparent; padding: 0 10px; font: 500 1rem var(--fuente-num, var(--fuente)); color: var(--texto); }
.rm-in input:focus { outline: none; }
.rm-in:focus-within { border-color: var(--primario); box-shadow: 0 0 0 3px var(--enfoque); }
.rm-in input.error { color: var(--peligro); }
.rm-in em { font-style: normal; color: var(--texto-2); font-size: var(--t-sm); }
.rm-op select { min-height: 44px; border-radius: 10px; border: 1px solid var(--borde-fuerte); background: var(--superficie); color: var(--texto); padding: 0 8px; font: inherit; }
.rm-acc { display: flex; gap: 8px; flex-wrap: wrap; margin: 10px 0; }
.rm-acc .btn { flex: 1 1 8rem; min-height: 48px; }
.rm-msg { padding: 8px 12px; border-radius: 10px; background: var(--aviso-suave); color: var(--aviso); }
.rm-msg.rm-info { background: var(--primario-suave); color: var(--primario-hover); }
.rm-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 8px; margin: 8px 0; }
.rm-res { display: grid; gap: 2px; padding: 8px 10px; }
.rm-res-t { font-size: var(--t-xs); color: var(--texto-2); }
.rm-res b { font: 700 1.15rem var(--fuente-num, var(--fuente)); }
.rm-res small { color: var(--texto-2); }
.chip.rm-mal { background: var(--peligro-suave); color: var(--peligro); }
.rm-nota { font-size: var(--t-sm); color: var(--texto-2); }
.rm-svg { display: block; width: 100%; max-width: 420px; height: auto; margin: 6px auto; background: var(--lienzo); border: 1px solid var(--borde); border-radius: 12px; }
.rm-svg-sec { max-width: 200px; }
.rm-eje { stroke: var(--texto-3); stroke-width: 1; }
.rm-circ { fill: color-mix(in srgb, var(--primario) 8%, transparent); stroke: var(--primario); stroke-width: 2; }
.rm-diam { stroke: var(--texto-2); stroke-width: 1.3; stroke-dasharray: 4 3; }
.rm-pto { fill: var(--seleccion); stroke: var(--superficie); stroke-width: 1.5; }
.rm-pp { fill: var(--primario); }
.rm-c { fill: var(--texto-2); }
.rm-t { font: 11px var(--fuente); fill: var(--texto); }
.rm-b { font-weight: 700; }
.rm-el { fill: color-mix(in srgb, var(--primario) 10%, transparent); stroke: var(--estructura); stroke-width: 1.6; }
.rm-fl { stroke: var(--carga); stroke-width: 1.8; fill: none; }
.rm-pu { fill: var(--carga); }
.rm-sec { fill: color-mix(in srgb, var(--estructura) 22%, transparent); stroke: var(--estructura); stroke-width: 1.4; }
.rm-hueco { fill: var(--lienzo); stroke: var(--estructura); stroke-width: 1.2; }
.rm-en { stroke: var(--primario); stroke-width: 1; stroke-dasharray: 5 3; }
.rm-modo { margin-top: 8px; }
.pasos-figura .rm-svg { margin: .3rem 0; }