:root {
  --bg: #f2f3fa;
  --bg-glow: radial-gradient(circle at 10% -10%, #dcdcff 0%, transparent 50%),
             radial-gradient(circle at 100% 0%, #fbdcef 0%, transparent 45%),
             radial-gradient(circle at 50% 120%, #d8f3ff 0%, transparent 50%);
  --card: rgba(255, 255, 255, 0.88);
  --surface: #ffffff;
  --border: #d5d8e6;
  --text: #13162a;
  --muted: #555a70;
  --input: #f8f9fd;
  --key: #ffffff;
  --key-fn: #eef0f8;
  --accent: #4646d8;
  --accent-soft: #ececfe;
  --accent-grad: linear-gradient(135deg, #5552f0 0%, #8338e8 100%);
  --error: #c4282d;
  --warn: #a34e00;
  --shadow: 0 10px 30px -12px rgba(30, 35, 90, 0.18);
  --key-shadow: 0 1px 0 rgba(255, 255, 255, .9) inset, 0 4px 12px -6px rgba(30, 35, 90, .22);
  --r-lg: 24px;   /* contenedores: teclado, pantalla */
  --r-md: 16px;   /* filas y tarjetas */
  --r-key: 14px;  /* teclas: radio del teclado menos su padding */
  --tag-dec: #4b4be0;
  --tag-bin: #0a7372;
  --tag-oct: #a35100;
  --tag-hex: #b81d5f;
  --tag-txt: #7c3aed;
}

:root[data-theme="dark"] {
  --bg: #0d0f1a;
  --bg-glow: radial-gradient(circle at 15% 0%, #1e1f4a 0%, transparent 45%),
             radial-gradient(circle at 90% 10%, #3a1531 0%, transparent 40%);
  --card: rgba(26, 29, 48, 0.9);
  --surface: #171a2b;
  --border: #353a56;
  --text: #f2f3fb;
  --muted: #a6abc6;
  --input: #11131f;
  --key: #1b1e31;
  --key-fn: #23263d;
  --accent: #a3a3ff;
  --accent-soft: #23254a;
  --error: #ff7b80;
  --key-shadow: 0 1px 0 rgba(255, 255, 255, .05) inset, 0 6px 14px -8px rgba(0, 0, 0, .7);
  --warn: #f5b062;
  --shadow: 0 10px 30px -12px rgba(0, 0, 0, 0.6);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

/* Letra grande para todos: como todo está en rem, la interfaz crece en proporción */
html { font-size: 112.5%; }

html, body { height: 100%; }

body {
  display: flex;
  align-items: center;
  font-family: "Inter", system-ui, sans-serif;
  background: var(--bg-glow), var(--bg);
  color: var(--text);
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
}

button {
  font-family: inherit;
  touch-action: manipulation; /* evita el zoom por doble toque */
  -webkit-user-select: none;
  user-select: none;
}

button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.app {
  position: relative;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  max-height: 940px;
  max-width: 480px;
  margin: 0 auto;
  padding: max(12px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right))
           max(12px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* ---------- Encabezado y pestañas ---------- */

.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
}

h1 {
  flex: 1;
  min-width: 0;
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.icon-btn {
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  box-shadow: var(--key-shadow);
  cursor: pointer;
  display: grid;
  place-items: center;
}

.top-actions { display: flex; gap: 8px; }

.icon-btn .moon { display: none; }
:root[data-theme="dark"] .icon-btn .moon { display: block; }
:root[data-theme="dark"] .icon-btn .sun { display: none; }

/* Navegación inferior: al alcance del pulgar, con ícono y nombre */
.tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  padding: 6px;
  background: var(--card);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  flex-shrink: 0;
}

.tab {
  text-decoration: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: .75rem;
  font-weight: 600;
  padding: 4px 2px;
  border-radius: 14px;
  cursor: pointer;
  white-space: nowrap;
  transition: color .2s;
}

.tab svg {
  box-sizing: content-box;
  width: 22px;
  height: 22px;
  padding: 4px 16px;
  border-radius: 999px;
  transition: background .2s;
}

.tab[aria-current="page"] { color: var(--accent); }
.tab[aria-current="page"] svg { background: var(--accent-soft); }

.panel {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.panel[hidden] { display: none; }

/* ---------- Etiquetas de base ---------- */

.tag {
  font-family: "JetBrains Mono", monospace;
  font-size: .75rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 999px;
  color: #fff;
  letter-spacing: .04em;
  text-align: center;
  background: var(--accent);
}

.tag-dec { background: var(--tag-dec); }
.tag-bin { background: var(--tag-bin); }
.tag-oct { background: var(--tag-oct); }
.tag-hex { background: var(--tag-hex); }
.tag-txt { background: var(--tag-txt); }

/* ---------- Convertir ---------- */

.conv-rows {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex-shrink: 0;
}

.conv-row {
  display: grid;
  grid-template-columns: 6.2em 1fr 36px;
  align-items: center;
  gap: 6px;
  padding: 6px 6px 6px 12px;
  background: var(--card);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border: 1.5px solid var(--border);
  border-radius: var(--r-md);
  box-shadow: var(--key-shadow);
  cursor: text;
  transition: border-color .2s, box-shadow .2s;
}

.conv-row.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}


.row-label {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  cursor: pointer;
}

.row-label small { font-size: .78rem; line-height: 1.15; color: var(--muted); font-weight: 500; }

.row-input {
  min-width: 0;
  width: 100%;
  border: none;
  background: transparent;
  color: var(--text);
  font: 500 1.05rem "JetBrains Mono", monospace;
  padding: 8px 4px;
  outline: none;
  caret-color: var(--accent);
}

.row-input::placeholder { color: var(--muted); opacity: .5; }

.copy-btn {
  width: 34px;
  height: 34px;
  border: none;
  border-radius: 50%;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  display: grid;
  place-items: center;
}


.msg {
  font-size: .88rem;
  color: var(--muted);
  min-height: 1.2em;
  line-height: 1.2;
  flex-shrink: 0;
  padding: 0 4px;
}

.msg.warn { color: var(--warn); font-weight: 500; }
.msg.error { color: var(--error); font-weight: 500; }

/* ---------- Teclado virtual ---------- */

.pad {
  flex: 1;
  min-height: 0;
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 10px;
  background: var(--card);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
}

.pad[hidden] { display: none; }

.hex-row {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
  flex: 0.8;
  min-height: 0;
}

.keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  min-height: 0;
}

.keys-prog { flex: 5; grid-template-rows: repeat(5, 1fr); }
.keys-conv { flex: 4; grid-template-rows: repeat(4, 1fr); }

.key {
  min-height: 0;
  border: none;
  background: var(--key);
  color: var(--text);
  font: 600 1.4rem "JetBrains Mono", monospace;
  border-radius: var(--r-key);
  box-shadow: var(--key-shadow);
  cursor: pointer;
  user-select: none;
  touch-action: manipulation;
  transition: background .15s, transform .08s, opacity .2s;
}

.key:active:not(:disabled) { transform: scale(.93); }
.key:disabled { opacity: .28; cursor: not-allowed; box-shadow: none; }

.key.hex { font-size: 1.1rem; background: var(--key-fn); }
.key.fn { background: var(--key-fn); font-family: "Inter", sans-serif; font-size: 1.1rem; font-weight: 700; }
.key.danger { color: var(--error); }
.key.op { background: var(--accent-soft); color: var(--accent); font-size: 1.5rem; }
.key.op.selected { background: var(--accent-grad); color: #fff; }
.key.eq {
  background: var(--accent-grad);
  color: #fff;
  font-size: 1.6rem;
  box-shadow: 0 10px 22px -10px rgba(109, 107, 255, .9);
}

/* ---------- Pantalla de las calculadoras ---------- */

.display {
  background: var(--card);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  padding: 10px 18px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.expr {
  font: 1rem "JetBrains Mono", monospace;
  color: var(--muted);
  text-align: right;
  min-height: 1.2em;
  overflow-wrap: anywhere;
}

.link-btn {
  border: none;
  background: none;
  color: var(--accent);
  font-size: .9rem;
  font-weight: 700;
  cursor: pointer;
  padding: 2px 0;
  margin-left: auto;
}

.link-btn[hidden] { display: none; }

/* ---------- Programador ---------- */

.prog-mode {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.prog-mode[hidden] { display: none; }

/* Calculadora en bases */
.pc-line { display: flex; align-items: center; gap: 10px; }

.pc-main {
  flex: 1;
  text-align: right;
  font: 600 2.2rem "JetBrains Mono", monospace;
  letter-spacing: -0.02em;
  line-height: 1.15;
  overflow-wrap: anywhere;
  cursor: pointer;
}

.pc-main.long { font-size: 1.5rem; }
.pc-main.xlong { font-size: 1.1rem; }
.pc-main.error { font: 600 1.05rem "Inter", sans-serif; color: var(--error); }

/* Línea superior: residuo a la izquierda y operación a la derecha */
.pc-top { display: flex; align-items: baseline; gap: 10px; }
.pc-top .expr { flex: 1; min-width: 0; }
.pc-rem { font: 600 .9rem "JetBrains Mono", monospace; color: var(--accent); white-space: nowrap; }

.pc-note {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  min-height: 32px;
}

.pc-links { display: flex; gap: 8px; margin-left: auto; }

/* Acciones secundarias de la pantalla: botones píldora separados */
.chip-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  min-height: 32px;
  padding: 4px 12px;
  border: 1.5px solid var(--border);
  border-radius: 999px;
  background: var(--card);
  color: var(--text);
  font: 600 .82rem "Inter", sans-serif;
  white-space: nowrap;
  cursor: pointer;
  transition: border-color .2s, background .2s, transform .08s;
}

.chip-btn:active { transform: scale(.96); }
.chip-btn[hidden] { display: none; }
.chip-btn.primary { border-color: transparent; background: var(--accent-soft); color: var(--accent); }

.pc-bases { display: flex; flex-direction: column; gap: 6px; flex-shrink: 0; }

.pc-base {
  display: grid;
  grid-template-columns: 6.6em 1fr;
  align-items: center;
  gap: 10px;
  padding: 4px 12px;
  font-size: 1rem; /* los botones no heredan el tamaño de letra */
  border: 1.5px solid var(--border);
  background: var(--card);
  color: var(--text);
  border-radius: var(--r-md);
  text-align: left;
  cursor: pointer;
  transition: border-color .2s, box-shadow .2s;
}

.pc-base.active { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }

.pc-base .val {
  font: 600 1rem "JetBrains Mono", monospace;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  direction: rtl;
  text-align: left;
  unicode-bidi: plaintext;
}

/* Conversor de bases */

.prog-status {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 1.7em;
  padding: 0 4px;
  flex-shrink: 0;
}

.prog-expr {
  flex: 1;
  min-width: 0;
  font: 500 .95rem "JetBrains Mono", monospace;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.prog-expr.hint { font: 500 .88rem "Inter", sans-serif; }
.prog-expr.warn { font: 600 .88rem "Inter", sans-serif; color: var(--warn); }
.prog-expr.error { font: 600 .88rem "Inter", sans-serif; color: var(--error); }
.prog-status .link-btn { margin-left: 0; flex-shrink: 0; }

/* ---------- Básica y Científica ---------- */

.ec, #panel-fin { position: relative; }

.ec-display { gap: 2px; }

.ec-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin: -2px -6px 2px 0;
}

.ec-chips { display: flex; gap: 6px; }

.chip {
  font: 700 .72rem "JetBrains Mono", monospace;
  letter-spacing: .04em;
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

.chip[hidden] { display: none; }

.ec-tools { display: flex; gap: 2px; }

.tool-btn {
  min-width: 40px;
  height: 34px;
  padding: 0 8px;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font: 700 .8rem "Inter", sans-serif;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: background .15s, color .15s, transform .08s;
}

.tool-btn:active { transform: scale(.94); }
.tool-btn[hidden] { display: none; }

.ec-main {
  font: 600 2.2rem "JetBrains Mono", monospace;
  letter-spacing: -0.02em;
  line-height: 1.25;
  text-align: right;
  white-space: nowrap;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
  cursor: pointer;
}

.ec-main::-webkit-scrollbar { display: none; }
.ec-main.long { font-size: 1.65rem; }
.ec-main.xlong { font-size: 1.3rem; }
.ec-main.is-empty { color: var(--muted); }
.ec-main .ghost { color: var(--muted); opacity: .55; }

.ec-preview {
  display: block;
  min-height: 1.45em;
  text-align: right;
  font: 500 1.05rem "JetBrains Mono", monospace;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.ec-preview.error { font: 600 .95rem "Inter", sans-serif; color: var(--error); }

.ec-keys { flex: 5; }

.keys-basic { grid-template-columns: repeat(4, 1fr); grid-template-rows: repeat(5, 1fr); }
.keys-basic .key { font-size: 1.65rem; }
.keys-basic .key.fn { font-size: 1.25rem; }
#panel-basic .ec-main { font-size: 2.8rem; }
#panel-basic .ec-main.long { font-size: 2rem; }
#panel-basic .ec-main.xlong { font-size: 1.4rem; }

.keys-sci-fn {
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(3, 1fr);
  flex: 2.55;
}

.keys-sci {
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(5, 1fr);
  flex: 5;
}

.keys-sci-fn .key { font: 600 1.02rem "Inter", sans-serif; background: var(--key-fn); }
.keys-sci-fn .key.angle { font: 700 .85rem "JetBrains Mono", monospace; color: var(--accent); }
.keys-sci .key { font-size: 1.3rem; }
.keys-sci .key.fn { font-size: 1rem; }
.key sup { font-size: .62em; line-height: 0; margin-left: 1px; }
.key.toggle.on { background: var(--accent-grad); color: #fff; }

/* Historial: se superpone dentro de la pestaña */
.history {
  position: absolute;
  inset: 0;
  z-index: 5;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
}

.history[hidden] { display: none; }

.history-head { display: flex; align-items: center; gap: 6px; }
.history-head h2 { flex: 1; font-size: 1.1rem; }
.history-head .tool-btn { color: var(--accent); }

.history-list {
  list-style: none;
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.history-item {
  width: 100%;
  text-align: right;
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  background: var(--card);
  color: var(--text);
  border-radius: var(--r-md);
  cursor: pointer;
}

.history-item .h-expr { display: block; font: .9rem "JetBrains Mono", monospace; color: var(--muted); overflow-wrap: anywhere; }
.history-item .h-res { display: block; font: 600 1.25rem "JetBrains Mono", monospace; overflow-wrap: anywhere; }

.history-empty { margin: auto; text-align: center; color: var(--muted); line-height: 1.6; }

/* ---------- Finanzas ---------- */

.seg-control {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 1fr;
  gap: 4px;
  padding: 4px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 999px;
  flex-shrink: 0;
}

.seg {
  display: grid;
  place-items: center;
  text-decoration: none;
  min-height: 40px;
  border: none;
  background: transparent;
  color: var(--muted);
  font: 600 .85rem "Inter", sans-serif;
  padding: 8px 2px;
  border-radius: 999px;
  white-space: nowrap;
  cursor: pointer;
  transition: background .2s, color .2s;
}

.seg.active {
  background: var(--accent-grad);
  color: #fff;
  box-shadow: 0 6px 16px -8px rgba(109, 107, 255, .8);
}

.fin-scroll {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 2px 2px 8px;
}

.fin-intro { color: var(--muted); font-size: .88rem; padding: 0 4px; }

.fin-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 12px;
  align-content: start;
}

.field { display: flex; flex-direction: column; gap: 5px; min-width: 0; }
.fin-form > .wide { grid-column: 1 / -1; }
.field label { font-size: .85rem; font-weight: 600; padding-left: 4px; }
.field .optional { color: var(--muted); font-weight: 500; }

.field-input {
  display: flex;
  align-items: center;
  min-height: 50px;
  padding: 0 12px;
  background: var(--card);
  border: 1.5px solid var(--border);
  border-radius: var(--r-md);
  transition: border-color .2s, box-shadow .2s;
}

.field-input:focus-within { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.field.invalid .field-input { border-color: var(--error); }

.field-input input {
  flex: 1;
  min-width: 0;
  border: none;
  background: transparent;
  color: var(--text);
  font: 600 1.1rem "JetBrains Mono", monospace;
  padding: 10px 0;
  outline: none;
}

.field-input input::placeholder { color: var(--muted); opacity: .5; }
.field-input .suffix { color: var(--muted); font-weight: 600; font-size: .9rem; margin-left: 6px; }

.field-input select {
  margin-left: 6px;
  padding: 6px 8px;
  border: none;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font: 600 .85rem "Inter", sans-serif;
  cursor: pointer;
}

.field-error { color: var(--error); font-size: .8rem; padding-left: 4px; }
.field-error:empty { display: none; }

.fin-result {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  align-self: start;
  width: 100%;
}

.fin-empty { color: var(--muted); text-align: center; padding: 6px 0; }

/* IGV: tres campos conectados, el que se escribe queda resaltado */
.igv-rows { display: flex; flex-direction: column; gap: 6px; }

.igv-row {
  display: grid;
  grid-template-columns: 8em 1fr 36px;
  align-items: center;
  gap: 6px;
  padding: 3px 6px 3px 14px;
  background: var(--card);
  border: 1.5px solid var(--border);
  border-radius: var(--r-md);
  box-shadow: var(--key-shadow);
  transition: border-color .2s, box-shadow .2s;
}

.igv-row.active { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.igv-row label { font-size: .9rem; font-weight: 600; cursor: pointer; }

.igv-row input {
  min-width: 0;
  padding: 11px 4px;
  border: none;
  background: transparent;
  color: var(--text);
  font: 600 1.15rem "JetBrains Mono", monospace;
  text-align: right;
  outline: none;
}

.igv-row input::placeholder { color: var(--muted); opacity: .5; }

.fin-main { display: flex; flex-direction: column; gap: 2px; }
.fin-main-label { color: var(--muted); font-size: .85rem; font-weight: 600; }

.fin-main-value {
  border: none;
  background: none;
  padding: 0;
  text-align: left;
  color: var(--text);
  font: 700 2rem "JetBrains Mono", monospace;
  letter-spacing: -0.02em;
  overflow-wrap: anywhere;
  cursor: pointer;
}

.fin-items { display: grid; gap: 6px; }
.fin-items div { display: flex; justify-content: space-between; gap: 12px; padding-top: 6px; border-top: 1px solid var(--border); }
.fin-items dt { color: var(--muted); font-size: .9rem; }
.fin-items dd { font: 600 .95rem "JetBrains Mono", monospace; text-align: right; }

.secondary-btn {
  min-height: 44px;
  padding: 10px 16px;
  border: 1.5px solid var(--border);
  border-radius: 999px;
  background: transparent;
  color: var(--accent);
  font: 700 .9rem "Inter", sans-serif;
  cursor: pointer;
}

.fin-sheet-body { flex: 1; min-height: 0; overflow: auto; }

.fin-table { width: 100%; border-collapse: collapse; font: .82rem "JetBrains Mono", monospace; }
.fin-table th {
  position: sticky;
  top: 0;
  padding: 6px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  font: 600 .75rem "Inter", sans-serif;
  text-align: right;
}
.fin-table td { padding: 6px; border-bottom: 1px solid var(--border); text-align: right; white-space: nowrap; }
.fin-table th:first-child, .fin-table td:first-child { text-align: left; }

/* ---------- Ayuda (guía y preguntas frecuentes de cada página) ---------- */

.info-sheet {
  position: absolute;
  inset: max(8px, env(safe-area-inset-top)) 8px max(8px, env(safe-area-inset-bottom));
  z-index: 20;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: 0 24px 60px -20px rgba(20, 22, 50, .45);
}

.info-sheet[hidden] { display: none; }
.info-sheet .history-head h2 { font-size: 1.15rem; }

.info-body { flex: 1; min-height: 0; overflow-y: auto; padding-right: 4px; }

.info-article { display: flex; flex-direction: column; gap: 10px; color: var(--text); line-height: 1.55; }
.info-article h2 { font-size: 1rem; margin-top: 8px; }
.info-article p, .info-article li { font-size: .95rem; color: var(--muted); }
.info-article .info-lead { font-size: 1rem; color: var(--text); }
.info-article ol, .info-article ul { padding-left: 1.3em; display: flex; flex-direction: column; gap: 6px; }

.faq { display: flex; flex-direction: column; gap: 8px; }

.faq details {
  border: 1.5px solid var(--border);
  border-radius: var(--r-md);
  background: var(--card);
  padding: 0 14px;
}

.faq summary {
  min-height: 46px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: .95rem;
  cursor: pointer;
  list-style: none;
}

.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; margin-left: auto; font-size: 1.3rem; color: var(--accent); }
.faq details[open] summary::after { content: "−"; }
.faq details p { padding-bottom: 12px; }

.info-links { list-style: none; padding-left: 0 !important; display: grid !important; grid-template-columns: 1fr 1fr; gap: 8px !important; }
.info-links a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--r-md);
  background: var(--card);
  color: var(--accent);
  font-weight: 600;
  font-size: .9rem;
  text-decoration: none;
}

.noscript {
  position: fixed;
  inset: auto 16px 16px;
  padding: 12px 16px;
  border-radius: var(--r-md);
  background: var(--error);
  color: #fff;
  font-weight: 600;
  text-align: center;
}

/* ---------- Paso a paso ---------- */

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  flex-shrink: 0;
  border: 1.5px solid var(--border);
  background: var(--card);
  color: var(--accent);
  font-size: .95rem;
  font-weight: 700;
  padding: 10px 18px;
  border-radius: 999px;
  cursor: pointer;
  min-height: 44px;
}

.steps {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-bottom: 4px;
}

.box {
  background: var(--card);
  border: 1px solid var(--border);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-radius: var(--r-md);
  padding: 14px 16px;
  flex-shrink: 0;
}

.box h3 { font-size: 1rem; margin-bottom: 6px; }
.box p, .box li { font-size: .95rem; line-height: 1.55; color: var(--muted); }
.box b, .box strong { color: var(--text); }
.box ol { padding-left: 1.4em; display: flex; flex-direction: column; gap: 4px; }

.op-summary {
  display: flex;
  align-items: center;
  gap: 10px;
  font: 600 1rem "JetBrains Mono", monospace;
  overflow-wrap: anywhere;
}

.colgrid-wrap { overflow-x: auto; padding: 4px 0; }

.colgrid {
  display: grid;
  font: 500 1.05rem "JetBrains Mono", monospace;
  row-gap: 2px;
  width: max-content;
  margin-left: auto;
}

.cg-cell, .cg-sign { text-align: center; line-height: 1.5; }
.cg-sign { color: var(--accent); font-weight: 600; }
.cg-cell.carry { font-size: .82rem; font-weight: 700; color: var(--warn); line-height: 1.2; align-self: end; }
.cg-cell.res { color: var(--accent); font-weight: 600; }
.ok-icon { display: inline-flex; vertical-align: -2px; color: var(--ok, #12a150); }

.cg-line { border-top: 2px solid var(--text); margin: 2px 0; }

.div-table {
  width: 100%;
  border-collapse: collapse;
  font: .9rem "JetBrains Mono", monospace;
}

.div-table th { text-align: left; font: 600 .8rem "Inter", sans-serif; color: var(--muted); padding: 4px; }
.div-table td { padding: 5px 4px; border-top: 1px solid var(--border); color: var(--text); }

.empty {
  margin: auto;
  text-align: center;
  color: var(--muted);
  font-size: .9rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 20px;
}

.primary-btn {
  border: none;
  background: var(--accent-grad);
  color: #fff;
  font-weight: 600;
  font-size: .88rem;
  padding: 11px 22px;
  border-radius: 999px;
  cursor: pointer;
}

/* ---------- Varios ---------- */

.shake { animation: shake .3s; }

@keyframes shake {
  20%, 60% { transform: translateX(-4px); }
  40%, 80% { transform: translateX(4px); }
}

.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translate(-50%, 20px);
  background: var(--text);
  color: var(--bg);
  padding: 10px 20px;
  border-radius: 999px;
  font-size: .88rem;
  font-weight: 500;
  opacity: 0;
  pointer-events: none;
  white-space: nowrap;
  transition: opacity .2s, transform .2s;
  z-index: 10;
}

.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- Adaptación a dispositivos ---------- */

/* Solo con mouse: en pantallas táctiles el hover se queda "pegado" */
@media (hover: hover) {
  .copy-btn:hover { background: var(--accent-soft); color: var(--accent); }
  .key:hover:not(:disabled) { filter: brightness(.97); }
  .seg:hover:not(.active) { color: var(--text); }
  .pc-base:hover:not(.active) { border-color: var(--muted); }
  .chip-btn:hover { border-color: var(--accent); }
  .info-links a:hover { border-color: var(--accent); }
  .tool-btn:hover { background: var(--accent-soft); color: var(--accent); }
  .history-item:hover { border-color: var(--accent); }
}

/* Pantallas bajas: la fila A–F solo aparece en hexadecimal y el nombre
   de cada base va al lado de su etiqueta para ahorrar alto */
@media (max-height: 860px) {
  .pad.no-hex .hex-row { display: none; }
  .conv-row { grid-template-columns: 7.8em 1fr 36px; padding-top: 3px; padding-bottom: 3px; }
  .conv-row .row-label { flex-direction: row; align-items: center; gap: 6px; }
  .pc-base { grid-template-columns: 9.5em 1fr; }
  .pc-base .row-label { flex-direction: row; align-items: center; gap: 8px; }
  .row-input { padding: 5px 4px; }
}

/* Altura reducida (laptops de 720 px y teléfonos): controles más compactos */
@media (max-height: 760px) {
  .tabs { padding: 4px; }
  .tab svg { padding-top: 2px; padding-bottom: 2px; }
  .seg { min-height: 34px; padding-top: 5px; padding-bottom: 5px; }
  .pc-bases { display: grid; grid-template-columns: 1fr 1fr; }
  .pc-base { grid-template-columns: auto 1fr; gap: 8px; padding: 3px 8px; }
  .pc-base .row-label small { display: none; }
}

/* Teléfonos pequeños */
@media (max-height: 700px) {
  .app { gap: 8px; padding-top: max(10px, env(safe-area-inset-top)); padding-bottom: max(10px, env(safe-area-inset-bottom)); }
  .panel { gap: 8px; }
  h1 { font-size: 1.1rem; }
  .icon-btn { width: 34px; height: 34px; }
  .tab { padding: 2px; gap: 2px; }
  .tab svg { width: 20px; height: 20px; padding: 3px 14px; }
  .conv-rows { gap: 5px; }
  .conv-row { grid-template-columns: 58px 1fr 34px; padding-top: 2px; padding-bottom: 2px; }
  .row-label small { display: none; }
  .row-input { padding: 3px 4px; }
  .display { padding: 8px 16px; }
  #panel-basic .ec-main { font-size: 2.2rem; }
  .pc-main { font-size: 1.7rem; }
  .pc-bases { display: grid; grid-template-columns: 1fr 1fr; }
  .pc-base { grid-template-columns: auto 1fr; gap: 6px; padding: 3px 8px; }
  .field-input { min-height: 46px; }
  .pad { padding: 8px; gap: 6px; }
  .keys, .hex-row { gap: 6px; }
  .pad { border-radius: 20px; }
  .key { border-radius: 12px; }
  .ec-main { font-size: 1.8rem; }
  .ec-main.long { font-size: 1.4rem; }
  .ec-main.xlong { font-size: 1.15rem; }
  .keys-sci-fn { flex: 2.2; }
  .keys-sci-fn .key { font-size: .9rem; }
  .tool-btn { height: 30px; min-width: 36px; }
}

/* Teléfonos angostos */
@media (max-width: 360px) {
  .tab { font-size: .7rem; }
  .seg { font-size: .78rem; }
  .igv-row { grid-template-columns: 6.6em 1fr 32px; padding-left: 10px; }
  .igv-row label { font-size: .8rem; }
  .igv-row input { font-size: 1.05rem; }
  .tab svg { padding-left: 10px; padding-right: 10px; }
  h1 { font-size: 1.05rem; }
}

/* Teléfono en horizontal: dos columnas (datos a la izquierda, teclado a la derecha) */
@media (orientation: landscape) and (min-width: 560px) and (max-height: 500px) {
  .app {
    max-width: 980px;
    max-height: none;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    grid-template-rows: auto minmax(0, 1fr);
    column-gap: 16px;
  }
  .top { display: contents; }
  h1 { grid-column: 1; grid-row: 1; align-self: center; }
  .tabs { grid-column: 2; grid-row: 1; justify-self: center; width: 100%; max-width: 560px; padding: 4px; border-radius: 999px; }
  .tab { flex-direction: row; justify-content: center; gap: 6px; padding: 6px 8px; border-radius: 999px; }
  .tab svg { width: 18px; height: 18px; padding: 0; }
  .tab[aria-current="page"] { background: var(--accent-soft); }
  .tab[aria-current="page"] svg { background: none; }
  .top-actions { grid-column: 3; grid-row: 1; }
  .panel { grid-column: 1 / -1; grid-row: 2; }

  /* Programador: datos a la izquierda y teclado a la derecha */
  .prog-mode:not([hidden]) {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(260px, 1fr);
    grid-template-rows: auto auto minmax(0, 1fr);
    gap: 6px 16px;
  }
  .prog-mode > :not(.pad) { grid-column: 1; }
  .pad { grid-column: 2; grid-row: 1 / -1; margin-top: 0; }

  /* Básica: pantalla a la izquierda y teclado a la derecha */
  #panel-basic:not([hidden]) {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 10px 16px;
  }
  #panel-basic .ec-display { grid-column: 1; grid-row: 1; justify-content: flex-end; }
  #panel-basic .ec-top { margin-bottom: auto; }
  #panel-basic .ec-pad { grid-row: 1; }

  /* Finanzas: formulario y resultado lado a lado */
  .fin-scroll { display: grid; grid-template-columns: 1fr 1fr; align-content: start; gap: 12px 16px; }
  .fin-intro { grid-column: 1 / -1; }
  .steps { width: 100%; max-width: 760px; margin: 0 auto; }

  /* Científica: pantalla a la izquierda; funciones y teclado básico lado a lado a la derecha */
  #panel-sci:not([hidden]) {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.7fr);
    gap: 10px 16px;
  }
  #panel-sci .ec-display { grid-column: 1; grid-row: 1; justify-content: flex-end; }
  #panel-sci .ec-top { margin-bottom: auto; }
  .sci-pad { grid-column: 2; grid-row: 1; flex-direction: row; margin-top: 0; }
  .keys-sci-fn { flex: 3; grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(5, 1fr); grid-auto-flow: column; }
  .keys-sci { flex: 5; }
}

/* El usuario pidió más contraste en su sistema */
@media (prefers-contrast: more) {
  :root { --border: #6b7088; --muted: #3a3e52; --card: #ffffff; }
  :root[data-theme="dark"] { --border: #8d92ad; --muted: #d0d3e6; --card: #12141f; }
  .key, .conv-row, .display, .tabs, .pad, .box, .fin-result, .field-input { border: 1.5px solid var(--border); backdrop-filter: none; }
}

/* Modo de colores forzados de Windows */
@media (forced-colors: active) {
  .key, .tab, .conv-row, .copy-btn, .icon-btn, .seg, .field-input, .igv-row, .pc-base, .chip-btn { border: 1px solid ButtonText; }
  .tab[aria-current="page"], .conv-row.active, .seg.active, .igv-row.active, .pc-base.active, .key.op.selected, .key.toggle.on { outline: 3px solid Highlight; }
  .key:disabled { color: GrayText; }
}

@media (prefers-reduced-motion: reduce) {
  .shake { animation: none; }
  * { transition: none !important; }
}