/* ==========================================================================
   ROASCALC — MASTER DESIGN SYSTEM (roascalculators.online)
   Architecture: Swiss Minimalist B2B SaaS / Zero CLS / 100% Multi-Device Responsive
   Palette: #000000 (Bg) | #0A0A0A (Surface) | #1E1E1E (Border) | #EDEDED (Text)
   ========================================================================== */

@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400 700;
  font-display: swap;
  src: local('Inter'), local('Inter-Regular'), url('/fonts/inter.woff2') format('woff2');
}

:root {
  --bg-primary: #000000;
  --bg-surface: #0A0A0A;
  --bg-elevated: #141414;
  --border-color: #1E1E1E;
  --border-hover: #363636;
  --border-focus: #FFFFFF;
  --text-primary: #EDEDED;
  --text-secondary: #999999;
  --text-muted: #666666;
  --accent-white: #FFFFFF;
  --accent-blue: #0070F3;
  --status-positive: #10B981;
  --status-warning: #F59E0B;
  --status-negative: #EF4444;
  --radius-sm: 4px;
  --radius-md: 6px;
  --transition-fast: 0.15s ease-in-out;
  --transition-drawer: 0.28s cubic-bezier(0.16, 1, 0.3, 1);
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;
  --container-max: 1260px;
}

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

html {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  overflow-x: hidden;
  width: 100%;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  width: 100%;
  max-width: 100vw;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  position: relative;
}

body.nav-open {
  overflow: hidden;
}

/* Prevent any grid/flex child from forcing horizontal overflow */
main,
article,
section,
aside,
footer,
form,
output,
.workspace-container,
.calculator-card,
.content-section,
.kpi-box,
.form-group {
  min-width: 0;
  max-width: 100%;
}

/* ==========================================================================
   TYPOGRAPHY & TABULAR NUMERALS
   ========================================================================== */

h1, h2, h3, h4 {
  color: var(--accent-white);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.25;
  overflow-wrap: break-word;
}

h1 {
  font-size: clamp(1.65rem, 3.2vw, 2.5rem);
  margin-bottom: 0.75rem;
}

h2 {
  font-size: clamp(1.25rem, 2.2vw, 1.55rem);
  margin-bottom: 0.85rem;
  padding-bottom: 0.55rem;
  border-bottom: 1px solid var(--border-color);
}

h3 {
  font-size: 1.075rem;
  margin-bottom: 0.45rem;
}

p {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 1rem;
  max-width: 72ch;
  overflow-wrap: break-word;
}

a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

a:hover,
a:focus-visible {
  color: var(--accent-white);
}

code, pre, .mono, output, input[type="number"] {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* ==========================================================================
   HEADER & OFF-CANVAS NAVIGATION (DESKTOP > 1180px | TABLET & MOBILE <= 1180px)
   ========================================================================== */

.site-header {
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  position: sticky;
  top: 0;
  z-index: 500;
  width: 100%;
}

.header-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0.8rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.025rem;
  letter-spacing: -0.02em;
  color: var(--accent-white);
  flex-shrink: 0;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  background-color: var(--accent-white);
  color: var(--bg-primary);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: 4px;
  flex-shrink: 0;
}

/* Desktop Horizontal Nav (> 1180px) */
.main-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex-wrap: nowrap;
}

.nav-drawer-top {
  display: none;
}

.nav-link {
  font-size: 0.84rem;
  color: #CCCCCC;
  padding: 0.4rem 0.62rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--accent-white);
  background-color: var(--bg-elevated);
  border-color: var(--border-hover);
}

.nav-link[aria-current="page"] {
  color: var(--accent-white);
  background-color: rgba(0, 112, 243, 0.14);
  border-color: var(--accent-blue);
  font-weight: 600;
}

/* Hamburger Toggle Button (Hidden on Desktop > 1180px, Shown on Tablet/Mobile <= 1180px) */
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  background-color: var(--bg-elevated);
  color: var(--accent-white);
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.85rem;
  min-height: 42px;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.menu-toggle:hover {
  border-color: var(--accent-white);
  background-color: #1F1F1F;
}

.hamburger-box {
  width: 18px;
  height: 12px;
  position: relative;
  display: inline-block;
}

.hamburger-line {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--accent-white);
  border-radius: 1px;
  transition: transform 0.22s ease, opacity 0.22s ease, top 0.22s ease;
}

.hamburger-line:nth-child(1) { top: 0; }
.hamburger-line:nth-child(2) { top: 5px; }
.hamburger-line:nth-child(3) { top: 10px; }

.menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
  top: 5px;
  transform: rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}

.menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
  top: 5px;
  transform: rotate(-45deg);
}

/* Backdrop Overlay for Off-Canvas Menu (Must stay BELOW .site-header z-index: 500) */
.nav-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.72);
  backdrop-filter: blur(2px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--transition-drawer), visibility var(--transition-drawer);
  z-index: 400;
}

.nav-backdrop.is-active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* Tablet & Mobile Off-Canvas Drawer (<= 1180px) */
@media (max-width: 1180px) {
  .menu-toggle {
    display: inline-flex;
  }

  .main-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(350px, 88vw);
    height: 100vh;
    height: 100dvh;
    background-color: #080808;
    border-left: 1px solid #2A2A2A;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    padding: 1.25rem;
    gap: 0.5rem;
    overflow-y: auto;
    transform: translateX(105%);
    visibility: hidden;
    pointer-events: none;
    transition: transform var(--transition-drawer), visibility var(--transition-drawer);
    z-index: 550;
  }

  .main-nav.is-open {
    transform: translateX(0);
    visibility: visible;
    pointer-events: auto;
  }

  .nav-drawer-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 1rem;
    margin-bottom: 0.4rem;
    border-bottom: 1px solid #262626;
  }

  .nav-drawer-title {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--accent-white);
  }

  .drawer-close-btn {
    background-color: #161616;
    color: var(--accent-white);
    border: 1px solid #333333;
    border-radius: var(--radius-sm);
    padding: 0.4rem 0.75rem;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
  }

  .drawer-close-btn:hover {
    background-color: var(--accent-white);
    color: var(--bg-primary);
    border-color: var(--accent-white);
  }

  .nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: #EDEDED;
    padding: 0.75rem 0.95rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: #121212;
    border: 1px solid #242424;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
  }

  .nav-link::after {
    content: "→";
    font-family: var(--font-mono);
    color: #888888;
    font-size: 0.95rem;
    transition: transform var(--transition-fast), color var(--transition-fast);
  }

  .nav-link:hover,
  .nav-link:focus-visible {
    color: var(--accent-white);
    background-color: #1C1C1C;
    border-color: var(--accent-blue);
    transform: translateX(3px);
  }

  .nav-link:hover::after,
  .nav-link:focus-visible::after {
    color: var(--accent-white);
    transform: translateX(3px);
  }

  .nav-link[aria-current="page"] {
    color: var(--accent-white);
    background-color: rgba(0, 112, 243, 0.18);
    border-color: var(--accent-blue);
    font-weight: 600;
  }

  .nav-link[aria-current="page"]::after {
    color: var(--accent-blue);
  }
}

/* ==========================================================================
   SEMANTIC BREADCRUMBS
   ========================================================================== */

.breadcrumb {
  margin-bottom: 0.75rem;
}

.breadcrumb-list {
  list-style: none;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.45rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.breadcrumb-list a {
  color: var(--text-secondary);
}

.breadcrumb-list a:hover {
  color: var(--accent-white);
  text-decoration: underline;
}

.breadcrumb-sep {
  color: var(--text-muted);
  font-family: var(--font-mono);
  user-select: none;
}

.breadcrumb-current {
  color: var(--text-primary);
  font-weight: 500;
}

/* ==========================================================================
   MAIN LAYOUT GRID (DESKTOP 2-COL -> TABLET/MOBILE 1-COL)
   ========================================================================== */

.workspace-container {
  max-width: var(--container-max);
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 2.25rem;
  flex: 1;
  align-items: start;
}

.page-hero {
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* ==========================================================================
   CALCULATOR MODULE, INTERACTIVE PRESETS & ZERO-CLS OUTPUT
   ========================================================================== */

.calculator-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  margin-bottom: 2.25rem;
}

.preset-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.preset-label {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-right: 0.25rem;
}

.preset-btn {
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.75rem;
  min-height: 36px;
  font-family: var(--font-sans);
  font-size: 0.825rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.preset-btn:hover,
.preset-btn.is-active {
  color: var(--accent-white);
  border-color: var(--accent-blue);
  background-color: rgba(0, 112, 243, 0.12);
}

.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.form-label {
  font-size: 0.925rem;
  font-weight: 500;
  color: var(--text-primary);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.label-unit {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  color: var(--text-secondary);
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  width: 100%;
}

.form-input {
  width: 100%;
  min-height: 46px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--accent-white);
  font-size: 1.05rem;
  padding: 0.7rem 0.9rem;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
  appearance: textfield;
  -moz-appearance: textfield;
}

.form-input::-webkit-outer-spin-button,
.form-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.form-input:hover {
  border-color: var(--border-hover);
}

.form-input:focus {
  outline: none;
  border-color: var(--border-focus);
  background-color: #050505;
}

.form-help {
  font-size: 0.825rem;
  color: var(--text-secondary);
  line-height: 1.45;
}

.calc-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  border-top: 1px solid var(--border-color);
  padding-top: 1.25rem;
  flex-wrap: wrap;
}

.btn-group {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 44px;
  font-family: var(--font-sans);
  font-size: 0.925rem;
  font-weight: 600;
  padding: 0.65rem 1.15rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  text-align: center;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background-color: var(--accent-white);
  color: var(--bg-primary);
  border-color: var(--accent-white);
}

.btn-primary:hover {
  background-color: #D8D8D8;
  border-color: #D8D8D8;
}

.btn-secondary {
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  color: var(--accent-white);
  border-color: var(--border-hover);
}

/* ZERO CLS PRE-ALLOCATED OUTPUT ENGINE */
.resultado-highlight {
  display: block;
  width: 100%;
  min-height: 190px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
}

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-bottom: 0.85rem;
  padding-bottom: 0.65rem;
  border-bottom: 1px solid var(--border-color);
}

.output-title {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}

.status-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  max-width: 100%;
  overflow-wrap: break-word;
}

.status-badge.is-positive {
  color: var(--status-positive);
  border-color: rgba(16, 185, 129, 0.35);
}

.status-badge.is-warning {
  color: var(--status-warning);
  border-color: rgba(245, 158, 11, 0.35);
}

.status-badge.is-negative {
  color: var(--status-negative);
  border-color: rgba(239, 68, 68, 0.35);
}

.telemetry-bar {
  width: 100%;
  height: 4px;
  background-color: var(--bg-surface);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.telemetry-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.25s ease, background-color 0.25s ease;
}

.telemetry-fill.is-positive { background-color: var(--status-positive); }
.telemetry-fill.is-warning { background-color: var(--status-warning); }
.telemetry-fill.is-negative { background-color: var(--status-negative); }

.kpi-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.9rem;
}

.kpi-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1rem;
  min-height: 90px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color var(--transition-fast);
}

.kpi-box:hover {
  border-color: var(--border-hover);
}

.kpi-label {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.kpi-value {
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 2.2vw, 1.6rem);
  font-weight: 700;
  color: var(--accent-white);
  letter-spacing: -0.03em;
  line-height: 1.2;
  overflow-wrap: break-word;
}

.kpi-value.accent-blue {
  color: var(--accent-blue);
}

.kpi-sub {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  overflow-wrap: break-word;
}

/* ==========================================================================
   EDITORIAL, RESPONSIVE TABLES & INTERACTIVE FAQ ACCORDIONS
   ========================================================================== */

.content-article {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.content-section {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
}

.formula-box {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-left: 3px solid var(--accent-blue);
  border-radius: var(--radius-sm);
  padding: 1rem 1.15rem;
  margin: 1rem 0;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--accent-white);
  white-space: normal;
  overflow-wrap: break-word;
  word-break: break-word;
  line-height: 1.6;
}

.table-responsive {
  width: 100%;
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin-top: 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
}

.benchmark-table {
  width: 100%;
  min-width: 480px;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.benchmark-table th,
.benchmark-table td {
  text-align: left;
  padding: 0.75rem 0.9rem;
  border-bottom: 1px solid var(--border-color);
}

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

.benchmark-table th {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  text-transform: uppercase;
  color: var(--text-secondary);
  background-color: var(--bg-primary);
}

.benchmark-table td {
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  margin-top: 1.25rem;
}

.faq-item {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.1rem 1.2rem;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-item h3 {
  color: var(--accent-white);
  font-size: 1rem;
  margin-bottom: 0;
  cursor: pointer;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.85rem;
  user-select: none;
}

.faq-item h3::after {
  content: "−";
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--accent-blue);
  flex-shrink: 0;
  line-height: 1.2;
}

.faq-item.is-collapsed h3::after {
  content: "+";
  color: var(--text-secondary);
}

.faq-item p {
  margin-top: 0.65rem;
  margin-bottom: 0;
  font-size: 0.925rem;
}

.faq-item.is-collapsed p {
  display: none;
}

.inline-link {
  color: var(--accent-white);
  border-bottom: 1px solid var(--accent-blue);
  padding-bottom: 1px;
}

.inline-link:hover {
  color: var(--accent-blue);
}

/* ==========================================================================
   LATERAL ASIDE (INTERNAL LINKING MATRIX)
   ========================================================================== */

.sidebar-aside {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: sticky;
  top: 4.75rem;
}

.aside-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.35rem;
}

.aside-card p {
  font-size: 0.9rem;
  margin-bottom: 0;
}

.aside-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.matrix-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.matrix-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.55rem 0.7rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.matrix-link::after {
  content: "→";
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.matrix-link:hover,
.matrix-link[aria-current="page"] {
  color: var(--accent-white);
  background-color: var(--bg-primary);
  border-color: var(--border-color);
}

.matrix-link:hover::after,
.matrix-link[aria-current="page"]::after {
  color: var(--accent-blue);
  transform: translateX(3px);
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

.site-footer {
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-surface);
  margin-top: auto;
  width: 100%;
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 2.75rem 1.5rem 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr repeat(2, minmax(0, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.825rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 0.85rem;
}

.footer-col p {
  font-size: 0.9rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.footer-links a:hover {
  color: var(--accent-white);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-size: 0.825rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   MULTI-DEVICE RESPONSIVE BREAKPOINTS (TABLET, PHABLET, MOBILE)
   ========================================================================== */

/* Tablet Landscape & Small Laptops (<= 1024px) */
@media (max-width: 1024px) {
  .workspace-container {
    grid-template-columns: minmax(0, 1fr);
    padding: 1.5rem 1.25rem 3rem;
    gap: 2rem;
  }

  .sidebar-aside {
    position: static;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
  }
}

/* Tablet Portrait (<= 768px) */
@media (max-width: 768px) {
  html {
    font-size: 16px;
  }

  .header-inner {
    padding: 0.75rem 1.15rem;
  }

  .calculator-card,
  .content-section,
  .aside-card {
    padding: 1.25rem;
  }

  .calc-grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
  }

  .kpi-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.75rem;
  }

  .kpi-box {
    min-height: auto;
    padding: 0.85rem 1rem;
  }

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem;
  }

  .footer-col:first-child {
    grid-column: 1 / -1;
  }
}

/* Mobile Phones (<= 540px down to 320px) */
@media (max-width: 540px) {
  .header-inner {
    padding: 0.7rem 0.9rem;
  }

  .brand-logo {
    font-size: 0.95rem;
    gap: 0.45rem;
  }

  .workspace-container {
    padding: 1.15rem 0.9rem 2.5rem;
    gap: 1.5rem;
  }

  .calculator-card,
  .content-section,
  .aside-card {
    padding: 1rem;
  }

  .preset-bar {
    gap: 0.4rem;
  }

  .preset-label {
    width: 100%;
    margin-bottom: 0.15rem;
  }

  .preset-btn {
    flex: 1 1 calc(50% - 0.4rem);
    text-align: center;
    font-size: 0.775rem;
    padding: 0.4rem 0.5rem;
  }

  .calc-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  /* 16px input font-size prevents iOS Safari auto-zoom on focus */
  .form-input {
    font-size: 16px;
  }

  .calc-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-group {
    flex-direction: column;
    width: 100%;
  }

  .btn-group .btn {
    width: 100%;
  }

  .resultado-highlight {
    padding: 1rem;
    min-height: 0;
  }

  .output-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .sidebar-aside {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-inner {
    padding: 2rem 0.9rem 1.5rem;
  }

  .footer-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}