/* ==========================================================================
   Modern Minimalist Design for MetalBend Engineering Calculators
   ========================================================================== */

:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --primary-border: #bfdbfe;
  --slate-50: #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  --success-bg: #f0fdf4;
  --success-border: #86efac;
  --success-text: #166534;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.07), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
}

/* CSS Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Inter, Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.6;
  color: var(--slate-700);
  background-color: var(--slate-100);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  padding-bottom: env(safe-area-inset-bottom, 0px);
}

/* Top Navigation Bar */
.navbar {
  background-color: #ffffff;
  border-bottom: 1px solid var(--slate-200);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  padding-top: env(safe-area-inset-top, 0px);
}

.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--slate-900);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

.nav-brand:hover {
  color: var(--primary);
}

.brand-icon {
  color: var(--primary);
}

.brand-icon-img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: block;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  color: var(--slate-600);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--primary);
  background-color: var(--primary-light);
}

.nav-link.active {
  color: var(--primary);
  background-color: var(--primary-light);
  font-weight: 600;
}

/* Main App Container */
.app-container {
  max-width: 1000px;
  width: 100%;
  margin: 28px auto 40px;
  padding: 0 20px;
  flex: 1;
}

/* Primary Card */
.calc-card {
  background-color: #ffffff;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  box-shadow: var(--shadow-md);
}

/* Headings */
h1 {
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--slate-900);
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.page-desc {
  color: var(--slate-500);
  font-size: 0.95rem;
  margin-bottom: 24px;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--slate-900);
  margin: 18px 0 12px;
}

/* Profile Selector Chips / Tabs */
.profile-selector {
  margin: 20px 0 24px;
}

.selector-label {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--slate-500);
  margin-bottom: 10px;
}

.profile-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.profile-list li {
  display: inline-flex;
  align-items: center;
  padding: 9px 18px;
  background-color: var(--slate-50);
  border: 1.5px solid var(--slate-200);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  color: var(--slate-700);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  user-select: none;
}

.profile-list li:hover {
  background-color: var(--primary-light);
  border-color: var(--primary-border);
  color: var(--primary);
  transform: translateY(-1px);
}

.profile-list li.active {
  background-color: var(--primary);
  border-color: var(--primary);
  color: #ffffff;
  box-shadow: 0 4px 10px -2px rgba(37, 99, 235, 0.35);
}

/* Helper Instructions */
.hint-text {
  font-size: 0.88rem;
  color: var(--slate-500);
  margin: 8px 0 16px;
  line-height: 1.5;
}

/* Input Elements & Form Controls */
input[type="text"] {
  font-family: inherit;
  font-size: 14px;
  padding: 7px 12px;
  height: 38px;
  border: 1.5px solid var(--slate-300);
  border-radius: var(--radius-sm);
  background-color: #ffffff;
  color: var(--slate-900);
  text-align: center;
  transition: all 0.15s ease;
  vertical-align: middle;
}

select {
  font-family: inherit;
  font-size: 14px;
  padding: 6px 10px;
  height: 38px;
  border: 1.5px solid var(--slate-300);
  border-radius: var(--radius-sm);
  background-color: #ffffff;
  color: var(--slate-900);
  cursor: pointer;
  transition: all 0.15s ease;
  vertical-align: middle;
}

input[type="text"]:focus,
select:focus,
.onfocus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.18);
  background-color: #ffffff;
}

input[type="checkbox"] {
  width: 17px;
  height: 17px;
  accent-color: var(--primary);
  cursor: pointer;
  vertical-align: middle;
  margin-right: 6px;
}

/* Disabled State for Form Controls */
input[type="text"]:disabled,
input[type="number"]:disabled,
input[type="text"][disabled],
select:disabled,
select[disabled] {
  background-color: var(--slate-100) !important;
  color: var(--slate-400) !important;
  -webkit-text-fill-color: var(--slate-400) !important;
  border-color: var(--slate-200) !important;
  cursor: not-allowed !important;
  box-shadow: none !important;
  opacity: 0.75;
  user-select: none;
}

input[type="text"]:disabled:focus,
input[type="text"]:disabled:hover,
input[type="text"][disabled]:focus,
input[type="text"][disabled]:hover,
input:disabled.onfocus {
  border-color: var(--slate-200) !important;
  outline: none !important;
  box-shadow: none !important;
  background-color: var(--slate-100) !important;
}

/* Placeholder styling */
input::placeholder {
  color: var(--slate-400);
  opacity: 0.85;
  font-size: 13px;
  font-style: italic;
}

/* Action Buttons */
input[type="button"],
input[type="submit"],
.btn-primary {
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  color: #ffffff;
  background-color: var(--primary);
  border: none;
  border-radius: var(--radius-sm);
  padding: 9px 24px;
  height: 38px;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
  vertical-align: middle;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

input[type="button"]:hover,
input[type="submit"]:hover,
.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

input[type="button"]:active,
input[type="submit"]:active,
.btn-primary:active {
  transform: translateY(0);
}

/* Diagrams and Visual Elements */
.leftimg {
  float: left;
  margin: 0 24px 16px 0;
}

.calc-card img,
.leftimg img {
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-md);
  background-color: #ffffff;
  padding: 12px;
  box-shadow: var(--shadow-sm);
  max-width: 100%;
  height: auto;
}

.dan {
  margin-top: 6px;
  line-height: 2.4;
  font-size: 14px;
  color: var(--slate-800);
}

.cls {
  clear: both;
}

/* Result Box */
#rez {
  background-color: var(--success-bg);
  border: 1.5px solid var(--success-border);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin-top: 24px;
  color: var(--success-text);
  font-size: 14.5px;
  line-height: 2.1;
  box-shadow: var(--shadow-sm);
}

#rez h2 {
  color: #15803d;
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0 0 12px 0;
}

/* Formula & Documentation Card */
.formula-card {
  margin-top: 32px;
  padding: 22px 26px;
  background-color: var(--slate-50);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-md);
  color: var(--slate-700);
  font-size: 14px;
}

.formula-card h3 {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--slate-900);
  margin-bottom: 8px;
}

.formula-math {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 15px;
  background: #ffffff;
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-sm);
  padding: 8px 16px;
  margin: 10px 0;
  display: inline-block;
  color: var(--slate-800);
}

.formula-card p {
  margin-bottom: 6px;
}

/* Backward compatibility fallbacks */
.containt {
  width: 100%;
}

.containt-row, main {
  display: block;
}

aside {
  display: none;
}

/* Responsive Styles */
@media (max-width: 820px) {
  .nav-container {
    flex-direction: column;
    height: auto;
    padding: 12px 16px;
    gap: 10px;
  }
  
  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
    justify-content: flex-start;
  }
  
  .nav-link {
    font-size: 13px;
    padding: 6px 10px;
  }
  
  .app-container {
    margin: 16px auto;
    padding: 0 12px;
  }
  
  .calc-card {
    padding: 20px 18px;
  }
  
  .leftimg {
    float: none;
    margin: 0 0 16px 0;
    text-align: center;
  }
  
  .leftimg img {
    margin: 0 auto;
  }
  
  .dan {
    clear: both;
  }
  
  /* Prevent iOS Safari auto-zoom on input focus */
  input[type="text"], input[type="number"], select {
    font-size: 16px !important;
  }
}

@media print {
  .navbar, .profile-selector, input[type="button"], input[type="submit"] {
    display: none !important;
  }
  body {
    background: #ffffff;
  }
  .calc-card {
    border: none;
    box-shadow: none;
    padding: 0;
  }
}