/* ===========================================================================
   Variables
   ======================================================================== */
:root {
  /* Colors */
  --color-background: #0b1220; /* deep navy background */
  --color-surface: #0f172a; /* slightly lighter surface */
  --color-surface-elevated: #111827;
  --color-text: #e5e7eb; /* light gray text */
  --color-text-muted: #9ca3af;
  --color-primary: #2563eb; /* secure blue */
  --color-primary-soft: rgba(37, 99, 235, 0.12);
  --color-primary-strong: #1d4ed8;
  --color-accent-silver: #cbd5f5;
  --color-success: #22c55e;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;

  /* Neutral grays */
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2933;
  --color-gray-900: #111827;

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji",
    "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;

  --font-size-xs: 0.75rem;   /* 12px */
  --font-size-sm: 0.875rem;  /* 14px */
  --font-size-base: 1rem;    /* 16px */
  --font-size-lg: 1.125rem;  /* 18px */
  --font-size-xl: 1.25rem;   /* 20px */
  --font-size-2xl: 1.5rem;   /* 24px */
  --font-size-3xl: 1.875rem; /* 30px */
  --font-size-4xl: 2.25rem;  /* 36px */

  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.7;

  /* Spacing scale (0–96px) */
  --space-0: 0;
  --space-1: 0.25rem;  /* 4px */
  --space-2: 0.5rem;   /* 8px */
  --space-3: 0.75rem;  /* 12px */
  --space-4: 1rem;     /* 16px */
  --space-5: 1.25rem;  /* 20px */
  --space-6: 1.5rem;   /* 24px */
  --space-8: 2rem;     /* 32px */
  --space-10: 2.5rem;  /* 40px */
  --space-12: 3rem;    /* 48px */
  --space-16: 4rem;    /* 64px */
  --space-20: 5rem;    /* 80px */
  --space-24: 6rem;    /* 96px */

  /* Radius */
  --radius-sm: 0.25rem;  /* 4px */
  --radius-md: 0.5rem;   /* 8px */
  --radius-lg: 0.75rem;  /* 12px */
  --radius-xl: 1rem;     /* 16px */
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.25);
  --shadow-md: 0 8px 20px rgba(15, 23, 42, 0.35);
  --shadow-lg: 0 18px 45px rgba(15, 23, 42, 0.45);

  /* Transitions */
  --transition-fast: 120ms ease-out;
  --transition-normal: 180ms ease-out;
  --transition-slow: 260ms ease-out;

  /* Layout */
  --container-max-width: 1200px;
  --container-padding-x: var(--space-4);

  /* Focus */
  --focus-ring-color: rgba(37, 99, 235, 0.7);
  --focus-ring-width: 2px;
  --focus-ring-offset: 2px;
}

/* ===========================================================================
   Reset / Normalize
   ======================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
}

h1, h2, h3, h4, h5, h6,
p, figure, blockquote,
dl, dd {
  margin: 0;
}

ul[role="list"],
ol[role="list"] {
  list-style: none;
  margin: 0;
  padding: 0;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
}

input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

button {
  border: none;
  padding: 0;
  background: none;
}

/* Remove default link underlines, will re-define in base styles */
a {
  text-decoration: none;
  color: inherit;
}

/* Respect reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===========================================================================
   Base Styles
   ======================================================================== */
body {
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  background-color: var(--color-background);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
}

main {
  display: block;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: var(--line-height-tight);
  color: #f9fafb;
}

h1 {
  font-size: var(--font-size-4xl);
  letter-spacing: 0.02em;
  margin-bottom: var(--space-4);
}

h2 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--space-3);
}

h3 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-3);
}

h4 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-2);
}

h5 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2);
}

h6 {
  font-size: var(--font-size-sm);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

p {
  margin-bottom: var(--space-4);
  }

small {
  font-size: var(--font-size-xs);
}

strong {
  font-weight: 600;
}

code, pre {
  font-family: var(--font-mono);
}

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

a:hover {
  color: var(--color-primary-strong);
  text-decoration: underline;
  text-decoration-color: currentColor;
}

a:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

hr {
  border: 0;
  height: 1px;
  background-color: rgba(148, 163, 184, 0.24);
  margin: var(--space-6) 0;
}

/* ===========================================================================
   Accessibility Helpers
   ======================================================================== */
:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.sr-only-focusable:active,
.sr-only-focusable:focus {
  position: static;
  width: auto;
  height: auto;
  margin: 0;
  overflow: visible;
  clip: auto;
  white-space: normal;
}

/* ===========================================================================
   Utilities
   ======================================================================== */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding-x);
  padding-right: var(--container-padding-x);
}

@media (min-width: 1200px) {
  .container {
    padding-left: var(--space-6);
    padding-right: var(--space-6);
  }
}

/* Layout helpers */
.flex {
  display: flex;
}

.inline-flex {
  display: inline-flex;
}

.flex-column {
  flex-direction: column;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.grid {
  display: grid;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-6);
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: minmax(0, 1fr);
  }
}

.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.m-auto {
  margin: auto;
}

.mt-0 { margin-top: 0; }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.mb-0 { margin-bottom: 0; }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.p-0 { padding: 0; }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

.w-full {
  width: 100%;
}

.max-w-readable {
  max-width: 70ch;
}

/* ===========================================================================
   Components
   ======================================================================== */
/* Buttons */
.button,
button,
input[type="button"],
input[type="submit"],
input[type="reset"] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.3rem;
  font-size: var(--font-size-sm);
  font-weight: 500;
  line-height: 1.1;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  cursor: pointer;
  background-color: var(--color-primary);
  color: #f9fafb;
  box-shadow: var(--shadow-sm);
  transition:
    background-color var(--transition-normal),
    box-shadow var(--transition-normal),
    transform var(--transition-fast),
    border-color var(--transition-fast);
}

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

.button:active,
button:active,
input[type="button"]:active,
input[type="submit"]:active,
input[type="reset"]:active {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

.button:disabled,
button:disabled,
input[type="button"]:disabled,
input[type="submit"]:disabled,
input[type="reset"]:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  box-shadow: none;
}

.button--secondary {
  background-color: transparent;
  color: var(--color-text);
  border-color: rgba(148, 163, 184, 0.6);
  box-shadow: none;
}

.button--secondary:hover {
  background-color: rgba(15, 23, 42, 0.85);
  border-color: rgba(148, 163, 184, 0.9);
}

.button--ghost {
  background-color: transparent;
  color: var(--color-primary);
  border-color: transparent;
  box-shadow: none;
}

.button--ghost:hover {
  background-color: var(--color-primary-soft);
}

.button:focus-visible,
button:focus-visible,
input[type="button"]:focus-visible,
input[type="submit"]:focus-visible,
input[type="reset"]:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: 2px;
}

/* Form fields */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="tel"],
input[type="url"],
input[type="number"],
select,
textarea {
  width: 100%;
  padding: 0.6rem 0.9rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(148, 163, 184, 0.6);
  background-color: rgba(15, 23, 42, 0.9);
  color: var(--color-text);
  font-size: var(--font-size-sm);
  line-height: 1.4;
  box-shadow: 0 0 0 1px rgba(15, 23, 42, 0.9);
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    background-color var(--transition-fast);
}

input::placeholder,
textarea::placeholder {
  color: rgba(148, 163, 184, 0.7);
}

input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary), 0 0 0 4px rgba(37, 99, 235, 0.35);
}

input:disabled,
select:disabled,
textarea:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

textarea {
  min-height: 120px;
  resize: vertical;
}

label {
  display: inline-block;
  margin-bottom: var(--space-2);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text);
}

/* Cards (product tiles, info boxes) */
.card {
  background: radial-gradient(circle at top left, rgba(148, 163, 184, 0.12), transparent 55%),
    var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  border: 1px solid rgba(148, 163, 184, 0.35);
  box-shadow: var(--shadow-md);
  transition:
    transform var(--transition-normal),
    box-shadow var(--transition-normal),
    border-color var(--transition-fast),
    background-color var(--transition-fast);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(191, 219, 254, 0.85);
}

.card--subtle {
  background: var(--color-surface);
  border-color: rgba(148, 163, 184, 0.25);
  box-shadow: var(--shadow-sm);
}

.card-header {
  margin-bottom: var(--space-4);
}

.card-title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-1);
}

.card-subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.card-body {
  font-size: var(--font-size-sm);
  color: var(--color-text);
}

.card-footer {
  margin-top: var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

/* Badges for security levels, availability, etc. */
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border: 1px solid rgba(148, 163, 184, 0.6);
  color: var(--color-text-muted);
}

.badge--success {
  border-color: rgba(34, 197, 94, 0.6);
  color: #bbf7d0;
  background-color: rgba(21, 128, 61, 0.2);
}

.badge--danger {
  border-color: rgba(239, 68, 68, 0.6);
  color: #fecaca;
  background-color: rgba(127, 29, 29, 0.25);
}

/* Header & Navigation (lightweight baseline) */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: linear-gradient(to bottom, rgba(15, 23, 42, 0.96), rgba(15, 23, 42, 0.85), transparent);
  border-bottom: 1px solid rgba(148, 163, 184, 0.35);
}

.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-top: var(--space-3);
  padding-bottom: var(--space-3);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  list-style: none;
}

.nav-link {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition:
    color var(--transition-fast),
    border-color var(--transition-fast);
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: #e5e7eb;
  border-color: var(--color-primary);
}

/* Hero section baseline */
.hero {
  padding-top: var(--space-12);
  padding-bottom: var(--space-12);
}

@media (max-width: 768px) {
  .hero {
    padding-top: var(--space-10);
    padding-bottom: var(--space-10);
  }
}

.hero-eyebrow {
  font-size: var(--font-size-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.hero-title {
  font-size: clamp(2.4rem, 3vw + 1.6rem, 3.4rem);
  line-height: 1.1;
  margin-bottom: var(--space-4);
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  max-width: 38rem;
}

/* Search bar (for advanced search) */
.search-bar {
  display: flex;
  align-items: stretch;
  gap: 0.5rem;
}

.search-bar-input {
  flex: 1 1 auto;
}

.search-bar-button {
  white-space: nowrap;
}

/* Checkout trust indicators */
.trust-strip {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

.trust-strip-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.55rem;
  border-radius: var(--radius-full);
  background-color: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(148, 163, 184, 0.5);
}

/* Step-by-step process layout */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-6);
}

.step {
  position: relative;
  padding-left: var(--space-6);
}

.step-number {
  position: absolute;
  left: 0;
  top: 0.1rem;
  width: 2rem;
  height: 2rem;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.7);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--color-accent-silver);
  background: radial-gradient(circle at 30% 0, rgba(191, 219, 254, 0.45), transparent 60%),
    rgba(15, 23, 42, 1);
}

/* Status text */
.text-muted {
  color: var(--color-text-muted);
}

.text-success {
  color: var(--color-success);
}

.text-warning {
  color: var(--color-warning);
}

.text-danger {
  color: var(--color-danger);
}

/* Tables minimal baseline (for product specs) */
.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

.table th,
.table td {
  padding: 0.55rem 0.75rem;
  border-bottom: 1px solid rgba(148, 163, 184, 0.25);
}

.table th {
  text-align: left;
  font-weight: 500;
  color: var(--color-text-muted);
}

.table-striped tbody tr:nth-child(odd) {
  background-color: rgba(15, 23, 42, 0.9);
}

/* Toast / Alert baseline (for system feedback) */
.alert {
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-size-sm);
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  border: 1px solid transparent;
}

.alert--success {
  background-color: rgba(22, 163, 74, 0.15);
  border-color: rgba(34, 197, 94, 0.7);
  color: #bbf7d0;
}

.alert--warning {
  background-color: rgba(202, 138, 4, 0.15);
  border-color: rgba(245, 158, 11, 0.7);
  color: #fef3c7;
}

.alert--danger {
  background-color: rgba(185, 28, 28, 0.2);
  border-color: rgba(248, 113, 113, 0.85);
  color: #fee2e2;
}

/* Footer baseline */
.site-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.4);
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
  background: linear-gradient(to top, #020617, transparent 40%);
}

.site-footer a {
  color: var(--color-text-muted);
}

.site-footer a:hover {
  color: #e5e7eb;
}

.site-footer-meta {
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: 1px solid rgba(148, 163, 184, 0.3);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}