/* ============================================================
   Secure Password Generator — Wristband Brand Theme
   Data rain hero + two-column tool layout + SEO content
   Min supported width: 320px
   ============================================================ */

/* --- Custom Properties (Wristband brand palette) --- */
:root {
  --color-bg: #0B1A28;
  --color-surface: #0F2336;
  --color-surface-alt: #132D45;
  --color-primary: #00D09C;
  --color-primary-hover: #00B888;
  --color-text: #E2E8F0;
  --color-text-muted: #7B8CA3;
  --color-text-hint: #4A5E75;
  --color-border: #1A3A54;
  --color-password-bg: #0A1C2E;

  /* Strength colors */
  --strength-weak: #EF4444;
  --strength-fair: #F59E0B;
  --strength-moderate: #EAB308;
  --strength-strong: #22C55E;
  --strength-very-strong: #00D09C;

  /* Sizing */
  --radius: 12px;
  --radius-sm: 8px;
  --tap-target: 44px;
  --container-max: 480px;
  --container-padding: 16px;
  --page-max: 1120px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
    Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', Arial, sans-serif;
  font-feature-settings: 'cv02', 'cv03', 'cv04';
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* --- Screen Reader Only --- */
.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;
}

/* ============================================================
   Hero — Data Rain + Unified Layout
   ============================================================ */
.hero {
  position: relative;
  width: 100%;
  max-width: var(--page-max);
  padding: 48px 24px 56px;
  overflow: hidden;
}

/* Vignette overlay — softer to let rain show through more */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 100% at 50% 30%, transparent 0%, var(--color-bg) 100%);
  pointer-events: none;
  z-index: 1;
}

/* Data rain container */
.hero-rain {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.rain-col {
  position: absolute;
  top: 0;
  font-family: 'DM Mono', monospace;
  font-size: 12px;
  line-height: 1.6;
  color: #00E6A8;
  text-shadow: 0 0 8px rgba(0, 208, 156, 0.5);
  opacity: 0;
  writing-mode: vertical-lr;
  letter-spacing: 3px;
  animation: rainFall linear infinite;
  pointer-events: none;
  user-select: none;
}

/* Second layer starts lower */
.rain-col--b {
  top: 45%;
}

@keyframes rainFall {
  0%   { transform: translateY(-100%); opacity: 0; }
  5%   { opacity: 0.35; }
  85%  { opacity: 0.2; }
  100% { transform: translateY(600px); opacity: 0; }
}

@media (max-width: 767px) {
  @keyframes rainFall {
    0%   { transform: translateY(-100%); opacity: 0; }
    5%   { opacity: 0.35; }
    85%  { opacity: 0.2; }
    100% { transform: translateY(700px); opacity: 0; }
  }
}

/* --- Hero Layout: two-column grid on desktop --- */
.hero-layout {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 40px;
}

@media (min-width: 768px) {
  .hero {
    padding: 64px 24px 72px;
  }

  .hero-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
  }
}

@media (min-width: 960px) {
  .hero {
    padding: 80px 40px 88px;
  }

  .hero-layout {
    gap: 64px;
  }
}

/* --- Hero Copy (left column) --- */
.hero-copy {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  text-align: center;
}

.hero-copy::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120%;
  height: 140%;
  background: radial-gradient(ellipse at center, rgba(11, 26, 40, 0.85) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

@media (min-width: 768px) {
  .hero-copy {
    align-items: flex-start;
    text-align: left;
  }
}

.hero-title {
  font-size: clamp(2.2rem, 6vw, 3.2rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -1.5px;
  color: #fff;
  animation: fadeUp 0.5s ease both;
}

.hero-title-accent {
  color: var(--color-primary);
}

.hero-subtitle {
  max-width: 480px;
  font-size: clamp(1rem, 2.5vw, 1.1rem);
  line-height: 1.65;
  color: var(--color-text-muted);
  animation: fadeUp 0.5s 0.1s ease both;
}

@media (min-width: 768px) {
  .hero-subtitle {
    max-width: none;
  }
}

.hero-privacy {
  display: inline-flex;
  align-items: center;
  align-self: center;
  gap: 8px;
  font-family: 'DM Mono', monospace;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: rgba(0, 208, 156, 0.08);
  border: 1px solid rgba(0, 208, 156, 0.2);
  border-radius: 100px;
  padding: 5px 16px 5px 12px;
  animation: fadeUp 0.5s 0.2s ease both;
}

@media (min-width: 768px) {
  .hero-privacy {
    align-self: flex-start;
  }
}

.hero-privacy svg {
  color: var(--color-primary);
  flex-shrink: 0;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* --- Hero Widget (right column) --- */
.hero-widget {
  width: 100%;
  display: flex;
  justify-content: center;
}

@media (min-width: 768px) {
  .hero-widget {
    justify-content: flex-end;
  }
}

/* ============================================================
   Widget Container (cards)
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--container-max);
  min-width: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--container-padding);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.25);
}

/* On desktop, let the card fill its grid column */
@media (min-width: 768px) {
  .hero-widget .container {
    max-width: none;
  }
}

/* --- Title --- */
.title {
  font-size: clamp(1.1rem, 3.5vw, 1.3rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: 24px;
  color: #fff;
}

/* ============================================================
   Mode Tabs (Password / Secret)
   ============================================================ */
.mode-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 8px;
  background: var(--color-password-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 4px;
}

.mode-tab {
  flex: 1;
  padding: 8px 16px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--color-text-muted);
  font-family: inherit;
  font-size: clamp(0.85rem, 2.8vw, 0.95rem);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.mode-tab:hover {
  color: var(--color-text);
}

.mode-tab.active {
  background: var(--color-surface-alt);
  color: var(--color-primary);
}

.mode-tab:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
}

.mode-description {
  font-size: clamp(0.75rem, 2.5vw, 0.82rem);
  color: var(--color-text);
  opacity: 0.8;
  text-align: center;
  margin: 16px 4px 24px;
}

.mode-panel {
  /* panels are toggled via .hidden */
}

/* --- Password Display --- */
.password-display {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--color-password-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px;
  margin-bottom: 24px;
  min-height: 56px;
}

.password-text {
  flex: 1;
  font-family: 'DM Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  font-size: clamp(0.85rem, 3.2vw, 1.05rem);
  color: var(--color-primary);
  word-break: break-all;
  line-height: 1.4;
  user-select: all;
  -webkit-user-select: all;
}

/* --- Copy Button --- */
.btn-icon {
  position: relative;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--tap-target);
  height: var(--tap-target);
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.btn-icon:hover {
  background: rgba(0, 208, 156, 0.15);
  color: var(--color-primary);
}

.btn-icon:active {
  transform: scale(0.92);
}

.btn-icon .icon-check {
  color: var(--strength-strong);
}

.btn-icon .hidden {
  display: none;
}

.copy-feedback {
  position: absolute;
  top: -28px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.75rem;
  color: var(--strength-strong);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 2px 8px;
  white-space: nowrap;
  pointer-events: none;
}

/* --- Controls Section --- */
.controls {
  margin-bottom: 24px;
}

/* --- Length Slider --- */
.length-control {
  margin-bottom: 16px;
}

.length-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: clamp(0.9rem, 3vw, 1rem);
  font-weight: 500;
  margin-bottom: 8px;
}

.length-value {
  font-variant-numeric: tabular-nums;
  font-family: 'DM Mono', monospace;
  color: var(--color-primary);
  font-weight: 700;
  min-width: 2.5ch;
  text-align: right;
}

/* --- Range Slider Styling --- */
.slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--color-border);
  outline: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid #fff;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
  transition: transform var(--transition-fast);
}

.slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid #fff;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

.slider:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
}

/* --- Checkbox Options --- */
.charset-options {
  border: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: var(--tap-target);
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition-fast);
  user-select: none;
  -webkit-user-select: none;
}

.checkbox-label:hover {
  background: rgba(0, 208, 156, 0.08);
}

/* Hide native checkbox */
.checkbox-label input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

/* Custom checkbox */
.checkbox-custom {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  border: 2px solid var(--color-text-muted);
  border-radius: 4px;
  position: relative;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.checkbox-label input[type="checkbox"]:checked ~ .checkbox-custom {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.checkbox-custom::after {
  content: '';
  position: absolute;
  display: none;
  left: 6px;
  top: 2px;
  width: 6px;
  height: 11px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-label input[type="checkbox"]:checked ~ .checkbox-custom::after {
  display: block;
}

.checkbox-label input[type="checkbox"]:focus-visible ~ .checkbox-custom {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.checkbox-text {
  flex: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: clamp(0.9rem, 3vw, 1rem);
}

.charset-hint {
  color: var(--color-text-hint);
  font-size: 0.85em;
  font-family: 'DM Mono', monospace;
  text-align: right;
}

/* --- Strength Indicator --- */
.strength-section {
  margin-bottom: 24px;
}

.strength-bar-track {
  width: 100%;
  height: 6px;
  background: var(--color-border);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 8px;
}

.strength-bar-fill {
  height: 100%;
  width: 0%;
  border-radius: 3px;
  background: var(--strength-weak);
  transition: width var(--transition-normal), background var(--transition-normal);
}

.strength-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
}

.strength-label {
  font-size: clamp(0.8rem, 2.8vw, 0.9rem);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.entropy-value {
  font-size: clamp(0.75rem, 2.5vw, 0.85rem);
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
  font-family: 'DM Mono', monospace;
}

/* --- Action Buttons --- */
.actions {
  display: flex;
  gap: 10px;
}

.btn {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: var(--tap-target);
  padding: 12px 24px;
  border: none;
  border-radius: 10px;
  font-size: clamp(0.9rem, 3vw, 1rem);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 2px 8px rgba(0, 208, 156, 0.25);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
}

.btn-primary:focus-visible {
  outline: 2px solid #fff;
  outline-offset: 2px;
}

/* ============================================================
   Content Sections
   ============================================================ */
.content-section {
  width: 100%;
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 24px;
  /* Gradient divider at top */
  background: linear-gradient(90deg, transparent, rgba(0, 208, 156, 0.3) 15%, rgba(0, 208, 156, 0.3) 85%, transparent);
  background-size: 100% 1px;
  background-repeat: no-repeat;
  background-position: top center;
}

.content-container {
  max-width: 800px;
  margin: 0 auto;
  padding-top: 32px;
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.content-heading {
  font-size: clamp(1.3rem, 3.5vw, 1.6rem);
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
  letter-spacing: -0.3px;
}

.content-block {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.content-block a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 208, 156, 0.3);
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.content-block a:visited {
  color: var(--color-primary);
}

.content-block a:hover {
  color: var(--color-primary-hover);
  border-color: var(--color-primary);
}

.content-block p {
  font-size: clamp(0.95rem, 2.5vw, 1.05rem);
  line-height: 1.7;
  color: var(--color-text);
}

.content-block code {
  background: var(--color-password-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 2px 6px;
  font-family: 'DM Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  font-size: 0.9em;
  color: var(--color-primary);
}

.content-list {
  padding-left: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  color: var(--color-text);
}

.content-list li {
  font-size: clamp(0.95rem, 2.5vw, 1.05rem);
  line-height: 1.7;
  padding-left: 8px;
}

.content-list strong {
  color: var(--color-primary);
  font-weight: 600;
}

.content-block p.content-note {
  padding-left: 16px;
  margin-top: 12px;
  border-left: 2px solid var(--color-primary);
  font-size: clamp(0.85rem, 2.4vw, 0.92rem);
  line-height: 1.6;
  color: var(--color-text-muted);
}

/* --- References --- */
.references-list {
  padding-left: 0;
  list-style: none;
}

.references-list li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 0;
}

.references-list li a.reference-link {
  border-bottom: none;
}

.references-list li a.reference-link:hover {
  border-bottom: none;
  text-decoration: underline;
  text-decoration-color: var(--color-primary-hover);
}

.reference-link {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: clamp(0.95rem, 2.5vw, 1.05rem);
  transition: color var(--transition-fast);
}

.reference-desc {
  font-size: clamp(0.82rem, 2.3vw, 0.9rem);
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  width: 100%;
  text-align: center;
  padding: 40px 24px;
  margin-top: 48px;
  max-width: var(--page-max);
  background: linear-gradient(90deg, transparent, rgba(0, 208, 156, 0.3) 15%, rgba(0, 208, 156, 0.3) 85%, transparent);
  background-size: 100% 1px;
  background-repeat: no-repeat;
  background-position: top center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.footer-content {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: clamp(0.95rem, 2.5vw, 1.05rem);
  font-weight: 600;
  color: #fff;
}

.footer-heart {
  font-size: 1.1em;
  line-height: 1;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  transition: opacity var(--transition-fast);
}

.footer-brand:hover {
  opacity: 0.8;
}

.footer-logo {
  height: 28px;
  width: auto;
  display: block;
}

.footer-contact {
  font-size: clamp(0.78rem, 2.2vw, 0.85rem);
  color: var(--color-text-hint);
}

.footer-link {
  color: var(--color-text-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border);
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.footer-link:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ============================================================
   Responsive Adjustments
   ============================================================ */
@media (min-width: 400px) {
  .container {
    padding: 24px;
  }

  .password-display {
    padding: 14px 16px;
  }
}

@media (min-width: 480px) {
  .container {
    padding: 28px;
  }
}

/* ============================================================
   Utility
   ============================================================ */
.hidden {
  display: none !important;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}