/* ============================================
 * Experiment Tools - Shared Base CSS
 * Minimal KISS design with dark mode support
 * ============================================ */

:root {
  --color-primary: #666;
  --color-primary-dark: #555;
  --color-primary-light: #777;
  --color-text: #333;
  --color-text-muted: #666;
  --color-text-light: #999;
  --color-bg: #fff;
  --color-bg-secondary: #f5f5f5;
  --color-border: #e1e1e8;
  --color-input-bg: #fff;
  --color-input-border: #ccc;
  --color-input-placeholder: #999;
  --color-link: #666;
  --color-link-hover: #555;
  --color-btn-bg: #f5f5f5;
  --color-btn-hover: #e5e5e5;
  --color-btn-border: #e1e1e8;
  --transition-fast: 0.1s;
  --transition-normal: 0.2s;
  --transition-theme: 0.3s;
  --spacing-xs: 5px;
  --spacing-sm: 10px;
  --spacing-md: 15px;
  --spacing-lg: 20px;
  --spacing-xl: 30px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --font-xs: 13px;
  --font-sm: 14px;
  --font-md: 15px;
  --font-lg: 16px;
  --font-xl: 18px;
  --font-xxl: 24px;
  --max-width: 1000px;
}

body.dark-mode {
  --color-primary: #999;
  --color-primary-dark: #888;
  --color-primary-light: #aaa;
  --color-text: #e0e0e0;
  --color-text-muted: #999;
  --color-text-light: #666;
  --color-bg: #1a1a1a;
  --color-bg-secondary: #2d2d2d;
  --color-border: #333;
  --color-input-bg: #2d2d2d;
  --color-input-border: #444;
  --color-input-placeholder: #666;
  --color-link: #999;
  --color-link-hover: #aaa;
  --color-btn-bg: #2d2d2d;
  --color-btn-hover: #3d3d3d;
  --color-btn-border: #444;
  transition:
    background-color var(--transition-theme) ease,
    color var(--transition-theme) ease,
    border-color var(--transition-theme) ease,
    background var(--transition-theme) ease;
}

* { box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.5;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px;
  color: var(--color-text);
  background: var(--color-bg);
}

a {
  color: var(--color-link);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 10px;
}
.titles { flex: 1; margin: 0; }
.titles h1 { margin-bottom: 5px; margin-top: 0; }
.titles h2 {
  margin-top: 0;
  margin-bottom: 15px;
  font-size: 1.25rem;
  font-weight: normal;
  color: var(--color-primary);
}

/* Theme toggle */
.btn-theme {
  background: var(--color-btn-bg);
  border: 1px solid var(--color-btn-border);
  border-radius: 50%;
  width: 48px;
  height: 48px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  padding: 0;
  transition: background-color var(--transition-normal) ease, transform var(--transition-fast) ease;
}
.btn-theme:hover { background: var(--color-btn-hover); }
.btn-theme:active { transform: scale(0.95); }
.btn-theme .icon { width: 24px; height: 24px; display: block; }
body.dark-mode .btn-theme .icon { filter: invert(1); }

hr {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: 15px 0;
}

/* Forms */
textarea, input, select { font-family: inherit; }

input.form-control, select.form-control {
  width: 100%;
  padding: 10px;
  font-size: var(--font-lg);
  border: 1px solid var(--color-input-border);
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
  color: var(--color-text);
  transition:
    background-color var(--transition-normal) ease,
    border-color var(--transition-normal) ease,
    color var(--transition-normal) ease;
}

.form-group { margin-bottom: var(--spacing-md); }
.form-group label {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
}

/* Layout */
.row {
  display: flex;
  flex-wrap: wrap;
  margin: 0 calc(-1 * var(--spacing-sm));
  align-items: flex-start;
}
.col {
  flex: 1 1 100%;
  padding: 0 var(--spacing-sm);
  min-width: 300px;
}
.col-md-6 {
  flex: 1 1 50%;
  padding: 0 var(--spacing-sm);
  min-width: 300px;
}

/* Status */
.text-success { color: #28a745; }
.text-danger { color: #dc3545; }

/* Buttons */
.btn-random {
  background: var(--color-btn-bg);
  border: 1px solid var(--color-btn-border);
  border-radius: var(--radius-sm);
  padding: 6px 14px;
  cursor: pointer;
  font-size: var(--font-sm);
  color: var(--color-text);
  flex-shrink: 0;
  transition: background-color var(--transition-normal) ease;
}
.btn-random:hover { background: var(--color-btn-hover); }

.btn-copy {
  background: var(--color-btn-bg);
  border: 1px solid var(--color-btn-border);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  cursor: pointer;
  font-size: var(--font-xs);
  color: var(--color-text-muted);
  flex-shrink: 0;
  margin-left: auto;
  transition: background-color var(--transition-normal) ease;
}
.btn-copy:hover {
  background: var(--color-btn-hover);
  color: var(--color-text);
}

/* Footer */
.footer {
  margin-top: 40px;
  padding: 30px 0;
  border-top: 1px solid var(--color-border);
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-bottom: 20px;
}
.footer-col h4 {
  font-size: var(--font-sm);
  font-weight: 600;
  margin: 0 0 12px 0;
  color: var(--color-text);
}
.footer-col p {
  font-size: var(--font-sm);
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.6;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col ul li { margin-bottom: 6px; }
.footer-col ul li a {
  color: var(--color-link);
  text-decoration: none;
  font-size: var(--font-sm);
  background-color: var(--color-btn-bg);
  padding: 4px 10px;
  border-radius: 16px;
  transition: background-color var(--transition-normal) ease;
  display: inline-block;
}
.footer-col ul li a:hover {
  text-decoration: none;
  background-color: var(--color-btn-hover);
}
.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 20px;
  text-align: center;
}
.footer-bottom p {
  margin: 0;
  font-size: var(--font-xs);
  color: var(--color-text-muted);
}
.footer-bottom a {
  color: var(--color-link);
  font-weight: 500;
  text-decoration: none;
}
.footer-bottom a:hover { text-decoration: underline; }

/* Hidden utility */
.hidden { display: none; }

/* Textarea */
textarea.form-control {
  width: 100%;
  padding: 10px;
  font-size: var(--font-lg);
  border: 1px solid var(--color-input-border);
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
  color: var(--color-text);
  resize: vertical;
  line-height: 1.4;
  min-height: 120px;
  transition:
    background-color var(--transition-normal) ease,
    border-color var(--transition-normal) ease,
    color var(--transition-normal) ease;
}
textarea[disabled], textarea[readonly] {
  background: var(--color-btn-bg);
  cursor: default;
}

/* Decoder button — prominent call to action */
.btn-decoder {
  background: var(--color-primary);
  color: var(--color-bg);
  border: none;
  border-radius: var(--radius-sm);
  padding: 12px 28px;
  cursor: pointer;
  font-size: var(--font-lg);
  font-weight: 500;
  transition: background-color var(--transition-normal) ease, opacity var(--transition-normal) ease;
}
.btn-decoder:hover {
  background: var(--color-primary-dark);
  opacity: 0.9;
}

/* Dark mode overrides */
body.dark-mode textarea {
  background: var(--color-input-bg);
  border-color: var(--color-input-border);
  color: var(--color-text);
}
body.dark-mode textarea[disabled] { background: #252525; }
body.dark-mode .btn-decoder { background: #888; }
body.dark-mode .btn-decoder:hover { background: #777; }

/* Mobile responsive */
@media (max-width: 768px) {
  body { padding: 15px; }
  .row { flex-direction: column; }
  .col, .col-md-6 { min-width: 100%; margin-bottom: 20px; }
  h1 { font-size: 1.5rem; }
  h2 { font-size: 1.2rem; }
  textarea { font-size: 16px; }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .footer-col ul li a,
  .footer-col p { display: block; }
}