/* Duba v1.0 Main Stylesheet
 * Modern, sleek, dark-mode-first aesthetic with light mode support
 * System font stack, touch targets >= 44x44px
 */

:root {
  --bg-color: #0f172a;
  --surface-color: #1e293b;
  --surface-hover: #334155;
  --card-bg: #1e293b;
  --card-border: #334155;
  --primary-color: #38bdf8;
  --primary-hover: #0284c7;
  --accent-color: #818cf8;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --input-bg: #0f172a;
  --input-border: #475569;
  --toast-bg: #0284c7;
  --toast-text: #ffffff;
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

[data-theme="light"] {
  --bg-color: #f8fafc;
  --surface-color: #ffffff;
  --surface-hover: #f1f5f9;
  --card-bg: #ffffff;
  --card-border: #e2e8f0;
  --primary-color: #0284c7;
  --primary-hover: #0369a1;
  --accent-color: #4f46e5;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --input-bg: #f1f5f9;
  --input-border: #cbd5e1;
  --toast-bg: #0f172a;
  --toast-text: #ffffff;
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
}

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

body {
  font-family: var(--font-stack);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.3s ease, color 0.3s ease;
  padding: 1rem;
}

.app-container {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  flex: 1;
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  border-bottom: 1px solid var(--card-border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-icon {
  width: 38px;
  height: 38px;
  fill: var(--primary-color);
}

.brand-text h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.2;
}

.brand-text p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.header-controls {
  display: flex;
  gap: 0.5rem;
}

/* Buttons */
.btn {
  min-height: 44px;
  min-width: 44px;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--card-border);
  background-color: var(--surface-color);
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: all 0.2s ease;
  user-select: none;
}

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

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

.btn-icon-only {
  padding: 0.5rem;
  width: 44px;
  height: 44px;
}

/* Main Cards */
.card {
  background-color: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Input Section */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.input-group label {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
}

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

.converter-input {
  width: 100%;
  min-height: 52px;
  padding: 0.75rem 1rem;
  padding-right: 2.75rem;
  border-radius: var(--radius-md);
  border: 2px solid var(--input-border);
  background-color: var(--input-bg);
  color: var(--text-main);
  font-size: 1.1rem;
  font-family: inherit;
  transition: border-color 0.2s ease;
}

[dir="rtl"] .converter-input {
  padding-right: 1rem;
  padding-left: 2.75rem;
}

.converter-input:focus {
  outline: none;
  border-color: var(--primary-color);
}

.clear-btn {
  position: absolute;
  right: 0.5rem;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  min-width: 36px;
  min-height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 1.2rem;
}

[dir="rtl"] .clear-btn {
  right: auto;
  left: 0.5rem;
}

.clear-btn:hover {
  color: var(--text-main);
  background-color: var(--surface-hover);
}

/* Results Display */
.results-grid {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 1.25rem;
}

@media (max-width: 640px) {
  .results-grid {
    grid-template-columns: 1fr;
  }
}

.preview-box {
  background-color: var(--input-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  min-height: 140px;
  cursor: pointer;
  transition: transform 0.2s ease, border-color 0.2s ease;
  position: relative;
}

.preview-box:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.preview-char {
  font-size: 3.5rem;
  line-height: 1;
  margin-bottom: 0.5rem;
  word-break: break-all;
}

.preview-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

.code-details-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
}

.code-card {
  background-color: var(--input-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 64px;
}

.code-card:hover {
  border-color: var(--primary-color);
  background-color: var(--surface-hover);
  transform: translateY(-2px);
}

.code-card .label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.code-card .value {
  font-family: monospace, monospace;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--primary-color);
  word-break: break-all;
}

/* Palette Section */
.palette-category {
  margin-bottom: 1.25rem;
}

.palette-category:last-child {
  margin-bottom: 0;
}

.category-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.symbol-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(52px, 1fr));
  gap: 0.5rem;
}

.symbol-btn {
  min-width: 48px;
  min-height: 48px;
  font-size: 1.4rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--card-border);
  background-color: var(--input-bg);
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  user-select: none;
}

.symbol-btn:hover {
  background-color: var(--surface-hover);
  border-color: var(--primary-color);
  transform: scale(1.08);
}

.symbol-btn:active {
  transform: scale(0.95);
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background-color: var(--toast-bg);
  color: var(--toast-text);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.25);
  opacity: 0;
  visibility: hidden;
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s ease, visibility 0.3s ease;
  z-index: 1000;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* Footer */
footer {
  margin-top: auto;
  padding: 1.5rem 0 0.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}