/* ===== CSS Variables & Design Tokens ===== */
:root {
  /* Color Palette */
  --color-primary: hsl(250, 84%, 54%);
  --color-primary-light: hsl(250, 84%, 64%);
  --color-primary-dark: hsl(250, 84%, 44%);
  --color-secondary: hsl(280, 100%, 65%);
  --color-accent: hsl(320, 100%, 60%);

  /* Background Colors */
  --color-bg-primary: hsl(240, 20%, 8%);
  --color-bg-secondary: hsl(240, 15%, 12%);
  --color-bg-tertiary: hsl(240, 12%, 16%);
  --color-bg-card: hsla(240, 15%, 12%, 0.6);

  /* Text Colors */
  --color-text-primary: hsl(0, 0%, 98%);
  --color-text-secondary: hsl(0, 0%, 75%);
  --color-text-tertiary: hsl(0, 0%, 55%);

  /* Border & Shadow */
  --color-border: hsla(240, 15%, 25%, 0.5);
  --color-border-focus: var(--color-primary);
  --shadow-sm: 0 2px 8px hsla(0, 0%, 0%, 0.1);
  --shadow-md: 0 4px 16px hsla(0, 0%, 0%, 0.2);
  --shadow-lg: 0 8px 32px hsla(0, 0%, 0%, 0.3);
  --shadow-glow: 0 0 20px hsla(250, 84%, 54%, 0.3);

  /* Gradients */
  --gradient-primary: linear-gradient(
    135deg,
    var(--color-primary) 0%,
    var(--color-secondary) 100%
  );
  --gradient-accent: linear-gradient(
    135deg,
    var(--color-secondary) 0%,
    var(--color-accent) 100%
  );
  --gradient-bg: radial-gradient(
    ellipse at top,
    hsl(250, 50%, 15%) 0%,
    var(--color-bg-primary) 50%
  );

  /* Spacing */
  --spacing-xs: 0.375rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 0.75rem;
  --spacing-lg: 1rem;
  --spacing-xl: 1.5rem;
  --spacing-2xl: 2rem;

  /* Border Radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;

  /* Typography */
  --font-primary: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  --font-mono: "JetBrains Mono", "Courier New", monospace;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base Styles ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* ===== Background Effects ===== */
.background-gradient {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-bg);
  z-index: -2;
}

.background-pattern {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: radial-gradient(
      circle at 20% 30%,
      hsla(250, 84%, 54%, 0.08) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 80% 70%,
      hsla(280, 100%, 65%, 0.08) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 50% 50%,
      hsla(320, 100%, 60%, 0.05) 0%,
      transparent 50%
    );
  z-index: -1;
  animation: patternFloat 20s ease-in-out infinite;
}

@keyframes patternFloat {
  0%,
  100% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(-20px, -20px) scale(1.05);
  }
}

/* ===== Container ===== */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-lg);
  position: relative;
  z-index: 1;
}

/* ===== Header ===== */
.header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  animation: fadeInDown 0.6s ease-out;
}

.logo-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.logo-icon {
  font-size: 2.25rem;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.logo-text {
  font-size: 2.25rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.highlight {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  font-weight: 300;
  letter-spacing: 0.02em;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Mode Switcher ===== */
.mode-switcher {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  margin-bottom: var(--spacing-xl);
  animation: fadeInUp 0.6s ease-out 0.1s backwards;
}

.mode-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  background: var(--color-bg-card);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-family: var(--font-primary);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
}

.mode-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition-base);
  z-index: -1;
}

.mode-btn:hover {
  border-color: var(--color-primary-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.mode-btn.active {
  color: var(--color-text-primary);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
}

.mode-btn.active::before {
  opacity: 0.15;
}

.mode-icon {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-base);
}

.mode-btn:hover .mode-icon {
  transform: scale(1.1);
}

/* ===== Converter Container ===== */
.converter-container {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-lg);
  margin-bottom: var(--spacing-xl);
  animation: fadeInUp 0.6s ease-out 0.2s backwards;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Section Styles ===== */
.input-section,
.output-section {
  margin-bottom: var(--spacing-lg);
}

.output-section {
  margin-bottom: 0;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.section-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

.label-icon {
  font-size: 1.125rem;
}

.char-counter {
  font-size: 0.875rem;
  color: var(--color-text-tertiary);
  font-family: var(--font-mono);
}

#input-count,
#output-count {
  color: var(--color-primary-light);
  font-weight: 600;
}

/* ===== Textarea Wrapper ===== */
.textarea-wrapper {
  position: relative;
}

.input-textarea,
.output-textarea {
  width: 100%;
  min-height: 140px;
  padding: var(--spacing-md);
  padding-right: 3.5rem;
  background: var(--color-bg-secondary);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  resize: vertical;
  transition: all var(--transition-base);
}

.input-textarea:focus,
.output-textarea:focus {
  outline: none;
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px hsla(250, 84%, 54%, 0.1);
}

.input-textarea::placeholder,
.output-textarea::placeholder {
  color: var(--color-text-tertiary);
}

.output-textarea {
  background: var(--color-bg-tertiary);
}

/* ===== Action Buttons ===== */
.clear-btn,
.copy-btn {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-base);
  opacity: 0;
  visibility: hidden;
}

.textarea-wrapper:hover .clear-btn,
.textarea-wrapper:hover .copy-btn {
  opacity: 1;
  visibility: visible;
}

.clear-btn svg,
.copy-btn svg {
  width: 18px;
  height: 18px;
}

.clear-btn:hover,
.copy-btn:hover {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
  transform: scale(1.05);
}

.copy-btn {
  width: auto;
  padding: 0 var(--spacing-md);
  gap: var(--spacing-xs);
}

.copy-text {
  font-size: 0.875rem;
  font-weight: 500;
}

/* ===== Action Buttons Section ===== */
.action-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  align-items: center;
  margin-bottom: var(--spacing-xl);
}

.convert-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--gradient-primary);
  border: none;
  border-radius: var(--radius-md);
  color: white;
  font-family: var(--font-primary);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.convert-btn::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.convert-btn:hover::before {
  width: 300px;
  height: 300px;
}

.convert-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.convert-btn:active {
  transform: translateY(0);
}

.convert-icon {
  width: 24px;
  height: 24px;
  transition: transform var(--transition-base);
}

.convert-btn:hover .convert-icon {
  transform: rotate(180deg);
}

.swap-btn {
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-secondary);
  border: 2px solid var(--color-border);
  border-radius: 50%;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-base);
}

.swap-btn svg {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-base);
}

.swap-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: rotate(180deg);
}

/* ===== SEO Content Section ===== */
.seo-content {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl);
    backdrop-filter: blur(10px);
    margin: 0 auto;
    max-width: 100%;
    animation: fadeInUp 0.6s ease-out backwards;
}

.seo-content article {
    max-width: 100%;
}

.seo-content h2 {
    font-size: 1.5rem;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
    margin-top: var(--spacing-xl);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
}

.seo-content h2:first-child {
    margin-top: 0;
}

.seo-content h3 {
    font-size: 1.125rem;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.seo-content p {
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
    font-size: 1rem;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.feature-item {
    background: var(--color-bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    transition: var(--transition-base);
}

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

.feature-item p {
    margin-bottom: 0;
    font-size: 0.9375rem;
}

/* ===== Google AdSense Containers ===== */
.ad-container {
    width: 100%;
    max-width: 100%;
    margin: var(--spacing-xl) auto;
    padding: var(--spacing-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    overflow: hidden;
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ad-top {
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.6s ease-out 0.15s backwards;
}

.ad-bottom {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.6s ease-out 0.7s backwards;
}

/* AdSense responsive adjustments */
.adsbygoogle {
    display: block;
    width: 100%;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: var(--spacing-xl) 0;
  color: var(--color-text-tertiary);
  font-size: 0.875rem;
  animation: fadeInUp 0.6s ease-out 0.6s backwards;
}

.footer p {
  margin-bottom: var(--spacing-xs);
}

.footer-note {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  opacity: 0.7;
}

/* ===== Toast Notification ===== */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg);
  color: var(--color-text-primary);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(150%);
  opacity: 0;
  transition: all var(--transition-base);
  z-index: 1000;
  backdrop-filter: blur(10px);
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.toast-icon {
  width: 20px;
  height: 20px;
  color: var(--color-primary);
}

.toast-message {
  font-weight: 500;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
  :root {
    font-size: 14px;
  }

  .container {
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .logo-text {
    font-size: 2.5rem;
  }

  .logo-icon {
    font-size: 2.5rem;
  }

  .tagline {
    font-size: 1rem;
  }

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

  .mode-btn {
    width: 100%;
    justify-content: center;
  }

  .converter-container {
    padding: var(--spacing-lg);
  }

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

  .convert-btn {
    width: 100%;
    justify-content: center;
  }

  .info-cards {
    grid-template-columns: 1fr;
  }

  .toast {
    right: 1rem;
    left: 1rem;
    bottom: 1rem;
  }
}

@media (max-width: 480px) {
  .section-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-xs);
  }

  .input-textarea,
  .output-textarea {
    min-height: 150px;
    font-size: 0.875rem;
  }
}

/* ===== Accessibility ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ===== Print Styles ===== */
@media print {
  .background-gradient,
  .background-pattern,
  .mode-switcher,
  .action-buttons,
  .info-cards,
  .footer,
  .toast {
    display: none;
  }

  body {
    background: white;
    color: black;
  }
}