:root {
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --accent-color: #667eea;
  --accent-hover: #5a67d8;
  --text-primary: #1a202c;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --bg-primary: #ffffff;
  --bg-secondary: #f7fafc;
  --bg-tertiary: #edf2f7;
  --border-color: #e2e8f0;
  --border-focus: #667eea;
  --shadow-light: 0 4px 20px rgba(0, 0, 0, 0.1);
  --shadow-medium: 0 10px 40px rgba(0, 0, 0, 0.15);
  --success-bg: #c6f6d5;
  --success-text: #22543d;
  --error-bg: #fed7d7;
  --error-text: #c53030;
  --backdrop-blur: blur(20px);
  --glass-bg: rgba(255, 255, 255, 0.9);
  --glass-border: rgba(255, 255, 255, 0.2);
}

[data-theme="dark"] {
  --dark-gradient: linear-gradient(
    135deg,
    rgba(13, 21, 58, 0.8) 0%,
    rgba(5, 0, 9, 0.8) 100%
  );
  --text-primary: #f7fafc;
  --text-secondary: #e2e8f0;
  --text-muted: #a0aec0;
  --bg-primary: #1a202c;
  --bg-secondary: #2d3748;
  --bg-tertiary: #4a5568;
  --border-color: #4a5568;
  --border-focus: #9f7aea;
  --shadow-light: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-medium: 0 10px 40px rgba(0, 0, 0, 0.4);
  --success-bg: #2d3748;
  --success-text: #68d391;
  --error-bg: #2d3748;
  --error-text: #fc8181;
  --glass-bg: rgba(26, 32, 44, 0.85);
  --glass-border: rgba(255, 255, 255, 0.1);
  --accent-color: #9f7aea;
  --accent-hover: #805ad5;
}

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

html,
body {
  overflow-x: hidden;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 20px;
  position: relative;
  transition: all 0.3s ease;
}

[data-theme="dark"] body {
  background: var(--dark-gradient);
}

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(
      circle at 20% 80%,
      rgba(120, 119, 198, 0.3) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 80% 20%,
      rgba(255, 119, 198, 0.3) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 40% 40%,
      rgba(120, 119, 198, 0.2) 0%,
      transparent 50%
    );
  pointer-events: none;
  z-index: -1;
}

/* Header Controls */
.header-controls {
  position: fixed;
  top: 20px;
  right: 20px;
  display: flex;
  gap: 12px;
  z-index: 1000;
}

.theme-toggle,
.settings-toggle {
  background: var(--glass-bg);
  backdrop-filter: var(--backdrop-blur);
  border: 1px solid var(--glass-border);
  border-radius: 50px;
  padding: 12px 16px;
  cursor: pointer;
  font-size: 1.2rem;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-light);
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
  font-weight: 500;
  min-width: 60px;
  justify-content: center;
}

.theme-toggle:hover,
.settings-toggle:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-medium);
  background: var(--bg-primary);
}

/* Settings Modal */
.settings-modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(10px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 1;
  transition: all 0.3s ease;
}

.settings-modal.hidden {
  opacity: 0;
  pointer-events: none;
}

.settings-content {
  background: var(--glass-bg);
  backdrop-filter: var(--backdrop-blur);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 0;
  max-width: 400px;
  width: 90%;
  box-shadow: var(--shadow-medium);
  transform: scale(1);
  transition: all 0.3s ease;
}

.settings-modal.hidden .settings-content {
  transform: scale(0.9);
}

.settings-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px;
  border-bottom: 1px solid var(--border-color);
}

.settings-header h3 {
  margin: 0;
  color: var(--text-primary);
  font-size: 1.25rem;
  font-weight: 600;
}

.close-settings {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-muted);
  padding: 4px;
  border-radius: 50%;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.close-settings:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.settings-body {
  padding: 24px;
}

.setting-group {
  margin-bottom: 20px;
}

.setting-group label {
  display: block;
  margin-bottom: 8px;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.875rem;
}

.settings-select {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--border-color);
  border-radius: 12px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 1rem;
  font-weight: 500;
  transition: all 0.3s ease;
  cursor: pointer;

  /* Remove default dropdown arrow */
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;

  /* Add custom dropdown arrow */
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23718096' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 40px;
}

.settings-select:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.15);
}

.settings-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}

.save-settings,
.reset-settings {
  flex: 1;
  padding: 12px 20px;
  border: none;
  border-radius: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 0.95rem;
}

.save-settings {
  background: var(--accent-color);
  color: white;
}

.save-settings:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.reset-settings {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
}

.reset-settings:hover {
  background: var(--border-color);
  color: var(--text-primary);
}

.container {
  background: var(--glass-bg);
  backdrop-filter: var(--backdrop-blur);
  border-radius: 24px;
  padding: 48px;
  box-shadow: var(--shadow-medium);
  width: 100%;
  max-width: 600px;
  border: 1px solid var(--glass-border);
  transition: all 0.3s ease;
  position: relative;
}

.container::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1) 0%,
    rgba(255, 255, 255, 0.05) 100%
  );
  border-radius: 24px;
  pointer-events: none;
}

.header {
  text-align: center;
  margin-bottom: 48px;
  position: relative;
  z-index: 1;
}

.header h1 {
  color: var(--text-primary);
  font-size: 2.75rem;
  font-weight: 800;
  margin-bottom: 12px;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.header p {
  color: var(--text-muted);
  font-size: 1.1rem;
  font-weight: 500;
  opacity: 0.8;
}

.converter-form {
  display: flex;
  flex-direction: column;
  gap: 32px;
  position: relative;
  z-index: 1;
}

.input-group {
  position: relative;
}

.input-group label {
  display: block;
  margin-bottom: 12px;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.currency-input {
  display: flex;
  align-items: stretch;
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-light);
  position: relative;
}

.currency-input::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 100%
  );
  pointer-events: none;
  border-radius: 14px;
}

.currency-input:focus-within {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.15);
  transform: translateY(-1px);
}

.currency-input input {
  flex: 1;
  padding: 20px 24px;
  border: none;
  background: transparent;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  outline: none;
  position: relative;
  z-index: 1;
}

.currency-input input::placeholder {
  color: var(--text-muted);
  opacity: 0.6;
}

.currency-select {
  padding: 20px 24px;
  border: none;
  background: var(--accent-color);
  color: white;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  outline: none;
  min-width: 120px;
  transition: all 0.3s ease;
  position: relative;
  z-index: 1;

  /* Remove default dropdown arrow */
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;

  /* Add custom dropdown arrow */
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 40px;
}

.currency-select:hover {
  background-color: var(--accent-hover);
}

.currency-select:focus {
  outline: none;
  background-color: var(--accent-hover);
}

.currency-select option {
  background: var(--bg-primary);
  color: var(--text-primary);
  padding: 12px;
  font-weight: 500;
}

.currency-select option:checked {
  background: var(--accent-color);
  color: white;
}

.swap-button {
  align-self: center;
  background: var(--glass-bg);
  backdrop-filter: var(--backdrop-blur);
  border: 2px solid var(--border-color);
  border-radius: 50%;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  color: var(--text-primary);
  font-size: 1.5rem;
  margin: -16px 0;
  z-index: 10;
  box-shadow: var(--shadow-light);
  position: relative;
  margin-top: 0.6rem;
}

.swap-button::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--accent-color);
  border-radius: 50%;
  opacity: 0;
  transition: all 0.3s ease;
  transform: scale(0.8);
}

.swap-button:hover {
  transform: rotate(180deg) translateY(-2px);
  border-color: var(--accent-color);
  box-shadow: var(--shadow-medium);
}

.swap-button:hover::before {
  opacity: 0.1;
  transform: scale(1);
}

.rate-display {
  background: var(--glass-bg);
  backdrop-filter: var(--backdrop-blur);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  padding: 24px;
  border-radius: 16px;
  text-align: center;
  margin-top: 24px;
  font-weight: 600;
  font-size: 1.1rem;
  box-shadow: var(--shadow-light);
  position: relative;
  overflow: hidden;
}

.rate-display::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(102, 126, 234, 0.1),
    transparent
  );
  transition: all 0.8s ease;
}

.rate-display:hover::before {
  left: 100%;
}

.rate-display.hidden {
  display: none;
}

.hidden {
  display: none !important;
}

.loading {
  text-align: center;
  color: var(--text-muted);
  font-style: italic;
  font-weight: 500;
  padding: 20px;
}

.error {
  background: var(--error-bg);
  color: var(--error-text);
  padding: 20px;
  border-radius: 12px;
  text-align: center;
  margin-top: 20px;
  font-weight: 500;
  border: 1px solid rgba(197, 48, 48, 0.2);
}

@media (max-width: 768px) {
  body {
    padding: 0;
    align-items: stretch;
  }

  .container {
    max-width: none;
    width: 100%;
    height: 100vh;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    border-radius: 0;
    border: none;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background: var(--glass-bg);
    backdrop-filter: var(--backdrop-blur);
  }

  .container::before {
    border-radius: 0;
  }

  .header {
    margin-bottom: 32px;
    padding-top: 40px;
  }

  .header h1 {
    font-size: 2.5rem;
    margin-bottom: 8px;
  }

  .header p {
    font-size: 1rem;
  }

  .converter-form {
    gap: 24px;
    justify-content: center;
  }

  .currency-input {
    border-radius: 18px;
    min-height: 68px;
  }

  .currency-input input {
    padding: 22px 20px;
    font-size: 1.3rem;
    flex: 2;
    min-width: 0;
  }

  .currency-select {
    padding: 22px 16px;
    font-size: 1rem;
    min-width: 90px;
    flex: 0 0 auto;
    background-size: 14px;
    background-position: right 12px center;
    padding-right: 36px;
  }

  .input-group label {
    font-size: 0.8rem;
    margin-bottom: 10px;
  }

  .swap-button {
    width: 64px;
    height: 64px;
    font-size: 1.8rem;
  }

  .rate-display {
    margin-top: 50px;
    padding: 20px;
    font-size: 1rem;
  }

  .header-controls {
    top: 15px;
    right: 15px;
    gap: 8px;
  }

  .theme-toggle,
  .settings-toggle {
    padding: 10px 12px;
    font-size: 1rem;
    min-width: 50px;
  }

  .settings-content {
    width: 95%;
    max-width: 350px;
  }

  .settings-header {
    padding: 20px;
  }

  .settings-body {
    padding: 20px;
  }

  .loading,
  .error {
    padding: 16px;
    font-size: 0.95rem;
  }
}

@media (max-width: 480px) {
  .header {
    padding-top: 30px;
    margin-bottom: 24px;
  }

  .header h1 {
    font-size: 2.1rem;
  }

  .container {
    padding: 16px;
    padding-bottom: 70px;
  }

  .converter-form {
    gap: 20px;
  }

  .currency-input {
    border-radius: 16px;
    min-height: 64px;
  }

  .currency-input input {
    padding: 20px 18px;
    font-size: 1.25rem;
  }

  .currency-select {
    padding: 20px 14px;
    font-size: 0.95rem;
    min-width: 85px;
    background-size: 12px;
    background-position: right 10px center;
    padding-right: 32px;
  }

  .swap-button {
    width: 56px;
    height: 56px;
    font-size: 1.6rem;
  }

  .header-controls {
    top: 12px;
    right: 12px;
    gap: 6px;
  }

  .theme-toggle,
  .settings-toggle {
    padding: 8px 10px;
    font-size: 0.95rem;
    min-width: 44px;
  }
}

@media (max-width: 375px) {
  .header h1 {
    font-size: 1.8rem;
  }

  .currency-input input {
    font-size: 1.2rem;
    padding: 18px 16px;
  }

  .currency-select {
    padding: 18px 12px;
    font-size: 0.9rem;
    min-width: 80px;
    background-size: 12px;
    background-position: right 8px center;
    padding-right: 28px;
  }

  .container {
    padding: 12px;
    padding-bottom: 70px;
  }
}

.fade-in {
  animation: fadeIn 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(30px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.slide-up {
  animation: slideUp 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* Smooth scroll behavior */
html {
  scroll-behavior: smooth;
}

/* Enhanced loading animation */
@keyframes pulse {
  0%,
  100% {
    opacity: 0.6;
  }
  50% {
    opacity: 1;
  }
}

/* Footer Styles */
.footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  text-align: center;
  padding: 16px 20px;
  background: var(--glass-bg);
  backdrop-filter: var(--backdrop-blur);
  border-top: 1px solid var(--glass-border);
  z-index: 500;
}

.footer p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 400;
}

.footer a {
  color: var(--accent-color);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.2s ease;
  position: relative;
}

.footer a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.footer a:focus {
  outline: 2px solid var(--accent-color);
  outline-offset: 2px;
  border-radius: 4px;
}

@media (max-width: 768px) {
  .footer {
    padding: 12px 16px;
  }

  .footer p {
    font-size: 0.8rem;
  }
}

.loading {
  animation: pulse 2s infinite;
}