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

html, body {
  overflow-x: hidden;
  width: 100%;
}

:root {
  --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #dbeafe 100%);
  --container-bg: #ffffff;
  --text-color: #1f2937;
  --header-bg: #2563eb;
  --header-text: #ffffff;
  --button-bg: #2563eb;
  --button-hover: #1d4ed8;
  --copy-bg: #14b8a6;
  --copy-hover: #0d9488;
  --clear-bg: #ef4444;
  --clear-hover: #dc2626;
  --footer-bg: #1e293b;
  --footer-text: #e2e8f0;
  --instruction-bg: #eff6ff;
  --shadow: 0 8px 32px rgba(31, 38, 135, 0.15);
  --spinner-color: #2563eb;
}

[data-theme="dark"] {
  --bg-gradient: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  --container-bg: #2d3748;
  --text-color: #e2e8f0;
  --header-bg: #3b82f6;
  --header-text: #f1f5f9;
  --button-bg: #3b82f6;
  --button-hover: #2563eb;
  --copy-bg: #14b8a6;
  --copy-hover: #0d9488;
  --clear-bg: #ef4444;
  --clear-hover: #dc2626;
  --footer-bg: #111827;
  --footer-text: #d1d5db;
  --instruction-bg: #374151;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  --spinner-color: #3b82f6;
}

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-gradient);
  min-height: 100vh;
  padding: 0;
  display: flex;
  flex-direction: column;
  color: var(--text-color);
  transition: background 0.3s, color 0.3s;
}

header {
  background: var(--header-bg);
  color: var(--header-text);
  padding: 10px 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  transform: perspective(1000px) translateZ(10px);
  transition: transform 0.3s, box-shadow 0.3s;
  animation: gradientShift 8s ease infinite;
  background-size: 200% 200%;
  max-width: 100%;
  overflow: hidden;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

header:hover {
  transform: perspective(1000px) translateZ(20px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
}

header h1 {
  font-size: 1.3rem;
  margin: 0;
  line-height: 1.2;
  transition: transform 0.3s, text-shadow 0.3s;
}

header h1:hover {
  transform: scale(1.05);
  text-shadow: 0 0 10px rgba(255, 255, 255, 0.8);
}

.toggle-container {
  display: inline-flex;
  align-items: center;
}

.theme-toggle {
  background: rgba(255, 255, 255, 0.2);
  border: none;
  outline: none;
  appearance: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--header-text);
  font-size: 20px;
  transition: transform 0.3s, background 0.3s;
  -webkit-tap-highlight-color: transparent;
}

.theme-toggle:hover {
  transform: scale(1.1);
  background: rgba(255, 255, 255, 0.3);
}

.theme-toggle:focus,
.theme-toggle:active {
  outline: none;
  box-shadow: none;
  background: rgba(255, 255, 255, 0.2);
}

.container {
  max-width: 800px;
  width: 100%;
  background: var(--container-bg);
  padding: 30px;
  border-radius: 16px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(4px);
  margin: 20px auto;
  transition: background 0.3s;
}

.input-group {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
  justify-content: center;
}

.input-container {
  position: relative;
  flex: 1;
  min-width: 200px;
}

input[type="text"] {
  width: 100%;
  padding: 12px 16px;
  font-size: 16px;
  border: 2px solid #e0e0e0;
  border-radius: 12px;
  outline: none;
  transition: border-color 0.3s;
  background: var(--container-bg);
  color: var(--text-color);
}

input[type="text"]:focus {
  border-color: var(--button-bg);
}

button {
  padding: 12px 24px;
  font-size: 16px;
  background: var(--button-bg);
  color: white;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.3s;
}

button:hover {
  background: var(--button-hover);
}

.clear-btn {
  background: var(--clear-bg);
}

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

.tags-container {
  background: var(--instruction-bg);
  padding: 15px;
  border-radius: 8px;
  margin-top: 20px;
  font-size: 14px;
  color: var(--text-color);
  word-wrap: break-word;
}

.paragraph-tags {
  background: var(--instruction-bg);
  padding: 15px;
  border-radius: 8px;
  margin-top: 20px;
  font-size: 14px;
  color: var(--text-color);
  word-wrap: break-word;
}

.copy-all-btn {
  display: block;
  margin: 10px auto;
  padding: 10px 20px;
  background: var(--copy-bg);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.3s;
}

.copy-all-btn:hover {
  background: var(--copy-hover);
}

.error {
  color: #e62117;
  text-align: center;
  margin-top: 20px;
}

.loading {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  gap: 10px;
  padding: 20px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--spinner-color);
  border-top: 4px solid transparent;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.char-count {
  text-align: center;
  font-size: 12px;
  margin-top: 10px;
  color: var(--text-color);
}

.char-count.warning {
  color: #e62117;
}

.instructions {
  max-width: 800px;
  width: 100%;
  margin: 0 auto 20px;
  padding: 15px;
  background: var(--instruction-bg);
  border-radius: 8px;
  text-align: left;
  font-size: 14px;
  color: var(--text-color);
  transition: background 0.3s, color 0.3s;
}

.instructions h3 {
  margin-bottom: 10px;
  color: var(--text-color);
}

.instructions ol {
  margin-left: 20px;
}

footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 15px 20px;
  text-align: center;
  margin-top: auto;
  transition: background 0.3s, color 0.3s;
  max-width: 100%;
}

footer p {
  margin: 0;
  font-size: 14px;
}

.footer-links {
  margin-top: 10px;
}

.footer-links a {
  color: var(--footer-text);
  text-decoration: none;
  margin: 0 10px;
  font-size: 14px;
  transition: color 0.3s;
}

.footer-links a:hover {
  color: var(--copy-bg);
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background: var(--container-bg);
  color: var(--text-color);
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 20px;
  border-radius: 12px;
  box-shadow: var(--shadow);
  position: relative;
  transition: background 0.3s, color 0.3s;
}

.modal-content h2 {
  margin-bottom: 15px;
  font-size: 1.5rem;
  color: var(--header-bg);
}

.modal-content p {
  margin-bottom: 10px;
  line-height: 1.6;
  font-size: 14px;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  background: var(--button-bg);
  color: white;
  border: none;
  border-radius: 50%;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 16px;
  transition: background 0.3s;
}

.close-btn:hover {
  background: var(--button-hover);
}

@media (max-width: 600px) {
  .container {
    max-width: 95%;
    padding: 15px;
    margin: 10px auto;
  }

  header h1 {
    font-size: 1rem;
  }

  .input-group {
    flex-direction: column;
    align-items: center;
  }

  .input-container {
    width: 100%;
  }

  input[type="text"] {
    padding: 10px 14px;
    font-size: 14px;
  }

  button {
    width: 100%;
    padding: 10px;
    font-size: 14px;
  }

  .instructions {
    max-width: 95%;
    margin: 0 10px 20px;
    padding: 10px;
    font-size: 13px;
  }

  .theme-toggle {
    width: 28px;
    height: 28px;
    font-size: 18px;
  }

  .spinner {
    width: 32px;
    height: 32px;
  }

  .footer-links a {
    margin: 0 5px;
    font-size: 13px;
  }

  .modal-content {
    width: 95%;
    padding: 15px;
  }

  .modal-content h2 {
    font-size: 1.2rem;
  }

  .modal-content p {
    font-size: 13px;
  }
}