:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fbff;
  --surface: #ffffff;
  --text-primary: #111827;
  --text-secondary: #4b5563;
  --border-color: #e5e7eb;
  --card-shadow: 0 24px 48px rgba(15, 23, 42, 0.08);
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.12);
  --header-bg: rgba(255, 255, 255, 0.92);
  --hero-bg: linear-gradient(135deg, rgba(37, 99, 235, 0.16) 0%, rgba(248, 250, 252, 0.98) 100%);
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #111827;
  --surface: #1f2937;
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --border-color: #374151;
  --card-shadow: 0 24px 48px rgba(15, 23, 42, 0.24);
  --accent: #60a5fa;
  --accent-hover: #3b82f6;
  --accent-soft: rgba(96, 165, 250, 0.16);
  --header-bg: rgba(15, 23, 42, 0.92);
  --hero-bg: linear-gradient(135deg, rgba(37, 99, 235, 0.12) 0%, rgba(15, 23, 42, 0.96) 100%);
}

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

html, body {
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100%;
  transition: background-color 0.35s ease, color 0.35s ease;
}

body {
  line-height: 1.65;
}

a {
  color: inherit;
}

button, .button {
  font: inherit;
}

/* Header */
header {
  background-color: var(--header-bg);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(37, 99, 235, 0.12);
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.07);
}

.header-content {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex: 1;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
}

.header-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.header-actions {
  display: flex;
  gap: 1rem;
  align-items: center;
}

/* Theme toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  color: var(--text-primary);
  font-size: 1.2rem;
  transition: background-color 0.2s ease;
}

.theme-toggle:hover {
  background-color: var(--bg-primary);
}

.language-select {
  min-width: 140px;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem 0.85rem;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  cursor: pointer;
  font: inherit;
}

.language-select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.hero {
  background: var(--hero-bg);
  padding: 3rem 0 2rem;
  border-bottom: 1px solid rgba(37, 99, 235, 0.08);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 2rem;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 1rem;
}

.hero-copy h2,
.section-intro h2 {
  font-size: clamp(2rem, 3vw, 3rem);
  line-height: 1.05;
  margin-bottom: 1rem;
}

.hero-description {
  max-width: 40rem;
  color: var(--text-secondary);
  margin-bottom: 1.8rem;
  font-size: 1.05rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 0.95rem 1.5rem;
  text-decoration: none;
  font-weight: 700;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button-primary {
  background-color: var(--accent);
  color: #fff;
}

.button-secondary {
  background-color: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
}

.hero-panel {
  display: grid;
  gap: 1rem;
}

.feature-card {
  display: flex;
  gap: 1rem;
  padding: 1.35rem;
  border-radius: 18px;
  background-color: var(--bg-secondary);
  border: 1px solid rgba(37, 99, 235, 0.08);
  box-shadow: var(--card-shadow);
}

.feature-icon {
  width: 3rem;
  height: 3rem;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background-color: var(--accent-soft);
  color: var(--accent);
  font-size: 1.4rem;
}

.feature-card h3 {
  font-size: 1rem;
  margin-bottom: 0.4rem;
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}

.section-intro {
  margin-bottom: 2rem;
}

.section-intro h2 {
  margin-top: 0.5rem;
}

.feature-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.feature-tile {
  padding: 1.5rem;
  border-radius: 18px;
  background-color: var(--surface);
  border: 1px solid var(--border-color);
  box-shadow: var(--card-shadow);
}

.feature-tile h3 {
  margin-bottom: 0.75rem;
}

.feature-tile p {
  color: var(--text-secondary);
}

/* Dashboard grid */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

/* Tool card */
.tool-card {
  background-color: var(--surface);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 1.5rem;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
  text-decoration: none;
  color: inherit;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 1rem;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow);
  border-color: var(--accent);
}

.tool-icon {
  font-size: 2.5rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tool-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.tool-copy {
  margin-top: 0.35rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  max-width: 26rem;
}

.tool-stats {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.click-count {
  font-weight: 700;
  color: var(--accent);
}

.stats-label {
  color: var(--text-secondary);
}

/* Loading state */
.loading {
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* Tool page */
.tool-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.tool-header-icon {
  font-size: 2rem;
}

.tool-header-info h1 {
  font-size: 1.8rem;
  margin-bottom: 0.5rem;
}

.tool-header-info p {
  color: var(--text-secondary);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.back-link:hover {
  color: var(--accent-hover);
}

/* Form elements */
.form-group {
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

label {
  font-weight: 500;
  color: var(--text-primary);
}

input[type="number"],
input[type="text"],
select,
textarea {
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 1rem;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

/* Buttons */
button {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 6px;
  background-color: var(--accent);
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s ease;
  font-size: 1rem;
}

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

button:disabled {
  background-color: var(--text-secondary);
  cursor: not-allowed;
  opacity: 0.6;
}

footer {
  padding: 2rem 0 3rem;
  background-color: var(--surface);
  border-top: 1px solid var(--border-color);
}

.footer-inner {
  display: flex;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 680px) {
  header {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .tools-grid {
    gap: 1.5rem;
  }

  .tool-card {
    grid-template-columns: 1fr;
  }
}

/* Results */
.results {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  margin-top: 2rem;
}

.results h3 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.result-item {
  display: flex;
  justify-content: space-between;
  padding: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.result-item:last-child {
  border-bottom: none;
}

.result-label {
  font-weight: 600;
  color: var(--text-secondary);
}

.result-value {
  font-weight: 700;
  color: var(--accent);
}

/* Responsive */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    gap: 1rem;
  }

  .header-content,
  .header-actions {
    width: 100%;
  }

  .container {
    padding: 1rem;
  }

  .tools-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .tool-card {
    padding: 1rem;
  }

  .logo {
    font-size: 1.25rem;
  }

  .tool-header {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.tool-card {
  animation: fadeIn 0.3s ease;
}