/* ==========================================================================
   BuatTools - Modern Web Tools Platform Design System
   Color Palette:
   - Primary: #1a237e (Navy Deep Blue)
   - Primary Accent: #42a5f5 (Vibrant Sky Blue)
   - Secondary Accent: #29b6f6
   - Light BG: #f8fafc
   - Dark BG: #0f172a
   - Surface Light: #ffffff
   - Surface Dark: #1e293b
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  --primary: #1a237e;
  --primary-light: #303f9f;
  --primary-dark: #000051;
  --accent: #42a5f5;
  --accent-hover: #1e88e5;
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px -5px rgba(26,35,126,0.12), 0 8px 10px -6px rgba(0,0,0,0.04);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
  --header-height: 70px;
}

[data-theme="dark"] {
  --bg-main: #0b0f19;
  --bg-card: #151d30;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --border: #2a364f;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.5);
}

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

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.3s ease, color 0.3s ease;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--accent-hover);
}

ul {
  list-style: none;
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(26, 35, 126, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: #ffffff;
  box-shadow: var(--shadow-md);
  height: var(--header-height);
}

.header-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.4rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent), #1565c0);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.2rem;
  box-shadow: 0 2px 8px rgba(66, 165, 245, 0.4);
}

.logo span {
  color: var(--accent);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: rgba(255, 255, 255, 0.85);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
}

/* Dropdown */
.dropdown {
  position: relative;
}

.dropdown-toggle {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  width: 240px;
  background-color: var(--bg-card);
  color: var(--text-main);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  padding: 0.5rem 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
  z-index: 100;
}

.dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  padding: 0.6rem 1.2rem;
  color: var(--text-main);
  font-size: 0.9rem;
  font-weight: 500;
}

.dropdown-item:hover {
  background-color: rgba(66, 165, 245, 0.08);
  color: var(--accent);
}

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

.theme-toggle {
  background: rgba(255, 255, 255, 0.15);
  border: none;
  color: #ffffff;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: var(--transition);
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: rotate(15deg);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: #ffffff;
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 60%, #0d47a1 100%);
  color: #ffffff;
  padding: 4rem 1.5rem 5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 50% 20%, rgba(66, 165, 245, 0.15) 0%, transparent 60%);
  pointer-events: none;
}

.hero-container {
  max-width: 850px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 1rem;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 2rem;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

/* Search Bar */
.search-container {
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}

.search-input {
  width: 100%;
  padding: 1rem 1.5rem;
  padding-left: 3.2rem;
  border-radius: 50px;
  border: 2px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.95);
  color: #1e293b;
  font-size: 1rem;
  font-family: inherit;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
  transition: var(--transition);
  outline: none;
}

.search-input:focus {
  background: #ffffff;
  border-color: var(--accent);
  box-shadow: 0 10px 25px rgba(66, 165, 245, 0.3);
}

.search-icon {
  position: absolute;
  left: 1.2rem;
  top: 50%;
  transform: translateY(-50%);
  color: #64748b;
  font-size: 1.2rem;
  pointer-events: none;
}

/* Layout Main */
.main-content {
  max-width: 1280px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
  flex: 1;
  width: 100%;
}

/* Breadcrumb */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.breadcrumb-separator {
  opacity: 0.5;
}

.breadcrumb-current {
  color: var(--text-main);
  font-weight: 600;
}

/* Category Grid / Section */
.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-desc {
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.tool-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  text-decoration: none;
  color: var(--text-main);
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0;
  transition: var(--transition);
}

.tool-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(66, 165, 245, 0.4);
}

.tool-card:hover::before {
  opacity: 1;
}

.tool-icon {
  width: 50px;
  height: 50px;
  background: rgba(26, 35, 126, 0.06);
  color: var(--primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
  transition: var(--transition);
}

[data-theme="dark"] .tool-icon {
  background: rgba(66, 165, 245, 0.12);
  color: var(--accent);
}

.tool-card:hover .tool-icon {
  background: var(--accent);
  color: #ffffff;
  transform: scale(1.05);
}

.tool-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.tool-badge {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  background: rgba(66, 165, 245, 0.12);
  color: var(--accent);
  margin-bottom: 0.75rem;
  text-transform: uppercase;
}

.tool-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.5;
  flex: 1;
}

.tool-card-footer {
  margin-top: 1.25rem;
  display: flex;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
}

.tool-card-footer svg {
  margin-left: 0.3rem;
  transition: transform 0.2s ease;
}

.tool-card:hover .tool-card-footer svg {
  transform: translateX(4px);
}

/* Tool Execution Container (Tool Workspace Page) */
.tool-workspace {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 3rem;
}

.tool-header {
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1.5rem;
}

.tool-header h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.tool-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Form Controls & Action Boxes */
.input-group {
  margin-bottom: 1.5rem;
}

.input-label {
  display: block;
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-control:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(66, 165, 245, 0.2);
}

textarea.form-control {
  min-height: 140px;
  resize: vertical;
}

/* File Upload Zone */
.upload-zone {
  border: 2px dashed var(--accent);
  border-radius: var(--radius-md);
  padding: 3rem 2rem;
  text-align: center;
  background: rgba(66, 165, 245, 0.03);
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.upload-zone:hover, .upload-zone.dragover {
  background: rgba(66, 165, 245, 0.08);
  border-color: var(--primary);
}

.upload-icon {
  font-size: 3rem;
  color: var(--accent);
  margin-bottom: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  min-height: 44px; /* Touch-friendly 44px minimum */
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(26, 35, 126, 0.25);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-light), var(--primary));
  box-shadow: 0 6px 16px rgba(26, 35, 126, 0.35);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg-main);
  color: var(--text-main);
  border: 1px solid var(--border);
}

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

.btn-accent {
  background: var(--accent);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(66, 165, 245, 0.3);
}

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

.btn-block {
  width: 100%;
}

.result-box {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: var(--bg-main);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  display: none;
}

.result-box.active {
  display: block;
  animation: fadeIn 0.4s ease;
}

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

/* Long Content & SEO Article Section */
.content-article {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  margin-bottom: 3rem;
  line-height: 1.8;
}

.content-article h2 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-top: 1.75rem;
  margin-bottom: 1rem;
  color: var(--text-main);
  border-bottom: 2px solid rgba(66, 165, 245, 0.2);
  padding-bottom: 0.4rem;
}

.content-article h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 1.25rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.content-article p {
  margin-bottom: 1.25rem;
  color: var(--text-main);
  font-size: 1rem;
}

.content-article ul, .content-article ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

.content-article li {
  margin-bottom: 0.5rem;
}

/* FAQ Accordion */
.faq-section {
  margin-top: 2.5rem;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
  overflow: hidden;
  background-color: var(--bg-card);
}

.faq-question {
  width: 100%;
  padding: 1.2rem 1.5rem;
  background: none;
  border: none;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: var(--transition);
}

.faq-question:hover {
  background-color: rgba(66, 165, 245, 0.05);
}

.faq-answer {
  padding: 0 1.5rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  color: var(--text-muted);
}

.faq-item.active .faq-answer {
  padding: 1rem 1.5rem 1.5rem;
  max-height: 500px;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-icon {
  transition: transform 0.3s ease;
}

/* Related Tools Bar */
.related-tools {
  margin-top: 3rem;
}

/* Footer */
.footer {
  background-color: var(--primary-dark);
  color: rgba(255, 255, 255, 0.8);
  padding: 4rem 1.5rem 2rem;
  margin-top: auto;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-container {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-col h4 {
  color: #ffffff;
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  position: relative;
}

.footer-col h4::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 30px;
  height: 2px;
  background-color: var(--accent);
}

.footer-links li {
  margin-bottom: 0.6rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: #ffffff;
  padding-left: 4px;
}

.footer-bottom {
  max-width: 1280px;
  margin: 0 auto;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.875rem;
}

/* Responsive Rules */
@media (max-width: 992px) {
  .hero h1 {
    font-size: 2.2rem;
  }
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: block;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background-color: var(--primary-dark);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1rem;
    box-shadow: var(--shadow-lg);
    display: none;
  }

  .nav-menu.active {
    display: flex;
  }

  .dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    width: 100%;
    box-shadow: none;
    border: none;
    background: rgba(255, 255, 255, 0.05);
  }

  .dropdown-item {
    color: #ffffff;
  }

  .hero {
    padding: 3rem 1rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .tool-workspace, .content-article {
    padding: 1.25rem;
  }
}