/* ==========================================================================
   HashGenie - Cryptographic Hash & Checksum Suite
   High-Performance, Accessible, Mobile-First Stylesheet (Pure CSS3)
   ========================================================================== */

:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --secondary: #475569;
  --success: #16a34a;
  --success-light: #f0fdf4;
  --danger: #dc2626;
  --danger-light: #fef2f2;
  --warning: #d97706;
  --warning-light: #fffbeb;
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-border: #e2e8f0;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --code-bg: #0f172a;
  --code-text: #38bdf8;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 9999px;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.07);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.04);
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: #1e293b;
  --bg: #0b0f19;
  --surface: #131b2e;
  --surface-border: #1e293b;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --code-bg: #070b14;
  --code-text: #38bdf8;
  --success-light: #064e3b;
  --warning-light: #451a03;
  --danger-light: #450a0a;
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-main);
  background-color: var(--bg);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Accessibility Focus States */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(1.75rem, 3.5vw, 2.4rem); }
h2 { font-size: clamp(1.3rem, 2.8vw, 1.8rem); margin-top: 2rem; }
h3 { font-size: clamp(1.1rem, 2.2vw, 1.3rem); margin-top: 1.25rem; }
p { margin-bottom: 1.15rem; color: var(--text-main); }
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-hover); text-decoration: underline; }

/* Layout Containers */
.container {
  width: 100%;
  max-width: 1120px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* Header & Navigation - Top Right Alignment */
.site-header {
  background-color: var(--surface);
  border-bottom: 1px solid var(--surface-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
  flex-shrink: 0;
}

.logo-badge {
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  color: white;
  padding: 0.25rem 0.55rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 700;
}

/* Header Right Navigation Container */
.header-nav-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-left: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
}

.nav-link:hover {
  color: var(--primary);
  background-color: var(--primary-light);
  text-decoration: none;
}

.nav-link.active {
  color: var(--primary);
  background-color: var(--primary-light);
  font-weight: 700;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-cta-btn {
  white-space: nowrap;
}

.theme-toggle-btn {
  background: var(--bg);
  border: 1px solid var(--surface-border);
  color: var(--text-main);
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: var(--transition);
  white-space: nowrap;
}

.theme-toggle-btn:hover {
  background-color: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

.mobile-menu-btn {
  display: none;
  background: var(--bg);
  border: 1px solid var(--surface-border);
  font-size: 1.35rem;
  color: var(--text-main);
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
}

.mobile-menu-btn:hover {
  border-color: var(--primary);
}

/* Breadcrumbs */
.breadcrumb-nav {
  background-color: var(--surface);
  border-bottom: 1px solid var(--surface-border);
  padding: 0.65rem 0;
  font-size: 0.85rem;
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  list-style: none;
  color: var(--text-muted);
}

.breadcrumb-list li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--surface-border);
}

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

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

/* Hero Section */
.hero-section {
  text-align: center;
  padding: 2.75rem 0 1.75rem 0;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0.75rem auto 1.25rem auto;
  line-height: 1.55;
}

.hero-trust-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.4);
  color: #065f46;
  padding: 0.45rem 1.15rem;
  border-radius: var(--radius-pill);
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}

[data-theme="dark"] .hero-trust-badge {
  background: rgba(16, 185, 129, 0.15);
  border-color: rgba(52, 211, 153, 0.4);
  color: #6ee7b7;
}

.hero-pill {
  display: inline-block;
  background-color: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(37, 99, 235, 0.2);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

/* Tool Workstation Card */
.tool-card {
  background-color: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 3rem;
}

.tool-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  border-bottom: 2px solid var(--surface-border);
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
}

.tool-tab {
  background: none;
  border: none;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-muted);
  padding: 0.6rem 1.15rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
}

.tool-tab:hover {
  color: var(--primary);
  background-color: var(--primary-light);
}

.tool-tab.active {
  color: var(--primary);
  background-color: var(--primary-light);
  border-bottom: 2px solid var(--primary);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.label-meta {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.tool-textarea {
  width: 100%;
  min-height: 130px;
  padding: 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.5;
  background-color: var(--bg);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  color: var(--text-main);
  resize: vertical;
  transition: var(--transition);
}

.tool-textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.tool-input {
  width: 100%;
  padding: 0.75rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  background-color: var(--bg);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  color: var(--text-main);
  transition: var(--transition);
}

.tool-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

/* Controls Bar */
.controls-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--surface-border);
}

.options-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.custom-checkbox {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  user-select: none;
}

.btn-group {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--primary);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  text-decoration: none;
}

.btn-outline {
  background-color: transparent;
  border-color: var(--surface-border);
  color: var(--text-main);
}

.btn-outline:hover {
  background-color: var(--bg);
  border-color: var(--primary);
  color: var(--primary);
  text-decoration: none;
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.825rem;
}

/* Drop Zone & File Security Badge */
.drop-zone {
  border: 2px dashed var(--surface-border);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.5rem;
  text-align: center;
  background-color: var(--bg);
  cursor: pointer;
  transition: var(--transition);
}

.drop-zone:hover, .drop-zone.dragover {
  border-color: var(--primary);
  background-color: var(--primary-light);
}

.drop-icon {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.drop-security-notice {
  margin-top: 1rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--success-light);
  color: #15803d;
  border: 1px solid rgba(22, 163, 74, 0.25);
  padding: 0.45rem 0.95rem;
  border-radius: var(--radius-md);
  font-size: 0.825rem;
  text-align: left;
}

[data-theme="dark"] .drop-security-notice {
  color: #86efac;
}

/* Progress Bar for File Hashing */
.progress-container {
  margin-top: 1rem;
  background-color: var(--surface-border);
  border-radius: var(--radius-pill);
  height: 8px;
  overflow: hidden;
  display: none;
}

.progress-bar {
  background-color: var(--primary);
  height: 100%;
  width: 0%;
  transition: width 0.15s ease;
}

/* Result Boxes */
.result-box {
  background-color: var(--code-bg);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin-top: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.4rem;
}

.result-title {
  color: #94a3b8;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.btn-copy {
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  border: none;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
}

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

.result-value {
  font-family: var(--font-mono);
  color: var(--code-text);
  font-size: 1rem;
  word-break: break-all;
  user-select: all;
}

/* Verification Status Box */
.verify-box {
  padding: 0.85rem 1.15rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 700;
  margin-top: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.verify-box.match {
  background-color: var(--success-light);
  color: var(--success);
  border: 1px solid var(--success);
}

.verify-box.mismatch {
  background-color: var(--danger-light);
  color: var(--danger);
  border: 1px solid var(--danger);
}

/* Alerts / Error Callouts */
.alert-box {
  padding: 0.85rem 1.15rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  margin-bottom: 1rem;
  display: none;
}

.alert-box.error {
  background-color: var(--danger-light);
  color: var(--danger);
  border: 1px solid var(--danger);
}

/* SEO Educational Articles */
.seo-content {
  background-color: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  margin-bottom: 3rem;
  box-shadow: var(--shadow-sm);
}

.seo-content h2 {
  border-bottom: 1px solid var(--surface-border);
  padding-bottom: 0.5rem;
}

.seo-content ul, .seo-content ol {
  margin-left: 1.5rem;
  margin-bottom: 1.5rem;
}

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

.callout {
  background-color: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 1.15rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0;
}

.callout-title {
  font-weight: 800;
  margin-bottom: 0.25rem;
  color: var(--primary);
}

.callout-warning {
  background-color: var(--warning-light);
  border-left-color: var(--warning);
}

.callout-warning .callout-title {
  color: var(--warning);
}

/* Data Tables */
.table-responsive {
  overflow-x: auto;
  margin: 1.5rem 0;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9rem;
}

.data-table th, .data-table td {
  padding: 0.85rem 1rem;
  border: 1px solid var(--surface-border);
}

.data-table th {
  background-color: var(--bg);
  font-weight: 700;
}

.data-table tr:hover {
  background-color: rgba(37, 99, 235, 0.03);
}

/* FAQ List */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1rem;
}

.faq-item {
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  background: var(--bg);
  border: none;
  padding: 1rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-question:hover {
  background-color: var(--primary-light);
}

.faq-answer {
  padding: 1.25rem;
  display: none;
  background-color: var(--surface);
  border-top: 1px solid var(--surface-border);
  font-size: 0.9rem;
  line-height: 1.6;
}

.faq-item.open .faq-answer {
  display: block;
}

/* Tools Grid for Home Page */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.tool-card-item {
  background-color: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.tool-card-item:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.tool-card-icon {
  width: 44px;
  height: 44px;
  background-color: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 1rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin: 1.5rem 0;
}

.feature-box {
  background-color: var(--bg);
  border: 1px solid var(--surface-border);
  padding: 1.25rem;
  border-radius: var(--radius-md);
}

/* Footer */
.site-footer {
  background-color: var(--surface);
  border-top: 1px solid var(--surface-border);
  padding: 3.5rem 0 2rem 0;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 800;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.875rem;
}

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

.footer-bottom {
  border-top: 1px solid var(--surface-border);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 1rem;
}

/* Copied Toast Message */
.copied-toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background-color: #0f172a;
  color: #ffffff;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  z-index: 100;
  opacity: 0;
  transform: translateY(10px);
  transition: var(--transition);
  pointer-events: none;
}

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

.header-cta-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.header-tool-btn {
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.45rem 0.9rem;
}

/* Homepage Hero CTAs */
.hero-cta-group {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1.5rem;
}

.btn-lg {
  padding: 0.8rem 1.6rem;
  font-size: 1.05rem;
  font-weight: 700;
  border-radius: var(--radius-md);
}

/* Homepage Steps / How It Works */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.step-card {
  background-color: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  position: relative;
  transition: var(--transition);
}

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

.step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-md);
  font-weight: 800;
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

/* CTA Banner */
.cta-banner {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.08), rgba(124, 58, 237, 0.08));
  border: 1px solid rgba(37, 99, 235, 0.25);
  border-radius: var(--radius-lg);
  padding: 3rem 2rem;
  text-align: center;
  margin: 3.5rem 0 2rem 0;
}

.cta-banner h2 {
  margin-top: 0;
  margin-bottom: 0.75rem;
}

.cta-banner p {
  max-width: 600px;
  margin: 0 auto 1.5rem auto;
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Quick Interactive Preview on Home */
.quick-preview-card {
  background-color: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-md);
  margin: 2rem 0 3rem 0;
}

.quick-preview-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .header-nav-right {
    gap: 0.5rem;
  }

  .header-tool-btn {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 4.25rem;
    left: 0;
    width: 100%;
    background-color: var(--surface);
    border-bottom: 1px solid var(--surface-border);
    flex-direction: column;
    padding: 1.25rem;
    gap: 0.5rem;
    box-shadow: var(--shadow-lg);
    z-index: 99;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-link {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .tool-card {
    padding: 1.25rem;
  }

  .hero-cta-group {
    flex-direction: column;
    width: 100%;
  }

  .hero-cta-group .btn {
    width: 100%;
  }
}