/* ============================================================
   MultiWeb — Common Stylesheet
   Shared across all pages for caching & performance
   ============================================================ */

/* ===== 0. RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ===== 1. DESIGN TOKENS ===== */
:root {
  --color-primary: #2563eb;
  --color-primary-light: #3b82f6;
  --color-primary-dark: #1d4ed8;
  --color-primary-bg: #eff6ff;
  --color-secondary: #7c3aed;
  --color-secondary-light: #8b5cf6;
  --color-secondary-dark: #6d28d9;
  --color-secondary-bg: #f5f3ff;
  --color-success: #10b981;
  --color-success-light: #34d399;
  --color-success-dark: #059669;
  --color-success-bg: #ecfdf5;
  --color-warning: #f59e0b;
  --color-warning-light: #fbbf24;
  --color-warning-dark: #d97706;
  --color-warning-bg: #fffbeb;
  --color-danger: #ef4444;
  --color-danger-light: #f87171;
  --color-danger-dark: #dc2626;
  --color-danger-bg: #fef2f2;

  --white: #ffffff;
  --black: #000000;

  --bg-body: #f4f6f9;
  --bg-surface: #ffffff;
  --bg-surface-hover: #f0f1f5;
  --bg-surface-raised: #ffffff;
  --bg-nav: rgba(255, 255, 255, 0.85);
  --bg-hero: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  --bg-card: #ffffff;
  --bg-ad: #e8ecf2;
  --bg-footer: #0f1117;
  --bg-tag: #f0f1f5;

  --text-primary: #0f1117;
  --text-secondary: #5a6072;
  --text-muted: #8a90a2;
  --text-on-hero: #ffffff;
  --text-on-primary: #ffffff;
  --text-on-secondary: #ffffff;
  --text-on-success: #ffffff;
  --text-on-warning: #ffffff;
  --text-on-danger: #ffffff;
  --text-footer: #6b7180;
  --text-footer-heading: #e4e5eb;
  --text-nav: #3a3e4a;
  --text-nav-active: var(--color-primary);
  --text-link: var(--color-primary);
  --text-link-hover: var(--color-primary-dark);

  --border-light: #e8ecf2;
  --border-medium: #d0d5dd;

  --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.10);
  --shadow-xl: 0 20px 60px rgba(0,0,0,0.12);

  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;

  --transition: 0.2s ease;
  --transition-fast: 0.12s ease;
  --transition-slow: 0.35s ease;
  --max-width: 1200px;
  --navbar-height: 64px;
}

[data-theme="dark"] {
  --color-primary-bg: rgba(37,99,235,0.15);
  --color-secondary-bg: rgba(124,58,237,0.15);
  --color-success-bg: rgba(16,185,129,0.15);
  --color-warning-bg: rgba(245,158,11,0.15);
  --color-danger-bg: rgba(239,68,68,0.15);

  --bg-body: #0b0d14;
  --bg-surface: #161822;
  --bg-surface-hover: #1e2030;
  --bg-surface-raised: #1e2030;
  --bg-nav: rgba(11,13,20,0.90);
  --bg-hero: linear-gradient(135deg, #1d4ed8 0%, #6d28d9 100%);
  --bg-card: #161822;
  --bg-ad: #1e2030;
  --bg-footer: #06070a;
  --bg-tag: #1e2030;

  --text-primary: #e8eaed;
  --text-secondary: #9ca0b0;
  --text-muted: #6b7180;
  --text-link: #60a5fa;
  --text-link-hover: #93bbfd;

  --border-light: #232635;
  --border-medium: #34384a;

  --shadow-xs: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.35), 0 1px 2px rgba(0,0,0,0.25);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.45), 0 2px 4px rgba(0,0,0,0.25);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.55);
  --shadow-xl: 0 20px 60px rgba(0,0,0,0.6);

  --text-nav: #c4c7d0;
  --text-nav-active: #60a5fa;
}

/* ===== 2. TYPOGRAPHY ===== */
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  font-size: 1rem;
  background: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1 { font-size: 2.5rem; font-weight: 700; line-height: 1.2; letter-spacing: -0.02em; }
h2 { font-size: 2rem; font-weight: 700; line-height: 1.25; letter-spacing: -0.015em; }
h3 { font-size: 1.5rem; font-weight: 600; line-height: 1.35; letter-spacing: -0.01em; }
h4 { font-size: 1.25rem; font-weight: 600; line-height: 1.4; }
h5 { font-size: 1.125rem; font-weight: 600; line-height: 1.45; }
h6 { font-size: 1rem; font-weight: 600; line-height: 1.5; }

a {
  color: var(--text-link);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--text-link-hover);
  text-decoration: underline;
}
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
img { max-width: 100%; display: block; }
code {
  font-size: 0.875em;
  background: var(--bg-tag);
  padding: 2px 6px;
  border-radius: var(--radius-xs);
}

/* ===== 3. SKIP LINK ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  background: var(--color-primary);
  color: var(--text-on-primary);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  z-index: 1000;
  font-weight: 600;
  font-size: 14px;
  transition: top var(--transition);
}
.skip-link:focus {
  top: 16px;
  text-decoration: none;
  color: var(--text-on-primary);
}

/* ===== 4. CONTAINER ===== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 5. THEME TOGGLE ===== */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-nav);
  transition: background var(--transition), color var(--transition);
  font-size: 20px;
  position: relative;
}
.theme-toggle:hover {
  background: var(--bg-surface-hover);
  color: var(--text-nav-active);
}
.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  position: absolute;
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
[data-theme="light"] .theme-toggle .icon-moon { opacity: 1; transform: rotate(0); }
[data-theme="light"] .theme-toggle .icon-sun { opacity: 0; transform: rotate(90deg); }
[data-theme="dark"] .theme-toggle .icon-sun { opacity: 1; transform: rotate(0); }
[data-theme="dark"] .theme-toggle .icon-moon { opacity: 0; transform: rotate(-90deg); }

/* ===== 6. NAVBAR ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--bg-nav);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border-light);
  transition: background var(--transition);
}
.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--navbar-height);
}
.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 22px;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}
.navbar-brand:hover {
  text-decoration: none;
  color: var(--text-primary);
}
.navbar-brand .logo-icon {
  width: 32px;
  height: 32px;
  background: var(--bg-hero);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  transition: transform var(--transition);
}
.navbar-brand:hover .logo-icon {
  transform: scale(1.08);
}
.navbar-actions {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* Hamburger */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.nav-toggle:hover { background: var(--bg-surface-hover); }
.nav-toggle span {
  display: block;
  height: 2.5px;
  background: var(--text-nav);
  border-radius: 2px;
  transition: transform var(--transition-slow), opacity var(--transition-slow);
}
.nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5.5px, 5.5px); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5.5px, -5.5px); }

/* Mobile nav */
.nav-menu {
  position: fixed;
  top: var(--navbar-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-surface);
  padding: 24px 20px;
  display: none;
  flex-direction: column;
  gap: 6px;
  overflow-y: auto;
  border-top: 1px solid var(--border-light);
}
.nav-menu.open { display: flex; }
.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 15px;
  color: var(--text-nav);
  transition: background var(--transition), color var(--transition);
}
.nav-link:hover {
  background: var(--bg-surface-hover);
  color: var(--text-nav-active);
  text-decoration: none;
}
.nav-link .nav-icon {
  font-size: 18px;
  width: 24px;
  text-align: center;
}
@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .nav-menu {
    position: static;
    display: flex !important;
    flex-direction: row;
    background: none;
    border: none;
    padding: 0;
    overflow: visible;
    gap: 2px;
  }
  .nav-link {
    padding: 8px 14px;
    font-size: 14px;
    border-radius: var(--radius-sm);
  }
}

/* ===== 6B. BREADCRUMBS ===== */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.65);
  margin-bottom: 16px;
}
.breadcrumbs a {
  color: rgba(255,255,255,0.75);
  text-decoration: none;
  transition: color var(--transition);
}
.breadcrumbs a:hover {
  color: #fff;
  text-decoration: underline;
}
.breadcrumbs span[aria-current="page"] {
  color: rgba(255,255,255,0.95);
  font-weight: 500;
}

/* ===== 7. PAGE HEADER / HERO ===== */
.hero {
  background: var(--bg-hero);
  padding: 120px 0 80px;
  margin-top: var(--navbar-height);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(255,255,255,0.10) 0%, transparent 60%),
    radial-gradient(circle at 80% 30%, rgba(255,255,255,0.06) 0%, transparent 50%);
  pointer-events: none;
}
.hero .container { position: relative; }
.hero h1 {
  font-size: clamp(32px, 6vw, 2.5rem);
  font-weight: 800;
  color: var(--text-on-hero);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}
.hero h1 span {
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: clamp(16px, 2.5vw, 20px);
  color: rgba(255,255,255,0.85);
  max-width: 560px;
  margin: 0 auto var(--space-8);
  line-height: 1.6;
}

.page-header {
  background: var(--bg-hero);
  padding: 120px 0 60px;
  margin-top: var(--navbar-height);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 20% 50%, rgba(255,255,255,0.10) 0%, transparent 60%),
              radial-gradient(circle at 80% 30%, rgba(255,255,255,0.06) 0%, transparent 50%);
  pointer-events: none;
}
.page-header .container { position: relative; }
.page-header h1 {
  font-size: clamp(28px, 5vw, 2.5rem);
  font-weight: 800;
  color: var(--text-on-hero);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}
.page-header p {
  font-size: clamp(15px, 2.5vw, 18px);
  color: rgba(255,255,255,0.85);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ===== 8. SECTION ===== */
.section { padding: 48px 0; }
.section-alt { background: var(--bg-surface); }
.section-header {
  text-align: center;
  margin-bottom: var(--space-10);
}
.section-header h2 {
  font-size: clamp(24px, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.015em;
  margin-bottom: var(--space-2);
}
.section-header p {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 500px;
  margin: 0 auto;
}

/* ===== 9. TOOL WORKSPACE ===== */
.tool-workspace {
  max-width: 800px;
  margin: -40px auto 0;
  position: relative;
  z-index: 2;
}
.tool-workspace .tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-lg);
}

/* ===== 10. FORM INPUTS ===== */
.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 10px 14px;
  font-family: var(--font);
  font-size: 0.875rem;
  color: var(--text-primary);
  background: var(--bg-surface);
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}
.form-input:hover,
.form-select:hover,
.form-textarea:hover { border-color: var(--border-medium); }
.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
  background: var(--bg-surface);
  outline: none;
}
.form-input::placeholder,
.form-textarea::placeholder { color: var(--text-muted); }
.form-input.is-invalid,
.form-select.is-invalid,
.form-textarea.is-invalid {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 3px rgba(239,68,68,0.12);
}

/* ===== 11. BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.875rem;
  line-height: 1;
  padding: 10px 20px;
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition), color var(--transition),
              border-color var(--transition), box-shadow var(--transition),
              transform var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
  user-select: none;
}
.btn:hover { text-decoration: none; }
.btn:disabled, .btn.disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }
.btn:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }
.btn-primary { background: var(--color-primary); color: var(--text-on-primary); border-color: var(--color-primary); }
.btn-primary:hover { background: var(--color-primary-dark); border-color: var(--color-primary-dark); box-shadow: 0 4px 14px rgba(37,99,235,0.35); }
.btn-primary:active { transform: scale(0.97); }
.btn-secondary { background: var(--color-secondary); color: var(--text-on-secondary); border-color: var(--color-secondary); }
.btn-secondary:hover { background: var(--color-secondary-dark); border-color: var(--color-secondary-dark); }
.btn-success { background: var(--color-success); color: var(--text-on-success); border-color: var(--color-success); }
.btn-success:hover { background: var(--color-success-dark); border-color: var(--color-success-dark); }
.btn-warning { background: var(--color-warning); color: var(--text-on-warning); border-color: var(--color-warning); }
.btn-warning:hover { background: var(--color-warning-dark); border-color: var(--color-warning-dark); }
.btn-danger { background: var(--color-danger); color: var(--text-on-danger); border-color: var(--color-danger); }
.btn-danger:hover { background: var(--color-danger-dark); border-color: var(--color-danger-dark); }
.btn-outline { background: transparent; color: var(--text-primary); border-color: var(--border-medium); }
.btn-outline:hover { background: var(--bg-surface-hover); border-color: var(--text-muted); }
.btn-outline-primary { background: transparent; color: var(--color-primary); border-color: var(--color-primary); }
.btn-outline-primary:hover { background: var(--color-primary); color: var(--text-on-primary); }
.btn-lg { padding: 14px 28px; font-size: 1rem; }
.btn-sm { padding: 6px 12px; font-size: 0.75rem; }
.btn-icon { width: 40px; height: 40px; padding: 0; border-radius: 50%; }
.w-full { width: 100%; }

/* ===== 12. ERROR / RESULT ===== */
.error-msg {
  display: none;
  background: var(--color-danger-bg);
  color: var(--color-danger-dark);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  margin-top: 16px;
}
.error-msg.visible { display: block; }

.result-area {
  display: none;
  margin-top: 20px;
  padding: 24px;
  background: var(--color-primary-bg);
  border-radius: var(--radius-md);
  text-align: center;
}
.result-area.visible { display: block; }
.result-value {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.2;
}
.result-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 8px;
}

/* ===== 13. TAG / BADGE ===== */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: var(--bg-tag);
  color: var(--text-secondary);
}
.tag-primary { background: var(--color-primary-bg); color: var(--color-primary); }
.tag-success { background: var(--color-success-bg); color: var(--color-success-dark); }
.tag-warning { background: var(--color-warning-bg); color: var(--color-warning-dark); }
.tag-danger { background: var(--color-danger-bg); color: var(--color-danger); }

/* ===== 14. FAQ ===== */
.faq-list { display: flex; flex-direction: column; gap: 8px; }
.faq-item {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg-surface);
  transition: box-shadow var(--transition);
}
.faq-item:hover { box-shadow: var(--shadow-sm); }
.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 20px;
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  transition: background var(--transition);
}
.faq-question:hover { background: var(--bg-surface-hover); }
.faq-question:focus-visible { outline: 2px solid var(--color-primary); outline-offset: -2px; }
.faq-question .faq-icon {
  flex-shrink: 0;
  font-size: 14px;
  color: var(--text-muted);
  transition: transform var(--transition);
}
.faq-item.open .faq-question .faq-icon { transform: rotate(180deg); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), padding var(--transition-slow);
}
.faq-item.open .faq-answer { max-height: 300px; padding: 0 20px 18px; }
.faq-answer p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== 15. SEO CONTENT ===== */
.content-section { max-width: 800px; margin: 0 auto; }
.intro-text { font-size: 1.0625rem; color: var(--text-secondary); line-height: 1.7; margin-bottom: 32px; }
.steps-list {
  list-style: none;
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 32px;
}
.steps-list li {
  counter-increment: step;
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px;
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  transition: box-shadow var(--transition), transform var(--transition);
}
.steps-list li:hover { box-shadow: var(--shadow-sm); transform: translateY(-1px); }
.steps-list li::before {
  content: counter(step);
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}
.steps-list li strong { display: block; font-weight: 600; margin-bottom: 4px; }
.steps-list li span { color: var(--text-secondary); font-size: 0.9375rem; line-height: 1.5; }

/* ===== 16. RELATED TOOLS ===== */
.related-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
@media (min-width: 600px) { .related-grid { grid-template-columns: repeat(3, 1fr); } }
.related-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  cursor: pointer;
  text-decoration: none;
  color: var(--text-primary);
  display: block;
}
.related-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-light);
  text-decoration: none;
  color: var(--text-primary);
}
.related-card .related-icon { font-size: 32px; margin-bottom: 12px; display: block; }
.related-card h4 { font-size: 1.0625rem; font-weight: 600; margin-bottom: 6px; }
.related-card p { font-size: 0.8125rem; color: var(--text-secondary); line-height: 1.5; }

/* ===== 17. FOOTER ===== */
.footer {
  background: var(--bg-footer);
  color: var(--text-footer);
  margin-top: auto;
  padding: 48px 0 32px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-bottom: 32px;
}
@media (min-width: 600px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }
.footer-brand h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-footer-heading);
  margin-bottom: 8px;
}
.footer-brand p { font-size: 0.875rem; line-height: 1.6; max-width: 300px; }
.footer-col h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-footer-heading);
  margin-bottom: 16px;
}
.footer-col nav { display: flex; flex-direction: column; gap: 10px; }
.footer-col nav a {
  font-size: 0.875rem;
  color: var(--text-footer);
  transition: color var(--transition);
}
.footer-col nav a:hover { color: var(--text-footer-heading); text-decoration: none; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
  font-size: 0.8125rem;
}
@media (min-width: 600px) { .footer-bottom { flex-direction: row; justify-content: space-between; } }

/* ===== 18. UTILITIES ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}
.mb-2 { margin-bottom: 8px; }
.mb-4 { margin-bottom: 16px; }
.mb-6 { margin-bottom: 24px; }
.mb-8 { margin-bottom: 32px; }
.mt-4 { margin-top: 16px; }
.mt-6 { margin-top: 24px; }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.gap-6 { gap: 24px; }
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.text-secondary { color: var(--text-secondary); }

.fade-in { animation: fadeIn 0.4s ease forwards; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== 19. MOBILE RESPONSIVE (Calculator Pages) ===== */
@media (max-width: 480px) {
  /* Tool workspace & card */
  .tool-workspace .tool-card { padding: 20px 16px; }
  .tool-workspace { margin-top: -24px; }

  /* Form inputs */
  .form-input, .form-select, .form-textarea {
    font-size: 1rem;
    padding: 10px 12px;
  }
  .calc-btn {
    font-size: 1rem;
    padding: 12px 20px;
  }

  /* Result area */
  .result-header { padding: 16px; }
  .result-value { font-size: 2rem; }
  .result-details { grid-template-columns: 1fr; }
  .result-item { padding: 12px 16px; border-right: none !important; }
  .result-item-label { font-size: 0.6875rem; }
  .result-item-value { font-size: 0.9375rem; }

  /* Page header */
  .page-header { padding: 100px 0 40px; }
  .page-header h1 { font-size: 1.75rem; }
  .page-header p { font-size: 0.9375rem; }

  /* Content sections */
  .content-section { padding: 0 4px; }
  .intro-text { font-size: 1rem; }
  .steps-list li { padding: 16px; gap: 12px; }
  .steps-list li::before { width: 32px; height: 32px; font-size: 0.875rem; }
  .steps-list li strong { font-size: 0.9375rem; }
  .steps-list li span { font-size: 0.875rem; }

  /* FAQ */
  .faq-question { padding: 14px 16px; font-size: 0.9375rem; }
  .faq-item.open .faq-answer { padding: 0 16px 14px; }
  .faq-answer p { font-size: 0.875rem; }

  /* Related tools */
  .related-card { padding: 16px; }
  .related-card h4 { font-size: 0.9375rem; }
  .related-card p { font-size: 0.75rem; }

  /* Error message */
  .error-msg { padding: 8px 12px; font-size: 0.875rem; }

  /* Calculator-specific elements */
  .calc-btn { min-height: 44px; }
  .formula-box { padding: 16px; overflow-x: auto; }
  .formula { font-size: 0.875rem; word-break: break-all; }
  .goal-presets button { padding: 6px 10px; font-size: 0.75rem; }
  .tip-pills button { padding: 8px 14px; font-size: 0.8125rem; }
  .breakdown-legend { gap: 12px; }
  .converter-box { grid-template-columns: 1fr; }
  .swap-btn { width: 40px; height: 40px; font-size: 1rem; margin: 8px auto; }
}

@media (min-width: 481px) and (max-width: 767px) {
  .tool-workspace .tool-card { padding: 28px 24px; }
  .result-value { font-size: 2.25rem; }
  .result-details { grid-template-columns: 1fr 1fr; }
  .result-item { padding: 14px 20px; }
}

/* ===== 20. COOKIE CONSENT BANNER ===== */
.cookie-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 9999;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-light);
  box-shadow: 0 -4px 24px rgba(0,0,0,0.12);
  padding: 0;
  transform: translateY(100%);
  opacity: 0;
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1),
              opacity 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}
[data-theme="dark"] .cookie-banner {
  box-shadow: 0 -4px 24px rgba(0,0,0,0.5);
}
.cookie-banner-visible {
  transform: translateY(0);
  opacity: 1;
}
.cookie-banner-hiding {
  transform: translateY(100%);
  opacity: 0;
}
.cookie-banner-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px 20px;
}
.cookie-banner-text {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  flex: 1;
}
.cookie-banner-icon {
  font-size: 24px;
  flex-shrink: 0;
  line-height: 1.4;
}
.cookie-banner-text p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0;
}
.cookie-banner-text a {
  color: var(--color-primary);
  font-weight: 500;
}
.cookie-banner-text a:hover {
  text-decoration: underline;
}
.cookie-banner-actions {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
}
@media (max-width: 600px) {
  .cookie-banner-inner {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    padding: 16px;
  }
  .cookie-banner-actions {
    justify-content: flex-end;
  }
}

/* ===== 21. DONATION BUTTON ===== */
@keyframes donate-pulse {
  0%, 100% { box-shadow: 0 2px 8px rgba(238, 90, 36, 0.3), 0 0 0 0 rgba(238, 90, 36, 0.4); }
  50% { box-shadow: 0 2px 8px rgba(238, 90, 36, 0.3), 0 0 0 6px rgba(238, 90, 36, 0); }
}
.donate-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 8px 20px;
  background: linear-gradient(135deg, #ff6b6b, #ee5a24);
  color: #fff;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.875rem;
  text-decoration: none;
  transition: transform var(--transition), box-shadow var(--transition),
              background var(--transition);
  box-shadow: 0 2px 8px rgba(238, 90, 36, 0.3);
  white-space: nowrap;
  line-height: 1;
  height: 40px;
  flex-shrink: 0;
  animation: donate-pulse 2.5s ease-in-out infinite;
  position: relative;
  z-index: 2;
}
.donate-btn:hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 6px 20px rgba(238, 90, 36, 0.5);
  background: linear-gradient(135deg, #ee5a24, #d63031);
  color: #fff;
  text-decoration: none;
  animation: none;
}
.donate-btn:active {
  transform: scale(0.97);
}
.donate-btn span[data-i18n] {
  display: inline;
}
@media (max-width: 767px) {
  .donate-btn {
    padding: 6px 12px;
    font-size: 0.8125rem;
    height: 36px;
    gap: 5px;
  }
  .donate-btn span[data-i18n] {
    display: none;
  }
}

/* ===== 22. FLOATING DONATE BUTTON ===== */
.floating-donate {
  position: fixed;
  bottom: 80px;
  left: 24px;
  z-index: 90;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: linear-gradient(135deg, #ff6b6b, #ee5a24);
  color: #fff;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.875rem;
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(238, 90, 36, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity 0.35s ease, visibility 0.35s ease, transform 0.35s ease, box-shadow 0.2s ease;
  white-space: nowrap;
  line-height: 1;
  height: 44px;
}
.floating-donate.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.floating-donate:hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 6px 24px rgba(238, 90, 36, 0.5);
  color: #fff;
  text-decoration: none;
}
.floating-donate:active {
  transform: scale(0.97);
}
.floating-donate span[data-i18n] {
  display: inline;
}
@media (max-width: 767px) {
  .floating-donate {
    bottom: 72px;
    left: 16px;
    padding: 8px 14px;
    font-size: 0.8125rem;
    height: 40px;
  }
  .floating-donate span[data-i18n] {
    display: none;
  }
}

/* ===== 23. PRINT ===== */
@media print {
  * { background: transparent !important; color: #000 !important; box-shadow: none !important; }
  .navbar, .theme-toggle, .nav-toggle, .skip-link { display: none !important; }
  .page-header, .hero { padding: 20px 0; margin-top: 0; }
  .tool-workspace { margin-top: 0; }
  @page { margin: 1.5cm; }
}