/* The Audio Toolkit — Styles */
/* Mobile-first, minimal, fast */

/* CSS Custom Properties */
:root {
  --color-bg: #0f0f0f;
  --color-bg-elevated: #1a1a1a;
  --color-bg-card: #161616;
  --color-text: #e8e8e8;
  --color-text-muted: #9a9a9a;
  --color-primary: #00d4aa;
  --color-primary-hover: #00e8bb;
  --color-primary-dim: rgba(0, 212, 170, 0.15);
  --color-border: #2a2a2a;
  --color-error: #ff6b6b;
  --color-success: #00d4aa;
  --color-warning: #ffd93d;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', Menlo, monospace;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 40px;
  --spacing-2xl: 64px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
  --transition: 150ms ease;
  --max-width: 720px;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Typography */
h1, h2, h3, h4 { line-height: 1.2; font-weight: 600; color: var(--color-text); }
h1 { font-size: clamp(1.75rem, 5vw, 2.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2rem); }
h3 { font-size: clamp(1.125rem, 3vw, 1.375rem); }
p { color: var(--color-text-muted); }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-hover); }
strong { color: var(--color-text); }
code, kbd, pre, .mono { font-family: var(--font-mono); font-size: 0.9em; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 14px 24px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  min-height: 48px;
  touch-action: manipulation;
}
.btn-primary {
  background: var(--color-primary);
  color: var(--color-bg);
}
.btn-primary:hover { background: var(--color-primary-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-primary:active { transform: translateY(0); }
.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}
.btn-outline:hover { background: var(--color-primary-dim); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 15, 15, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.logo { display: flex; align-items: center; gap: var(--spacing-sm); text-decoration: none; color: var(--color-text); }
.logo:hover { color: var(--color-primary); }
.logo-icon { width: 28px; height: 28px; color: var(--color-primary); }
.main-nav { display: none; gap: var(--spacing-lg); }
@media (min-width: 640px) { .main-nav { display: flex; } }
.nav-link { font-weight: 500; color: var(--color-text-muted); padding: var(--spacing-sm) 0; }
.nav-link:hover { color: var(--color-primary); }

/* Mobile Nav Toggle */
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  touch-action: manipulation;
}
@media (min-width: 640px) { .nav-toggle { display: none; } }
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-nav {
  display: none;
  position: fixed;
  top: 60px;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 15, 15, 0.98);
  z-index: 99;
  padding: var(--spacing-lg);
  flex-direction: column;
  gap: var(--spacing-md);
  overflow-y: auto;
}
.mobile-nav.open { display: flex; }
.mobile-nav a {
  display: block;
  padding: var(--spacing-md);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-md);
  transition: background var(--transition);
}
.mobile-nav a:hover, .mobile-nav a:active { background: var(--color-primary-dim); color: var(--color-primary); }

/* Hero */
.hero { padding: var(--spacing-2xl) 0; text-align: center; }
.hero-subtitle { max-width: 560px; margin: var(--spacing-lg) auto 0; font-size: 1.125rem; }
.hero-cta { margin-top: var(--spacing-xl); }
.hero-trust { margin-top: var(--spacing-lg); font-size: 0.875rem; color: var(--color-text-muted); opacity: 0.7; }

/* Sections */
.section-title { text-align: center; margin-bottom: var(--spacing-xl); }
section { padding: var(--spacing-2xl) 0; }

/* Tool Cards */
.tools-grid { background: var(--color-bg-elevated); border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); }
.tool-cards { display: grid; gap: var(--spacing-lg); }
@media (min-width: 768px) { .tool-cards { grid-template-columns: repeat(3, 1fr); } }
.tool-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.tool-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--color-primary); }
.tool-icon { width: 48px; height: 48px; color: var(--color-primary); margin-bottom: var(--spacing-md); }
.tool-card h3 { margin-bottom: var(--spacing-sm); }
.tool-card p { font-size: 0.9rem; margin-bottom: var(--spacing-md); }
.tool-features { list-style: none; font-size: 0.8125rem; color: var(--color-text-muted); margin-bottom: var(--spacing-lg); }
.tool-features li { padding: var(--spacing-xs) 0; position: relative; padding-left: var(--spacing-lg); }
.tool-features li::before { content: "✓"; position: absolute; left: 0; color: var(--color-primary); font-weight: bold; }

/* Lead Magnet */
.lead-magnet { background: linear-gradient(135deg, var(--color-primary-dim) 0%, transparent 100%); border-radius: var(--radius-lg); padding: var(--spacing-xl); margin: var(--spacing-xl) 0; text-align: center; border: 1px solid var(--color-primary-dim); }
.lead-content h2 { margin-bottom: var(--spacing-sm); }
.lead-content > p { margin-bottom: var(--spacing-lg); max-width: 480px; margin-left: auto; margin-right: auto; }
.email-form { display: flex; flex-direction: column; gap: var(--spacing-sm); max-width: 360px; margin: 0 auto; }
@media (min-width: 480px) { .email-form { flex-direction: row; } }
.email-form input { flex: 1; padding: 14px 16px; border: 1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-bg); color: var(--color-text); font-size: 1rem; min-height: 48px; }
.email-form input:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-dim); }
.form-note { font-size: 0.75rem; color: var(--color-text-muted); text-align: center; margin-top: var(--spacing-sm); }

/* Why Us */
.why-us { background: var(--color-bg-elevated); border-top: 1px solid var(--color-border); }
.why-grid { display: grid; gap: var(--spacing-lg); }
@media (min-width: 640px) { .why-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .why-grid { grid-template-columns: repeat(4, 1fr); } }
.why-item { padding: var(--spacing-md); }
.why-item strong { display: block; margin-bottom: var(--spacing-xs); font-size: 1rem; }
.why-item p { font-size: 0.875rem; margin: 0; }

/* Footer */
.site-footer { margin-top: auto; padding: var(--spacing-xl) 0; border-top: 1px solid var(--color-border); background: var(--color-bg-elevated); }
.footer-nav { display: flex; flex-wrap: wrap; gap: var(--spacing-md); justify-content: center; margin-bottom: var(--spacing-md); font-size: 0.875rem; }
.copyright { text-align: center; font-size: 0.75rem; color: var(--color-text-muted); opacity: 0.6; }

/* Tool Page Specific */
.tool-page { padding: var(--spacing-xl) 0 var(--spacing-2xl); }
.tool-header { text-align: center; margin-bottom: var(--spacing-xl); }
.tool-header h1 { margin-bottom: var(--spacing-sm); }
.tool-header p { max-width: 560px; margin: 0 auto; }
.tool-calculator { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--spacing-xl); margin-bottom: var(--spacing-xl); }
@media (max-width: 480px) { .tool-calculator { padding: var(--spacing-md); } }
.calculator-row { display: grid; gap: var(--spacing-md); margin-bottom: var(--spacing-md); }
@media (min-width: 640px) { .calculator-row { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); } }
.field-group { display: flex; flex-direction: column; gap: var(--spacing-xs); }
.field-group label { font-size: 0.875rem; font-weight: 500; color: var(--color-text-muted); }
.field-group input, .field-group select {
  padding: 14px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 1.125rem;
  font-family: var(--font-mono);
  min-height: 48px;
}
.field-group input:focus, .field-group select:focus { outline: none; border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-dim); }
.field-group input::placeholder { color: var(--color-text-muted); opacity: 0.5; }
.field-group .unit { position: absolute; right: 16px; top: 50%; transform: translateY(-50%); color: var(--color-text-muted); pointer-events: none; }
.field-group.has-unit { position: relative; }
.field-group.has-unit input { padding-right: 50px; }
.field-group .hint { font-size: 0.75rem; color: var(--color-text-muted); opacity: 0.7; }
@media (max-width: 480px) { .field-group input, .field-group select { font-size: 16px; } }
.results { background: var(--color-bg); border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: var(--spacing-lg); margin-top: var(--spacing-lg); }
@media (max-width: 480px) { .results { padding: var(--spacing-md); } }
.results h3 { margin-bottom: var(--spacing-md); font-size: 1rem; }
.result-row { display: flex; justify-content: space-between; align-items: center; padding: var(--spacing-sm) 0; border-bottom: 1px solid var(--color-border); font-family: var(--font-mono); }
.result-row:last-child { border-bottom: none; }
.result-label { color: var(--color-text-muted); }
.result-value { color: var(--color-primary); font-weight: 600; font-size: 1.125rem; }
.result-value.warning { color: var(--color-warning); }
.result-value.error { color: var(--color-error); }

/* Content Sections */
.content-section { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: var(--spacing-xl); margin-bottom: var(--spacing-xl); }
@media (max-width: 480px) { .content-section { padding: var(--spacing-md); } }
.content-section h2 { margin-bottom: var(--spacing-lg); padding-bottom: var(--spacing-sm); border-bottom: 1px solid var(--color-border); }
.content-section h3 { margin: var(--spacing-lg) 0 var(--spacing-sm); }
.content-section p { margin-bottom: var(--spacing-md); }
.content-section ul, .content-section ol { margin-bottom: var(--spacing-md); padding-left: var(--spacing-xl); }
.content-section li { margin-bottom: var(--spacing-xs); }
.content-section code { background: var(--color-bg); padding: 2px 6px; border-radius: var(--radius-sm); font-size: 0.875em; }
.content-section pre { background: var(--color-bg); border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: var(--spacing-md); overflow-x: auto; margin-bottom: var(--spacing-md); }
.content-section pre code { background: none; padding: 0; }
.content-section table { width: 100%; border-collapse: collapse; margin-bottom: var(--spacing-md); font-size: 0.875rem; }
@media (max-width: 480px) { .content-section table { font-size: 0.75rem; } }
.content-section .table-wrap { overflow-x: auto; margin-bottom: var(--spacing-md); }
.content-section .table-wrap table { margin-bottom: 0; }
.content-section th, .content-section td { padding: var(--spacing-sm) var(--spacing-md); border: 1px solid var(--color-border); text-align: left; }
@media (max-width: 480px) { .content-section th, .content-section td { padding: var(--spacing-xs) var(--spacing-sm); } }
.content-section th { background: var(--color-bg); font-weight: 600; }
.faq { margin-top: var(--spacing-lg); }
.faq details { border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: var(--spacing-sm); overflow: hidden; }
.faq summary { padding: var(--spacing-md); cursor: pointer; font-weight: 500; list-style: none; background: var(--color-bg); }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; float: right; transition: transform var(--transition); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details[open] summary { border-bottom: 1px solid var(--color-border); }
.faq .faq-content { padding: var(--spacing-md); }
.affiliate-box { background: var(--color-primary-dim); border: 1px solid var(--color-primary); border-radius: var(--radius-md); padding: var(--spacing-lg); margin: var(--spacing-lg) 0; }
.affiliate-box h4 { color: var(--color-primary); margin-bottom: var(--spacing-sm); }
.affiliate-box a { font-weight: 600; }

/* Utilities */
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.text-center { text-align: center; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }

/* Print */
@media print { .site-header, .hero-cta, .email-form, .site-footer, .btn { display: none; } .tool-calculator { break-inside: avoid; } }