/* ==========================================================================
   Center Light Tools - Main Stylesheet
   ライト/ダーク両対応 / レスポンシブ / アクセシビリティ配慮
   ========================================================================== */

/* CSS Variables -------------------------------------------------------- */
:root {
  --bg-base: #ffffff;
  --bg-elevated: #f8fafc;
  --bg-card: #ffffff;
  --bg-subtle: #f1f5f9;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text-base: #0f172a;
  --text-muted: #475569;
  --text-soft: #64748b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --accent-soft: rgba(59, 130, 246, 0.1);
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
  --shadow-lg: 0 10px 25px -5px rgba(15, 23, 42, 0.1), 0 8px 10px -6px rgba(15, 23, 42, 0.06);
  --radius: 10px;
  --radius-sm: 6px;
  --radius-lg: 16px;
  --container: 1200px;
  --header-h: 64px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  --font-mono: "SF Mono", "Monaco", "Cascadia Mono", "Roboto Mono", Consolas, "Courier New", monospace;
  --font-display: "Inter", "Helvetica Neue", -apple-system, sans-serif;
  --trans: 180ms cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-base: #0a0e1a;
  --bg-elevated: #111827;
  --bg-card: #151b2c;
  --bg-subtle: #1e2638;
  --border: #2a334a;
  --border-strong: #3b4660;
  --text-base: #f1f5f9;
  --text-muted: #cbd5e1;
  --text-soft: #94a3b8;
  --accent: #60a5fa;
  --accent-hover: #3b82f6;
  --accent-soft: rgba(96, 165, 250, 0.15);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
}

/* Reset & Base -------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-base);
  background: var(--bg-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--trans), color var(--trans);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
main { flex: 1; }

img, svg, video, canvas { max-width: 100%; height: auto; display: block; }
a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--trans);
}
a:hover { color: var(--accent-hover); text-decoration: underline; }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}
h1, h2, h3, h4 {
  margin: 0 0 0.6em;
  line-height: 1.3;
  font-weight: 700;
  color: var(--text-base);
}
h1 { font-size: clamp(1.75rem, 4vw, 2.5rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.4rem, 3vw, 1.875rem); letter-spacing: -0.01em; }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1em; }
code, kbd, pre, samp { font-family: var(--font-mono); }

/* Utilities ----------------------------------------------------------- */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: absolute;
  left: 0; top: -40px;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  z-index: 1000;
  transition: top var(--trans);
}
.skip-link:focus { top: 0; }

/* Header -------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-base);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  height: var(--header-h);
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-base);
  text-decoration: none;
  flex-shrink: 0;
}
.site-logo:hover { text-decoration: none; }
.logo-mark { color: var(--accent); display: flex; }
.logo-text { display: flex; flex-direction: column; line-height: 1.15; }
.logo-text-main { font-weight: 700; font-size: 1.0625rem; }
.logo-text-sub { font-size: 0.6875rem; color: var(--text-soft); }

.header-search {
  flex: 1;
  max-width: 480px;
  display: flex;
  position: relative;
}
.header-search input {
  width: 100%;
  height: 40px;
  padding: 0 44px 0 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elevated);
  color: var(--text-base);
  font-size: 0.9375rem;
  font-family: inherit;
  transition: border-color var(--trans), box-shadow var(--trans);
}
.header-search input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.header-search button {
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  width: 36px;
  height: 32px;
  border: none;
  background: transparent;
  color: var(--text-soft);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: background var(--trans);
}
.header-search button:hover {
  background: var(--bg-subtle);
  color: var(--accent);
}

.header-nav { display: flex; align-items: center; gap: 8px; }
.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 4px;
}
.nav-menu a {
  display: block;
  padding: 8px 14px;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.9375rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: background var(--trans), color var(--trans);
}
.nav-menu a:hover {
  background: var(--bg-subtle);
  color: var(--text-base);
  text-decoration: none;
}
.theme-toggle, .nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--trans);
}
.theme-toggle:hover, .nav-toggle:hover {
  border-color: var(--border-strong);
  color: var(--text-base);
}
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }
[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

.nav-toggle { display: none; flex-direction: column; gap: 4px; padding: 10px; }
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform var(--trans), opacity var(--trans);
}

/* Hero ---------------------------------------------------------------- */
.hero {
  padding: clamp(48px, 8vw, 96px) 0 clamp(40px, 6vw, 72px);
  background: linear-gradient(180deg, var(--bg-elevated) 0%, var(--bg-base) 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, var(--accent-soft) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.08) 0%, transparent 50%);
  pointer-events: none;
}
.hero-inner { position: relative; text-align: center; max-width: 800px; margin: 0 auto; }
.hero-eyebrow {
  display: inline-block;
  padding: 6px 14px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.8125rem;
  font-weight: 600;
  border-radius: 999px;
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}
.hero h1 { margin-bottom: 16px; }
.hero-lead {
  font-size: clamp(1rem, 2vw, 1.1875rem);
  color: var(--text-muted);
  margin-bottom: 32px;
}
.hero-search {
  max-width: 560px;
  margin: 0 auto;
  display: flex;
  position: relative;
}
.hero-search input {
  width: 100%;
  height: 56px;
  padding: 0 64px 0 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  color: var(--text-base);
  font-size: 1.0625rem;
  font-family: inherit;
  box-shadow: var(--shadow);
  transition: all var(--trans);
}
.hero-search input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft), var(--shadow-lg);
}
.hero-search button {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border: none;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--trans), transform var(--trans);
}
.hero-search button:hover {
  background: var(--accent-hover);
  transform: translateY(-50%) scale(1.05);
}

/* Categories ---------------------------------------------------------- */
.section { padding: clamp(48px, 6vw, 72px) 0; }
.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  margin-bottom: 32px;
  flex-wrap: wrap;
  gap: 16px;
}
.section-head h2 { margin: 0; }
.section-head p { margin: 0; color: var(--text-muted); }

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: all var(--trans);
  text-decoration: none;
  color: inherit;
  display: block;
  position: relative;
  overflow: hidden;
}
.category-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 4px;
  height: 100%;
  background: var(--cat-color, var(--accent));
  opacity: 0;
  transition: opacity var(--trans);
}
.category-card:hover {
  border-color: var(--cat-color, var(--accent));
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}
.category-card:hover::before { opacity: 1; }
.category-card-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: color-mix(in srgb, var(--cat-color, var(--accent)) 12%, transparent);
  color: var(--cat-color, var(--accent));
  border-radius: var(--radius);
  margin-bottom: 16px;
}
.category-card-name {
  font-weight: 700;
  font-size: 1.0625rem;
  margin-bottom: 4px;
  color: var(--text-base);
}
.category-card-count {
  font-size: 0.875rem;
  color: var(--text-soft);
}

/* Tools Grid ---------------------------------------------------------- */
.tools-section { padding-top: 24px; }
.category-block { margin-bottom: 56px; }
.category-block-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}
.category-block-bullet {
  width: 6px;
  height: 24px;
  border-radius: 3px;
  background: var(--cat-color, var(--accent));
}
.category-block-head h2 { margin: 0; font-size: 1.375rem; }
.category-block-head .count {
  margin-left: auto;
  color: var(--text-soft);
  font-size: 0.875rem;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}
.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--trans);
}
.tool-card:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
  text-decoration: none;
}
.tool-card.is-coming {
  opacity: 0.55;
  pointer-events: none;
  cursor: not-allowed;
}
.tool-card-name {
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text-base);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.tool-card-name .badge-soon {
  font-size: 0.625rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--bg-subtle);
  color: var(--text-soft);
  letter-spacing: 0.04em;
}
.tool-card-desc {
  font-size: 0.8125rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin: 0;
}

/* Footer -------------------------------------------------------------- */
.site-footer {
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  padding: 48px 0 24px;
  margin-top: 56px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 32px;
  margin-bottom: 32px;
}
.footer-col-brand { padding-right: 24px; }
.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-base);
  margin-bottom: 12px;
}
.footer-logo .logo-mark { color: var(--accent); }
.footer-desc {
  font-size: 0.8125rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0;
}
.footer-heading {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--text-soft);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 0 0 12px;
}
.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
}
.footer-links li { margin-bottom: 8px; }
.footer-links a {
  color: var(--text-muted);
  font-size: 0.875rem;
  text-decoration: none;
}
.footer-links a:hover { color: var(--accent); }
.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.copyright, .footer-meta {
  margin: 0;
  font-size: 0.75rem;
  color: var(--text-soft);
}

/* Generic Page -------------------------------------------------------- */
.page {
  padding: 40px 0 64px;
}
.page-inner {
  max-width: 820px;
  margin: 0 auto;
}
.page h1 { margin-bottom: 16px; }
.page-lead {
  font-size: 1.0625rem;
  color: var(--text-muted);
  margin-bottom: 32px;
}
.prose h2 { margin-top: 2em; }
.prose h3 { margin-top: 1.6em; }
.prose ul, .prose ol { padding-left: 1.5em; }
.prose li { margin-bottom: 0.4em; }

/* Form ---------------------------------------------------------------- */
.form-row { margin-bottom: 20px; }
.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-base);
  margin-bottom: 6px;
}
.form-label .req { color: var(--danger); margin-left: 4px; }
.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  color: var(--text-base);
  font-size: 0.9375rem;
  font-family: inherit;
  line-height: 1.5;
  transition: border-color var(--trans), box-shadow var(--trans);
}
.form-textarea { min-height: 160px; resize: vertical; }
.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.form-help {
  font-size: 0.75rem;
  color: var(--text-soft);
  margin-top: 4px;
}
.honeypot { position: absolute; left: -9999px; height: 0; width: 0; overflow: hidden; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: #fff;
  font-size: 0.9375rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  text-decoration: none;
  line-height: 1;
  transition: all var(--trans);
}
.btn:hover { background: var(--accent-hover); color: #fff; text-decoration: none; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn-ghost {
  background: transparent;
  color: var(--text-base);
  border-color: var(--border);
}
.btn-ghost:hover { background: var(--bg-subtle); color: var(--text-base); }
.btn-sm { padding: 8px 14px; font-size: 0.8125rem; }

.alert {
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  border: 1px solid var(--border);
  font-size: 0.9375rem;
}
.alert-success { background: rgba(16, 185, 129, 0.08); border-color: rgba(16, 185, 129, 0.3); color: var(--success); }
.alert-error   { background: rgba(239, 68, 68, 0.08); border-color: rgba(239, 68, 68, 0.3); color: var(--danger); }
.alert-info    { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }

/* Breadcrumb ---------------------------------------------------------- */
.breadcrumb { margin-bottom: 20px; font-size: 0.8125rem; }
.breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.breadcrumb li {
  display: flex;
  align-items: center;
  color: var(--text-soft);
}
.breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--text-soft);
  opacity: 0.6;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent); }

/* Responsive ---------------------------------------------------------- */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-col-brand { grid-column: 1 / -1; padding-right: 0; }
}

@media (max-width: 768px) {
  .container { padding: 0 16px; }
  .header-inner { gap: 12px; }
  .header-search { display: none; }
  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg-base);
    border-bottom: 1px solid var(--border);
    padding: 12px 16px;
    gap: 0;
    transform: translateY(-110%);
    transition: transform var(--trans);
    box-shadow: var(--shadow);
  }
  .nav-menu.is-open { transform: translateY(0); }
  .nav-menu li { width: 100%; }
  .nav-menu a {
    padding: 14px 12px;
    border-bottom: 1px solid var(--border);
  }
  .logo-text-sub { display: none; }
}

@media (max-width: 600px) {
  .category-grid { grid-template-columns: 1fr; }
  .tools-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}

/* Print --------------------------------------------------------------- */
@media print {
  .site-header, .site-footer, .header-search, .header-nav, .breadcrumb { display: none !important; }
  body { background: #fff; color: #000; }
}

/* Reduced motion ------------------------------------------------------ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}