:root {
  --color-background: #edf8f7;
  --color-background-cool: #f4f7fb;
  --color-surface: #ffffff;
  --color-surface-soft: #f7fafb;
  --color-surface-teal: #f4fbfa;
  --color-text: #153644;
  --color-text-muted: #58717f;
  --color-border: #dce7ea;
  --color-primary: #087f75;
  --color-primary-hover: #056a62;
  --color-primary-soft: #dff4ef;
  --color-danger: #9e353a;
  --color-danger-soft: #fff0f0;
  --color-warning: #8a5a00;
  --color-success: #17665e;
  --color-focus: #0b6acb;
  --color-on-primary: #ffffff;
  --color-ambient-top: rgba(196, 232, 226, 0.56);
  --color-ambient-bottom: rgba(210, 229, 245, 0.66);
  --color-glass-soft: rgba(255, 255, 255, 0.68);
  --color-card-border: rgba(220, 231, 234, 0.8);
  --color-teal-border: #b9dfd8;
  --color-drop-border: #69b8b1;
  --color-drop-hover: #eaf8f5;
  --color-accent-warm: #f0aa4b;
  --color-error-border: #f2c6c8;
  --color-count-surface: #e7f2f6;
  --color-count-text: #275667;
  --color-processing-border: #78bdb6;
  --color-processing-surface: #f1fbf9;
  --color-success-border: #b8ddd6;
  --color-error-strong-border: #edb9bc;
  --color-error-surface: #fff8f8;
  --color-thumb-surface: #edf3f5;
  --color-secondary-border: #b9cdd4;
  --color-secondary-hover: #f1f6f7;
  --color-progress-surface: #f0faf8;
  --color-progress-track: #d9e9e7;
  --color-glass-border: rgba(179, 207, 211, 0.85);
  --color-glass-surface: rgba(255, 255, 255, 0.72);
  --shadow-card: 0 24px 64px rgba(20, 56, 74, 0.12);
  --radius-sm: 10px;
  --radius-md: 15px;
  --radius-lg: 24px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;
  font-family: "Yu Gothic UI", "Hiragino Kaku Gothic ProN", "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--color-text);
  background: var(--color-background);
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }

html { min-width: 320px; scroll-behavior: smooth; }

body {
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  background: linear-gradient(145deg, var(--color-background) 0%, var(--color-background-cool) 100%);
  color: var(--color-text);
  font-size: 16px;
  line-height: 1.65;
}

button, input { font: inherit; }
button { color: inherit; }

[hidden] { display: none !important; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background: var(--color-text);
  color: var(--color-on-primary);
  transform: translateY(-160%);
  transition: transform 150ms ease;
}

.skip-link:focus { transform: translateY(0); }

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

.ambient {
  position: fixed;
  z-index: -1;
  border-radius: 999px;
  pointer-events: none;
}

.ambient--top {
  top: -245px;
  right: -120px;
  width: 520px;
  height: 520px;
  background: var(--color-ambient-top);
}

.ambient--bottom {
  bottom: -225px;
  left: -175px;
  width: 470px;
  height: 470px;
  background: var(--color-ambient-bottom);
}

.site-header {
  display: flex;
  align-items: center;
  width: min(1064px, calc(100% - 40px));
  margin: 0 auto;
  padding-top: 42px;
}

.brand-mark {
  display: grid;
  place-content: center;
  gap: 4px;
  width: 46px;
  height: 46px;
  margin-right: 14px;
  border-radius: 13px;
  background: var(--color-primary);
}

.brand-mark span {
  width: 21px;
  height: 3px;
  border-radius: 2px;
  background: var(--color-on-primary);
}

.brand-name, .brand-caption, .eyebrow, .progress-kicker { margin: 0; }
.brand-name { color: var(--color-primary); font-size: 0.95rem; font-weight: 800; letter-spacing: 0.04em; }
.brand-caption { color: var(--color-text-muted); font-size: 0.77rem; line-height: 1.4; }

.version-badge {
  margin-left: auto;
  padding: 3px 9px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-glass-soft);
  color: var(--color-text-muted);
  font-size: 0.75rem;
  font-weight: 700;
}

.page-shell {
  width: min(1064px, calc(100% - 40px));
  margin: 0 auto;
  padding: 46px 0 34px;
}

.hero { text-align: center; }
.eyebrow { color: var(--color-primary); font-size: 0.78rem; font-weight: 800; letter-spacing: 0.12em; }

.hero h1 {
  margin: 8px 0 10px;
  font-size: clamp(2rem, 4vw, 2.65rem);
  line-height: 1.2;
  letter-spacing: -0.025em;
}

.hero-copy { margin: 0; color: var(--color-text-muted); font-size: 1.05rem; }

.privacy-note {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  max-width: 100%;
  margin-top: 24px;
  padding: 10px 22px;
  border: 1px solid var(--color-teal-border);
  border-radius: 999px;
  background: var(--color-primary-soft);
  color: var(--color-success);
  font-size: 0.92rem;
}

.privacy-note svg { flex: 0 0 auto; width: 22px; height: 22px; fill: var(--color-primary); }

.tool-card {
  margin-top: 38px;
  padding: 46px 56px 42px;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-card);
}

.section-heading { display: flex; align-items: center; gap: 14px; }
.section-heading h2 { margin: 0; font-size: 1.35rem; line-height: 1.35; }
.section-heading p { margin: 1px 0 0; color: var(--color-text-muted); font-size: 0.86rem; }

.step-number {
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 999px;
  background: var(--color-text);
  color: var(--color-on-primary);
  font-weight: 800;
}

.drop-zone {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 232px;
  margin-top: 20px;
  padding: 30px 20px 24px;
  border: 2px dashed var(--color-drop-border);
  border-radius: 19px;
  background: var(--color-surface-teal);
  cursor: pointer;
  transition: border-color 150ms ease, background 150ms ease, transform 150ms ease;
}

.drop-zone:hover, .drop-zone.is-dragging { border-color: var(--color-primary); background: var(--color-drop-hover); }
.drop-zone.is-dragging { transform: translateY(-2px); }
.drop-zone.is-disabled { cursor: wait; opacity: 0.58; }
.visually-hidden:focus-visible + .drop-zone { outline: 3px solid var(--color-focus); outline-offset: 3px; }

.drop-icon { width: 78px; height: 62px; margin-bottom: 10px; }
.drop-icon rect { fill: var(--color-primary-soft); }
.drop-icon path { fill: var(--color-primary); }
.drop-icon circle { fill: var(--color-accent-warm); }
.drop-title { font-size: 1.05rem; font-weight: 800; }
.drop-or { margin: 1px 0 8px; color: var(--color-text-muted); font-size: 0.87rem; }

.file-button {
  min-width: 180px;
  padding: 10px 22px;
  border-radius: 12px;
  background: var(--color-primary);
  color: var(--color-on-primary);
  font-weight: 800;
  text-align: center;
}

.drop-help { margin-top: 10px; color: var(--color-text-muted); font-size: 0.78rem; }

.inline-message {
  margin-top: 14px;
  padding: 12px 15px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 700;
}

.inline-message--error { border: 1px solid var(--color-error-border); background: var(--color-danger-soft); color: var(--color-danger); }

.selection-section { margin-top: 38px; }
.selection-header { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.section-heading--compact { min-width: 0; }
.selection-title-row { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }

.count-badge {
  padding: 3px 12px;
  border-radius: 999px;
  background: var(--color-count-surface);
  color: var(--color-count-text);
  font-size: 0.84rem;
  font-weight: 800;
  white-space: nowrap;
}

.text-button {
  min-height: 44px;
  padding: 7px 9px;
  border: 0;
  background: transparent;
  font-weight: 800;
  cursor: pointer;
}

.text-button--danger { color: var(--color-danger); }
.text-button:hover { text-decoration: underline; text-underline-offset: 3px; }

.file-list { display: grid; gap: 10px; margin: 18px 0 0; padding: 0; list-style: none; }

.file-item {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  min-height: 70px;
  padding: 9px 14px 9px 10px;
  border: 1px solid var(--color-border);
  border-radius: 14px;
  background: var(--color-surface-soft);
}

.file-item[data-status="processing"] { border-color: var(--color-processing-border); background: var(--color-processing-surface); }
.file-item[data-status="success"] { border-color: var(--color-success-border); }
.file-item[data-status="error"] { border-color: var(--color-error-strong-border); background: var(--color-error-surface); }

.file-thumb {
  width: 48px;
  height: 48px;
  border-radius: 9px;
  background: var(--color-thumb-surface);
  object-fit: cover;
}

.file-copy { min-width: 0; }
.file-name { display: block; overflow-wrap: anywhere; font-size: 0.94rem; font-weight: 800; line-height: 1.35; }
.file-meta { margin: 3px 0 0; color: var(--color-text-muted); font-size: 0.78rem; line-height: 1.4; }

.file-state {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 0.75rem;
  font-weight: 700;
}

.file-state--success { color: var(--color-success); }
.file-state--error { color: var(--color-danger); }

.remove-button {
  min-width: 52px;
  min-height: 44px;
  padding: 8px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--color-danger);
  font-size: 0.86rem;
  font-weight: 800;
  cursor: pointer;
}

.remove-button:hover { background: var(--color-danger-soft); }

.action-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 24px;
  padding-top: 22px;
  border-top: 1px solid var(--color-border);
}

.output-hint { margin: 0; color: var(--color-text-muted); font-size: 0.88rem; }

.button {
  min-height: 50px;
  padding: 11px 24px;
  border: 1px solid transparent;
  border-radius: 13px;
  font-weight: 800;
  cursor: pointer;
  transition: background 150ms ease, border-color 150ms ease, transform 100ms ease;
}

.button:active:not(:disabled) { transform: translateY(1px); }
.button:disabled { cursor: not-allowed; opacity: 0.5; }
.button--primary { min-width: 220px; background: var(--color-primary); color: var(--color-on-primary); }
.button--primary:hover:not(:disabled) { background: var(--color-primary-hover); }
.button--secondary { border-color: var(--color-secondary-border); background: var(--color-on-primary); color: var(--color-text); }
.button--secondary:hover:not(:disabled) { background: var(--color-secondary-hover); }

.progress-panel, .completion-panel {
  margin-top: 30px;
  padding: 24px;
  border: 1px solid var(--color-teal-border);
  border-radius: var(--radius-md);
  background: var(--color-progress-surface);
}

.progress-copy { display: flex; align-items: start; justify-content: space-between; gap: 20px; }
.progress-kicker { color: var(--color-primary); font-size: 0.75rem; font-weight: 900; letter-spacing: 0.08em; }
.progress-copy h2, .completion-copy h2 { margin: 2px 0 0; font-size: 1.15rem; }
.progress-copy strong { color: var(--color-primary); font-size: 1.4rem; line-height: 1.3; }

.progress-track { height: 12px; margin-top: 18px; overflow: hidden; border-radius: 999px; background: var(--color-progress-track); }
.progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--color-primary); transition: width 180ms ease; }
.current-file { margin: 10px 0 0; overflow-wrap: anywhere; color: var(--color-text-muted); font-size: 0.87rem; }

.completion-panel { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; align-items: center; gap: 18px; }
.completion-icon { display: grid; place-items: center; width: 50px; height: 50px; border-radius: 999px; background: var(--color-primary); color: var(--color-on-primary); font-size: 1.5rem; font-weight: 900; }
.completion-copy p:not(.progress-kicker) { margin: 5px 0 0; color: var(--color-text-muted); }
.completion-actions { display: flex; flex-direction: column; gap: 8px; }
.completion-actions .button { min-width: 190px; }

.error-list { margin: 12px 0 0; padding: 10px 10px 10px 30px; border-radius: 10px; background: var(--color-danger-soft); color: var(--color-danger); font-size: 0.84rem; }
.error-list li { overflow-wrap: anywhere; }

.info-card {
  display: flex;
  gap: 14px;
  margin-top: 20px;
  padding: 18px 22px;
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-md);
  background: var(--color-glass-surface);
  backdrop-filter: blur(7px);
}

.info-card svg { flex: 0 0 auto; width: 23px; height: 23px; margin-top: 1px; fill: var(--color-primary); }
.info-card h2 { margin: 0; font-size: 0.96rem; }
.info-card p { margin: 2px 0 0; color: var(--color-text-muted); font-size: 0.84rem; }

.site-footer { padding: 0 20px 28px; color: var(--color-text-muted); font-size: 0.76rem; text-align: center; }
.noscript { padding: 16px; border-radius: 10px; background: var(--color-danger-soft); color: var(--color-danger); }

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

@media (max-width: 760px) {
  .ambient--top { right: -230px; top: -300px; }
  .site-header, .page-shell { width: min(100% - 28px, 620px); }
  .site-header { padding-top: 24px; }
  .page-shell { padding-top: 34px; }
  .hero h1 { font-size: 2rem; }
  .hero-copy { font-size: 0.95rem; }
  .privacy-note { align-items: flex-start; width: 100%; padding: 11px 15px; border-radius: 14px; text-align: left; }
  .tool-card { margin-top: 26px; padding: 28px 18px 24px; border-radius: 20px; }
  .drop-zone { min-height: 220px; padding-inline: 14px; }
  .selection-header { align-items: flex-start; }
  .section-heading h2 { font-size: 1.18rem; }
  .file-item { grid-template-columns: 48px minmax(0, 1fr); gap: 10px; padding: 10px; }
  .file-thumb { width: 44px; height: 44px; }
  .remove-button { grid-column: 2; justify-self: start; margin-top: -4px; padding-inline: 0; }
  .action-row { align-items: stretch; flex-direction: column; gap: 14px; }
  .button--primary { width: 100%; min-width: 0; }
  .completion-panel { grid-template-columns: auto 1fr; align-items: start; }
  .completion-actions { grid-column: 1 / -1; width: 100%; margin-top: 4px; }
  .completion-actions .button { width: 100%; min-width: 0; }
}

@media (max-width: 420px) {
  .brand-caption, .version-badge { display: none; }
  .hero h1 { font-size: 1.78rem; }
  .drop-title { font-size: 0.98rem; }
  .selection-header { gap: 8px; }
  .text-button { font-size: 0.82rem; }
  .progress-copy { align-items: center; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; }
}