:root {
  --bg: #0f1220;
  --bg-soft: #171b2e;
  --card: #1c2138;
  --card-2: #232a47;
  --text: #e8ebf5;
  --muted: #9aa3c0;
  --accent: #7c6cff;
  --accent-2: #4dd0e1;
  --accent-grad: linear-gradient(135deg, #7c6cff 0%, #4dd0e1 100%);
  --border: #2c3358;
  --ok: #35d07f;
  --radius: 14px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f5f6fb;
    --bg-soft: #ffffff;
    --card: #ffffff;
    --card-2: #f0f2fa;
    --text: #1a1d2b;
    --muted: #5c6484;
    --border: #e2e5f0;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  background: radial-gradient(1200px 600px at 50% -200px, rgba(124,108,255,.25), transparent), var(--bg);
  color: var(--text);
  line-height: 1.7;
}
.wrap { width: 100%; max-width: 760px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header { border-bottom: 1px solid var(--border); background: rgba(0,0,0,.05); }
.site-header .wrap { display: flex; align-items: center; gap: 12px; height: 60px; }
.logo { font-weight: 700; font-size: 18px; }
.tag {
  font-size: 12px; color: var(--accent-2); border: 1px solid var(--border);
  padding: 3px 10px; border-radius: 999px; margin-left: auto;
}

/* Hero */
h1 { font-size: clamp(24px, 5vw, 34px); line-height: 1.35; margin: 36px 0 14px; }
.lead { color: var(--muted); font-size: 16px; margin: 0 0 26px; }

/* Tool */
.tool {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px; margin-bottom: 14px;
}
.dropzone {
  border: 2px dashed var(--border); border-radius: var(--radius);
  padding: 40px 20px; text-align: center; cursor: pointer;
  transition: border-color .2s, background .2s;
}
.dropzone:hover, .dropzone:focus, .dropzone.drag {
  border-color: var(--accent); background: var(--card-2); outline: none;
}
.dz-icon { font-size: 40px; }
.dz-title { font-weight: 600; margin: 10px 0 4px; }
.dz-sub { color: var(--muted); font-size: 14px; margin: 0; }

.hidden { display: none !important; }

/* Controls */
.controls { margin-top: 4px; }
.file-row {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 12px 14px; background: var(--card-2); border-radius: 10px; margin-bottom: 18px;
}
.file-name { font-weight: 600; word-break: break-all; }
.link-btn {
  background: none; border: none; color: var(--accent-2);
  cursor: pointer; font-size: 14px; padding: 0; margin-left: auto;
}
.link-btn:hover { text-decoration: underline; }

.field { margin-bottom: 20px; }
.field-label { display: block; font-weight: 600; font-size: 14px; margin-bottom: 10px; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 560px) { .grid2 { grid-template-columns: 1fr; } }

.preset-row { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.preset {
  flex: 1; min-width: 90px; padding: 12px 8px; border-radius: 10px;
  border: 1px solid var(--border); background: var(--card-2); color: var(--text);
  font-size: 15px; font-weight: 600; cursor: pointer; transition: .15s;
}
.preset.is-active { border-color: transparent; background: var(--accent-grad); color: #fff; }

.custom-row { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--muted); }
.custom-row input {
  width: 90px; padding: 8px 10px; border-radius: 8px;
  border: 1px solid var(--border); background: var(--bg-soft); color: var(--text); font-size: 15px;
}
.hint { font-size: 13px; }

.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.seg-btn {
  padding: 10px 16px; border: none; background: var(--card-2);
  color: var(--text); cursor: pointer; font-size: 14px; font-weight: 600;
}
.seg-btn.is-active { background: var(--accent-grad); color: #fff; }

.check { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--muted); cursor: pointer; }
.check input { width: 18px; height: 18px; accent-color: var(--accent); }

.primary {
  display: inline-block; width: 100%; text-align: center;
  padding: 15px; border: none; border-radius: 12px;
  background: var(--accent-grad); color: #fff; font-size: 16px; font-weight: 700;
  cursor: pointer; text-decoration: none; transition: transform .1s, opacity .2s;
}
.primary:hover { opacity: .93; }
.primary:active { transform: translateY(1px); }
.primary:disabled { opacity: .5; cursor: not-allowed; }

.status { margin-top: 14px; font-size: 14px; color: var(--muted); text-align: center; min-height: 20px; }
.status.err { color: #ff6b6b; }

/* Result */
.result { text-align: center; }
.result h2 { color: var(--ok); font-size: 20px; }
.result audio { width: 100%; margin: 8px 0 18px; }
.download { margin-bottom: 12px; }

.privacy-note { text-align: center; color: var(--muted); font-size: 13px; margin: 0 0 40px; }

/* Article */
.article { border-top: 1px solid var(--border); padding-top: 20px; }
.article h2 { font-size: 22px; margin: 34px 0 12px; }
.article p { color: var(--text); }
.steps, .features, .faq { color: var(--text); }
.steps li, .features li { margin-bottom: 8px; }
.faq dt { font-weight: 700; margin-top: 16px; }
.faq dd { margin: 4px 0 0; color: var(--muted); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); margin-top: 50px; padding: 24px 0; }
.site-footer p { margin: 4px 0; color: var(--muted); font-size: 13px; }
.disclaimer { font-size: 12px; }