:root {
  --bg: #f5f7f4;
  --panel: #fff;
  --text: #1f2524;
  --muted: #6e7773;
  --line: #dde5df;
  --green: #2f755f;
  --green-dark: #245c4b;
  --green-soft: #e6f2ed;
  --red: #a94d49;
  --shadow: 0 14px 30px rgba(36, 45, 40, .07);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0;
}
button, textarea, input { font: inherit; }
a { color: inherit; }

.download-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  grid-template-areas: "topbar topbar" "sidebar main";
  gap: 12px;
  max-width: 1480px;
  margin: 0 auto;
  padding: 14px;
}

.topbar {
  grid-area: topbar;
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { display: flex; align-items: center; gap: 11px; text-decoration: none; }
.brand-mark {
  width: 38px; height: 38px; display: grid; place-items: center;
  border-radius: 8px; background: var(--green); color: #fff; font-weight: 900;
}
.brand strong { display: block; font-size: 19px; }
.brand small { display: block; margin-top: 2px; color: var(--muted); }
.top-actions { display: flex; align-items: center; gap: 10px; font-size: 13px; }
.top-actions a { padding: 8px 11px; border: 1px solid var(--line); border-radius: 7px; background: #fff; text-decoration: none; }
.free-pill { padding: 7px 10px; border: 1px solid #c7e3d7; border-radius: 999px; background: var(--green-soft); color: var(--green); font-weight: 800; }

.side-nav {
  grid-area: sidebar; position: sticky; top: 14px; align-self: start;
  display: grid; gap: 9px; padding: 9px 7px;
  border: 1px solid var(--line); border-radius: 8px; background: rgba(255,255,255,.9); box-shadow: var(--shadow);
}
.side-nav a {
  min-height: 62px; display: grid; place-items: center; gap: 5px; padding: 7px 5px;
  border: 1px solid transparent; border-radius: 8px; color: var(--muted); text-decoration: none; font-size: 12px;
}
.side-nav a span { width: 30px; height: 30px; display: grid; place-items: center; border-radius: 7px; background: #f2f6f2; color: var(--green); font-weight: 900; }
.side-nav a strong { font-weight: 800; }
.side-nav a:hover, .side-nav a.is-active { color: var(--green); border-color: #c7e3d7; background: var(--green-soft); }

.download-main { grid-area: main; display: grid; gap: 12px; min-width: 0; }
.hero-panel, .panel { border: 1px solid var(--line); border-radius: 8px; background: var(--panel); box-shadow: var(--shadow); }
.hero-panel { min-height: 132px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 24px 28px; }
.eyebrow { color: var(--green); font-size: 12px; font-weight: 900; }
.hero-panel h1 { margin: 7px 0 8px; font-size: 28px; }
.hero-panel p { margin: 0; color: var(--muted); }
.hero-note { min-width: 190px; padding: 12px 14px; border-left: 3px solid var(--green); background: #f4faf7; color: #456158; font-size: 13px; line-height: 1.7; }

.tool-layout { display: grid; grid-template-columns: minmax(360px, .82fr) minmax(460px, 1.18fr); gap: 12px; align-items: start; }
.panel { padding: 20px; }
.input-panel, .result-panel { min-height: 482px; }
.section-title { display: flex; align-items: center; gap: 11px; margin-bottom: 16px; }
.section-title.compact { justify-content: space-between; }
.section-title h2 { margin: 0 0 4px; font-size: 18px; }
.section-title p { margin: 0; color: var(--muted); font-size: 12px; }
.step { width: 30px; height: 30px; display: grid; place-items: center; border-radius: 50%; background: var(--green-soft); color: var(--green); font-weight: 900; }

form { display: grid; gap: 9px; }
label { font-size: 13px; font-weight: 800; }
textarea { width: 100%; min-height: 142px; resize: vertical; padding: 13px 14px; border: 1px solid #cfdad4; border-radius: 7px; background: #fbfcfa; color: var(--text); line-height: 1.65; outline: 0; }
textarea:focus { border-color: var(--green); box-shadow: 0 0 0 3px rgba(47,117,95,.11); }
button, .save-link { min-height: 44px; padding: 10px 16px; border: 1px solid #cfdad4; border-radius: 7px; background: #fff; cursor: pointer; text-align: center; text-decoration: none; }
.primary { border-color: var(--green); background: var(--green); color: #fff; font-weight: 850; }
.primary:hover { background: var(--green-dark); }
button:disabled { cursor: wait; opacity: .68; }

.status-box { display: flex; align-items: flex-start; gap: 9px; margin-top: 12px; padding: 11px 12px; border: 1px solid var(--line); border-radius: 7px; background: #f8faf8; color: var(--muted); font-size: 13px; line-height: 1.55; }
.status-dot { width: 8px; height: 8px; flex: 0 0 8px; margin-top: 5px; border-radius: 50%; background: #9aa59f; }
.status-box[data-state="working"] .status-dot { background: #c58936; box-shadow: 0 0 0 4px #f7eee4; }
.status-box[data-state="success"] { color: var(--green); background: #f0faf6; }
.status-box[data-state="success"] .status-dot { background: var(--green); }
.status-box[data-state="warning"] { color: #8a5a18; background: #fffaf0; border-color: #ead4ad; }
.status-box[data-state="warning"] .status-dot { background: #c58936; }
.status-box[data-state="error"] { color: var(--red); background: #fff7f5; }
.status-box[data-state="error"] .status-dot { background: var(--red); }
.tips { margin-top: 16px; padding-top: 14px; border-top: 1px dashed var(--line); }
.tips h3 { margin: 0 0 8px; font-size: 14px; }
.tips ul { margin: 0; padding-left: 19px; color: var(--muted); font-size: 12px; line-height: 1.8; }

.or-divider { display: flex; align-items: center; gap: 10px; margin: 13px 0; color: var(--muted); font-size: 12px; }
.or-divider::before, .or-divider::after { content: ""; flex: 1; border-top: 1px solid var(--line); }
.secondary-import { width: 100%; display: flex; align-items: center; justify-content: center; gap: 11px; border-style: dashed; background: #f8fbf9; color: var(--green); text-align: left; }
.secondary-import:hover { border-color: var(--green); background: var(--green-soft); }
.secondary-import span { display: block; }
.secondary-import strong { display: block; font-size: 14px; }
.secondary-import small { display: block; margin-top: 3px; color: var(--muted); font-size: 11px; font-weight: 500; }
.secondary-import.compact { width: auto; min-width: 168px; border-style: solid; text-align: center; }
.import-icon { width: 30px; height: 30px; display: grid !important; place-items: center; border-radius: 7px; background: var(--green-soft); font-size: 18px; font-weight: 900; }

.result-empty {
  min-height: 380px;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 10px;
  padding: 32px;
  border: 1px dashed #cbd9d1;
  border-radius: 8px;
  background: linear-gradient(180deg, #fbfdfb 0%, #f3f8f5 100%);
  text-align: center;
}
.result-empty-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--green-soft);
  color: var(--green);
  font-size: 24px;
  font-weight: 900;
}
.result-empty strong { font-size: 17px; }
.result-empty p { max-width: 390px; margin: 0; color: var(--muted); font-size: 13px; line-height: 1.75; }
.import-methods { width: min(100%, 520px); display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin: 4px 0 6px; text-align: left; }
.import-methods article { display: flex; align-items: flex-start; gap: 10px; padding: 14px; border: 1px solid var(--line); border-radius: 7px; background: #fff; }
.import-methods article > span { width: 26px; height: 26px; flex: 0 0 26px; display: grid; place-items: center; border-radius: 6px; background: var(--green-soft); color: var(--green); font-weight: 900; }
.import-methods b { display: block; font-size: 13px; }
.import-methods p { margin-top: 4px; font-size: 11px; line-height: 1.55; }
.parse-failure { min-height: 380px; display: grid; place-content: center; justify-items: center; gap: 11px; padding: 34px; border: 1px solid #ecd1cd; border-radius: 8px; background: #fff9f7; text-align: center; }
.parse-failure strong { font-size: 17px; }
.parse-failure p { max-width: 490px; margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.failure-actions { display: flex; gap: 9px; margin-top: 5px; }

.video-result { display: grid; grid-template-columns: minmax(250px, .95fr) minmax(240px, 1.05fr); gap: 20px; }
.cover-wrap { position: relative; min-height: 310px; overflow: hidden; border: 1px solid var(--line); border-radius: 8px; background: #eef2ee; }
.cover-empty { position: absolute; inset: 0; display: grid; place-items: center; color: var(--muted); font-size: 13px; }
.cover-wrap img, .cover-wrap video { width: 100%; height: 100%; min-height: 310px; display: block; object-fit: cover; }
.duration-badge { position: absolute; right: 9px; bottom: 9px; padding: 4px 7px; border-radius: 5px; background: rgba(20,26,23,.78); color: #fff; font-size: 12px; }
.video-details { display: flex; flex-direction: column; min-width: 0; }
.video-details h3 { margin: 0 0 16px; font-size: 19px; line-height: 1.5; word-break: break-word; }
dl { display: grid; gap: 0; margin: 0 0 18px; }
dl div { display: grid; grid-template-columns: 76px 1fr; gap: 10px; padding: 10px 0; border-bottom: 1px solid #edf1ee; }
dt { color: var(--muted); font-size: 12px; }
dd { margin: 0; font-size: 13px; font-weight: 700; word-break: break-word; }
.download-hint { margin: 10px 0 0; color: var(--muted); font-size: 12px; line-height: 1.6; }
.result-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.save-link { display: block; margin-top: 8px; }

.icon-button { min-height: 34px; padding: 5px 10px; font-size: 18px; }
.recent-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px; }
.recent-item { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 11px 12px; border: 1px solid var(--line); border-radius: 7px; background: #fbfcfa; }
.recent-item div { min-width: 0; }
.recent-item strong, .recent-item span { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.recent-item strong { font-size: 13px; }
.recent-item span { margin-top: 4px; color: var(--muted); font-size: 11px; }
.recent-actions { display: inline-flex; flex: 0 0 auto; gap: 6px; }
.recent-item a { flex: 0 0 auto; padding: 6px 9px; border: 1px solid #c7e3d7; border-radius: 6px; color: var(--green); text-decoration: none; font-size: 12px; font-weight: 800; }
.empty-state { grid-column: 1 / -1; padding: 24px; border: 1px dashed #cfdad4; border-radius: 7px; color: var(--muted); text-align: center; font-size: 13px; }

[hidden] { display: none !important; }

@media (max-width: 980px) {
  .tool-layout { grid-template-columns: 1fr; }
  .input-panel, .result-panel { min-height: 0; }
  .video-result { grid-template-columns: minmax(260px, .8fr) 1fr; }
}

@media (max-width: 720px) {
  body { padding-bottom: 76px; }
  .download-shell { display: block; padding: 10px; }
  .topbar { min-height: 54px; }
  .brand small, .free-pill { display: none; }
  .brand strong { font-size: 16px; }
  .top-actions a { padding: 7px 8px; font-size: 12px; }
  .side-nav { position: fixed; z-index: 30; left: 10px; right: 10px; bottom: 8px; top: auto; display: grid; grid-template-columns: repeat(3, 1fr); padding: 6px; }
  .side-nav a { min-height: 52px; grid-auto-flow: column; justify-content: center; gap: 7px; }
  .side-nav a strong { display: none; }
  .side-nav a::after { content: attr(data-mobile-label); font-size: 12px; font-weight: 800; }
  .side-nav a span { width: 26px; height: 26px; }
  .download-main { margin-top: 10px; }
  .hero-panel { min-height: 0; display: block; padding: 20px; }
  .hero-panel h1 { font-size: 24px; }
  .hero-note { margin-top: 16px; min-width: 0; }
  .panel { padding: 16px; }
  .result-empty { min-height: 240px; padding: 24px 18px; }
  .parse-failure { min-height: 260px; padding: 24px 18px; }
  .import-methods { grid-template-columns: 1fr; }
  .failure-actions, .result-actions { width: 100%; display: grid; grid-template-columns: 1fr; }
  .video-result { grid-template-columns: 1fr; }
  .cover-wrap, .cover-wrap img, .cover-wrap video { min-height: 0; aspect-ratio: 9 / 12; }
  .recent-list { grid-template-columns: 1fr; }
  textarea { min-height: 126px; }
  form .primary, .video-details .primary, .secondary-import { width: 100%; }
}