:root {
  color-scheme: light dark;
  --bg: #f4f7fb;
  --card: #ffffff;
  --card-2: #f8fafc;
  --text: #121826;
  --muted: #697586;
  --line: #dde5f0;
  --blue: #2563eb;
  --blue-2: #4f46e5;
  --blue-soft: #edf4ff;
  --danger: #b42318;
  --danger-bg: #fff1f0;
  --shadow: 0 24px 80px rgba(18, 24, 38, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1320;
    --card: #151c2c;
    --card-2: #101827;
    --text: #edf2ff;
    --muted: #9aa8bd;
    --line: #2b364d;
    --blue: #6ea8ff;
    --blue-2: #9b8cff;
    --blue-soft: #12233f;
    --danger: #ffb4ab;
    --danger-bg: #3b1817;
    --shadow: 0 24px 80px rgba(0, 0, 0, 0.36);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 18%, rgba(37, 99, 235, 0.13), transparent 26rem),
    radial-gradient(circle at 88% 8%, rgba(79, 70, 229, 0.12), transparent 24rem),
    var(--bg);
}

.app-shell {
  width: min(1080px, calc(100% - 32px));
  min-height: 100vh;
  margin: 0 auto;
  padding: 44px 0;
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 28px;
  align-items: center;
}

.intro {
  padding: 8px 6px;
}
.brand-mark {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  color: white;
  font-weight: 900;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  box-shadow: 0 16px 32px rgba(37, 99, 235, 0.28);
}
.eyebrow {
  margin: 28px 0 12px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}
h1 {
  margin: 0 0 16px;
  font-size: clamp(42px, 7vw, 72px);
  line-height: 0.96;
  letter-spacing: -0.06em;
}
.lead {
  max-width: 430px;
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}
.flow-list {
  display: grid;
  gap: 14px;
  margin-top: 34px;
  max-width: 460px;
}
.flow-list div {
  display: grid;
  grid-template-columns: 44px 1fr;
  align-items: center;
  gap: 14px;
  padding: 14px;
  border: 1px solid color-mix(in srgb, var(--blue) 22%, var(--line));
  border-radius: 18px;
  color: var(--text);
  background: color-mix(in srgb, var(--card) 82%, var(--blue-soft));
  box-shadow: 0 12px 28px rgba(37, 99, 235, 0.1);
}
.flow-list b {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 15px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  box-shadow: 0 10px 22px rgba(37, 99, 235, 0.24);
}
.flow-list span {
  display: grid;
  gap: 4px;
}
.flow-list strong {
  font-size: 15px;
  line-height: 1.25;
}
.flow-list em {
  color: var(--muted);
  font-size: 12px;
  font-style: normal;
  line-height: 1.45;
}

.form-card {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 30px;
  background: color-mix(in srgb, var(--card) 94%, transparent);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}
form { display: grid; gap: 20px; }

.alert, .info {
  display: grid;
  gap: 4px;
  margin-bottom: 16px;
  padding: 14px 16px;
  border-radius: 18px;
}
.alert {
  border: 1px solid color-mix(in srgb, var(--danger) 28%, transparent);
  color: var(--danger);
  background: var(--danger-bg);
}
.info {
  border: 1px solid color-mix(in srgb, var(--blue) 28%, transparent);
  color: var(--blue);
  background: var(--blue-soft);
}
.alert strong, .info strong { font-size: 14px; }
.alert span, .info span { font-size: 13px; line-height: 1.55; }

.tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--card-2);
}
.tab {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 46px;
  border-radius: 14px;
  color: var(--muted);
  font-weight: 800;
  cursor: pointer;
}
.tab input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.tab:has(input:checked) {
  color: var(--text);
  background: var(--card);
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.12);
}

.provider-panel { display: grid; gap: 16px; }
body[data-provider="gmail"] .qq-panel { display: none; }
body[data-provider="qq"] .gmail-panel { display: grid; }

.helper-card {
  display: grid;
  gap: 12px;
  padding: 16px;
  border-radius: 20px;
  border: 1px solid color-mix(in srgb, var(--blue) 18%, var(--line));
  background: linear-gradient(135deg, var(--blue-soft), color-mix(in srgb, var(--card) 72%, var(--blue-soft)));
}
.helper-card strong { display: block; margin-bottom: 4px; }
.helper-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}
.link-guide {
  display: grid;
  gap: 10px;
  padding-top: 4px;
}
.link-guide > strong {
  color: var(--text);
  font-size: 14px;
}
.link-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.link-row a {
  display: grid;
  gap: 5px;
  min-height: 76px;
  padding: 12px;
  border: 1px solid color-mix(in srgb, var(--blue) 32%, var(--line));
  border-radius: 16px;
  color: var(--text);
  background: var(--card);
  font-size: 13px;
  font-weight: 850;
  text-decoration: none;
  box-shadow: 0 10px 22px rgba(37, 99, 235, 0.1);
}
.link-row a:hover {
  transform: translateY(-1px);
  border-color: var(--blue);
  box-shadow: 0 14px 28px rgba(37, 99, 235, 0.18);
}
.link-row a b {
  width: fit-content;
  padding: 3px 7px;
  border-radius: 999px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  font-size: 11px;
}
.link-row a span {
  line-height: 1.35;
}

.prepare-hint {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.gmail-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
.step-card {
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px solid color-mix(in srgb, var(--blue) 26%, var(--line));
  border-radius: 18px;
  color: var(--text);
  background: color-mix(in srgb, var(--card) 88%, var(--blue-soft));
  text-decoration: none;
  box-shadow: 0 10px 22px rgba(37, 99, 235, 0.1);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}
.step-card:hover {
  transform: translateY(-2px);
  border-color: var(--blue);
  box-shadow: 0 16px 32px rgba(37, 99, 235, 0.18);
}
.step-card b {
  width: fit-content;
  padding: 4px 8px;
  border-radius: 999px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  font-size: 12px;
  letter-spacing: 0.04em;
}
.step-card strong {
  font-size: 14px;
}
.step-card p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}
.step-card code {
  font-size: 11px;
  word-break: break-all;
}

.field {
  display: grid;
  gap: 8px;
}
.field span {
  font-size: 14px;
  font-weight: 850;
}
.field span em {
  color: var(--muted);
  font-style: normal;
  font-weight: 650;
}
.field small, .actions small {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}
input, textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card-2);
  color: var(--text);
  font: inherit;
  padding: 13px 14px;
}
textarea {
  min-height: 112px;
  resize: vertical;
}
input:focus, textarea:focus {
  outline: 3px solid color-mix(in srgb, var(--blue) 22%, transparent);
  border-color: var(--blue);
}
.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  padding-top: 2px;
}
button {
  border: 0;
  border-radius: 999px;
  padding: 13px 22px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  box-shadow: 0 14px 30px rgba(37, 99, 235, 0.28);
  font-size: 15px;
  font-weight: 900;
  cursor: pointer;
}
button:hover { transform: translateY(-1px); }
button:disabled {
  cursor: wait;
  opacity: 0.68;
  transform: none;
}
.task-panel {
  display: grid;
  gap: 12px;
  margin-top: 18px;
  padding: 16px;
  border: 1px solid color-mix(in srgb, var(--blue) 26%, var(--line));
  border-radius: 20px;
  background: var(--blue-soft);
}
.task-panel[hidden] { display: none; }
.task-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.task-head strong { font-size: 15px; }
.task-head span {
  padding: 5px 10px;
  border-radius: 999px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  font-size: 12px;
  font-weight: 900;
}
.task-panel p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}
.progress-track {
  height: 9px;
  overflow: hidden;
  border-radius: 999px;
  background: color-mix(in srgb, var(--card) 70%, var(--line));
}
.progress-bar {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--blue), var(--blue-2));
  transition: width 0.35s ease;
}
.download-link {
  width: fit-content;
  padding: 10px 14px;
  border-radius: 999px;
  color: white;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  font-size: 13px;
  font-weight: 900;
  text-decoration: none;
}

@media (max-width: 860px) {
  .app-shell {
    grid-template-columns: 1fr;
    align-items: start;
    padding: 24px 0;
  }
  .intro { padding: 0; }
  .gmail-steps { grid-template-columns: 1fr; }
  h1 { font-size: 44px; }
}

@media (max-width: 560px) {
  .app-shell { width: min(100% - 22px, 1080px); }
  .form-card { padding: 16px; border-radius: 24px; }
  .field-grid, .tabs { grid-template-columns: 1fr; }
}