:root {
  --bg-start: #050d18;
  --bg-end: #101827;
  --panel: rgba(15, 23, 42, 0.78);
  --panel-alt: rgba(17, 24, 39, 0.9);
  --panel-soft: #1f2937;
  --border: rgba(148, 163, 184, 0.2);
  --border-strong: rgba(125, 211, 252, 0.35);
  --text: #edf6ff;
  --muted: #b9c7dc;
  --accent: #7dd3fc;
  --accent-strong: #38bdf8;
  --accent-dark: #0284c7;
  --green: #34d399;
  --yellow: #fbbf24;
  --red: #f87171;
  --purple: #a78bfa;
  --pink: #f472b6;
  --shadow: 0 18px 40px rgba(14, 165, 233, 0.18);
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 0%, rgba(56, 189, 248, 0.2), transparent 28%),
    radial-gradient(circle at 92% 100%, rgba(244, 114, 182, 0.12), transparent 27%),
    linear-gradient(135deg, var(--bg-start), var(--bg-end));
  display: flex;
  justify-content: center;
  align-items: flex-start;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
}

.app-shell {
  width: min(1240px, calc(100% - 40px));
  margin: 30px auto 36px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.82), rgba(30, 41, 59, 0.74));
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
  flex-wrap: wrap;
}

.brand-wrap {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-mark {
  width: 46px;
  height: 46px;
  border-radius: 13px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.25rem;
  background: linear-gradient(135deg, var(--accent), var(--purple), var(--pink));
  color: #051923;
  box-shadow: 0 12px 30px rgba(125, 211, 252, 0.38);
}

.topbar h1 {
  margin: 0;
  font-size: clamp(1.8rem, 2.2vw, 2.5rem);
  color: var(--accent);
  letter-spacing: 0;
}

.subtitle {
  display: block;
  color: var(--muted);
  font-size: 0.78rem;
  margin-top: 2px;
}

.server-status {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(15, 23, 42, 0.68);
  color: var(--muted);
  font-size: 0.8rem;
}

.notification-region {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 20;
  width: min(360px, calc(100% - 40px));
  display: grid;
  gap: 10px;
}

.notification {
  display: grid;
  gap: 6px;
  padding: 14px;
  border: 1px solid var(--border-strong);
  border-radius: 14px;
  background: rgba(15, 23, 42, 0.96);
  box-shadow: var(--shadow);
}

.notification span { color: var(--muted); font-size: .82rem; }
.notification-actions { display: flex; gap: 8px; margin-top: 6px; }
.notification-actions button { flex: 1; }

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  background: var(--red);
  box-shadow: 0 0 12px rgba(248, 113, 113, 0.7);
}
.dot.online { background: var(--green); box-shadow: 0 0 12px rgba(52, 211, 153, 0.7); }
.dot.pending { background: var(--yellow); box-shadow: 0 0 12px rgba(251, 191, 36, 0.7); }

.layout {
  display: grid;
  grid-template-columns: minmax(320px, 0.82fr) minmax(0, 1.18fr);
  gap: 20px;
  width: 100%;
}

.panel {
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.85), rgba(17, 24, 39, 0.8));
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 26px;
  min-width: 0;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.panel h2 {
  margin: 5px 0 0;
  color: var(--accent);
  font-size: 1.15rem;
  letter-spacing: 0;
  text-transform: none;
}

.panel-heading,
.section-heading {
  gap: 12px;
}

.panel-heading { display: flex; align-items: flex-start; justify-content: space-between; }
.section-heading { display: block; }
.section-heading { margin-top: 28px; }
.manual-heading { margin-top: 30px; }

.advanced-options {
  margin-top: 24px;
  border-top: 1px solid var(--border);
  padding-top: 15px;
  color: var(--muted);
  font-size: 0.76rem;
}

.advanced-options summary {
  cursor: pointer;
  color: var(--muted);
}

.advanced-options[open] summary { margin-bottom: 12px; color: var(--accent); }

.eyebrow {
  display: block;
  color: var(--accent-strong);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.step-badge {
  color: #062033;
  background: var(--accent);
  border-radius: 7px;
  padding: 5px 8px;
  font-size: 0.68rem;
  font-weight: 800;
  white-space: nowrap;
}

.quick-start {
  display: grid;
  gap: 9px;
  margin: 22px 0 24px;
  padding: 13px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(15, 23, 42, 0.44);
}

.quick-start > div {
  display: flex;
  align-items: center;
  gap: 10px;
}

.quick-start > div > span {
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  flex: 0 0 24px;
  border-radius: 50%;
  color: #062033;
  background: var(--accent);
  font-size: 0.72rem;
  font-weight: 800;
}

.quick-start p { margin: 0; }
.quick-start strong,
.quick-start small { display: block; }
.quick-start strong { font-size: 0.8rem; }
.quick-start small { margin-top: 2px; color: var(--muted); font-size: 0.7rem; }

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.field-row { margin-top: 20px; }
.field-row > label { display: block; margin-bottom: 7px; }
.input-action { display: flex; align-items: stretch; gap: 9px; }
.input-action input { min-width: 0; }

label {
  font-size: 0.8rem;
  color: var(--muted);
}

input[type="text"] {
  flex: 1;
  min-width: 140px;
  padding: 13px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.7);
  color: var(--text);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input[type="text"]:focus {
  border-color: rgba(125, 211, 252, 0.9);
  box-shadow: 0 0 0 3px rgba(125, 211, 252, 0.12);
}

select {
  min-width: 140px;
  padding: 11px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(15, 23, 42, 0.9);
  color: var(--text);
  font: inherit;
}

select:disabled { opacity: .55; cursor: not-allowed; }

textarea {
  width: 100%;
  resize: vertical;
  padding: 13px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.7);
  color: var(--text);
  font: inherit;
  line-height: 1.5;
}

textarea:focus { border-color: var(--accent); outline: 3px solid rgba(125, 211, 252, 0.12); }

button {
  border: none;
  border-radius: 10px;
  padding: 11px 16px;
  font-size: 0.84rem;
  font-weight: 700;
  cursor: pointer;
  color: #031b2c;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  box-shadow: 0 12px 22px rgba(14, 165, 233, 0.28);
  transition: transform 0.18s ease, box-shadow 0.18s ease, opacity 0.2s ease;
}
button:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 16px 26px rgba(14, 165, 233, 0.35);
}
button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  box-shadow: none;
}
button:focus-visible,
input:focus-visible,
.drop-zone:focus-within {
  outline: 3px solid rgba(125, 211, 252, 0.25);
  outline-offset: 2px;
}
button.danger {
  background: linear-gradient(135deg, #f87171, #ef4444);
  color: white;
}

code {
  background: rgba(15, 23, 42, 0.82);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 6px 10px;
  font-size: 0.8rem;
  user-select: all;
}

.peer-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.peer-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 13px 14px;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.85rem;
}
.peer-list li.empty {
  justify-content: flex-start;
  color: var(--muted);
}

.connection-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.connection-header h2 {
  margin: 0;
  font-size: 1.15rem;
  text-transform: none;
  letter-spacing: normal;
}

.connection-status {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 0.78rem;
  color: var(--muted);
}

.connected-peer-list {
  display: flex;
  gap: 8px;
  list-style: none;
  padding: 0;
  margin: 13px 0 0;
  flex-wrap: wrap;
}
.connected-peer-list li {
  padding: 6px 9px;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  font-size: .74rem;
  background: rgba(15, 23, 42, .65);
}
.connected-peer-list li.empty { color: var(--muted); }
.recipient-label { display: block; margin: 0 0 6px; }
.recipient-select { width: 100%; margin-bottom: 12px; }

.tabs {
  display: flex;
  gap: 8px;
  margin: 22px 0 14px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 4px;
  flex-wrap: wrap;
}

.tab-btn {
  background: transparent;
  color: var(--muted);
  padding: 10px 16px;
  border-radius: 12px 12px 0 0;
  border: 1px solid transparent;
  box-shadow: none;
}
.tab-btn.active {
  background: rgba(15, 23, 42, 0.82);
  border-color: var(--border);
  color: var(--accent);
}

.chat-log {
  height: 330px;
  overflow-y: auto;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  margin-bottom: 12px;
  font-size: 0.9rem;
}

.chat-empty {
  min-height: 100%;
  display: grid;
  place-content: center;
  gap: 6px;
  text-align: center;
  color: var(--muted);
  padding: 20px;
}

.chat-empty strong {
  color: var(--text);
  font-size: 1rem;
}

.chat-empty span,
.drop-zone span {
  font-size: 0.78rem;
}

.chat-msg { margin-bottom: 12px; }
.chat-msg .meta {
  font-size: 0.7rem;
  color: var(--muted);
  margin: 0 0 4px;
}
.chat-msg.me { text-align: right; }
.chat-msg.me .bubble {
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: #041823;
}
.bubble {
  display: inline-block;
  max-width: 82%;
  padding: 9px 12px;
  border-radius: 14px;
  background: rgba(51, 65, 85, 0.9);
  border: 1px solid rgba(148, 163, 184, 0.18);
  word-break: break-word;
}

.drop-zone {
  border: 2px dashed rgba(125, 211, 252, 0.6);
  background: rgba(15, 23, 42, 0.56);
  border-radius: 12px;
  padding: 42px 18px;
  text-align: center;
  color: var(--muted);
  margin-bottom: 16px;
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.drop-zone strong,
.drop-zone span,
.drop-zone .file-picker {
  display: block;
}

.drop-zone strong { color: var(--text); margin-bottom: 7px; }
.drop-zone span { margin-bottom: 5px; }
.drop-zone.disabled { opacity: 0.5; pointer-events: none; }
.drop-zone.drag-over {
  border-color: var(--accent);
  background: rgba(14, 165, 233, 0.08);
  transform: scale(1.01);
  color: var(--accent);
}
.file-picker {
  color: var(--accent);
  text-decoration: underline;
  cursor: pointer;
  font-weight: 600;
}

.transfer-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.transfer-item {
  background: rgba(15, 23, 42, 0.74);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 12px;
  font-size: 0.8rem;
}

.transfer-empty {
  list-style: none;
  color: var(--muted);
  font-size: 0.78rem;
  text-align: center;
  padding: 16px;
}

.transfer-item a {
  display: inline-block;
  margin-top: 10px;
  color: var(--accent);
  font-weight: 700;
}
.transfer-item .top-row {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
}
.progress-track {
  height: 10px;
  background: rgba(148, 163, 184, 0.2);
  border-radius: 999px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(135deg, var(--accent), var(--purple));
  width: 0%;
  transition: width 0.15s ease;
}

.video-grid {
  position: relative;
  min-height: 360px;
  margin-bottom: 14px;
}

.remote-video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
  min-height: 360px;
}

.video-box {
  position: relative;
  background: #000;
  border: 1px solid var(--border);
  border-radius: 20px;
  overflow: hidden;
  width: 100%;
  min-height: 360px;
}

.local-video-box {
  position: absolute;
  z-index: 2;
  right: 16px;
  bottom: 16px;
  width: clamp(112px, 24%, 190px);
  min-height: 0;
  height: clamp(82px, 18vw, 130px);
  border-radius: 14px;
  border-color: rgba(125, 211, 252, 0.65);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.45);
}

.video-box video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.video-label {
  position: absolute;
  bottom: 10px;
  left: 10px;
  font-size: 0.72rem;
  background: rgba(15, 23, 42, 0.76);
  padding: 4px 8px;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.12);
}

.local-video-box .video-label {
  bottom: 6px;
  left: 6px;
  font-size: 0.65rem;
  padding: 3px 6px;
}

.footer {
  text-align: center;
  padding: 10px 16px 18px;
  color: var(--muted);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
}

.note-status, .snapshot-actions, .snapshot-output, .state-card, .event-timeline li {
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.note-status { padding: 11px 13px; margin-bottom: 12px; color: var(--muted); font-size: .82rem; }
.note-status.held { color: var(--green); border-color: rgba(52, 211, 153, .45); }
.note-status.waiting { color: var(--yellow); border-color: rgba(251, 191, 36, .45); }
.note-controls { margin-top: 12px; }
.help-text { color: var(--muted); font-size: .76rem; margin: 0; }
.state-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin-bottom: 12px; }
.state-card { padding: 12px; min-width: 0; display: flex; flex-direction: column; gap: 6px; }
.state-card span { color: var(--muted); font-size: .7rem; text-transform: uppercase; letter-spacing: .06em; }
.state-card strong { color: var(--accent); font-size: .9rem; overflow-wrap: anywhere; }
.state-card code { padding: 4px 6px; font-size: .68rem; white-space: normal; overflow-wrap: anywhere; }
.snapshot-actions { display: flex; align-items: center; gap: 12px; padding: 10px; margin-bottom: 12px; font-size: .76rem; color: var(--muted); flex-wrap: wrap; }
.snapshot-output { padding: 10px 12px; margin-bottom: 16px; color: var(--muted); font-size: .76rem; min-height: 40px; }
.snapshot-output strong { color: var(--accent); }
.tab-content h3 { margin: 0 0 8px; color: var(--accent); font-size: .9rem; }
.event-timeline { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; max-height: 260px; overflow-y: auto; }
.event-timeline li { padding: 9px 11px; font-size: .76rem; color: var(--muted); }
.event-timeline li strong { color: var(--text); }
.event-timeline li.empty { text-align: center; }

@media (max-width: 640px) {
  .app-shell {
    width: min(100% - 16px, 1200px);
    margin: 16px auto 20px;
  }

  .topbar,
  .panel {
    border-radius: 16px;
  }

  .topbar {
    padding: 16px 18px;
  }

  .brand-wrap {
    width: 100%;
  }

  .server-status {
    width: 100%;
    justify-content: center;
  }

  .connection-header {
    align-items: flex-start;
  }

  .layout { grid-template-columns: 1fr; }
  .panel { padding: 20px; }
  .input-action { flex-direction: column; }
  .input-action button { width: 100%; }
  .chat-log { height: 260px; }
  .state-grid { grid-template-columns: 1fr; }
  .video-grid,
  .remote-video-grid {
    min-height: 270px;
  }
  .remote-video-grid {
    grid-template-columns: 1fr;
  }
  .remote-video-grid .video-box {
    min-height: 270px;
  }
  .local-video-box {
    right: 10px;
    bottom: 10px;
    width: 120px;
    height: 88px;
  }
}

@media (min-width: 641px) and (max-width: 900px) {
  .layout { grid-template-columns: 1fr 1fr; }
  .panel { padding: 20px; }
}