:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1f2a44;
  --muted: #5a6787;
  --accent: #4e60e6;
  --border: #e6e9f2;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", Tahoma, sans-serif;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 4px 18px rgba(31, 42, 68, 0.08);
  position: sticky;
  top: 0;
  z-index: 2;
  gap: 12px;
}

.title {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0;
  color: var(--text);
  letter-spacing: 0.2px;
}

.actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn {
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  border-radius: 10px;
  padding: 10px 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  transition: transform 120ms ease, box-shadow 120ms ease, border-color 120ms ease;
}

.icon-btn .fa-solid { font-size: 0.95rem; }

.icon-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 20px rgba(31, 42, 68, 0.12);
  border-color: #d0d7f0;
}

.icon-btn.accent {
  background: linear-gradient(135deg, #6b7bff, #4e60e6);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 12px 24px rgba(79, 96, 230, 0.24);
}

.frame-wrap {
  flex: 1;
  min-height: 0;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

#content-frame {
  width: 100%;
  height: 100%;
  flex: 1;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 10px 26px rgba(31, 42, 68, 0.08);
  background: #fff;
}
.player-container {
  margin-bottom: 12px;
  overflow: hidden;
}
#player-frame {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 10px 26px rgba(31, 42, 68, 0.08);
  background: #fff;
  display: block;
  overflow: hidden;
}

@media (max-width: 640px) {
  .title { font-size: 1rem; }
  .icon-btn { padding: 8px 10px; }
  .icon-btn span { display: none; }
}

.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--card);
  border-top: 1px solid var(--border);
  box-shadow: 0 -6px 18px rgba(31, 42, 68, 0.1);
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: 6px;
  padding: 10px 12px;
}

.nav-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
  transition: transform 120ms ease, box-shadow 120ms ease, border-color 120ms ease;
}

.nav-btn .fa-solid { font-size: 1rem; }

.nav-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 16px rgba(31, 42, 68, 0.12);
  border-color: #d0d7f0;
}

.nav-btn.active {
  background: linear-gradient(135deg, #6b7bff, #4e60e6);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 12px 24px rgba(79, 96, 230, 0.22);
}

@media (max-width: 640px) {
  .nav-btn { padding: 10px; font-size: 0.95rem; }
  .nav-btn span { display: none; }
  .bottom-nav { padding: 8px 10px; }
}