/* =========================================================
   Notebook Premium UI Layer
   Visual-only enhancements + unavailable-feature toast states.
   ========================================================= */
:root {
  --premium-accent: #4f46e5;
  --premium-accent-2: #7c3aed;
  --premium-accent-soft: rgba(79, 70, 229, .09);
  --premium-border: rgba(15, 23, 42, .09);
  --premium-shadow: 0 20px 60px rgba(15, 23, 42, .08), 0 4px 16px rgba(15, 23, 42, .04);
  --premium-shadow-hover: 0 24px 70px rgba(15, 23, 42, .12), 0 8px 24px rgba(79, 70, 229, .08);
}

[data-theme="dark"] {
  --premium-border: rgba(255, 255, 255, .08);
  --premium-shadow: 0 24px 70px rgba(0, 0, 0, .28), 0 6px 20px rgba(0, 0, 0, .2);
  --premium-shadow-hover: 0 28px 80px rgba(0, 0, 0, .4), 0 8px 28px rgba(79, 70, 229, .14);
}

body {
  background-image:
    radial-gradient(circle at 8% 8%, rgba(99, 102, 241, .055), transparent 26%),
    radial-gradient(circle at 92% 18%, rgba(124, 58, 237, .045), transparent 24%),
    radial-gradient(circle, rgba(13, 15, 20, .025) 1px, transparent 1px);
  background-size: auto, auto, 28px 28px;
}

.top-nav {
  height: 70px;
  padding: 0 1.5rem;
  border-bottom-color: var(--premium-border);
  box-shadow: 0 8px 30px rgba(15, 23, 42, .035);
}

.logo {
  width: 36px;
  height: 36px;
  border-radius: 11px;
  background: linear-gradient(145deg, #111827, #334155);
  box-shadow: 0 8px 22px rgba(15, 23, 42, .18), inset 0 1px rgba(255,255,255,.12);
}

.app-name {
  font-size: 1.18rem;
  letter-spacing: -.035em;
}

.nav-center {
  padding: 4px;
  border: 1px solid var(--premium-border);
  background: rgba(255,255,255,.55);
  border-radius: 14px;
  box-shadow: 0 5px 20px rgba(15,23,42,.04);
}

[data-theme="dark"] .nav-center {
  background: rgba(21,25,35,.65);
}

.nav-center .module-btn {
  min-height: 36px;
  padding: 7px 12px;
  border-radius: 10px;
  transition: all .22s var(--ease-out);
}

.nav-center .module-btn:hover {
  background: var(--hover-bg);
  color: var(--ink);
}

.nav-center .module-btn.active {
  color: #fff;
  background: linear-gradient(135deg, var(--premium-accent), var(--premium-accent-2));
  box-shadow: 0 7px 18px rgba(79,70,229,.22);
}

.nav-center .module-btn.active i { color: #fff; }

.layout-wrapper {
  padding-top: 70px;
}

.sidebar {
  background: rgba(255,255,255,.72);
  border-color: var(--premium-border);
  padding: 1.25rem 1rem;
}

[data-theme="dark"] .sidebar {
  background: rgba(21,25,35,.72);
}

.sidebar-links {
  gap: 5px;
}

.menu-item-btn {
  padding: 10px 11px;
  border-radius: 11px;
  font-size: .86rem;
}

.menu-item-btn:hover {
  transform: translateX(2px);
  background: var(--hover-bg);
}

.menu-item-btn.active,
.direct-link.active {
  background: linear-gradient(90deg, var(--premium-accent-soft), transparent) !important;
  box-shadow: inset 3px 0 var(--premium-accent);
}

.main-content {
  padding: 2.5rem 2.5rem 5rem;
}

.content-inner {
  max-width: 1180px;
}

.content-header {
  margin-bottom: 2.25rem;
}

.content-eyebrow {
  letter-spacing: .16em;
  color: var(--premium-accent);
}

.badge {
  border: 1px solid rgba(79,70,229,.12);
  background: var(--premium-accent-soft);
  color: var(--premium-accent);
  padding: 4px 9px;
}

.header-metrics {
  padding: 6px 12px;
  border-radius: 12px;
  border-color: var(--premium-border);
  box-shadow: 0 4px 18px rgba(15,23,42,.035);
}

.content-title {
  font-size: clamp(2rem, 4vw, 3.15rem);
  font-weight: 600;
  letter-spacing: -.045em;
  line-height: 1.02;
}

.content-sub {
  font-size: .98rem;
  color: var(--muted);
  max-width: 60ch;
}

.cards-section {
  margin-bottom: 2.2rem;
}

.cards-section-header {
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: .7rem;
  letter-spacing: .12em;
}

.btn-toggle-cards {
  padding: 7px 11px;
  border-radius: 10px;
  background: rgba(255,255,255,.65);
  border-color: var(--premium-border);
}

[data-theme="dark"] .btn-toggle-cards { background: rgba(21,25,35,.7); }

.content-grid {
  grid-template-columns: repeat(auto-fit, minmax(245px, 1fr));
  gap: 1rem;
}

.card {
  min-height: 166px;
  padding: 1.35rem;
  border-radius: 18px;
  border-color: var(--premium-border);
  box-shadow: var(--premium-shadow);
  background:
    linear-gradient(145deg, rgba(255,255,255,.98), rgba(248,250,252,.88));
  overflow: hidden;
}

[data-theme="dark"] .card {
  background: linear-gradient(145deg, rgba(25,29,41,.98), rgba(18,22,31,.92));
}

.card::before {
  width: 90px;
  height: 90px;
  top: -35px;
  left: auto;
  right: -30px;
  border: 0;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(79,70,229,.12), transparent 68%);
  opacity: 1;
}

.card::after {
  display: none;
}

.card:hover {
  border-color: rgba(79,70,229,.22);
  transform: translateY(-5px);
  box-shadow: var(--premium-shadow-hover);
}

.card-icon {
  width: 42px;
  height: 42px;
  border-radius: 13px;
  color: var(--premium-accent);
  background: var(--premium-accent-soft);
  border-color: transparent;
}

.card:hover .card-icon {
  color: #fff;
  background: linear-gradient(135deg, var(--premium-accent), var(--premium-accent-2));
  box-shadow: 0 8px 20px rgba(79,70,229,.22);
}

.card-tag {
  border-radius: 999px;
  padding: 4px 8px;
  background: var(--bg);
}

.card-title {
  font-size: 1.02rem;
  letter-spacing: -.02em;
}

.card-desc {
  font-size: .83rem;
  line-height: 1.55;
}

.create-post-card {
  padding: 1.35rem;
  border-radius: 20px;
  border-color: var(--premium-border);
  box-shadow: var(--premium-shadow);
  margin-bottom: 2.2rem;
  background: linear-gradient(145deg, rgba(255,255,255,.98), rgba(248,250,252,.94));
}

[data-theme="dark"] .create-post-card {
  background: linear-gradient(145deg, rgba(25,29,41,.98), rgba(18,22,31,.94));
}

#post-input {
  min-height: 88px;
  height: 88px;
  border-radius: 14px;
  background: var(--bg);
  border-color: var(--premium-border);
  padding: 13px 15px;
}

#post-input:focus {
  box-shadow: 0 0 0 4px rgba(79,70,229,.09), 0 8px 25px rgba(79,70,229,.06);
}

.post-option-btn {
  padding: 8px 11px;
  border-radius: 10px;
}

.post-option-btn:hover {
  background: var(--premium-accent-soft);
}

.dropdown-trigger {
  min-height: 38px;
  border-radius: 10px;
}

.dropdown-menu,
.post-popover-menu {
  border-radius: 14px;
  box-shadow: var(--premium-shadow-hover);
  border-color: var(--premium-border);
  backdrop-filter: blur(18px);
}

.btn-publish {
  min-height: 38px;
  padding: 8px 17px;
  border-radius: 11px;
  background: linear-gradient(135deg, var(--premium-accent), var(--premium-accent-2));
  box-shadow: 0 8px 20px rgba(79,70,229,.18);
}

.btn-publish:hover {
  background: linear-gradient(135deg, #4338ca, #6d28d9);
  transform: translateY(-1px);
}

.feed-section-header {
  margin-bottom: 1rem;
}

.feed-title {
  font-size: 1.45rem;
  font-weight: 600;
  letter-spacing: -.025em;
}

.feed-filter-tag {
  padding: 5px 10px;
  border: 1px solid rgba(79,70,229,.12);
  background: var(--premium-accent-soft);
}

.posts-feed {
  gap: 1rem;
}

.post-card {
  padding: 1.4rem;
  border-radius: 18px;
  border-color: var(--premium-border);
  box-shadow: var(--premium-shadow);
}

.post-card:hover {
  border-color: rgba(79,70,229,.15);
  box-shadow: var(--premium-shadow-hover);
}

.post-media {
  border-radius: 14px;
}

.action-btn {
  border-radius: 10px;
  padding: 9px 6px;
}

.action-btn:hover {
  background: var(--premium-accent-soft);
  color: var(--premium-accent);
}

/* Unavailable feature affordance */
.feature-unavailable {
  position: relative;
}

.feature-unavailable::after {
  content: "Coming soon";
  position: absolute;
  top: 9px;
  right: 9px;
  font-family: var(--font-mono);
  font-size: .52rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--premium-accent);
  background: var(--premium-accent-soft);
  border: 1px solid rgba(79,70,229,.12);
  border-radius: 999px;
  padding: 3px 6px;
  pointer-events: none;
}

.feature-unavailable.card:hover {
  border-color: rgba(79,70,229,.18);
}

/* Premium toast */
.feature-toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  z-index: 10000;
  display: flex;
  align-items: center;
  gap: 11px;
  min-width: min(360px, calc(100vw - 32px));
  max-width: calc(100vw - 32px);
  padding: 12px 15px;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 14px;
  color: #fff;
  background: rgba(15, 23, 42, .94);
  box-shadow: 0 20px 50px rgba(15,23,42,.28);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  transform: translate(-50%, 18px);
  opacity: 0;
  pointer-events: none;
  transition: opacity .28s var(--ease-out), transform .28s var(--ease-out);
}

.feature-toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

.feature-toast-icon {
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  display: grid;
  place-items: center;
  border-radius: 9px;
  color: #c7d2fe;
  background: rgba(99,102,241,.18);
}

.feature-toast-icon svg { width: 16px; height: 16px; }
.feature-toast-copy { min-width: 0; }
.feature-toast-title { font-size: .72rem; font-weight: 700; letter-spacing: .03em; text-transform: uppercase; color: #a5b4fc; }
.feature-toast-message { margin-top: 2px; font-size: .84rem; line-height: 1.35; color: rgba(255,255,255,.92); }

@media (max-width: 1280px) {
  .top-nav { height: 64px; }
  .layout-wrapper { padding-top: 64px; }
  .main-content { padding: 1.6rem 1.25rem 5.5rem; }
}

@media (max-width: 640px) {
  .top-nav { padding: 0 .8rem; }
  .main-content { padding: 1.15rem .85rem 5.5rem; }
  .content-title { font-size: 2rem; }
  .header-metrics { width: 100%; justify-content: space-between; }
  .create-post-card, .post-card { border-radius: 16px; }
  .feature-toast { bottom: 82px; }
}

.module-btn[data-feature-status="unavailable"] {
  opacity: .58;
  cursor: pointer;
}

.module-btn[data-feature-status="unavailable"]:hover {
  opacity: .9;
}

.menu-item-btn.feature-unavailable,
.submenu-item.feature-unavailable {
  position: relative;
}

.menu-item-btn.feature-unavailable::after {
  position: absolute;
  top: 50%;
  right: 9px;
  transform: translateY(-50%);
  margin: 0;
}

.submenu-item.feature-unavailable {
  padding-right: 8px;
}

.submenu-item.feature-unavailable::after {
  position: static;
  margin-left: auto;
  transform: none;
  white-space: nowrap;
}