/* ============================================================
   UPSC Knowledge System — Main Stylesheet
   UI-only · responsive · animation-rich
   ============================================================ */

/* ── Reset & Base ── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  overflow-x: hidden;
  overflow-y: auto;
  transition: background-color var(--duration-normal) var(--ease-out),
              color var(--duration-normal) var(--ease-out);
}

body.app-active {
  overflow: hidden;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input {
  font-family: inherit;
  border: none;
  outline: none;
  background: none;
  color: inherit;
}

ul[role="list"] {
  list-style: none;
}

/* ── App Shell ── */
.app {
  display: flex;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

/* ============================================================
   SIDEBAR
   ============================================================ */
.sidebar {
  position: relative;
  display: flex;
  flex-direction: column;
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  height: 100%;
  background-color: var(--color-bg-elevated);
  border-right: 1px solid var(--color-border);
  z-index: 100;
  transition: width var(--duration-slow) var(--ease-out),
              min-width var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out);
  overflow: hidden;
}

/* Collapsed state */
.sidebar.is-collapsed {
  width: var(--sidebar-width-collapsed);
  min-width: var(--sidebar-width-collapsed);
}

.sidebar.is-collapsed .sidebar__title,
.sidebar.is-collapsed .sidebar__section-label,
.sidebar.is-collapsed .subject-item__label,
.sidebar.is-collapsed .sidebar__footer {
  opacity: 0;
  width: 0;
  overflow: hidden;
  white-space: nowrap;
}

.sidebar.is-collapsed .sidebar__collapse-btn svg {
  transform: rotate(180deg);
}

.sidebar.is-collapsed .subject-item {
  justify-content: center;
  padding-inline: 0;
}

.sidebar.is-collapsed .sidebar__brand {
  justify-content: center;
}

/* Sidebar header */
.sidebar__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 14px 12px;
  flex-shrink: 0;
}

.sidebar__brand-btn {
  cursor: pointer;
  border: none;
  background: none;
  font: inherit;
  color: inherit;
  text-align: left;
  border-radius: var(--radius-sm);
  transition: background-color var(--duration-fast) var(--ease-out);
}

.sidebar__brand-btn:hover {
  background-color: var(--color-bg-hover);
}

.sidebar__brand-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.sidebar__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  transition: justify-content var(--duration-normal) var(--ease-out);
}

.sidebar__logo {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-md);
  background: var(--gradient-gold);
  color: var(--color-royal-deep);
  box-shadow: var(--shadow-gold);
  flex-shrink: 0;
}

.sidebar__title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-tight);
  color: var(--color-text-primary);
  white-space: nowrap;
  transition: opacity var(--duration-normal) var(--ease-out),
              width var(--duration-slow) var(--ease-out);
}

.sidebar__collapse-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  color: var(--color-text-tertiary);
  flex-shrink: 0;
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out),
              transform var(--duration-normal) var(--ease-out);
}

.sidebar__collapse-btn:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-secondary);
}

.sidebar__collapse-btn svg {
  transition: transform var(--duration-slow) var(--ease-out);
}

/* Sidebar navigation */
.sidebar__nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 4px 10px;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-strong) transparent;
}

.sidebar__nav::-webkit-scrollbar {
  width: 4px;
}

.sidebar__nav::-webkit-scrollbar-thumb {
  background-color: var(--color-border-strong);
  border-radius: var(--radius-full);
}

.sidebar__section-label {
  padding: 8px 10px 6px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-tertiary);
  white-space: nowrap;
  transition: opacity var(--duration-normal) var(--ease-out);
}

/* Subject list items */
.subject-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar__subjects-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding-right: 4px;
}

.sidebar__add-subject-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  color: var(--color-accent);
  background: var(--color-accent-soft);
  border: 1px solid var(--color-border-gold);
  flex-shrink: 0;
  transition: transform var(--duration-fast) var(--ease-spring), background var(--duration-fast);
}

.sidebar__add-subject-btn:hover {
  transform: scale(1.08);
  background: var(--color-accent-muted);
}

.sidebar.is-collapsed .sidebar__add-subject-btn {
  display: none;
}

.subject-list__item {
  position: relative;
  display: flex;
  align-items: stretch;
}

.subject-list__item .subject-item {
  flex: 1;
  min-width: 0;
  padding-right: 36px;
}

.subject-item__delete {
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 6px;
  color: var(--color-text-tertiary);
  opacity: 0;
  transition: opacity var(--duration-fast), color var(--duration-fast), background var(--duration-fast);
}

.subject-list__item:hover .subject-item__delete,
.subject-item__delete:focus-visible {
  opacity: 1;
}

.subject-item__delete:hover {
  color: #dc2626;
  background: rgba(239, 68, 68, 0.12);
}

.sidebar.is-collapsed .subject-item__delete {
  display: none;
}

.subject-list__empty {
  padding: 0.75rem 10px;
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  text-align: center;
}

.subject-item__icon--custom {
  background-color: color-mix(in srgb, var(--color-accent) 14%, transparent);
  color: var(--color-accent);
}

/* Add subject modal */
.subject-modal[hidden] {
  display: none;
}

.subject-modal {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.subject-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10, 16, 12, 0.55);
  backdrop-filter: blur(4px);
}

.subject-modal__panel {
  position: relative;
  width: 100%;
  max-width: 400px;
  padding: 1.5rem;
  border-radius: var(--radius-xl);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-gold);
  box-shadow: var(--shadow-lg);
  animation: foresstStaggerIn 0.35s var(--ease-out) both;
}

.subject-modal__title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  margin-bottom: 0.35rem;
}

.subject-modal__desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-bottom: 1.25rem;
}

.subject-modal__field {
  display: block;
  margin-bottom: 1rem;
}

.subject-modal__field span {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 0.35rem;
  color: var(--color-text-secondary);
}

.subject-modal__field em {
  font-style: normal;
  font-weight: 400;
  opacity: 0.7;
}

.subject-modal__field input {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text-primary);
}

.subject-modal__field input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.subject-modal__error {
  margin: 0 0 0.75rem;
  padding: 0.5rem 0.65rem;
  border-radius: 8px;
  font-size: 0.85rem;
  background: rgba(239, 68, 68, 0.1);
  color: #dc2626;
}

.subject-modal__actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
}

.subject-modal__btn {
  padding: 0.55rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
}

.subject-modal__btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
}

.subject-modal__btn--ghost:hover {
  background: var(--color-bg-subtle);
}

.subject-modal__btn--primary {
  background: var(--gradient-gold);
  color: var(--color-royal-deep);
  box-shadow: var(--shadow-gold);
}

.subject-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  text-align: left;
  position: relative;
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out),
              padding var(--duration-slow) var(--ease-out);
}

.subject-item:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-primary);
  transform: translateX(2px);
}

.subject-item:active {
  transform: translateX(0) scale(0.98);
}

.subject-item.is-active {
  background-color: var(--color-bg-active);
  color: var(--color-accent);
  box-shadow: var(--shadow-xs);
}

.subject-item.is-active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 60%;
  background-color: var(--color-accent);
  border-radius: 0 2px 2px 0;
}

.subject-item__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  transition: transform var(--duration-fast) var(--ease-out),
              background-color var(--duration-fast) var(--ease-out);
}

.subject-item:hover .subject-item__icon {
  transform: scale(1.08);
}

/* Per-subject icon background tints */
.subject-item__icon--history    { background-color: color-mix(in srgb, var(--icon-history) 12%, transparent);    color: var(--icon-history); }
.subject-item__icon--ancient    { background-color: color-mix(in srgb, var(--icon-ancient) 12%, transparent);    color: var(--icon-ancient); }
.subject-item__icon--medieval   { background-color: color-mix(in srgb, var(--icon-medieval) 12%, transparent);   color: var(--icon-medieval); }
.subject-item__icon--polity     { background-color: color-mix(in srgb, var(--icon-polity) 12%, transparent);     color: var(--icon-polity); }
.subject-item__icon--economics  { background-color: color-mix(in srgb, var(--icon-economics) 12%, transparent);  color: var(--icon-economics); }
.subject-item__icon--economics-opt { background-color: color-mix(in srgb, var(--icon-econ-opt) 12%, transparent); color: var(--icon-econ-opt); }
.subject-item__icon--geography  { background-color: color-mix(in srgb, var(--icon-geography) 12%, transparent);  color: var(--icon-geography); }
.subject-item__icon--environment{ background-color: color-mix(in srgb, var(--icon-environment) 12%, transparent);color: var(--icon-environment); }
.subject-item__icon--science    { background-color: color-mix(in srgb, var(--icon-science) 12%, transparent);    color: var(--icon-science); }
.subject-item__icon--current    { background-color: color-mix(in srgb, var(--icon-current) 12%, transparent);    color: var(--icon-current); }
.subject-item__icon--ssc        { background-color: color-mix(in srgb, var(--icon-ssc) 12%, transparent);        color: var(--icon-ssc); }

.subject-item__label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: opacity var(--duration-normal) var(--ease-out),
              width var(--duration-slow) var(--ease-out);
}

/* Sidebar footer */
.sidebar__footer {
  padding: 12px 16px;
  border-top: 1px solid var(--color-border);
  flex-shrink: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.sidebar__footer-text {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

/* Mobile overlay */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.4);
  z-index: 90;
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
  pointer-events: none;
}

.sidebar-overlay.is-visible {
  opacity: 1;
  pointer-events: auto;
}

/* ============================================================
   MAIN SHELL
   ============================================================ */
.main-shell {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-width: 0;
  height: 100%;
  overflow: hidden;
}

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  height: var(--navbar-height);
  min-height: var(--navbar-height);
  padding: 0 20px;
  background-color: var(--color-bg-elevated);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.navbar__left {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  min-width: 0;
}

.navbar__right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

/* Mobile menu button */
.navbar__menu-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out);
}

.navbar__menu-btn:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-primary);
}

/* Search bar */
.search-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  max-width: 480px;
  height: 36px;
  padding: 0 12px;
  background-color: var(--color-bg-subtle);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  transition: background-color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}

.search-bar:hover {
  background-color: var(--color-bg-hover);
  border-color: var(--color-border);
}

.search-bar:focus-within {
  background-color: var(--color-bg-elevated);
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.search-bar__icon {
  display: flex;
  color: var(--color-text-tertiary);
  flex-shrink: 0;
}

.search-bar__input {
  flex: 1;
  min-width: 0;
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
}

.search-bar__input::placeholder {
  color: var(--color-text-tertiary);
}

.search-bar__shortcut {
  display: inline-flex;
  align-items: center;
  padding: 2px 6px;
  font-size: 11px;
  font-family: inherit;
  color: var(--color-text-tertiary);
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  flex-shrink: 0;
}

/* Navbar buttons */
.navbar__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 36px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}

.navbar__btn:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-primary);
}

.navbar__btn:active {
  transform: scale(0.96);
}

.navbar__btn--primary {
  background: var(--gradient-gold);
  color: var(--color-royal-deep);
  padding: 0 16px;
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-gold);
  border: 1px solid rgba(201, 169, 98, 0.35);
}

.navbar__btn--primary:hover {
  filter: brightness(1.06);
  color: var(--color-royal-deep);
  box-shadow: 0 6px 24px rgba(201, 169, 98, 0.28);
}

.navbar__btn--icon {
  width: 36px;
  padding: 0;
}

/* Theme toggle icons */
#themeToggleBtn .icon-sun  { display: none; }
#themeToggleBtn .icon-moon { display: block; }

[data-theme="dark"] #themeToggleBtn .icon-sun  { display: block; }
[data-theme="dark"] #themeToggleBtn .icon-moon { display: none; }

/* ============================================================
   MAIN CONTENT — Welcome Screen
   ============================================================ */
.main-content {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  background-color: var(--color-bg);
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-strong) transparent;
}

.main-content::-webkit-scrollbar {
  width: 6px;
}

.main-content::-webkit-scrollbar-thumb {
  background-color: var(--color-border-strong);
  border-radius: var(--radius-full);
}

.welcome-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100%;
  padding: 48px 24px 32px;
  gap: 48px;
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Welcome card */
.welcome-screen__card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  max-width: 480px;
  padding: 48px 40px;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: box-shadow var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out);
}

.welcome-screen__card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.welcome-screen__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  margin-bottom: 24px;
  border-radius: var(--radius-lg);
  background-color: var(--color-accent-muted);
  color: var(--color-accent);
  animation: pulseIcon 3s var(--ease-in-out) infinite;
}

@keyframes pulseIcon {
  0%, 100% { transform: scale(1); }
  50%       { transform: scale(1.04); }
}

.welcome-screen__kicker {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-wide);
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.welcome-screen__title {
  font-family: var(--font-display);
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-display);
  color: var(--color-text-primary);
  margin-bottom: 12px;
  line-height: var(--line-height-tight);
}

.welcome-screen__subtitle {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  max-width: 360px;
  margin-bottom: 28px;
}

/* Hint chips */
.welcome-screen__hints {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.hint-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-tertiary);
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out);
}

.hint-chip:hover {
  background-color: var(--color-accent-soft);
  color: var(--color-accent);
  border-color: transparent;
  transform: translateY(-1px);
}

/* Quote */
.welcome-screen__quote {
  position: relative;
  font-size: var(--font-size-sm);
  font-style: italic;
  font-weight: var(--font-weight-normal);
  color: var(--color-text-tertiary);
  text-align: center;
  max-width: 360px;
  line-height: var(--line-height-relaxed);
  animation: fadeInUp var(--duration-slow) var(--ease-out) 0.15s both;
}

.welcome-screen__quote-mark {
  font-size: var(--font-size-xl);
  font-style: normal;
  color: var(--color-accent);
  opacity: 0.5;
  margin-right: 2px;
  vertical-align: -2px;
}

/* ── Main content view transitions ── */
.main-content--exiting {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 180ms var(--ease-out), transform 180ms var(--ease-out);
}

.main-content--entering > .kg-view,
.main-content--entering > .revision-mode,
.main-content--entering > .global-dashboard,
.main-content--entering > .workspace,
.main-content--entering > .welcome-screen,
.main-content--entering > .notes-dashboard,
.main-content--entering > .note-editor,
.main-content--entering > .keywords-dashboard,
.main-content--entering > .kb-dashboard,
.main-content--entering > .kb-article {
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
}

/* ============================================================
   SUBJECT WORKSPACE
   ============================================================ */
.workspace {
  max-width: 1080px;
  margin: 0 auto;
  padding: 36px 40px 48px;
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
}

.workspace__header {
  margin-bottom: 32px;
}

.workspace__breadcrumb {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.workspace__title {
  font-family: var(--font-display);
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-display);
  color: var(--color-text-primary);
  line-height: var(--line-height-tight);
  margin-bottom: 8px;
}

.workspace__tagline {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  max-width: 560px;
}

/* Module cards grid */
.workspace__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

/* Individual workspace module card */
.workspace-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 20px;
  width: 100%;
  min-height: 220px;
  padding: 28px;
  text-align: left;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  transition:
    transform var(--duration-normal) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out),
    border-color var(--duration-normal) var(--ease-out),
    background-color var(--duration-fast) var(--ease-out);
}

.workspace-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    var(--color-accent-muted) 0%,
    transparent 60%
  );
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
  pointer-events: none;
}

.workspace-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-strong);
}

.workspace-card:hover::before {
  opacity: 1;
}

.workspace-card:hover .workspace-card__icon {
  transform: scale(1.08);
  background-color: var(--color-accent-soft);
  color: var(--color-accent);
}

.workspace-card:hover .workspace-card__arrow {
  opacity: 1;
  transform: translateX(0);
}

.workspace-card.is-pressed {
  transform: translateY(-2px) scale(0.97);
  box-shadow: var(--shadow-xs);
  transition-duration: 80ms;
}

.workspace-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background-color: var(--color-bg-subtle);
  color: var(--color-text-secondary);
  flex-shrink: 0;
  transition:
    transform var(--duration-normal) var(--ease-out),
    background-color var(--duration-normal) var(--ease-out),
    color var(--duration-normal) var(--ease-out);
}

.workspace-card__body {
  flex: 1;
  width: 100%;
}

.workspace-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.workspace-card__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  letter-spacing: var(--letter-spacing-tight);
}

.workspace-card__count {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  height: 28px;
  padding: 0 10px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-accent);
  background-color: var(--color-accent-soft);
  border-radius: var(--radius-full);
  flex-shrink: 0;
}

.workspace-card__description {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

.workspace-card__arrow {
  position: absolute;
  right: 24px;
  bottom: 24px;
  display: flex;
  color: var(--color-accent);
  opacity: 0;
  transform: translateX(-6px);
  transition:
    opacity var(--duration-normal) var(--ease-out),
    transform var(--duration-normal) var(--ease-out);
}

/* Per-module icon accent on hover */
.workspace-card--notes:hover .workspace-card__icon {
  color: var(--icon-history);
  background-color: color-mix(in srgb, var(--icon-history) 14%, transparent);
}

.workspace-card--knowledge-base:hover .workspace-card__icon {
  color: var(--icon-polity);
  background-color: color-mix(in srgb, var(--icon-polity) 14%, transparent);
}

.workspace-card--keywords:hover .workspace-card__icon {
  color: var(--icon-environment);
  background-color: color-mix(in srgb, var(--icon-environment) 14%, transparent);
}

.workspace-card--revision:hover .workspace-card__icon {
  color: var(--color-accent);
  background-color: var(--color-accent-soft);
}

.workspace-card--knowledge-graph:hover .workspace-card__icon {
  color: var(--icon-polity);
  background-color: color-mix(in srgb, var(--icon-polity) 14%, transparent);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

/* Tablet */
@media (max-width: 1024px) {
  .search-bar {
    max-width: 320px;
  }

  .search-bar__shortcut {
    display: none;
  }
}

/* Mobile */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    height: 100%;
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
    z-index: 200;
  }

  .sidebar.is-mobile-open {
    transform: translateX(0);
  }

  .sidebar-overlay {
    display: block;
  }

  .sidebar__collapse-btn {
    display: none;
  }

  .navbar__menu-btn {
    display: flex;
  }

  .search-bar {
    max-width: none;
  }

  .navbar__btn-label {
    display: none;
  }

  .navbar__btn--primary {
    width: 36px;
    padding: 0;
  }

  .welcome-screen__card {
    padding: 36px 24px;
  }

  .welcome-screen__title {
    font-size: var(--font-size-xl);
  }

  .workspace {
    padding: 28px 20px 40px;
  }

  .workspace__grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .workspace-card {
    min-height: auto;
    padding: 24px;
  }
}

/* Tablet workspace */
@media (max-width: 1024px) and (min-width: 769px) {
  .workspace__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Small mobile */
@media (max-width: 480px) {
  .navbar {
    padding: 0 12px;
    gap: 8px;
  }

  .navbar__right {
    gap: 4px;
  }

  .welcome-screen {
    padding: 32px 16px 24px;
    gap: 36px;
  }

  .welcome-screen__icon {
    width: 64px;
    height: 64px;
  }

  .welcome-screen__icon svg {
    width: 36px;
    height: 36px;
  }
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}