/* ============================================
   GLOBAL LAYOUT SYSTEM - LearnVaultX
   Professional 3-Pane Layout (ChatGPT + VS Code Style)
   ============================================ */

/* ============================================
   BASE RESET
   ============================================ */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    min-height: 100%;
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Only hide overflow for app-layout pages (dashboards, live class) */
body.app-page {
    height: 100%;
    overflow: hidden;
}

/* ============================================
   3-PANE LAYOUT CONTAINER
   ============================================ */

.app-layout {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    grid-template-rows: 1fr;
    height: 100vh;
    width: 100vw;
    overflow: hidden;
    position: relative;
}

/* Collapsed Sidebar State */
.app-layout.sidebar-collapsed {
    grid-template-columns: var(--sidebar-collapsed) 1fr;
}

/* Panel Open State */
.app-layout.panel-open {
    grid-template-columns: var(--sidebar-width) 1fr var(--panel-width);
}

.app-layout.sidebar-collapsed.panel-open {
    grid-template-columns: var(--sidebar-collapsed) 1fr var(--panel-width);
}

/* ============================================
   LEFT SIDEBAR
   ============================================ */

.app-sidebar {
    grid-column: 1;
    grid-row: 1;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--sidebar-border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: width var(--transition-slow);
    z-index: var(--z-sidebar);
    position: relative;
}

/* Futuristic Mode: Add sidebar glow */
[data-theme="futuristic"] .app-sidebar {
    box-shadow: var(--sidebar-shadow);
}

/* Sidebar Header */
.sidebar-header {
    padding: var(--space-3);
    border-bottom: 1px solid var(--border-primary);
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: var(--header-height);
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xl);
    font-weight: var(--font-bold);
    color: var(--text-primary);
    text-decoration: none;
    transition: opacity var(--transition-base);
}

.sidebar-brand-logo {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: var(--font-bold);
    flex-shrink: 0;
}

.sidebar-brand-text {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    white-space: nowrap;
}

.sidebar-toggle {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

.sidebar-toggle:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* Sidebar Navigation */
.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--space-2);
}

.sidebar-nav::-webkit-scrollbar {
    width: 4px;
}

.sidebar-nav::-webkit-scrollbar-thumb {
    background: var(--border-primary);
    border-radius: var(--radius-full);
}

.nav-section {
    margin-bottom: var(--space-4);
}

.nav-section-title {
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: var(--space-1) var(--space-2);
    margin-bottom: var(--space-1);
}

.nav-menu {
    list-style: none;
}

.nav-item {
    margin-bottom: 2px;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-2);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    background: transparent;
    width: 100%;
    text-align: left;
}

.nav-link:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-link.active {
    background: linear-gradient(135deg, rgba(96, 165, 250, 0.1), rgba(167, 139, 250, 0.1));
    color: var(--primary);
    border-left: 3px solid var(--primary);
}

.nav-icon {
    font-size: var(--text-lg);
    flex-shrink: 0;
    width: 24px;
    text-align: center;
}

.nav-label {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Sidebar Footer */
.sidebar-footer {
    padding: var(--space-3);
    border-top: 1px solid var(--border-primary);
}

.sidebar-user {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition-base);
}

.sidebar-user:hover {
    background: var(--bg-tertiary);
}

.sidebar-user-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: var(--font-semibold);
    flex-shrink: 0;
}

.sidebar-user-info {
    flex: 1;
    overflow: hidden;
}

.sidebar-user-name {
    font-size: var(--text-sm);
    font-weight: var(--font-semibold);
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-user-role {
    font-size: var(--text-xs);
    color: var(--text-tertiary);
}

/* Collapsed Sidebar Styles */
.app-layout.sidebar-collapsed .sidebar-brand-text,
.app-layout.sidebar-collapsed .nav-label,
.app-layout.sidebar-collapsed .nav-section-title,
.app-layout.sidebar-collapsed .sidebar-user-info {
    opacity: 0;
    width: 0;
    overflow: hidden;
}

/* ============================================
   CENTER CONTENT
   ============================================ */

.app-center {
    grid-column: 2;
    grid-row: 1;
    background: var(--bg-primary);
    overflow-y: auto;
    overflow-x: hidden;
    position: relative;
    transition: margin-right var(--transition-slow);
}

.app-center::-webkit-scrollbar {
    width: 8px;
}

.app-center::-webkit-scrollbar-thumb {
    background: var(--border-primary);
    border-radius: var(--radius-full);
}

.app-center::-webkit-scrollbar-thumb:hover {
    background: var(--border-secondary);
}

/* Center Content Header */
.center-header {
    position: sticky;
    top: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-primary);
    padding: var(--space-3) var(--space-4);
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: var(--z-header);
}

/* Futuristic Mode: Add backdrop filter to header */
[data-theme="futuristic"] .center-header {
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
}

.center-title {
    font-size: var(--text-2xl);
    font-weight: var(--font-bold);
    color: var(--text-primary);
}

.center-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

/* Center Content Body */
.center-body {
    padding: var(--space-4);
}

/* ============================================
   RIGHT PANEL
   ============================================ */

.app-panel {
    position: fixed;
    right: calc(-1 * var(--panel-width));
    top: 0;
    bottom: 0;
    width: var(--panel-width);
    background: var(--panel-bg);
    border-left: 1px solid var(--panel-border);
    display: flex;
    flex-direction: column;
    transition: right var(--transition-slow);
    z-index: var(--z-panel);
    box-shadow: var(--shadow-xl);
}

/* Futuristic Mode: Add panel glow */
[data-theme="futuristic"] .app-panel {
    box-shadow: var(--shadow-xl), var(--panel-shadow);
}

.app-panel.active {
    right: 0;
}

/* Panel Header */
.panel-header {
    padding: var(--space-3) var(--space-4);
    border-bottom: 1px solid var(--border-primary);
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: var(--header-height);
}

.panel-title {
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.panel-close {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-full);
    border: none;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xl);
    transition: all var(--transition-base);
}

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

/* Panel Body */
.panel-body {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--space-4);
}

.panel-body::-webkit-scrollbar {
    width: 6px;
}

.panel-body::-webkit-scrollbar-thumb {
    background: var(--border-primary);
    border-radius: var(--radius-full);
}

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

/* Tablet */
@media (max-width: 1024px) {
    .app-layout {
        grid-template-columns: var(--sidebar-collapsed) 1fr;
    }

    .app-sidebar {
        position: fixed;
        left: calc(-1 * var(--sidebar-width));
        top: 0;
        bottom: 0;
        width: var(--sidebar-width);
        z-index: var(--z-modal);
        transition: left var(--transition-slow);
    }

    .app-sidebar.active {
        left: 0;
    }

    .app-panel {
        width: 100%;
        right: -100%;
    }
}

/* Mobile */
@media (max-width: 640px) {
    .center-header {
        padding: var(--space-2) var(--space-3);
    }

    .center-body {
        padding: var(--space-3);
    }

    .center-title {
        font-size: var(--text-xl);
    }
}

/* ============================================
   OVERLAY FOR MOBILE
   ============================================ */

.app-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: calc(var(--z-modal) - 1);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.app-overlay.active {
    opacity: 1;
    pointer-events: all;
}

/* ============================================
   SMOOTH SCROLLING
   ============================================ */

@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}