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

html, body {
    height: 100%;
    font-family: var(--font-body);
    font-size: var(--text-base);
    color: var(--color-text-primary);
    background: var(--color-base);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

#app {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.view { height: 100%; }
.hidden { display: none !important; }

/* Login */
#login-view {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-base);
}

.login-card {
    width: 100%;
    max-width: 380px;
    padding: var(--space-8);
    background: var(--color-surface-1);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}

.login-title {
    font-size: var(--text-xl);
    font-weight: var(--font-bold);
    margin-bottom: var(--space-6);
    text-align: center;
    color: var(--color-accent);
}

/* Main Layout */
#main-view {
    display: flex;
    height: 100%;
    overflow: hidden;
}

.sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    background: var(--color-surface-1);
    border-right: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    transition: width var(--transition-base), min-width var(--transition-base);
    position: relative;
}

.sidebar.collapsed {
    width: var(--sidebar-collapsed);
    min-width: var(--sidebar-collapsed);
}

.sidebar.collapsed .nav-label,
.sidebar.collapsed .sidebar-section-title,
.sidebar.collapsed .sidebar-folder-list,
.sidebar.collapsed .badge,
.sidebar.collapsed .btn-sync,
.sidebar.collapsed .btn-expand {
    display: none;
}

.sidebar.collapsed .btn-compose {
    padding: var(--space-2);
    font-size: var(--text-sm);
}

.sidebar.collapsed .btn-compose .nav-label {
    display: none;
}

.sidebar.collapsed .sidebar-nav-item {
    justify-content: center;
    padding: var(--space-2) var(--space-3);
}

.sidebar-collapse-btn {
    position: absolute;
    top: var(--space-2);
    right: var(--space-2);
    font-size: var(--text-xs);
    padding: 2px 6px;
    z-index: 5;
}

.nav-icon {
    flex-shrink: 0;
}

.content {
    flex: 1;
    display: flex;
    overflow: hidden;
}

.panel-list {
    width: var(--list-panel-width);
    min-width: var(--list-panel-width);
    border-right: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--color-surface-2);
}

.panel-reader {
    flex: 1;
    overflow-y: auto;
    background: var(--color-base);
    padding: var(--space-6);
}

/* Resizable Panels */
.resize-handle {
    width: 4px;
    cursor: col-resize;
    background: transparent;
    position: relative;
    flex-shrink: 0;
    z-index: 10;
}

.resize-handle:hover,
.resize-handle.active {
    background: var(--color-accent);
}

.resize-handle::after {
    content: '';
    position: absolute;
    inset: 0 -3px;
}

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 900;
}

.modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 1000;
    background: var(--color-surface-1);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    max-height: 90vh;
    overflow-y: auto;
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

/* Responsive */
@media (max-width: 1024px) {
    .sidebar {
        width: var(--sidebar-collapsed);
        min-width: var(--sidebar-collapsed);
    }
    .panel-list {
        width: 300px;
        min-width: 300px;
    }
}

@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -100%;
        top: 0;
        bottom: 0;
        width: var(--sidebar-width);
        min-width: var(--sidebar-width);
        z-index: 800;
        transition: left var(--transition-base);
    }
    .sidebar.open {
        left: 0;
    }
    .mobile-hamburger {
        display: flex;
    }
    .mobile-overlay.active {
        display: block;
    }
    #resize-sidebar {
        display: none;
    }
    .content {
        flex-direction: column;
    }
    .panel-list {
        width: 100% !important;
        min-width: 100% !important;
    }
    #resize-list {
        display: none;
    }
    .panel-reader {
        position: fixed;
        inset: 0;
        z-index: 700;
        transform: translateX(100%);
        transition: transform var(--transition-base);
        background: var(--color-base);
    }
    .panel-reader.active {
        transform: translateX(0);
    }
    .composer {
        width: 100vw !important;
        max-width: 100vw !important;
        height: 100vh;
        border-radius: 0;
    }
}

.mobile-hamburger {
    display: none;
    position: fixed;
    top: var(--space-2);
    left: var(--space-2);
    z-index: 600;
    background: var(--color-surface-1);
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
    font-size: 20px;
    width: 36px;
    height: 36px;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.mobile-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 790;
}