/* App Shell Layout */
#app-shell {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    background: var(--color-bg);
    overflow: hidden;
}

/* Loading State */
.app-loading {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--color-bg);
    z-index: 9999;
}

.app-loading .spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.app-loading p {
    margin-top: var(--spacing-md);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Header */
.app-header {
    position: relative;
    height: calc(var(--header-height) + var(--safe-area-top));
    padding-top: var(--safe-area-top);
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    z-index: var(--z-header);
    flex-shrink: 0;
}

.header-content {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-md);
}

.header-left,
.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.header-center {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.header-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
}

.header-subtitle {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
}

.header-btn {
    width: var(--touch-target-min);
    height: var(--touch-target-min);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    color: var(--color-text);
    transition: background var(--transition-fast);
}

.header-btn:active {
    background: var(--color-bg-secondary);
}

/* Main Content Area */
.app-main {
    position: relative;
    flex: 1;
    overflow: hidden;
}

/* Map Layer */
.map-layer {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: var(--z-map);
}

.map-container {
    width: 100%;
    height: 100%;
}

/* Content Layer */
.content-layer {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: var(--z-content);
    pointer-events: none;
}

.content-layer > * {
    pointer-events: auto;
}

/* Sheet Container */
.sheet-container {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: var(--z-sheet);
    pointer-events: none;
}

.sheet-container > * {
    pointer-events: auto;
}

/* Tab Bar */
.app-tabbar {
    position: relative;
    height: calc(var(--tabbar-height) + var(--safe-area-bottom));
    padding-bottom: var(--safe-area-bottom);
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    z-index: var(--z-tabbar);
    flex-shrink: 0;
}

.tabbar-content {
    height: var(--tabbar-height);
    display: flex;
    align-items: center;
    justify-content: space-around;
    padding: 0 var(--spacing-md);
}

.tab-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
    min-width: var(--touch-target-min);
    min-height: var(--touch-target-min);
}

.tab-item.active {
    color: var(--color-primary);
}

.tab-icon {
    font-size: 24px;
    line-height: 1;
}

.tab-label {
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-medium);
}

/* Hidden class */
.hidden {
    display: none !important;
}

/* Visibility */
.invisible {
    visibility: hidden !important;
}

/* No scroll */
.no-scroll {
    overflow: hidden !important;
}