/* ==========================================================================
   Layout Styles - Header, Sidebar, Main Content Area
   ========================================================================== */

/* --- Header Bar --- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--header-bg);
    color: var(--header-text);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1rem;
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.sidebar-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: none;
    background: none;
    color: #cbd5e1;
    font-size: 1.25rem;
    cursor: pointer;
    border-radius: var(--radius);
    transition: background-color var(--transition);
}

.sidebar-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.header-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: #fff;
    text-decoration: none;
}

.header-logo:hover {
    color: #fff;
    text-decoration: none;
}

.header-logo img {
    height: 28px;
    width: auto;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-countdowns {
    display: flex;
    gap: 0.75rem;
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.7);
}

.countdown-item {
    display: none; /* 由 JS 控制顯示 */
    align-items: center;
    gap: 0.25rem;
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.1);
    white-space: nowrap;
}

#cd-session.cd-show {
    cursor: pointer;
    user-select: none;
}

#cd-session.cd-show:hover {
    background: rgba(255, 255, 255, 0.2);
}

.countdown-item.cd-show {
    display: inline-flex;
}

.countdown-item.cd-urgent {
    color: #fbbf24;
    background: rgba(251, 191, 36, 0.15);
}

.countdown-item.cd-critical {
    color: #f87171;
    background: rgba(248, 113, 113, 0.15);
    animation: cd-blink 1s infinite;
}

@keyframes cd-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

/* --- Session 警告：全頁紅框 + Header 閃爍 --- */
body.session-urgent::before,
body.session-critical::before {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9998;
    box-shadow: inset 0 0 0 4px #ef4444;
}

body.session-critical::before {
    animation: border-pulse 0.5s infinite;
}

body.session-critical .header {
    animation: header-flash 0.5s infinite;
}

@keyframes border-pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

@keyframes header-flash {
    0%, 100% { background-color: var(--header-bg); }
    50% { background-color: #dc2626; }
}

/* --- User Settings Button & Panel --- */
.user-settings-wrap {
    position: relative;
}

.header-icon-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: none;
    background: none;
    color: #cbd5e1;
    font-size: 1.2rem;
    cursor: pointer;
    border-radius: var(--radius);
    transition: background-color var(--transition);
}

.header-icon-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: #fff;
}

#btn-pin-page.pin-active {
    color: #f59e0b;
}

.user-settings-panel {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 0.25rem;
    min-width: 220px;
    background-color: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: all var(--transition);
    z-index: 1010;
    padding: 0.75rem;
}

.user-settings-wrap.open .user-settings-panel {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.settings-panel-title {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border);
}

.settings-item {
    margin-bottom: 0.5rem;
}

.settings-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.375rem;
}

.font-size-options {
    display: flex;
    gap: 0.25rem;
}

.font-size-btn {
    flex: 1;
    padding: 0.35rem 0;
    font-size: 0.8125rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-white);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
    text-align: center;
}

.font-size-btn:hover {
    background: var(--bg);
    color: var(--text);
}

.font-size-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}

/* --- User Dropdown --- */
.user-dropdown {
    position: relative;
}

.user-dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0.75rem;
    border: none;
    background: none;
    color: #e2e8f0;
    cursor: pointer;
    border-radius: var(--radius);
    transition: background-color var(--transition);
    font-size: 0.875rem;
}

.user-dropdown-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.user-avatar {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background-color: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8125rem;
    font-weight: 600;
}

.user-dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 0.25rem;
    min-width: 180px;
    background-color: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: all var(--transition);
    z-index: 1010;
}

.user-dropdown.open .user-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.user-dropdown-menu a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    color: var(--text);
    font-size: 0.875rem;
    transition: background-color var(--transition);
}

.user-dropdown-menu a:hover {
    background-color: var(--bg);
    text-decoration: none;
}

.user-dropdown-menu .divider {
    height: 1px;
    background-color: var(--border);
    margin: 0.25rem 0;
}

/* --- Sidebar --- */
.sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--sidebar-border);
    overflow-y: auto;
    overflow-x: hidden;
    z-index: 900;
    transition: width 0.25s ease, transform 0.25s ease;
}

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

.sidebar::-webkit-scrollbar-thumb {
    background-color: var(--sidebar-section-text);
    border-radius: 2px;
}

/* --- Sidebar Tabs --- */
.sidebar-tabs {
    display: flex;
    justify-content: center;
    gap: 0.25rem;
    padding: 0.5rem;
    border-bottom: 1px solid var(--sidebar-border);
}

.sidebar-tabs--hidden {
    display: none;
}

.sidebar-tab {
    width: 2.25rem;
    height: 2.25rem;
    padding: 0;
    font-size: 1.1rem;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--sidebar-tab-border);
    background: var(--sidebar-hover-bg);
    color: var(--sidebar-text);
    border-radius: var(--radius);
    cursor: pointer;
    white-space: nowrap;
}

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

.sidebar-tab.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* --- Sidebar Menu --- */
.sidebar-menu {
    padding: 0.5rem 0;
}

.menu-section {
    margin-bottom: 0.25rem;
}

.menu-section-title {
    padding: 0.75rem 1rem 0.375rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--sidebar-section-text);
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1rem;
    margin: 1px 0.5rem;
    color: var(--sidebar-text);
    font-size: 0.875rem;
    border-radius: var(--radius);
    transition: all var(--transition);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;
}

.menu-item:hover {
    background-color: var(--sidebar-hover-bg);
    color: var(--sidebar-active-text);
    text-decoration: none;
}

.menu-item.active {
    background-color: var(--sidebar-active-bg);
    color: var(--sidebar-active-text);
    font-weight: 500;
}

.menu-item-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    font-size: 1rem;
}

.menu-item-text {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
}

.menu-item-badge {
    background-color: var(--danger);
    color: #fff;
    font-size: 0.6875rem;
    padding: 0.1rem 0.4rem;
    border-radius: 10px;
    font-weight: 600;
    min-width: 18px;
    text-align: center;
}

/* --- Sidebar Collapsed State --- */
.sidebar-collapsed .sidebar {
    transform: translateX(-100%);
}

.sidebar-collapsed .main-content {
    margin-left: 0;
}

/* --- Main Content Area --- */
.main-content {
    margin-left: var(--sidebar-width);
    margin-top: var(--header-height);
    padding: 1.5rem;
    min-height: calc(100vh - var(--header-height));
    transition: margin-left 0.25s ease;
}


.page-title {
    font-size: 1.375rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
    color: var(--text);
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    margin-bottom: 1rem;
    font-size: 0.8125rem;
    color: var(--text-light);
}

.breadcrumb a {
    color: var(--text-secondary);
}

.breadcrumb a:hover {
    color: var(--primary);
}

.breadcrumb-separator {
    color: var(--border-dark);
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        width: var(--sidebar-width);
        box-shadow: none;
    }

    .sidebar-open .sidebar {
        transform: translateX(0);
        box-shadow: var(--shadow-lg);
    }

    .main-content {
        margin-left: 0;
    }

    .main-content::after {
        left: 1.5rem;
    }

    .sidebar-collapsed .main-content {
        margin-left: 0;
    }

    /* Overlay when sidebar is open on mobile */
    .sidebar-overlay {
        display: none;
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background-color: rgba(0, 0, 0, 0.3);
        z-index: 899;
    }

    .sidebar-open .sidebar-overlay {
        display: block;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 1rem;
    }

    .header {
        padding: 0 0.75rem;
    }

    .user-dropdown-toggle span {
        display: none;
    }
}