:root {
    /* Light Theme Variables */
    --bg-app: #ffffff;
    --bg-sidebar: #ffffff;
    --bg-card: #ffffff;
    --border-color: #eaecf0;
    --text-primary: #101828;
    --text-secondary: #475467;
    --text-muted: #98a2b3;
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #eef2ff;
    --danger: #d92d20;
    --danger-light: #fee4e2;
    --success: #027a48;
    --success-light: #ecfdf3;
    --warning: #b54708;
    --warning-light: #fffaeb;
    --row-hover: #f9fafb;
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-card: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.025);
    --hero-gradient: linear-gradient(135deg, #4f46e5 0%, #3b82f6 100%);
    --card-border-radius: 12px;
    --scrollbar-track: transparent;
    --scrollbar-thumb: #d1d5db;
}

body.dark-mode {
    /* Dark Theme Variables */
    --bg-app: #0f1115;
    --bg-sidebar: #161920;
    --bg-card: #1c1f26;
    --border-color: #2a2e37;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --primary: #6366f1;
    --primary-hover: #818cf8;
    --primary-light: rgba(99, 102, 241, 0.15);
    --danger: #ef4444;
    --danger-light: rgba(239, 68, 68, 0.15);
    --success: #10b981;
    --success-light: rgba(16, 185, 129, 0.15);
    --warning: #f59e0b;
    --warning-light: rgba(245, 158, 11, 0.15);
    --row-hover: #22262f;
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-card: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --hero-gradient: linear-gradient(135deg, #1e1b4b 0%, #172554 100%);
    --scrollbar-thumb: #374151;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-app);
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
    overflow: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--scrollbar-track); }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Layout */
.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Sidebar */
.sidebar {
    width: 270px;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 24px 0;
    transition: background-color 0.3s ease, border-color 0.3s ease;
    z-index: 10;
}

.sidebar-header {
    padding: 0 24px 32px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 22px;
    font-weight: 800;
    color: #03285c;
    letter-spacing: -0.5px;
    cursor: pointer;
}
.dark-mode .logo { color: var(--text-primary); }

.logo-icon {
    color: var(--primary);
}

.sidebar-section {
    padding: 0 16px;
    margin-bottom: 24px;
}

.section-title {
    font-size: 11px;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1.2px;
    margin-bottom: 12px;
    padding-left: 8px;
}

.sidebar-menu {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.sidebar-menu li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 500;
    font-size: 15px;
    color: var(--text-secondary);
    transition: all 0.2s ease;
}

.sidebar-menu li:hover {
    background-color: var(--row-hover);
    color: var(--text-primary);
}

.sidebar-menu li.active {
    background-color: var(--primary-light);
    color: var(--primary);
    font-weight: 600;
}

.shortcut-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding-left: 8px;
    padding-right: 8px;
}

.shortcut-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 14px;
    color: var(--text-secondary);
    cursor: pointer;
}
.shortcut-item:hover { color: var(--text-primary); }

.keys {
    display: flex;
    gap: 6px;
}

kbd {
    background-color: var(--bg-app);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 2px 6px;
    font-size: 12px;
    font-family: inherit;
    color: var(--text-muted);
    box-shadow: 0 1px 1px rgba(0,0,0,0.05);
}

.sidebar-footer {
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 0 24px;
    margin-top: auto;
}

.theme-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    background: transparent;
    border: 1.5px solid var(--text-primary);
    color: var(--text-primary);
    padding: 10px 16px;
    border-radius: 12px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 500;
    transition: all 0.2s ease;
    width: 100%;
}
.theme-btn:hover {
    background-color: var(--text-primary);
    color: var(--bg-card);
}
.dark-mode .theme-btn {
    border-color: var(--border-color);
}
.dark-mode .theme-btn:hover {
    background-color: var(--row-hover);
    color: var(--text-primary);
}

.clear-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    background: transparent;
    border: none;
    color: var(--danger);
    padding: 4px 16px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 500;
    transition: all 0.2s ease;
}
.clear-btn:hover {
    background-color: var(--danger-light);
    border-radius: 8px;
    padding: 10px 16px;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 0 0 0;
    margin-top: 8px;
    border-top: 1px solid var(--border-color);
    cursor: pointer;
}
.user-profile:hover .user-info strong {
    color: var(--primary);
}

.avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
}

.user-info {
    display: flex;
    flex-direction: column;
    font-size: 14px;
}

.user-info strong {
    color: var(--text-primary);
}

.user-info span {
    color: var(--text-muted);
    font-size: 12px;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    position: relative;
    background-color: #f9fafb;
}
.dark-mode .main-content { background-color: var(--bg-app); }

.top-header {
    height: 72px;
    min-height: 72px;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
    transition: background-color 0.3s ease, border-color 0.3s ease;
    position: sticky;
    top: 0;
    z-index: 5;
}

.breadcrumbs {
    display: flex;
    align-items: center;
    font-size: 16px;
    gap: 12px;
}
.breadcrumbs .text-muted { color: var(--text-muted); font-weight: 500; }
.breadcrumbs .separator { color: var(--border-color); font-size: 18px; }
.breadcrumbs .text-strong { font-weight: 600; color: #03285c; }
.dark-mode .breadcrumbs .text-strong { color: var(--text-primary); }

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.search-bar-mock {
    display: flex;
    align-items: center;
    gap: 10px;
    background-color: #f3f4f6;
    border: 1px solid transparent;
    border-radius: 8px;
    padding: 8px 16px;
    width: 280px;
    cursor: pointer;
    transition: all 0.2s;
}
.dark-mode .search-bar-mock { background-color: var(--row-hover); }
.search-bar-mock:hover {
    border-color: var(--border-color);
}

.search-bar-mock svg {
    color: var(--text-muted);
}

.search-bar-mock input {
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 14px;
    width: 100%;
}

.header-status-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    background-color: #d1fae5;
    padding: 4px 6px 4px 10px;
    border-radius: 20px;
    cursor: pointer;
}
.dark-mode .header-status-badge { background-color: rgba(16, 185, 129, 0.2); }

.header-status-badge .dot {
    width: 6px;
    height: 6px;
    background-color: #059669;
    border-radius: 50%;
}

.header-status-badge .status-inner {
    background-color: #2563eb;
    color: white;
    font-size: 12px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 12px;
}

.dashboard-content {
    padding: 32px 40px;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Hero Banner */
.hero-card {
    position: relative;
    border-radius: var(--card-border-radius);
    overflow: hidden;
    padding: 40px;
    box-shadow: var(--shadow-card);
    display: flex;
    flex-direction: column;
    justify-content: center;
    border: 1px solid var(--border-color);
}

.hero-bg {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: var(--hero-gradient);
    opacity: 0.05;
    z-index: 0;
    transition: background 0.3s ease;
}
.hero-card { background-color: var(--bg-card); }

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
}

.hero-label {
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--primary);
    margin-bottom: 20px;
}

.current-page-display {
    font-size: 42px;
    font-weight: 800;
    color: var(--text-primary);
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    word-break: break-all;
    animation: fadeIn 0.4s ease-out;
    letter-spacing: -1px;
}

.empty-state {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 28px;
    letter-spacing: -0.5px;
}

/* Action Card */
.action-card {
    background-color: var(--bg-card);
    border-radius: var(--card-border-radius);
    padding: 28px;
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 20px;
    transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.card-header-inner h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}

.card-header-inner .text-muted {
    font-size: 14px;
}

.action-inputs {
    display: flex;
    gap: 16px;
}

.input-group {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 12px;
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 0 16px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.input-group:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.protocol {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 15px;
}

.input-group input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    padding: 16px 0;
    font-size: 16px;
    color: var(--text-primary);
    font-weight: 500;
}

.primary-btn {
    background-color: var(--primary);
    color: #ffffff;
    border: none;
    border-radius: 10px;
    padding: 0 28px;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.4);
}

.primary-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 8px -1px rgba(79, 70, 229, 0.5);
}

.primary-btn:active {
    transform: translateY(1px);
    box-shadow: 0 2px 4px -1px rgba(79, 70, 229, 0.4);
}

.controls-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.nav-controls {
    display: flex;
    gap: 16px;
}

.control-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-soft);
}

.control-btn:hover:not(:disabled) {
    border-color: var(--text-secondary);
    background-color: var(--row-hover);
}

.control-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    background-color: var(--bg-app);
    box-shadow: none;
}

.control-btn:active:not(:disabled) {
    transform: scale(0.97);
}

.controls-hint {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
}

/* Stacks Area */
.stacks-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.stack-card {
    background-color: var(--bg-card);
    border-radius: var(--card-border-radius);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    height: 450px;
}

.stack-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--bg-card);
}

.header-title h3 {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
}

.badge {
    background-color: var(--primary-light);
    color: var(--primary);
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 13px;
    font-weight: 700;
}

.table-container {
    flex: 1;
    overflow-y: auto;
}

.stack-table {
    width: 100%;
    border-collapse: collapse;
}

.stack-table th {
    text-align: left;
    padding: 16px 24px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    background-color: rgba(var(--bg-card), 0.95);
    backdrop-filter: blur(4px);
    z-index: 2;
}

.stack-table td {
    padding: 16px 24px;
    font-size: 14px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

.stack-table tbody tr {
    transition: background-color 0.2s ease, transform 0.2s ease;
    animation: slideIn 0.3s ease-out forwards;
}

.stack-table tbody tr:hover:not(:has(.empty-row)) {
    background-color: var(--row-hover);
}

.stack-table td:first-child { width: 60px; color: var(--text-muted); font-weight: 500; }
.stack-table td:nth-child(2) { font-weight: 600; }

.type-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
}

.type-badge.push { background-color: var(--success-light); color: var(--success); }
.type-badge.pop { background-color: var(--warning-light); color: var(--warning); }
.type-badge.current { background-color: var(--primary-light); color: var(--primary); }

.empty-row {
    text-align: center !important;
    color: var(--text-muted) !important;
    padding: 60px 24px !important;
    font-size: 14px;
}

/* Toast System */
.toast-container {
    position: fixed;
    bottom: 32px;
    right: 32px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    z-index: 1000;
    pointer-events: none;
}

.toast {
    background-color: var(--text-primary);
    color: var(--bg-sidebar);
    padding: 16px 24px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 12px;
    transform: translateY(100%);
    opacity: 0;
    animation: toastIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.toast.error {
    background-color: var(--danger);
    color: #ffffff;
}

.toast svg {
    flex-shrink: 0;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-15px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes toastIn {
    to { transform: translateY(0); opacity: 1; }
}

@keyframes toastOut {
    to { transform: translateY(20px); opacity: 0; }
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4); }
    70% { box-shadow: 0 0 0 6px rgba(16, 185, 129, 0); }
    100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}