/* ═══════════════════════════════════════════════════════════
   NEXUS CAD - Premium Dark Theme Design System
   ═══════════════════════════════════════════════════════════ */

:root {
    /* Core palette */
    --bg-darkest: #0a0a14;
    --bg-darker: #0f0f1e;
    --bg-dark: #141428;
    --bg-medium: #1a1a35;
    --bg-light: #222244;
    --bg-lighter: #2a2a50;
    --bg-hover: #32325a;

    /* Accent colors */
    --accent-primary: #6C5CE7;
    --accent-secondary: #00B4D8;
    --accent-gradient: linear-gradient(135deg, #6C5CE7, #00B4D8);
    --accent-success: #00E676;
    --accent-warning: #FFB300;
    --accent-danger: #FF5252;
    --accent-info: #448AFF;

    /* Text colors */
    --text-primary: #E8E8F0;
    --text-secondary: #A0A0C0;
    --text-muted: #606080;
    --text-accent: #B0B0FF;

    /* Axis colors */
    --axis-x: #FF4444;
    --axis-y: #44FF44;
    --axis-z: #4488FF;

    /* Borders */
    --border-color: #2a2a4a;
    --border-light: #3a3a5a;
    --border-focus: #6C5CE7;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.6);
    --shadow-glow: 0 0 20px rgba(108,92,231,0.3);

    /* Dimensions */
    --menu-height: 36px;
    --toolbar-height: 44px;
    --panel-width: 280px;
    --status-height: 26px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;

    /* Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 10px;
}

/* ═══════════ Reset & Base ═══════════ */
*, *::before, *::after {
    margin: 0; padding: 0; box-sizing: border-box;
}

html, body {
    width: 100%; height: 100%;
    overflow: hidden;
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 13px;
    color: var(--text-primary);
    background: var(--bg-darkest);
    -webkit-font-smoothing: antialiased;
    user-select: none;
}

input, select, textarea, button {
    font-family: inherit;
    font-size: inherit;
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--bg-lighter); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent-primary); }

::selection { background: rgba(108,92,231,0.4); }

/* ═══════════ Auth Screen ═══════════ */
.screen { width: 100%; height: 100%; }

#auth-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-darkest);
    background-image:
        radial-gradient(ellipse at 20% 50%, rgba(108,92,231,0.08) 0%, transparent 60%),
        radial-gradient(ellipse at 80% 50%, rgba(0,180,216,0.08) 0%, transparent 60%);
}

.auth-container {
    width: 400px;
    padding: 40px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.auth-logo {
    text-align: center;
    margin-bottom: 32px;
}

.logo-icon {
    margin-bottom: 12px;
}

.auth-logo h1 {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 4px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.auth-subtitle {
    color: var(--text-muted);
    font-size: 12px;
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-top: 4px;
}

.auth-tabs {
    display: flex;
    gap: 0;
    margin-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
}

.auth-tab {
    flex: 1;
    padding: 10px;
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 13px;
    transition: var(--transition-fast);
    border-bottom: 2px solid transparent;
}

.auth-tab.active {
    color: var(--text-primary);
    border-bottom-color: var(--accent-primary);
}

.auth-form { display: none; }
.auth-form.active { display: block; }

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition-fast);
}

.form-group input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(108,92,231,0.2);
}

.form-group input::placeholder {
    color: var(--text-muted);
}

.btn-primary {
    width: 100%;
    padding: 12px;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-sm);
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-fast);
    margin-top: 8px;
}

.btn-primary:hover {
    opacity: 0.9;
    box-shadow: var(--shadow-glow);
}

.btn-ghost {
    width: 100%;
    padding: 10px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    margin-top: 8px;
}

.btn-ghost:hover {
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

.auth-error {
    color: var(--accent-danger);
    font-size: 12px;
    text-align: center;
    margin-top: 12px;
    min-height: 20px;
}

/* ═══════════ Menu Bar ═══════════ */
#menu-bar {
    height: var(--menu-height);
    background: var(--bg-darker);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 8px;
    z-index: 100;
}

.menu-left, .menu-right {
    display: flex;
    align-items: center;
    gap: 4px;
}

.menu-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.app-logo {
    display: flex;
    align-items: center;
    padding: 4px 8px;
}

.menu-items {
    display: flex;
    gap: 0;
}

.menu-dropdown {
    position: relative;
}

.menu-btn {
    padding: 6px 12px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.menu-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 220px;
    background: var(--bg-medium);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 4px;
    z-index: 1000;
}

.menu-dropdown:hover .dropdown-content {
    display: block;
}

.dropdown-content button {
    width: 100%;
    padding: 7px 12px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    text-align: left;
    cursor: pointer;
    border-radius: var(--radius-sm);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition-fast);
}

.dropdown-content button:hover {
    background: var(--accent-primary);
    color: white;
}

.shortcut {
    font-size: 11px;
    color: var(--text-muted);
    margin-left: 20px;
}

.dropdown-content button:hover .shortcut {
    color: rgba(255,255,255,0.7);
}

.dropdown-divider {
    height: 1px;
    background: var(--border-color);
    margin: 4px 8px;
}

.dropdown-submenu {
    position: relative;
}

.submenu-content {
    display: none;
    position: absolute;
    left: 100%;
    top: 0;
    min-width: 180px;
    background: var(--bg-medium);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 4px;
}

.dropdown-submenu:hover .submenu-content {
    display: block;
}

.project-title {
    font-size: 13px;
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    outline: none;
    transition: var(--transition-fast);
}

.project-title:hover {
    border-color: var(--border-color);
}

.project-title:focus {
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

.icon-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.icon-btn:hover {
    background: var(--bg-hover);
    color: var(--accent-secondary);
}

.icon-btn.active {
    background: rgba(108,92,231,0.2);
    color: var(--accent-primary);
}

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

.user-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 2px;
}

.user-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 12px;
    font-weight: 600;
}

.user-dropdown {
    display: none;
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    min-width: 200px;
    background: var(--bg-medium);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 4px;
    z-index: 1000;
}

.user-menu:hover .user-dropdown { display: block; }

.user-info {
    padding: 8px 12px;
    display: flex;
    flex-direction: column;
}

.user-info span:first-child { font-weight: 600; color: var(--text-primary); }
.user-email-display { font-size: 11px; color: var(--text-muted); margin-top: 2px; }

.user-dropdown button {
    width: 100%;
    padding: 7px 12px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    text-align: left;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.user-dropdown button:hover {
    background: var(--accent-primary);
    color: white;
}

/* ═══════════ Toolbar ═══════════ */
#toolbar {
    height: var(--toolbar-height);
    background: var(--bg-dark);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 12px;
    gap: 4px;
}

.tool-section {
    display: flex;
    gap: 2px;
    align-items: center;
}

.tool-divider {
    width: 1px;
    height: 28px;
    background: var(--border-color);
    margin: 0 8px;
}

.tool-btn {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
    position: relative;
}

.tool-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--border-color);
}

.tool-btn.active {
    background: rgba(108,92,231,0.15);
    color: var(--accent-primary);
    border-color: var(--accent-primary);
}

.snap-section {
    gap: 6px;
}

.snap-btn {
    width: auto;
    padding: 0 10px;
    gap: 4px;
}

.snap-label {
    font-size: 11px;
}

.snap-value {
    width: 56px;
    padding: 4px 6px;
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    text-align: center;
    outline: none;
}

.snap-value:focus {
    border-color: var(--accent-primary);
}

/* ═══════════ Main Content Layout ═══════════ */
#main-content {
    display: flex;
    height: calc(100vh - var(--menu-height) - var(--toolbar-height));
}

/* ═══════════ Viewport ═══════════ */
#viewport-container {
    flex: 1;
    position: relative;
    overflow: hidden;
    background: var(--bg-darkest);
}

#viewport {
    width: 100%;
    height: 100%;
    display: block;
    outline: none;
}

#viewport-controls {
    position: absolute;
    top: 12px;
    right: 12px;
    z-index: 10;
}

.view-cube {
    width: 80px;
    height: 80px;
    position: relative;
    perspective: 200px;
}

.cube-face {
    position: absolute;
    width: 26px;
    height: 26px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-medium);
    border: 1px solid var(--border-color);
    border-radius: 3px;
    font-size: 9px;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-fast);
    font-weight: 600;
}

.cube-face:hover {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
}

.cube-face.front { top: 27px; left: 27px; }
.cube-face.back { top: 0; left: 0; }
.cube-face.left { top: 27px; left: 0; }
.cube-face.right { top: 27px; right: 0; }
.cube-face.top { top: 0; left: 27px; }
.cube-face.bottom { bottom: 0; left: 27px; }

#viewport-status {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--status-height);
    background: var(--bg-darker);
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 12px;
    gap: 24px;
    font-size: 11px;
    color: var(--text-muted);
    z-index: 10;
}

#status-fps {
    margin-left: auto;
}

#gizmo-controls {
    position: absolute;
    top: 12px;
    left: 12px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    z-index: 10;
}

.gizmo-btn {
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-medium);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
}

.gizmo-btn:hover {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
}

/* ═══════════ AI Panel ═══════════ */
.ai-panel {
    position: fixed;
    right: calc(var(--panel-width) + 1px);
    top: calc(var(--menu-height) + var(--toolbar-height));
    width: 360px;
    height: calc(100vh - var(--menu-height) - var(--toolbar-height));
    background: var(--bg-dark);
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    z-index: 50;
    box-shadow: var(--shadow-lg);
}

.ai-panel.open {
    transform: translateX(0);
}

.ai-panel-header {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.ai-panel-header h3 {
    font-size: 14px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.close-btn {
    width: 24px;
    height: 24px;
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
}

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

.ai-chat {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.ai-message {
    padding: 10px 14px;
    border-radius: var(--radius-md);
    font-size: 13px;
    line-height: 1.5;
    max-width: 90%;
}

.ai-message.assistant {
    background: var(--bg-medium);
    color: var(--text-secondary);
    align-self: flex-start;
}

.ai-message.user {
    background: var(--accent-primary);
    color: white;
    align-self: flex-end;
}

.ai-message ul {
    margin: 8px 0 0 16px;
    list-style: disc;
}

.ai-message li { margin: 2px 0; }

.ai-input-container {
    padding: 12px;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 8px;
}

.ai-input {
    flex: 1;
    padding: 10px 14px;
    background: var(--bg-darker);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition-fast);
}

.ai-input:focus {
    border-color: var(--accent-primary);
}

.ai-input::placeholder {
    color: var(--text-muted);
}

.ai-send-btn {
    width: 40px;
    height: 40px;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.ai-send-btn:hover {
    opacity: 0.9;
    box-shadow: var(--shadow-glow);
}

/* ═══════════ Responsive ═══════════ */
@media (max-width: 1200px) {
    :root {
        --panel-width: 240px;
    }
}

@media (max-width: 900px) {
    .panel { display: none; }
    :root { --panel-width: 0px; }
}