:root {
    --primary: #FF6B35;
    --primary-light: #FF8F65;
    --primary-dark: #E55A2B;
    --secondary: #FF3366;
    --accent: #6C5CE7;
    --success: #00B894;
    --warning: #FDCB6E;
    --danger: #E17055;
    --info: #74B9FF;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FA;
    --bg-tertiary: #F0F2F5;
    --bg-hover: #E9ECEF;
    --bg-active: #DEE2E6;
    --text-primary: #1A1A2E;
    --text-secondary: #6C757D;
    --text-tertiary: #ADB5BD;
    --text-inverse: #FFFFFF;
    --border: #E9ECEF;
    --border-light: #F0F2F5;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    --shadow-xl: 0 16px 48px rgba(0,0,0,0.16);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s ease;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --sidebar-width: 72px;
    --panel-list-width: 340px;
    --chat-min-width: 400px;
}

[data-theme="dark"] {
    --bg-primary: #0D1117;
    --bg-secondary: #161B22;
    --bg-tertiary: #21262D;
    --bg-hover: #30363D;
    --bg-active: #3D444D;
    --text-primary: #E6EDF3;
    --text-secondary: #8B949E;
    --text-tertiary: #6E7681;
    --text-inverse: #0D1117;
    --border: #30363D;
    --border-light: #21262D;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.4);
    --shadow-xl: 0 16px 48px rgba(0,0,0,0.5);
}

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background var(--transition-normal), color var(--transition-normal);
}

.hidden { display: none !important; }

.loading-screen {
    position: fixed;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    z-index: 9999;
    animation: fadeIn 0.3s ease;
}

.loading-logo {
    width: 80px;
    height: 80px;
    margin-bottom: 16px;
}

.logo-svg {
    width: 100%;
    height: 100%;
    animation: logoPulse 2s ease-in-out infinite;
}

@keyframes logoPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.loading-text {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 24px;
}

.loading-bar {
    width: 200px;
    height: 3px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.loading-bar-inner {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: var(--radius-full);
    animation: loadingProgress 1.5s ease-in-out forwards;
}

@keyframes loadingProgress {
    0% { width: 0%; }
    50% { width: 70%; }
    100% { width: 100%; }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeOut {
    from { opacity: 1; }
    to { opacity: 0; }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(20px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-4px); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.btn-primary {
    width: 100%;
    padding: 14px 24px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    position: relative;
    overflow: hidden;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(255, 107, 53, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-link {
    background: none;
    border: none;
    color: var(--primary);
    font-size: 14px;
    cursor: pointer;
    padding: 8px 0;
    width: 100%;
    text-align: center;
    transition: color var(--transition-fast);
}

.btn-link:hover {
    color: var(--primary-dark);
}

.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

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

.icon-btn svg {
    width: 20px;
    height: 20px;
}

.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    padding: 12px 20px;
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--primary);
    animation: slideInRight 0.3s ease;
    font-size: 14px;
    max-width: 360px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--danger); }
.toast.warning { border-left-color: var(--warning); }

.btn-loader {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

.mobile-only { display: none; }

@media (max-width: 768px) {
    .mobile-only { display: flex; }
    :root {
        --sidebar-width: 0px;
        --panel-list-width: 100%;
    }
}