/* ===== CSS Variables - Enterprise SaaS Theme ===== */
:root {
    --primary-dark: #0F172A;
    --primary: #1E3A5F;
    --primary-light: #334155;
    --accent-gold: #F59E0B;
    --accent-gold-light: #FBBF24;
    --accent-gold-dim: rgba(245, 158, 11, 0.15);
    --bg-primary: #F8FAFC;
    --bg-secondary: #FFFFFF;
    --bg-glass: rgba(255, 255, 255, 0.7);
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    --border-light: rgba(148, 163, 184, 0.2);
    --border-medium: rgba(148, 163, 184, 0.3);
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
    --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 12px 40px rgba(15, 23, 42, 0.12);
    --shadow-glow: 0 0 40px rgba(245, 158, 11, 0.15);
    --level-operation: #10B981;
    --level-analysis: #3B82F6;
    --level-strategy: #8B5CF6;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    --sidebar-width: 240px;
    --nav-height: 64px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

/* ===== Fixed Navigation ===== */
.nav-fixed {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    height: var(--nav-height);
}
.nav-container {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}
.nav-brand {
    font-size: 1rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.95);
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.nav-brand::before { content: '◆'; color: var(--accent-gold); }

/* Company Info */
.nav-company {
    display: flex;
    align-items: center;
    gap: 12px;
}
.nav-company-logo {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--accent-gold), var(--accent-gold-light));
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    color: var(--primary-dark);
    font-weight: bold;
}
.nav-company-name {
    font-size: 0.9rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
}
.nav-divider {
    width: 1px;
    height: 24px;
    background: rgba(255, 255, 255, 0.2);
    margin: 0 8px;
}

/* User Profile */
.nav-user {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 6px 12px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition-fast);
}
.nav-user:hover {
    background: rgba(255, 255, 255, 0.12);
}
.nav-user-avatar {
    width: 28px;
    height: 28px;
    background: linear-gradient(135deg, #60A5FA, #3B82F6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    color: #fff;
}
.nav-user-info {
    display: flex;
    flex-direction: column;
}
.nav-user-name {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}
.nav-user-role {
    font-size: 0.7rem;
    color: var(--accent-gold);
}
.nav-stats {
    display: flex;
    gap: 24px;
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.7);
}
.nav-stat { display: flex; align-items: center; gap: 6px; }
.nav-stat strong { color: var(--accent-gold); font-weight: 600; }
@media (max-width: 900px) { .nav-stats { display: none; } .nav-user-info { display: none; } }

/* ===== Footer ===== */
.footer {
    margin-left: var(--sidebar-width);
    padding: 40px;
    text-align: center;
    border-top: 1px solid var(--border-light);
    background: var(--bg-secondary);
}
.footer-brand {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 8px;
}
.footer-brand::before { content: '◆ '; color: var(--accent-gold); }
.footer-desc {
    font-size: 0.85rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Buttons ===== */
.skill-chat-btn {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
}
.skill-chat-btn:hover {
    background: var(--accent-gold);
    color: var(--primary-dark);
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ===== Utility Classes ===== */
.hidden { display: none !important; }
.text-center { text-align: center; }