/* --- Feature 4: Navigation Sidebar Styles --- */

:root {
    --sidebar-bg: #1e293b;       /* Slate 800 */
    --sidebar-width: 280px;
    --header-height: 60px;
    --accent-color: #FFCC00;     /* Brand Yellow */
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --glass-border: rgba(255, 255, 255, 0.08);
}

/* 1. Header Area (Top Left) */
.main-header {
    display: flex;
    align-items: center;
    height: 50px;
    padding: 0 10px;
    margin-bottom: 10px;
}

.header-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-left: 15px;
    color: var(--accent-color);
    letter-spacing: 1px;
    text-transform: uppercase;
    font-family: 'Segoe UI', sans-serif;
}

/* 2. Hamburger Icon */
.hamburger {
    cursor: pointer;
    width: 30px;
    height: 30px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000; /* Above sidebar */
}

.hamburger .line {
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    display: block;
    position: absolute;
    transition: all 0.3s ease-in-out;
}

.hamburger .line:nth-child(1) { transform: translateY(-7px); }
.hamburger .line:nth-child(2) { opacity: 1; }
.hamburger .line:nth-child(3) { transform: translateY(7px); }

/* Hamburger Active State (X shape) */
.hamburger.is-active .line:nth-child(1) { transform: translateY(0) rotate(45deg); }
.hamburger.is-active .line:nth-child(2) { opacity: 0; }
.hamburger.is-active .line:nth-child(3) { transform: translateY(0) rotate(-45deg); }

/* 3. Navigation Drawer */
.navigation-drawer {
    position: fixed;
    top: 0;
    left: -280px; /* Hidden by default */
    width: 280px;
    height: 100vh;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--glass-border);
    box-shadow: 5px 0 25px rgba(0,0,0,0.5);
    z-index: 1500;
    padding-top: 80px; /* Space for hamburger */
    transition: transform 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
}

.navigation-drawer.active {
    transform: translateX(280px);
}

/* 4. Overlay (Darken background) */
.sidebar-overlay {
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(2px);
    z-index: 1400;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.sidebar-overlay.active {
    opacity: 1;
    pointer-events: all;
}

/* 5. Navigation Links */
.nav-list { list-style: none; padding: 0; margin: 0; }

.nav-section-title {
    padding: 20px 25px 8px 25px;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1.2px;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 25px;
    text-decoration: none;
    font-size: 0.95rem;
    color: var(--text-primary);
    border-left: 3px solid transparent; 
    transition: all 0.2s;
    opacity: 0.8;
}

.nav-link i { width: 20px; text-align: center; font-size: 1rem; }

.nav-link:hover { 
    background-color: rgba(255, 255, 255, 0.03);
    opacity: 1;
    color: #fff;
}

/* Active Link State */
.nav-link.active {
    background: linear-gradient(90deg, rgba(255, 204, 0, 0.1) 0%, transparent 100%);
    border-left-color: var(--accent-color);
    color: var(--accent-color);
    opacity: 1;
}
.nav-link.active i { color: var(--accent-color); }