/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700&display=swap');

:root {
    --bg-color: #0f172a;
    --sidebar-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --card-bg: #1e293b;
    --sidebar-width: 260px;
    --sidebar-collapsed-width: 80px;
    --header-height: 70px;
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--accent-hover);
}

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

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    padding: 20px;
    transition: width var(--transition-speed) ease;
    position: fixed;
    height: 100vh;
    z-index: 100;
}

.sidebar.collapsed {
    width: var(--sidebar-collapsed-width);
}

.brand {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 40px;
    display: flex;
    align-items: center;
    gap: 10px;
    overflow: hidden;
    white-space: nowrap;
}

.brand span {
    transition: opacity var(--transition-speed);
}

.sidebar.collapsed .brand span {
    opacity: 0;
    width: 0;
}

.nav-links {
    list-style: none;
    flex-grow: 1;
}

.nav-links li {
    margin-bottom: 10px;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px;
    border-radius: 8px;
    color: var(--text-secondary);
    transition: background 0.2s, color 0.2s;
    white-space: nowrap;
    overflow: hidden;
}

.nav-links a:hover, .nav-links a.active {
    background-color: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.nav-icon {
    font-size: 1.2rem;
    min-width: 24px;
    text-align: center;
}

/* Sidebar Toggle */
.toggle-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.5rem;
    margin-bottom: 20px;
    align-self: flex-start;
}

/* Main Content */
.main-content {
    flex-grow: 1;
    margin-left: var(--sidebar-width);
    transition: margin-left var(--transition-speed) ease;
    padding: 40px;
    max-width: 1200px;
}

.sidebar.collapsed + .main-content {
    margin-left: var(--sidebar-collapsed-width);
}

/* Header */
header {
    margin-bottom: 40px;
    animation: fadeIn 0.8s ease-out;
}

header h1 {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(to right, var(--accent-color), #a855f7);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 15px;
}

header p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
}

/* Cards / Sections */
section {
    background: var(--card-bg); /* Fallback */
    background: linear-gradient(135deg, rgba(30, 41, 59, 0.8), rgba(15, 23, 42, 0.8));
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    transition: transform 0.2s;
}

section:hover {
    transform: translateY(-2px);
}

section h2 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--text-primary);
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 10px;
}

/* List Styles */
ul {
    list-style: none;
}

ul li {
    margin-bottom: 15px;
    padding-left: 20px;
    position: relative;
}

ul li::before {
    content: "•";
    color: var(--accent-color);
    font-weight: bold;
    position: absolute;
    left: 0;
}

footer {
    margin-top: 60px;
    color: var(--text-secondary);
    text-align: center;
    font-size: 0.9rem;
    padding-bottom: 20px;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --sidebar-width: 250px; /* Full width mobile sidebar */
    }

    .app-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        padding: 15px 20px;
    }
    
    .sidebar.collapsed {
        width: 100%; /* Don't collapse width on mobile like desktop */
    }

    .nav-links {
        display: none; /* Hide links by default on mobile, show via JS/menu logic if needed, but for now simple stacking */
    }
    
    /* Simplified Mobile Navigation for this task: Sidebar becomes a top header */
    .toggle-btn {
        display: none; /* Hide toggle on mobile for simplicity, or implement hamburger */
    }

    .brand {
        margin-bottom: 0;
    }

    .sidebar .nav-links {
         /* Keep it simple for reliable mobile view without complex hamburger JS logic initially unless requested */
         display: flex;
         gap: 15px;
    }
    
    .sidebar .nav-links li {
        margin-bottom: 0;
    }
    
    .sidebar .nav-links a span {
        display: none; /* Icons only on mobile top bar */
    }

    .main-content {
        margin-left: 0;
        padding: 20px;
    }

    .sidebar.collapsed + .main-content {
        margin-left: 0;
    }

    header h1 {
        font-size: 2rem;
    }
}