:root {
    --bg-color: #fff;
    --text-color: #000;
    --accent: #007bff;
    --loader-color: #007bff;
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #fff;
    --accent: #0d6efd;
    --loader-color: #0d6efd;
}

body {
    background: var(--bg-color);
    color: var(--text-color);
    font-family: Arial, sans-serif;
    display: flex;
    margin: 0;
    position: relative;
}

.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    text-align: center;
}

.login-btn {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    background: var(--accent);
    color: white;
    text-decoration: none;
    border-radius: 5px;
    font-size: 1.2rem;
}

.login-btn:hover {
    background: darken(var(--accent), 10%);
}

.sidebar {
    width: 250px;
    background: var(--accent);
    color: white;
    height: 100vh;
    padding: 1rem;
}

.sidebar ul {
    list-style: none;
    padding: 0;
}

.sidebar a {
    color: white;
    display: block;
    padding: 0.5rem;
    text-decoration: none;
}

.sidebar a:hover {
    background: darken(var(--accent), 10%);
}

.sidebar button {
    margin-top: 1rem;
    padding: 0.5rem;
    background: var(--bg-color);
    color: var(--accent);
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

.content {
    flex: 1;
    padding: 2rem;
    position: relative;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

th, td {
    border: 1px solid var(--text-color);
    padding: 0.5rem;
    text-align: left;
}

form {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

input[type="text"], select {
    padding: 0.5rem;
    border: 1px solid var(--text-color);
    border-radius: 5px;
}

button {
    padding: 0.5rem 1rem;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button:hover {
    background: darken(var(--accent), 10%);
}

/* Loader (Z4drus/horrible-cow-36) */
.loader {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: none;
    width: 80px;
    height: 80px;
    border: 8px solid var(--loader-color);
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s linear infinite;
    z-index: 1000;
}

.loader.show {
    display: block;
}

@keyframes spin {
    to {
        transform: translate(-50%, -50%) rotate(360deg);
    }
}

/* Button (neerajbaniwal/hungry-mule-59, modified) */
.deadline-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 150px;
    height: 50px;
    border-radius: 25px;
    background: var(--accent);
    border: 2px solid var(--text-color);
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-color);
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
}

.deadline-btn:hover {
    background: darken(var(--accent), 10%);
    transform: scale(1.05);
}

@media (max-width: 768px) {
    body {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        height: auto;
    }
    .deadline-btn {
        width: 120px;
        height: 40px;
        font-size: 1.2rem;
    }
}