:root {
    --bg-color: #f4f4f9;
    --text-color: #333;
    --container-bg: rgba(255, 255, 255, 0.4);
    --border-color: rgba(0, 0, 0, 0.1);
    --nav-bg: #007bff;
    --nav-text: white;
    --card-bg: rgba(255, 255, 255, 0.5);
    --card-border: rgba(0, 0, 0, 0.1);
    --btn-primary: #007bff;
    --btn-success: #28a745;
    --btn-danger: #dc3545;
    --btn-text: white;
    --grid-bg: rgba(0, 0, 0, 0.05);
    --today-bg: rgba(0, 123, 255, 0.1);
    --today-border: #007bff;
    --other-month: rgba(0, 0, 0, 0.02);
    --other-month-text: #6c757d;
    --header-bg: rgba(0, 0, 0, 0.05);
    --input-border: rgba(0, 0, 0, 0.2);
    --input-bg: rgba(255, 255, 255, 0.5);
    --input-text: #333;
    --pending-bg: rgba(255, 193, 7, 0.9);
    --pending-text: #333;
    --week-header-bg: rgba(0, 0, 0, 0.08);
    --week-header-text: #333;
    --bg-opacity: 0.6;
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --container-bg: rgba(30, 30, 30, 0.4);
    --border-color: rgba(255, 255, 255, 0.1);
    --nav-bg: rgba(34, 34, 34, 0.9);
    --nav-text: #e0e0e0;
    --card-bg: rgba(45, 45, 45, 0.5);
    --card-border: rgba(255, 255, 255, 0.1);
    --btn-primary: #3b82f6;
    --btn-success: #10b981;
    --btn-danger: #ef4444;
    --btn-text: #fff;
    --grid-bg: rgba(255, 255, 255, 0.05);
    --today-bg: rgba(59, 130, 246, 0.2);
    --today-border: #3b82f6;
    --other-month: rgba(255, 255, 255, 0.02);
    --other-month-text: #a0a0a0;
    --header-bg: rgba(255, 255, 255, 0.05);
    --input-border: rgba(255, 255, 255, 0.2);
    --input-bg: rgba(45, 45, 45, 0.5);
    --input-text: #e0e0e0;
    --pending-bg: rgba(245, 158, 11, 0.9);
    --pending-text: #111;
    --week-header-bg: rgba(255, 255, 255, 0.08);
    --week-header-text: #e0e0e0;
    --bg-opacity: 0.15;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    transition: background-color 0.3s, color 0.3s;
}

body::before {
    content: "";
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background-image: url('/static/img/bg.png');
    background-repeat: repeat;
    background-size: 300px;
    opacity: var(--bg-opacity);
    z-index: -1;
    pointer-events: none;
}

nav {
    background-color: var(--nav-bg);
    color: var(--nav-text);
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    display: flex;
    gap: 1rem;
    align-items: center;
}

nav a {
    color: var(--nav-text);
    text-decoration: none;
    font-weight: bold;
}

.container {
    max-width: 1400px;
    width: 95%;
    margin: 2rem auto;
    background: transparent;
    padding: 1rem;
    position: relative;
}

.narrow-container {
    max-width: 600px;
}

.login-container form div {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
}

input[type="text"], input[type="password"], input[type="number"], input[type="date"], select {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--input-border);
    background-color: var(--input-bg);
    color: var(--input-text);
    border-radius: 4px;
    box-sizing: border-box;
}

button {
    background-color: var(--btn-success);
    color: var(--btn-text);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
}

button.btn-primary {
    background-color: var(--btn-primary);
}

button.btn-danger {
    background-color: var(--btn-danger);
}

button:hover {
    opacity: 0.9;
}

.error {
    color: var(--btn-danger);
    margin-bottom: 1rem;
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: 1px solid var(--nav-text);
    color: var(--nav-text);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9em;
}