:root {
    --bg-color: #f6f8f9;
    --text-color: #151b26;
    --text-muted: #6d6e6f;
    --border-color: #e8ecee;
    --primary-color: #f06a6a;
    --primary-hover: #e05b5b;
    --secondary-bg: #ffffff;
    --nav-bg: #2a2b2c;
    --nav-text: #ffffff;
    --nav-text-muted: #a2a2a2;
    --nav-hover: #3b3c3d;
    --status-todo: #e8ecee;
    --status-in-progress: #008cc9;
    --status-review: #f5a623;
    --status-done: #00875a;
    --status-archive: #909399;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 14px;
    line-height: 1.5;
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Sidebar Navigation */
.sidebar {
    width: 240px;
    background-color: var(--nav-bg);
    color: var(--nav-text);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.sidebar-header {
    padding: 20px;
    font-weight: 600;
    font-size: 16px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-nav {
    flex: 1;
    padding: 10px 0;
}

.sidebar-nav a {
    display: block;
    padding: 10px 20px;
    color: var(--nav-text-muted);
    text-decoration: none;
    transition: all 0.2s;
}

.sidebar-nav a:hover, .sidebar-nav a.active {
    background-color: var(--nav-hover);
    color: var(--nav-text);
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.user-info {
    margin-bottom: 10px;
    font-size: 13px;
    color: var(--nav-text-muted);
}

.logout-btn {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 13px;
}

/* Main Content Area */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.topbar {
    height: 60px;
    background-color: var(--secondary-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 20px;
    justify-content: space-between;
}

.page-title {
    font-size: 20px;
    font-weight: 500;
}

.content-wrapper {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
}

/* UI Elements */
.btn {
    display: inline-block;
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    border: 1px solid transparent;
    transition: background-color 0.2s;
}

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

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

.btn-secondary {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-color);
}

.btn-secondary:hover {
    background-color: var(--bg-color);
}

.btn-danger {
    background-color: #e11d48;
    color: white;
}

.card {
    background-color: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

/* Forms */
.form-group {
    margin-bottom: 15px;
}

.form-label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    color: var(--text-muted);
}

.form-control {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 14px;
    transition: border-color 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Tables */
.table {
    width: 100%;
    border-collapse: collapse;
}

.table th, .table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    font-weight: 500;
    color: var(--text-muted);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.table tr:hover {
    background-color: var(--bg-color);
}

/* Login Page Specific */
.login-page {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-color);
}

.login-card {
    width: 100%;
    max-width: 400px;
}

.error-msg {
    color: #e11d48;
    background-color: #ffe4e6;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 15px;
    font-size: 13px;
}

.success-msg {
    color: #00875a;
    background-color: #e3fcef;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 15px;
    font-size: 13px;
}