/* =========================
   RESET & GLOBALS
========================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root{
    --primary: #3498db;
    --primary-dark: #2980b9;
    --sidebar: #2c3e50;
    --sidebar-hover: #34495e;
    --bg: #f4f6f9;
    --white: #ffffff;
    --text: #333;
    --border: #dcdfe3;
    --shadow: 0 2px 8px rgba(0,0,0,0.08);
    --radius: 8px;
    --transition: 0.2s ease;
}

body {
    font-family: Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
}

/* =========================
   LAYOUT
========================= */
.wrapper {
    display: flex;
    min-height: 100vh;
}

.main {
    flex: 1;
    padding: 24px;
}

.container {
    width: min(1200px, 90%);
    margin: auto;
}

/* =========================
   SIDEBAR
========================= */
.sidebar {
    width: 240px;
    background: var(--sidebar);
    color: var(--white);
    padding: 20px 0;
    flex-shrink: 0;
}

.sidebar h2 {
    text-align: center;
    margin-bottom: 24px;
    font-size: 22px;
}

.sidebar a {
    display: block;
    color: var(--white);
    padding: 12px 20px;
    text-decoration: none;
    transition: background var(--transition);
}

.sidebar a:hover {
    background: var(--sidebar-hover);
}

/* =========================
   HEADER / NAV
========================= */
header {
    background: var(--sidebar);
    color: var(--white);
    padding: 16px 24px;
}

header h1 {
    font-size: 24px;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

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

/* =========================
   TYPOGRAPHY
========================= */
h3 {
    margin-bottom: 20px;
}

/* =========================
   LINKS
========================= */
a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

/* =========================
   CARDS / BOXES
========================= */
.card,
.form-box,
table,
form {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.card,
.form-box {
    padding: 20px;
}

/* =========================
   FORMS
========================= */
form {
    padding: 24px;
    max-width: 450px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
}

input,
textarea,
select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font: inherit;
    transition: border-color var(--transition);
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary);
}

/* =========================
   BUTTONS
========================= */
button,
.btn {
    display: inline-block;
    padding: 10px 18px;
    border: none;
    border-radius: 6px;
    background: var(--primary);
    color: var(--white);
    cursor: pointer;
    transition: background var(--transition);
    font: inherit;
}

button:hover,
.btn:hover {
    background: var(--primary-dark);
}

/* =========================
   TABLES
========================= */
table {
    width: 100%;
    border-collapse: collapse;
    overflow: hidden;
}

th,
td {
    padding: 14px 16px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

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

tr:hover {
    background: #f8f9fb;
}

/* =========================
   GRID
========================= */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

/* =========================
   ALERTS
========================= */
.alert {
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 16px;
    color: var(--white);
}

.alert-success {
    background: #2ecc71;
}

.alert-error {
    background: #e74c3c;
}

/* =========================
   FOOTER
========================= */
footer {
    margin-top: 40px;
    padding: 20px;
    text-align: center;
    background: var(--sidebar);
    color: var(--white);
}

/* =========================
   RESPONSIVE
========================= */
@media (max-width: 768px) {

    .wrapper {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        display: flex;
        flex-wrap: wrap;
        padding: 10px;
    }

    .sidebar h2 {
        width: 100%;
        margin-bottom: 12px;
    }

    .sidebar a {
        flex: 1 1 50%;
        text-align: center;
    }

    nav {
        flex-direction: column;
        gap: 12px;
    }

    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }

    .main {
        padding: 16px;
    }
}