* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    font-size: 15px;
    line-height: 1.5;
    color: #1a1a1a;
    background: #f5f5f5;
    margin: 0;
    min-height: 100vh;
}

nav {
    background: #2c3e50;
    padding: 0.75rem 1.5rem;
}

nav a {
    color: #ecf0f1;
    text-decoration: none;
    margin-right: 1.25rem;
}

nav a:hover {
    color: #fff;
    text-decoration: underline;
}

main {
    max-width: 95%;
    margin: 0 auto;
    padding: 1.5rem;
    background: #fff;
    min-height: calc(100vh - 52px);
    box-shadow: 0 0 12px rgba(0,0,0,0.06);
}

h1 {
    margin: 0 0 1rem;
    font-size: 1.5rem;
    font-weight: 600;
}

input[type="text"],
input[type="number"],
input[type="password"],
input[type="date"],
input[type="file"],
select,
textarea {
    font: inherit;
    font-size: 0.9375rem;
    padding: 0.5rem 0.75rem;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    background: #fff;
    color: #1e293b;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    transition: border-color 0.15s, box-shadow 0.15s;
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

input::placeholder,
textarea::placeholder {
    color: #94a3b8;
}

textarea {
    min-height: 60px;
    resize: vertical;
}

select {
    cursor: pointer;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748b' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

button,
.btn {
    font: inherit;
    font-size: 0.9375rem;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 8px;
    background: #3498db;
    color: #fff;
    cursor: pointer;
    transition: background 0.15s;
    display: inline-block;
    text-decoration: none;
    text-align: center;
    line-height: 1.4;
}

button:hover,
.btn:hover {
    background: #2980b9;
}

button:disabled,
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-secondary {
    background: #e2e8f0;
    color: #334155;
}

.btn-secondary:hover {
    background: #cbd5e1;
}

.btn-danger {
    background: #dc2626;
    color: #fff;
}

.btn-danger:hover {
    background: #b91c1c;
}

.form-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
}

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

th, td {
    padding: 0.5rem 0.75rem;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

th {
    background: #f8f9fa;
    font-weight: 600;
}

tr:hover td {
    background: #fafafa;
}

code {
    font-size: 0.85em;
    background: #f0f0f0;
    padding: 0.15rem 0.35rem;
    border-radius: 3px;
    word-break: break-all;
}

a {
    color: #3498db;
}

a:hover {
    text-decoration: underline;
}