:root {
    --brown: #4a2c17;
    --brown-dark: #331e0f;
    --cream: #f5e6c8;
    --cream-dark: #e8d4a8;
    --ink: #2b2118;
    --danger: #a83232;
    --danger-bg: #fbe9e9;
    --radius: 10px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 1rem;
    max-width: 32rem;
    margin-inline: auto;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    font-size: 17px;
    line-height: 1.4;
    color: var(--ink);
    background: var(--cream);
}

h1 {
    font-size: 1.4rem;
    margin: 0.5rem 0 1rem;
    color: var(--brown-dark);
}

h2 {
    font-size: 1.15rem;
    margin: 0 0 0.75rem;
    color: var(--brown-dark);
}

a {
    color: var(--brown);
}

nav {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    margin: 1rem 0;
}

nav a {
    display: block;
    padding: 0.9rem 1rem;
    background: white;
    border: 1px solid var(--cream-dark);
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    color: var(--brown-dark);
}

nav a:active {
    background: var(--cream-dark);
}

form {
    display: flex;
    gap: 0.5rem;
    margin: 1rem 0;
}

label {
    display: block;
    margin: 0.75rem 0;
    font-weight: 600;
}

input[type="text"],
input[type="number"],
input[type="password"] {
    display: block;
    width: 100%;
    padding: 0.7rem 0.8rem;
    margin-top: 0.3rem;
    font-size: 1rem;
    border: 1px solid var(--cream-dark);
    border-radius: var(--radius);
    background: white;
    color: var(--ink);
}

form input[type="text"] {
    flex: 1 1 auto;
}

button {
    padding: 0.7rem 1.1rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius);
    background: var(--brown);
    color: white;
    cursor: pointer;
}

button:active {
    background: var(--brown-dark);
}

button:disabled {
    opacity: 0.6;
    cursor: default;
}

/* Client tabs, and a client list row's Save/Remove pair */
#client-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 1rem 0;
}

#client-tabs button {
    background: white;
    color: var(--brown-dark);
    border: 1px solid var(--cream-dark);
}

#client-tabs button:disabled {
    background: var(--brown);
    color: white;
    opacity: 1;
}

#client-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

#client-list li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 0;
    border-bottom: 1px solid var(--cream-dark);
}

#client-list li input[type="text"] {
    margin-top: 0;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    background: white;
    border-radius: var(--radius);
    overflow: hidden;
}

th,
td {
    text-align: left;
    padding: 0.5rem 0.6rem;
    border-bottom: 1px solid var(--cream-dark);
    font-size: 0.95rem;
}

th {
    background: var(--cream-dark);
    color: var(--brown-dark);
}

/* Inline validation/warning text next to a field, or a form-level error */
form p {
    margin: 0.2rem 0 0.5rem;
    font-size: 0.9rem;
    color: var(--danger);
}

form p:not([hidden]) {
    padding: 0.4rem 0.6rem;
    background: var(--danger-bg);
    border-radius: var(--radius);
}

/* Stacked login form, unlike the single-row add-client form */
#login-form {
    flex-direction: column;
    align-items: stretch;
}

#login-form label {
    margin-bottom: 0;
}

/* Six columns can be wider than a small phone: scroll the table sideways
   rather than squashing or clipping it. */
#history-table-container {
    overflow-x: auto;
}

details {
    margin: 1rem 0;
}

summary {
    font-weight: 600;
    cursor: pointer;
}