:root {
    --primary: #2563eb;
    --bg: #f8fafc;
    --card: #ffffff;
    --text: #0f172a;
    --muted: #64748b;
    --border: #e5e7eb;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont;
    background: var(--bg);
    color: var(--text);
}

/* HEADER */
.header {
    background: linear-gradient(135deg, #2563eb, #1e40af);
    color: white;
    padding: 18px 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    width: 38px;
    height: 38px;
    border-radius: 10px;
}

.header h1 {
    font-size: 18px;
    font-weight: 600;
    margin: 0;
}

/* TABS */
.tabs {
    display: flex;
    background: var(--card);
    border-bottom: 1px solid var(--border);
}

.tab {
    flex: 1;
    padding: 12px 0;
    background: transparent;
    border: none;
    font-size: 14px;
    font-weight: 500;
    color: var(--muted);
    cursor: pointer;
}

.tab.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
}

/* CARD */
.card {
    max-width: 420px;
    margin: 16px auto;
    background: var(--card);
    padding: 18px;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(15, 23, 42, 0.06);
}

h3 {
    font-size: 16px;
    margin: 0 0 12px 0;
    font-weight: 600;
}

/* FORM */
label {
    font-size: 12px;
    font-weight: 500;
    color: var(--muted);
    margin-top: 12px;
    display: block;
}

input {
    width: 100%;
    padding: 10px 12px;
    margin-top: 4px;
    font-size: 14px;
    border-radius: 10px;
    border: 1px solid var(--border);
    outline: none;
    background: #ffffff;
}

input:focus {
    border-color: var(--primary);
}

/* BUTTON */
button {
    width: 100%;
    padding: 12px;
    margin-top: 18px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
}

button:active {
    transform: scale(0.98);
}

/* RESULT */
.result {
    margin-top: 16px;
    padding-top: 12px;
    border-top: 1px dashed var(--border);
}

.result p {
    font-size: 14px;
    margin: 6px 0;
    display: flex;
    justify-content: space-between;
}

.result span {
    font-weight: 600;
}

/* HELPERS */
.hidden {
    display: none;
}