:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --green: #16a34a;
    --red: #dc2626;
    --orange: #d97706;
    --bg: #f3f4f6;
    --card: #ffffff;
    --text: #1f2937;
    --text-light: #6b7280;
    --border: #e5e7eb;
    --radius: 14px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    padding-bottom: 80px;
}

.container {
    max-width: 480px;
    margin: 0 auto;
    padding: 16px;
}

/* --- Login --- */
.login-wrap {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 32px 24px;
    width: 100%;
    max-width: 360px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    text-align: center;
}

.login-card h1 {
    font-size: 22px;
    margin-bottom: 24px;
}

.login-card input {
    width: 100%;
    padding: 12px 14px;
    margin-bottom: 12px;
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 16px;
}

.btn {
    display: inline-block;
    width: 100%;
    padding: 12px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
}

.btn:active { background: var(--primary-dark); }

.error-msg {
    background: #fef2f2;
    color: var(--red);
    padding: 10px;
    border-radius: 8px;
    margin-bottom: 12px;
    font-size: 14px;
}

/* --- Header / nav --- */
.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 4px 0 16px;
}

.topbar h1 { font-size: 18px; margin: 0; }
.topbar a { color: var(--text-light); text-decoration: none; font-size: 14px; }

.tabbar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--card);
    display: flex;
    border-top: 1px solid var(--border);
    max-width: 480px;
    margin: 0 auto;
}

.tabbar a {
    flex: 1;
    text-align: center;
    padding: 12px 4px;
    text-decoration: none;
    color: var(--text-light);
    font-size: 12px;
    font-weight: 600;
}

.tabbar a.active { color: var(--primary); }

/* --- Cards --- */
.card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 18px;
    margin-bottom: 16px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
}

.balance-hero {
    text-align: center;
    padding: 24px 18px;
}

.balance-hero .amount {
    font-size: 38px;
    font-weight: 700;
    margin: 8px 0 4px;
}

.balance-hero .label {
    color: var(--text-light);
    font-size: 14px;
}

.amount.positive { color: var(--green); }
.amount.negative { color: var(--red); }

.cat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}

.cat-row:last-child { border-bottom: none; }

.cat-name { font-size: 15px; }
.cat-amount { font-weight: 600; }

.form-group { margin-bottom: 14px; }
.form-group label {
    display: block;
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 6px;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 11px 12px;
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 15px;
    background: white;
}

.list-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
}

.list-item:last-child { border-bottom: none; }

.list-item .meta { font-size: 12px; color: var(--text-light); }
.list-item .who { font-size: 11px; color: var(--primary); font-weight: 600; }

.section-title {
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-light);
    margin: 20px 0 8px;
}

.empty-state {
    text-align: center;
    color: var(--text-light);
    padding: 24px 0;
    font-size: 14px;
}