:root {
    --color-primary: #2f6690;
    --color-primary-dark: #1d425f;
    --color-primary-soft: #e7f0f5;
    --color-accent: #ccdfe0;
    --color-accent-dark: #4d7477;
    --color-accent-soft: #eaf4f4;
    --color-bg: #f6f8f7;
    --color-surface: #ffffff;
    --color-border: #e3e9e7;
    --color-text: #22302f;
    --color-text-muted: #647270;
    --color-danger: #c1443b;
    --color-danger-soft: #fbeae8;
    --color-success: #2f7d5a;
    --color-success-soft: #e6f4ec;
    --font-display: Arial, Helvetica, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-body: Arial, Helvetica, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 2px rgba(29, 66, 95, 0.06);
    --shadow: 0 4px 16px rgba(29, 66, 95, 0.08), 0 1px 3px rgba(29, 66, 95, 0.06);
    --shadow-lg: 0 12px 32px rgba(29, 66, 95, 0.14);
    font-size: 16px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: var(--font-body);
    background: var(--color-bg);
    background-image:
        radial-gradient(circle at 8% 0%, rgba(204, 223, 224, 0.35), transparent 40%),
        radial-gradient(circle at 100% 12%, rgba(204, 223, 224, 0.3), transparent 35%);
    background-attachment: fixed;
    color: var(--color-text);
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Topbar ---------- */
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--color-accent);
    color: var(--color-primary-dark);
    padding: 0.85rem clamp(1rem, 4vw, 2rem);
    box-shadow: 0 2px 10px rgba(29, 66, 95, 0.1);
    flex-wrap: wrap;
    gap: 0.75rem;
    border-bottom: 1px solid rgba(29, 66, 95, 0.08);
}
.topbar .brand {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    color: var(--color-primary-dark);
    text-decoration: none;
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: 0.01em;
}
.topbar .brand img {
    height: 36px;
    width: 36px;
    border-radius: 50%;
    object-fit: cover;
    background: #fff;
    box-shadow: 0 0 0 2px rgba(29, 66, 95, 0.15);
}
.topbar nav { display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; }
.topbar nav a {
    color: var(--color-primary-dark);
    font-size: 0.86rem;
    font-weight: 700;
    padding: 0.5rem 1rem;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.55);
    border: 1.5px solid rgba(29, 66, 95, 0.12);
    box-shadow: 0 1px 3px rgba(29, 66, 95, 0.08);
    transition: background 0.15s ease, transform 0.1s ease, box-shadow 0.15s ease;
}
.topbar nav a:hover { background: #fff; text-decoration: none; transform: translateY(-1px); box-shadow: 0 3px 8px rgba(29, 66, 95, 0.15); }

@media (max-width: 640px) {
    .topbar nav {
        width: 100%;
        flex-wrap: nowrap;
        gap: 0.4rem;
    }
    .topbar nav a {
        flex: 1 1 0;
        text-align: center;
        padding: 0.5rem 0.3rem;
        font-size: 0.68rem;
        white-space: nowrap;
    }
}

.container {
    max-width: 1020px;
    margin: 0 auto;
    padding: clamp(1.25rem, 4vw, 2.5rem) clamp(1rem, 4vw, 1.5rem) 4rem;
}

.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    padding: clamp(1.1rem, 3vw, 1.75rem);
    margin-bottom: 1.5rem;
    transition: box-shadow 0.15s ease;
}

h1, h2, h3 { font-family: var(--font-display); color: var(--color-primary-dark); font-weight: 700; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.5rem, 3vw, 1.9rem); margin: 0 0 1.1rem; }
h2 { font-size: clamp(1.1rem, 2vw, 1.3rem); margin: 0 0 0.85rem; }
h3 { font-size: 1.05rem; margin: 0 0 0.5rem; }

.flash { padding: 0.8rem 1.1rem; border-radius: var(--radius-sm); margin-bottom: 1.25rem; font-size: 0.95rem; border: 1px solid transparent; }
.flash-success { background: var(--color-success-soft); color: var(--color-success); border-color: #c7e6d5; }
.flash-error { background: var(--color-danger-soft); color: var(--color-danger); border-color: #f2c7c2; }

label { display: block; font-size: 0.82rem; font-weight: 600; color: var(--color-text-muted); margin-bottom: 0.35rem; letter-spacing: 0.01em; }
input[type=text], input[type=email], input[type=tel], input[type=date], input[type=password],
input[type=number], input[type=file], select, textarea {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: inherit;
    background: #fff;
    color: var(--color-text);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(47, 102, 144, 0.15);
}
textarea { resize: vertical; }

.form-row { margin-bottom: 1.1rem; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 1rem; }
@media (max-width: 640px) { .form-grid, .form-grid-3 { grid-template-columns: 1fr; } }

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--color-primary);
    color: #fff;
    border: none;
    padding: 0.62rem 1.3rem;
    border-radius: 999px;
    font-size: 0.92rem;
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    box-shadow: 0 2px 8px rgba(47, 102, 144, 0.25);
    transition: background 0.15s ease, transform 0.1s ease, box-shadow 0.15s ease;
}
.btn:hover { background: var(--color-primary-dark); text-decoration: none; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(47, 102, 144, 0.3); }
.btn:active { transform: translateY(0); }
.btn-secondary { background: #fff; color: var(--color-primary); border: 1.5px solid var(--color-primary); box-shadow: none; }
.btn-secondary:hover { background: var(--color-primary-soft); color: var(--color-primary-dark); box-shadow: none; }
.btn-danger { background: var(--color-danger); box-shadow: 0 2px 8px rgba(193, 68, 59, 0.25); }
.btn-danger:hover { background: #9c332b; box-shadow: 0 4px 12px rgba(193, 68, 59, 0.3); }
.btn-sm { padding: 0.4rem 0.9rem; font-size: 0.85rem; }

table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 0.7rem 0.6rem; border-bottom: 1px solid var(--color-border); font-size: 0.92rem; }
th { color: var(--color-text-muted); font-weight: 700; font-size: 0.76rem; text-transform: uppercase; letter-spacing: 0.05em; }
tr:hover td { background: var(--color-accent-soft); }

.badge { display: inline-block; padding: 0.2rem 0.65rem; border-radius: 999px; font-size: 0.72rem; font-weight: 700; letter-spacing: 0.02em; text-transform: uppercase; }
.badge-single { background: var(--color-accent); color: var(--color-primary-dark); }
.badge-couple { background: #fdecd9; color: #93601a; }
.badge-paid { background: var(--color-success-soft); color: var(--color-success); }
.badge-unpaid { background: var(--color-danger-soft); color: var(--color-danger); }

.login-wrap {
    max-width: 400px;
    margin: 9vh auto;
    padding: 0 1rem;
}
.login-wrap .login-logo { display: block; margin: 0 auto 1.5rem; height: 84px; width: 84px; border-radius: 50%; box-shadow: var(--shadow-lg); }
.login-wrap .card { text-align: left; box-shadow: var(--shadow-lg); border: none; }
.login-wrap h1 { text-align: center; font-size: 1.35rem; margin-bottom: 1.5rem; }

.checkbox-row { display: flex; align-items: center; gap: 0.5rem; }
.checkbox-row input { width: auto; }

.muted { color: var(--color-text-muted); font-size: 0.88rem; }
.actions-bar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.4rem; gap: 1rem; flex-wrap: wrap; }

.item-row { border: 1.5px solid var(--color-border); border-radius: var(--radius-sm); padding: 1.1rem; margin-bottom: 0.85rem; background: #fbfdfc; }
.item-row-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 0.6rem; }
.item-row-head strong { font-family: var(--font-display); color: var(--color-primary-dark); }
.remove-item { background: none; border: none; color: var(--color-danger); cursor: pointer; font-size: 0.85rem; font-weight: 600; }
.remove-item:hover { text-decoration: underline; }

.totals { margin-top: 1rem; text-align: right; font-size: 0.95rem; color: var(--color-text-muted); }
.totals > div { margin-bottom: 0.3rem; }
.totals .grand { font-family: var(--font-display); font-size: 1.3rem; font-weight: 700; color: var(--color-primary-dark); margin-top: 0.4rem; }

.category-picker { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-bottom: 1.25rem; }
.category-picker a {
    padding: 0.5rem 1.1rem; border: 1.5px solid var(--color-border); border-radius: 999px;
    background: #fff; color: var(--color-text); font-size: 0.88rem; font-weight: 600;
    transition: all 0.15s ease;
}
.category-picker a.active, .category-picker a:hover { background: var(--color-primary); color: #fff; border-color: var(--color-primary); text-decoration: none; }

.client-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 640px) { .client-grid { grid-template-columns: 1fr; } }
.client-card {
    display: block;
    background: var(--color-surface);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    padding: 1.1rem 1.25rem;
    text-decoration: none;
    color: inherit;
    transition: box-shadow 0.15s ease, transform 0.1s ease, border-color 0.15s ease;
}
.client-card:hover { text-decoration: none; box-shadow: var(--shadow); transform: translateY(-2px); border-color: var(--color-primary); }
.client-card-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 0.5rem; margin-bottom: 0.5rem; }
.client-card-name {
    display: inline-block;
    background: var(--color-primary);
    color: #fff;
    font-weight: 700;
    font-size: 0.98rem;
    padding: 0.5rem 1rem;
    border-radius: 999px;
}
.client-card-address { color: var(--color-text-muted); font-size: 0.88rem; line-height: 1.5; }
.client-card-footer { margin-top: 0.6rem; font-size: 0.8rem; color: var(--color-text-muted); }