:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #16a34a;
    --warning: #d97706;
    --danger: #dc2626;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-500: #6b7280;
    --gray-700: #374151;
    --gray-900: #111827;
    --radius: 8px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--gray-50);
    color: var(--gray-900);
    line-height: 1.5;
}

/* Nav */
nav {
    background: var(--gray-900);
    color: white;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}
nav .brand { font-weight: 700; font-size: 1.1rem; }
nav .links { display: flex; gap: 0.25rem; }
nav .links a {
    color: var(--gray-300);
    text-decoration: none;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius);
    font-size: 0.9rem;
}
nav .links a:hover, nav .links a.active {
    color: white;
    background: rgba(255,255,255,0.1);
}
nav .user-info {
    font-size: 0.85rem;
    color: var(--gray-300);
    display: flex;
    align-items: center;
    gap: 1rem;
}
nav .user-info a { color: var(--gray-300); text-decoration: none; font-size: 0.85rem; }
nav .user-info a:hover { color: white; }

/* Layout */
.container { max-width: 1000px; margin: 0 auto; padding: 1.5rem; }

/* Cards */
.card {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    padding: 1.5rem;
    margin-bottom: 1rem;
}
.card h2 { font-size: 1.1rem; margin-bottom: 1rem; color: var(--gray-700); }

/* Stats grid */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.stat-card {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    padding: 1.25rem;
    text-align: center;
}
.stat-card .label { font-size: 0.8rem; color: var(--gray-500); text-transform: uppercase; letter-spacing: 0.05em; }
.stat-card .value { font-size: 1.75rem; font-weight: 700; color: var(--gray-900); margin-top: 0.25rem; }
.stat-card .value.primary { color: var(--primary); }

/* Tables */
table { width: 100%; border-collapse: collapse; }
th { text-align: left; font-size: 0.8rem; color: var(--gray-500); text-transform: uppercase; letter-spacing: 0.05em; padding: 0.75rem; border-bottom: 2px solid var(--gray-200); }
td { padding: 0.75rem; border-bottom: 1px solid var(--gray-100); font-size: 0.9rem; }
tr:hover td { background: var(--gray-50); }
.amount { text-align: right; font-weight: 600; font-variant-numeric: tabular-nums; }
.category-badge {
    display: inline-block;
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: 99px;
    background: var(--gray-100);
    color: var(--gray-700);
}

/* Forms */
.form-group { margin-bottom: 1rem; }
.form-group label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--gray-700); margin-bottom: 0.3rem; }
input[type="text"], input[type="number"], input[type="date"],
input[type="email"], select, textarea {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-family: inherit;
    background: white;
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}
textarea { resize: vertical; min-height: 60px; }

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}
.form-row.three { grid-template-columns: 1fr 1fr 1fr; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1.25rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: background 0.15s;
}
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--gray-100); color: var(--gray-700); border: 1px solid var(--gray-300); }
.btn-secondary:hover { background: var(--gray-200); }
.btn-danger { background: white; color: var(--danger); border: 1px solid var(--gray-200); padding: 0.35rem 0.6rem; font-size: 0.8rem; }
.btn-danger:hover { background: #fef2f2; }
.btn-sm { padding: 0.35rem 0.75rem; font-size: 0.8rem; }

.actions { display: flex; gap: 0.75rem; margin-top: 1.5rem; }

/* Upload area */
.upload-area {
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s;
}
.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.03);
}
.upload-area .icon { font-size: 2.5rem; margin-bottom: 0.5rem; }
.upload-area p { color: var(--gray-500); font-size: 0.9rem; }
.upload-area .formats { font-size: 0.8rem; color: var(--gray-500); margin-top: 0.5rem; }

/* Line items table in review */
.items-table input {
    width: 100%;
    padding: 0.4rem;
    border: 1px solid var(--gray-200);
    border-radius: 4px;
    font-size: 0.85rem;
}

/* Mileage calc */
.calc-fields {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 0.75rem;
    margin-top: 0.75rem;
}
.calc-fields label { font-size: 0.8rem; font-weight: 600; color: var(--gray-500); }
.calc-fields input { margin-top: 0.25rem; }
.resolved { font-size: 0.85rem; color: var(--gray-500); margin-bottom: 0.5rem; }

/* Filter bar */
.filter-bar {
    display: flex;
    gap: 0.75rem;
    align-items: end;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}
.filter-bar .form-group { margin-bottom: 0; }
.filter-bar select { width: auto; min-width: 120px; }

/* Login */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 56px);
}
.login-card {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    padding: 3rem;
    text-align: center;
    max-width: 400px;
    width: 100%;
}
.login-card h1 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.login-card p { color: var(--gray-500); margin-bottom: 2rem; }
.login-card .btn { width: 100%; justify-content: center; padding: 0.75rem; font-size: 1rem; }

/* Alerts */
.alert { padding: 0.75rem 1rem; border-radius: var(--radius); margin-bottom: 1rem; font-size: 0.9rem; }
.alert-error { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: var(--success); border: 1px solid #bbf7d0; }

/* Loading indicator */
.htmx-indicator { display: none; }
.htmx-request .htmx-indicator { display: inline-block; }
.spinner {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--gray-300);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Category breakdown */
.cat-row { display: flex; justify-content: space-between; padding: 0.5rem 0; border-bottom: 1px solid var(--gray-100); }
.cat-row:last-child { border-bottom: none; }
.cat-bar {
    height: 6px;
    background: var(--primary);
    border-radius: 3px;
    margin-top: 0.3rem;
    transition: width 0.3s;
}

/* Quick actions */
.quick-actions {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

/* Responsive */
@media (max-width: 640px) {
    .container { padding: 1rem; }
    .stats { grid-template-columns: 1fr 1fr; }
    .form-row { grid-template-columns: 1fr; }
    .form-row.three { grid-template-columns: 1fr; }
    .calc-fields { grid-template-columns: 1fr; }
    nav .links a { padding: 0.5rem 0.5rem; font-size: 0.8rem; }
    .quick-actions { flex-direction: column; }
    .filter-bar { flex-direction: column; align-items: stretch; }
}