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

:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --danger: #dc2626;
    --danger-hover: #b91c1c;
    --bg: #f8fafc;
    --card-bg: #fff;
    --border: #e2e8f0;
    --text: #1e293b;
    --text-muted: #64748b;
    --sent: #f59e0b;
    --delivered: #10b981;
    --received: #8b5cf6;
}

body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; }

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

/* Navbar */
.navbar { display: flex; align-items: center; justify-content: space-between; padding: .75rem 1.5rem; background: #fff; border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 10; }
.nav-brand { font-size: 1.15rem; font-weight: 700; color: var(--text); }
.nav-brand:hover { text-decoration: none; }
.nav-links { display: flex; gap: 1.25rem; align-items: center; }
.nav-links a { color: var(--text-muted); font-size: .9rem; }
.nav-links a:hover { color: var(--primary); text-decoration: none; }
.nav-logout { color: var(--danger) !important; }

/* Container */
.container { max-width: 960px; margin: 2rem auto; padding: 0 1.5rem; }

/* Auth forms */
.auth-form { max-width: 360px; margin: 4rem auto; background: var(--card-bg); padding: 2rem; border-radius: 8px; border: 1px solid var(--border); }
.auth-form h2 { margin-bottom: 1.25rem; }
.auth-form button[type="submit"] { margin-top: 1.25rem; }
.auth-link { margin-top: 1.5rem; text-align: center; font-size: .9rem; }

/* Forms */
label { display: block; margin-top: 1rem; font-size: .85rem; font-weight: 500; color: var(--text-muted); }
input[type="text"], input[type="password"], input[type="datetime-local"], input[type="date"], select, textarea {
    width: 100%; padding: .5rem .75rem; margin-top: .25rem; border: 1px solid var(--border); border-radius: 6px; font-size: .95rem; background: #fff;
}
input:focus, select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,.1); }
input[type="text"] + label, input[type="password"] + label, input[type="datetime-local"] + label, select + label { margin-top: 1.1rem; }
.form-card { background: var(--card-bg); padding: 1.5rem; border-radius: 8px; border: 1px solid var(--border); }
.form-actions { display: flex; gap: .75rem; margin-top: 1.25rem; align-items: center; }
.form-actions .btn, .form-actions button { display: inline-flex; align-items: center; justify-content: center; white-space: nowrap; height: 2.1rem; margin-top: 0; }
.form-row { display: flex; gap: .5rem; align-items: center; }
.form-row input[type="text"], .form-row select { flex: 1; width: auto; min-width: 0; }
.form-row .btn { white-space: nowrap; flex-shrink: 0; }
.filter-bar .form-row select { flex: 0 0 auto; width: auto; }
.inline-form { margin-bottom: 1.25rem; }
.rename-form { display: inline-flex; gap: .35rem; align-items: center; margin-right: .5rem; }
.nickname-display { display: inline; }
.nickname-edit { display: inline-flex; gap: .35rem; align-items: center; }
.nickname-edit input[type="text"] { width: 140px; flex: none; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: .5rem 1rem; border: 1px solid var(--border); border-radius: 6px; background: #fff; cursor: pointer; font-size: .9rem; text-align: center; white-space: nowrap; text-decoration: none; line-height: 1; }
.btn:hover { background: var(--bg); text-decoration: none; }
.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); }
.btn-danger { background: var(--danger); color: #fff; border-color: var(--danger); }
.btn-danger:hover { background: var(--danger-hover); }
.btn-sm { padding: .25rem .6rem; font-size: .8rem; }

/* Alert */
.alert { padding: .75rem 1rem; border-radius: 6px; margin-bottom: 1rem; font-size: .9rem; }
.alert-error { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }

/* Table */
table { width: 100%; border-collapse: collapse; background: var(--card-bg); border-radius: 8px; overflow: hidden; border: 1px solid var(--border); }
th, td { padding: .65rem 1rem; text-align: left; border-bottom: 1px solid var(--border); font-size: .9rem; }
th { background: var(--bg); font-weight: 600; color: var(--text-muted); font-size: .8rem; text-transform: uppercase; letter-spacing: .03em; }
tr:last-child td { border-bottom: none; }
code { background: var(--bg); padding: .15rem .4rem; border-radius: 4px; font-size: .85rem; word-break: break-all; }
.inline { display: inline; }

/* Section */
.section { margin-bottom: 2rem; }
.section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }

/* Card grid */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 1rem; }
.card { display: block; background: var(--card-bg); border: 1px solid var(--border); border-radius: 8px; padding: 1.25rem; transition: box-shadow .15s; }
.card:hover { box-shadow: 0 4px 12px rgba(0,0,0,.06); text-decoration: none; }
.card h3 { margin-bottom: .5rem; }
.stats { display: flex; gap: .75rem; font-size: .85rem; color: var(--text-muted); flex-wrap: wrap; }
.stat { white-space: nowrap; }

/* Dashboard cards */
.dashboard-card { padding: 1.5rem; transition: transform .15s, box-shadow .15s; }
.dashboard-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.08); }
.dc-header { display: flex; align-items: center; gap: .6rem; margin-bottom: 1rem; }
.dc-icon { font-size: 1.6rem; }
.dc-header h3 { font-size: 1.1rem; margin: 0; }
.dc-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: .25rem; text-align: center; padding-top: .75rem; border-top: 1px solid var(--border); }
.dc-stat { display: flex; flex-direction: column; gap: .15rem; }
.dc-num { font-size: 1.4rem; font-weight: 700; color: var(--text); }
.dc-label { font-size: .7rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: .04em; }
.dc-sent { color: var(--sent); }
.dc-delivered { color: var(--delivered); }
.dc-received { color: var(--received); }
.dc-tags { display: flex; flex-wrap: wrap; gap: .35rem; margin-top: .75rem; }
.dc-tag { display: inline-block; padding: .15rem .5rem; background: var(--bg); border: 1px solid var(--border); border-radius: 999px; font-size: .7rem; color: var(--text-muted); font-weight: 500; }
.dc-recent { display: flex; align-items: center; gap: .4rem; margin-top: .6rem; font-size: .75rem; color: var(--text-muted); }
.dc-recent-label { flex-shrink: 0; }
.dc-recent-item { padding: .1rem .4rem; background: var(--bg); border-radius: 4px; font-family: monospace; font-size: .7rem; }

/* Postcard grid */
.postcard-card { display: flex; gap: 1rem; background: var(--card-bg); border: 1px solid var(--border); border-radius: 8px; padding: .75rem; transition: box-shadow .15s; }
.postcard-card:hover { box-shadow: 0 4px 12px rgba(0,0,0,.06); text-decoration: none; }
.thumb { width: 80px; height: 60px; object-fit: cover; border-radius: 4px; flex-shrink: 0; }
.thumb.placeholder { display: flex; align-items: center; justify-content: center; background: var(--bg); font-size: 1.5rem; }
.postcard-info { display: flex; flex-direction: column; gap: .15rem; font-size: .9rem; }

/* Badge */
.badge { display: inline-block; padding: .1rem .4rem; border-radius: 999px; font-size: .7rem; font-weight: 600; color: #fff; white-space: nowrap; line-height: 1.4; align-self: flex-start; }
.badge-sent { background: var(--sent); }
.badge-delivered { background: var(--delivered); }
.badge-received { background: var(--received); }

/* Detail page */
.detail-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; margin-top: 1.5rem; }
.detail-images { display: flex; flex-direction: column; gap: 1.5rem; }
.image-block h3 { margin-bottom: .5rem; font-size: .95rem; }
.detail-img { width: 100%; max-width: 400px; border-radius: 8px; border: 1px solid var(--border); }
.detail-img.placeholder { display: flex; align-items: center; justify-content: center; height: 200px; background: var(--bg); color: var(--text-muted); font-size: .95rem; }
.upload-form { margin-top: .5rem; display: flex; gap: .5rem; align-items: center; }
.upload-form input[type="file"] { font-size: .85rem; min-width: 0; max-width: 260px; }
.upload-form .btn { white-space: nowrap; flex-shrink: 0; }
.detail-meta dl { display: grid; grid-template-columns: auto 1fr; gap: .3rem 1rem; }
.detail-meta dt { font-weight: 600; font-size: .85rem; color: var(--text-muted); }
.detail-meta dd { font-size: .95rem; }

/* Filter */
.filter-bar { margin-bottom: 1.25rem; }

/* Empty state */
.empty { color: var(--text-muted); padding: 2rem; text-align: center; }

/* Responsive */
@media (max-width: 640px) {
    .detail-grid { grid-template-columns: 1fr; }
    .card-grid { grid-template-columns: 1fr; }
}