:root {
  --sidebar-width: 280px;
  --bg-dark: #0f1115;
  --bg-card: rgba(20, 24, 32, 0.88);
  --text: #f5f7fb;
  --muted: #b7bfd1;
  --accent: #e11d48;
  --accent-2: #7c3aed;
  --ok: #16a34a;
  --error: #dc2626;
  --border: rgba(255,255,255,.12);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  min-height: 100%;
}

body.bg-rock,
body.app-bg {
  background:
    linear-gradient(135deg, rgba(10,12,16,.88), rgba(17,24,39,.84)),
    url('../img/rock-bg.jpg') center/cover no-repeat fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

.login-wrapper {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.login-card {
  width: 100%;
  max-width: 460px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--bg-card);
  box-shadow: 0 20px 40px rgba(0,0,0,.35);
  padding: 24px;
  backdrop-filter: blur(6px);
}

.brand-block {
  text-align: center;
  margin-bottom: 16px;
}

.brand-logo {
  width: 82px;
  height: 82px;
  object-fit: contain;
  display: block;
  margin: 0 auto 10px;
  border-radius: 10px;
  background: rgba(255,255,255,.06);
  padding: 8px;
}

.brand-block h1 {
  font-size: 1.15rem;
  margin: 4px 0 0;
}

.login-form {
  display: grid;
  gap: 10px;
}

.login-form label {
  color: var(--muted);
  font-size: .92rem;
}

.login-form input {
  height: 42px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  color: #fff;
  padding: 0 12px;
}

.login-form button {
  margin-top: 8px;
  height: 44px;
  border: 0;
  border-radius: 10px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  color: #fff;
  font-weight: 700;
  cursor: pointer;
}

.alert {
  padding: 10px 12px;
  border-radius: 10px;
  margin: 10px 0 14px;
  font-size: .92rem;
  border: 1px solid transparent;
}

.alert-error {
  background: rgba(220,38,38,.15);
  border-color: rgba(220,38,38,.5);
  color: #fecaca;
}

.alert-ok {
  background: rgba(22,163,74,.14);
  border-color: rgba(22,163,74,.45);
  color: #bbf7d0;
}

.sidebar {
  width: var(--sidebar-width);
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  border-right: 1px solid var(--border);
  background: rgba(15,17,21,.96);
  padding: 18px 14px;
  overflow-y: auto;
}

.sidebar-top {
  text-align: center;
  margin-bottom: 16px;
}

.sidebar-logo {
  width: 84px;
  height: 84px;
  object-fit: contain;
  border-radius: 12px;
  background: rgba(255,255,255,.06);
  padding: 8px;
  margin-bottom: 8px;
}

.sidebar-top h2 {
  margin: 0;
  font-size: 1rem;
}

.sidebar-top p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: .85rem;
  text-transform: capitalize;
}

.menu {
  display: grid;
  gap: 8px;
}

.menu-item {
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: rgba(255,255,255,.03);
  font-size: .92rem;
}

.menu-item:hover,
.menu-item.active {
  border-color: rgba(255,255,255,.2);
  background: rgba(255,255,255,.08);
}

.menu-item.logout {
  margin-top: 12px;
  background: rgba(220,38,38,.16);
  border-color: rgba(220,38,38,.35);
}

.content {
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  padding: 24px;
}

.card {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--bg-card);
  box-shadow: 0 10px 30px rgba(0,0,0,.25);
  padding: 18px;
  backdrop-filter: blur(4px);
}

.page-title {
  margin: 0 0 6px;
  font-size: 1.35rem;
}

.page-subtitle {
  margin: 0;
  color: var(--muted);
}

.mt-16 {
  margin-top: 16px;
}

.instrument-form {
  margin-top: 14px;
  display: grid;
  gap: 10px;
  max-width: 520px;
}

.instrument-main-card {
  max-width: 980px;
}

.instrument-form-large {
  max-width: 860px;
  gap: 16px;
}

.form-field {
  display: grid;
  gap: 8px;
}

.form-actions {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-top: 8px;
}

.instrument-form label {
  color: var(--muted);
  font-size: .92rem;
}

.instrument-form input[type="text"],
.instrument-form input[type="file"] {
  min-height: 42px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  color: #fff;
  padding: 10px 12px;
}

.instrument-form button {
  margin-top: 6px;
  height: 42px;
  border: 0;
  border-radius: 10px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  color: #fff;
  font-weight: 700;
  cursor: pointer;
  padding: 0 18px;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 42px;
  padding: 0 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  color: #fff;
}

.instrument-grid {
  margin-top: 14px;
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.instrument-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px;
  background: rgba(255,255,255,.04);
}

.instrument-image {
  width: 100%;
  height: 160px;
  object-fit: cover;
  border-radius: 10px;
  border: 1px solid var(--border);
  display: block;
}

.instrument-card h3 {
  margin: 10px 0 8px;
  font-size: 1rem;
}

.btn-edit {
  display: inline-block;
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(124,58,237,.25);
  font-size: .9rem;
}

@media (max-width: 960px) {
  .sidebar {
    position: static;
    width: auto;
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }
  .content {
    margin-left: 0;
  }
}