/* =========================
   PLAYLIST PULSE THEME
   Upskilled: CSS variables, grid, transitions, responsive layout
   ========================= */

:root {
  --color-bg: #000000;
  --color-bg-elevated: #121212;
  --color-card: #181818;
  --color-accent: #1db954;
  --color-accent-soft: rgba(29, 185, 84, 0.15);
  --color-text: #ffffff;
  --color-text-muted: #b3b3b3;
  --color-border: #262626;
  --radius-lg: 18px;
  --radius-md: 10px;
  --shadow-soft: 0 18px 45px rgba(0, 0, 0, 0.7);
  --transition-fast: 0.18s ease-out;
  --max-width: 1100px;
  --font-base: "Inter", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

/* Basic reset */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  min-height: 100vh;
  font-family: var(--font-base);
  background: radial-gradient(circle at top left, #1db954 0%, #000 45%, #000 100%);
  color: var(--color-text);
}

/* Back link */

.back-link {
  display: inline-block;
  margin: 18px auto 0;
  padding-left: 16px;
  font-size: 0.9rem;
  text-decoration: none;
  color: var(--color-text-muted);
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.back-link:hover,
.back-link:focus-visible {
  color: var(--color-accent);
  transform: translateX(-2px);
}

/* Header */

.app-header {
  max-width: var(--max-width);
  margin: 16px auto 10px;
  padding: 16px 18px 0;
}

.app-title-wrapper {
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo-circle {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-accent-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
}

h1 {
  font-size: clamp(1.9rem, 2.6vw, 2.3rem);
  margin: 0;
}

.subtitle {
  margin: 4px 0 0;
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

/* Main layout */

.app-main {
  max-width: var(--max-width);
  margin: 0 auto 40px;
  padding: 0 18px 32px;
}

/* Card */

.card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 18px 18px 20px;
  box-shadow: var(--shadow-soft);
  border: 1px solid var(--color-border);
}

.add-section {
  margin-top: 8px;
  margin-bottom: 20px;
}

.card-header h2 {
  margin: 0;
  font-size: 1.2rem;
}

.card-subtitle {
  margin-top: 4px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Form layout */

.form-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px 18px;
  margin-top: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.form-group-full {
  grid-column: 1 / -1;
}

label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

input,
select,
textarea {
  background: #101010;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  padding: 8px 10px;
  font-size: 0.95rem;
  color: var(--color-text);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

input::placeholder,
textarea::placeholder {
  color: #777;
}

input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent-soft);
}

textarea {
  resize: vertical;
  min-height: 60px;
}

/* Buttons */

.btn-primary,
.btn-secondary,
.song-delete {
  border-radius: 999px;
  padding: 8px 18px;
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  font-family: inherit;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.btn-primary {
  background: var(--color-accent);
  color: #000;
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.6);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.8);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  border-color: var(--color-accent);
  background: #101010;
}

.song-delete {
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid #333;
}

.song-delete:hover,
.song-delete:focus-visible {
  background: #2a0000;
  border-color: #ff4b5c;
  color: #ff9aa6;
}

/* Form footer */

.form-footer {
  margin-top: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.required-hint {
  margin: 0;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.form-error {
  margin-top: 6px;
  font-size: 0.85rem;
  color: #ff6b81;
  min-height: 1em;
}

/* Library layout */

.library-layout {
  display: grid;
  grid-template-columns: minmax(0, 2.3fr) minmax(0, 1.2fr);
  gap: 18px;
}

/* Filters */

.filters-card {
  min-height: 260px;
}

.filters-grid {
  margin-top: 14px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px 16px;
  align-items: flex-end;
}

.filters-actions {
  display: flex;
  justify-content: flex-start;
}

/* Songs list */

.songs-list {
  margin-top: 14px;
  display: grid;
  gap: 10px;
}

.empty-state {
  margin: 12px 0 4px;
  font-size: 0.95rem;
  color: var(--color-text-muted);
  text-align: center;
}

/* Individual song card */

.song-card {
  display: grid;
  grid-template-columns: minmax(0, 3fr) auto;
  gap: 6px 12px;
  padding: 10px 12px;
  background: #101010;
  border-radius: 12px;
  border: 1px solid #262626;
  transition: background var(--transition-fast), transform var(--transition-fast), border-color var(--transition-fast);
}

.song-card:hover {
  background: #151515;
  transform: translateY(-1px);
  border-color: var(--color-accent-soft);
}

.song-main {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.song-title {
  font-size: 1rem;
  font-weight: 600;
}

.song-artist {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.song-meta {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.song-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 4px;
}

.tag-pill {
  border-radius: 999px;
  padding: 3px 9px;
  font-size: 0.75rem;
  background: var(--color-accent-soft);
  color: var(--color-accent);
}

.tag-outline {
  border-radius: 999px;
  padding: 3px 9px;
  font-size: 0.75rem;
  border: 1px solid #333;
  color: var(--color-text-muted);
}

.song-notes {
  margin-top: 4px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.song-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

/* Stats card */

.stats-card {
  align-self: flex-start;
}

.stats-content {
  margin-top: 14px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.stat-label {
  color: var(--color-text);
  font-weight: 500;
}

.recommendation-text {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  background: #101010;
  border: 1px dashed var(--color-accent-soft);
  font-size: 0.85rem;
}

/* =========================
   Responsive breakpoints
   ========================= */

@media (min-width: 640px) {
  .form-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .form-group-full {
    grid-column: 1 / -1;
  }

  .filters-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .filters-actions {
    justify-content: flex-end;
  }
}

@media (max-width: 768px) {
  .library-layout {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 520px) {
  .card {
    padding: 16px 14px 18px;
  }

  .song-card {
    grid-template-columns: minmax(0, 1fr);
  }

  .form-footer {
    flex-direction: column;
    align-items: flex-start;
  }

  .filters-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}