/* Theme tự động theo thiết bị (sáng/tối) */
:root {
  --bg: #f0f2f5;
  --bg-card: #ffffff;
  --text: #1a1d23;
  --text-muted: #5c6370;
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --border: #e2e6eb;
  --shadow: rgba(0, 0, 0, 0.06);
  --error-bg: #fef2f2;
  --error-text: #b91c1c;
  --success-bg: #f0fdf4;
  --success-text: #166534;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --bg-card: #1a1d24;
    --text: #e8eaed;
    --text-muted: #9aa0a6;
    --accent: #818cf8;
    --accent-hover: #a5b4fc;
    --border: #2d3239;
    --shadow: rgba(0, 0, 0, 0.3);
    --error-bg: #450a0a;
    --error-text: #fca5a5;
    --success-bg: #052e16;
    --success-text: #86efac;
  }
}

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

body {
  margin: 0;
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

.app {
  max-width: 640px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: 2rem;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.35rem;
}

.logo-icon {
  width: 2.25rem;
  height: 2.25rem;
  color: var(--accent);
}

.logo h1 {
  margin: 0;
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Form */
.form {
  margin-bottom: 1.25rem;
}

.input-wrap {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.35rem 0.5rem 0.35rem 0.85rem;
  box-shadow: 0 1px 3px var(--shadow);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.input-wrap:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.input-icon {
  flex-shrink: 0;
  width: 1.2rem;
  height: 1.2rem;
  color: var(--text-muted);
}

.input {
  flex: 1;
  min-width: 0;
  border: none;
  background: transparent;
  font-size: 1rem;
  color: var(--text);
  padding: 0.65rem 0;
}

.input::placeholder {
  color: var(--text-muted);
}

.input:focus {
  outline: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.6rem 1.1rem;
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-primary:disabled {
  opacity: 0.7;
  cursor: not-allowed;
  transform: none;
}

.btn-icon {
  width: 1.1rem;
  height: 1.1rem;
}

/* Message (loading / error) */
.message {
  padding: 0.85rem 1rem;
  border-radius: 10px;
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.message.loading {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
}

.message.error {
  background: var(--error-bg);
  color: var(--error-text);
}

.message:not([hidden]) {
  display: block;
}

/* Result card */
.result {
  margin-top: 0.5rem;
}

.result:not([hidden]) {
  display: block;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 12px var(--shadow);
}

.card-thumb-wrap {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--border);
}

.card-thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.card-badge {
  position: absolute;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.3rem 0.6rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
}

.card-body {
  padding: 1.25rem 1.25rem 1.5rem;
}

.card-title {
  margin: 0 0 0.35rem;
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.35;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-desc {
  margin: 0 0 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.downloads {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.download-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1rem;
  background: var(--bg);
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.2s, border-color 0.2s;
}

.download-link:hover {
  background: var(--border);
  border-color: var(--accent);
}

.download-link .icon {
  width: 1.1rem;
  height: 1.1rem;
  flex-shrink: 0;
}

/* Footer */
.footer {
  margin-top: auto;
  padding-top: 2rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer p {
  margin: 0;
}

@media (max-width: 480px) {
  .input-wrap {
    flex-wrap: wrap;
  }
  .btn span {
    display: none;
  }
  .btn {
    padding: 0.6rem;
  }
}