:root {
  --bg: #08101d;
  --surface: rgba(12, 20, 34, 0.95);
  --surface-strong: rgba(20, 30, 52, 0.96);
  --border: rgba(255, 255, 255, 0.08);
  --text: #eef4ff;
  --muted: #9bb5dd;
  --accent: #5e7bff;
  --accent-2: #7ca6ff;
  --accent-soft: rgba(94, 123, 255, 0.16);
  --accent-strong: #a3c0ff;
  --body-bg: radial-gradient(circle at 20% 10%, rgba(94, 123, 255, 0.12), transparent 18%),
    linear-gradient(180deg, #06101c 0%, #081324 45%, #09101d 100%);
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.22);
  --radius: 28px;
  --radius-sm: 16px;
  --transition: 220ms ease;
  --max-width: 1180px;
}

body.theme-ocean {
  --surface: rgba(12, 20, 34, 0.95);
  --surface-strong: rgba(20, 30, 52, 0.96);
  --border: rgba(255, 255, 255, 0.08);
  --text: #eef4ff;
  --muted: #9bb5dd;
  --accent: #5e7bff;
  --accent-2: #7ca6ff;
  --accent-soft: rgba(94, 123, 255, 0.16);
  --body-bg: radial-gradient(circle at 20% 10%, rgba(94, 123, 255, 0.12), transparent 18%),
    linear-gradient(180deg, #06101c 0%, #081324 45%, #09101d 100%);
}

body.theme-forest {
  --surface: rgba(6, 18, 22, 0.92);
  --surface-strong: rgba(12, 32, 23, 0.96);
  --border: rgba(115, 178, 103, 0.18);
  --text: #e9f8ea;
  --muted: #a7cfad;
  --accent: #75d699;
  --accent-2: #4aa26d;
  --accent-soft: rgba(117, 214, 153, 0.14);
  --body-bg: radial-gradient(circle at 25% 15%, rgba(117, 214, 153, 0.16), transparent 18%),
    linear-gradient(180deg, #04110c 0%, #081d14 45%, #081b14 100%);
}

body.theme-beach {
  --surface: rgba(255, 255, 255, 0.92);
  --surface-strong: rgba(255, 255, 255, 0.98);
  --border: rgba(107, 163, 223, 0.18);
  --text: #102a3f;
  --muted: #5f7f9f;
  --accent: #4ea1ff;
  --accent-2: #ffd58d;
  --accent-soft: rgba(78, 161, 255, 0.14);
  --body-bg: radial-gradient(circle at 20% 15%, rgba(255, 213, 141, 0.16), transparent 18%),
    linear-gradient(180deg, #cfe7ff 0%, #e5f2ff 45%, #f0f7ff 100%);
}

body.theme-sunset {
  --surface: rgba(36, 18, 40, 0.94);
  --surface-strong: rgba(30, 10, 28, 0.98);
  --border: rgba(255, 122, 92, 0.18);
  --text: #fff0ea;
  --muted: #e7bec6;
  --accent: #ff805c;
  --accent-2: #d286e0;
  --accent-soft: rgba(255, 122, 92, 0.16);
  --body-bg: radial-gradient(circle at 20% 15%, rgba(255, 122, 92, 0.14), transparent 18%),
    linear-gradient(180deg, #22071a 0%, #3f1342 45%, #120b24 100%);
}

body.theme-sunrise {
  --surface: rgba(22, 16, 32, 0.93);
  --surface-strong: rgba(28, 21, 42, 0.96);
  --border: rgba(255, 179, 125, 0.16);
  --text: #f9f1e8;
  --muted: #d7c1b4;
  --accent: #ffb37d;
  --accent-2: #7c5fbd;
  --accent-soft: rgba(255, 179, 125, 0.14);
  --body-bg: radial-gradient(circle at 25% 15%, rgba(255, 179, 125, 0.18), transparent 20%),
    linear-gradient(180deg, #150c1d 0%, #2b1a34 45%, #10101d 100%);
}

body.theme-moonlight {
  --surface: rgba(8, 12, 20, 0.95);
  --surface-strong: rgba(15, 18, 28, 0.96);
  --border: rgba(255, 255, 255, 0.08);
  --text: #f0f4ff;
  --muted: #b8c5e1;
  --accent: #c0c7ff;
  --accent-2: #e0e7ff;
  --accent-soft: rgba(192, 199, 255, 0.16);
  --body-bg: radial-gradient(circle at 20% 10%, rgba(192, 199, 255, 0.08), transparent 18%),
    linear-gradient(180deg, #0a0e1a 0%, #0f141e 45%, #0d1119 100%);
}

body.theme-raspberry {
  --surface: rgba(28, 8, 16, 0.94);
  --surface-strong: rgba(40, 12, 24, 0.96);
  --border: rgba(255, 92, 128, 0.18);
  --text: #ffe8f0;
  --muted: #e7b8c6;
  --accent: #ff5c80;
  --accent-2: #ff8aa3;
  --accent-soft: rgba(255, 92, 128, 0.16);
  --body-bg: radial-gradient(circle at 20% 15%, rgba(255, 92, 128, 0.12), transparent 18%),
    linear-gradient(180deg, #1c0a10 0%, #281824 45%, #120b14 100%);
}

body.theme-simplelight {
  --surface: rgba(255, 255, 255, 0.95);
  --surface-strong: rgba(248, 250, 252, 0.98);
  --border: rgba(0, 0, 0, 0.08);
  --text: #1a202c;
  --muted: #718096;
  --accent: #3182ce;
  --accent-2: #63b3ed;
  --accent-soft: rgba(49, 130, 206, 0.1);
  --body-bg: radial-gradient(circle at 20% 10%, rgba(49, 130, 206, 0.05), transparent 18%),
    linear-gradient(180deg, #f7fafc 0%, #edf2f7 45%, #e2e8f0 100%);
}

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

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif, -apple-system, BlinkMacSystemFont;
  color: var(--text);
  background: var(--body-bg);
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(circle at 85% 20%, rgba(94, 123, 255, 0.08), transparent 22%);
}

#particles-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

.particle {
  position: absolute;
  width: 2px;
  height: 2px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  filter: blur(0.4px);
  animation: floaty 18s linear infinite;
}

@keyframes floaty {
  0% {
    transform: translateY(0) scale(1);
    opacity: 0.6;
  }
  50% {
    transform: translateY(-100px) scale(0.9);
    opacity: 0.35;
  }
  100% {
    transform: translateY(0) scale(1);
    opacity: 0.6;
  }
}

header {
  position: relative;
  z-index: 1;
  padding: 2rem 1.5rem;
  background: rgba(9, 15, 27, 0.96);
  border-bottom: 1px solid var(--border);
  text-align: center;
}

header h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--accent);
  letter-spacing: -0.03em;
  text-shadow: 0 16px 40px rgba(14, 40, 90, 0.24);
}

.app-shell {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 1.5rem;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
}

.sidebar {
  position: sticky;
  top: 1.5rem;
  align-self: start;
  background: rgba(11, 18, 32, 0.95);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: 0 20px 55px rgba(0, 0, 0, 0.16);
  backdrop-filter: blur(24px);
}

.sidebar nav {
  background: transparent;
  border: none;
  padding: 0;
}

.sidebar ul {
  display: grid;
  gap: 0.75rem;
}

.section-header {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  margin-bottom: 1.5rem;
}

.section-header h2 {
  margin: 0;
  font-size: clamp(1.8rem, 2.4vw, 2.2rem);
}

.section-header p {
  margin: 0;
  color: var(--muted);
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.info-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 24px;
  padding: 1.5rem;
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.12);
  transition: transform var(--transition), border-color var(--transition);
}

.info-card:hover {
  transform: translateY(-2px);
  border-color: rgba(94, 123, 255, 0.16);
}

nav {
  position: static;
  background: transparent;
  border: none;
  border-radius: 0;
  padding: 0;
  max-height: calc(100vh - 3rem);
  overflow-y: auto;
  backdrop-filter: none;
}

nav::-webkit-scrollbar {
  width: 8px;
}

nav::-webkit-scrollbar-thumb {
  background: rgba(94, 123, 255, 0.24);
  border-radius: 999px;
}

nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

nav a {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1rem 1.1rem;
  border-radius: 18px;
  color: var(--text);
  text-decoration: none;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  transition: transform var(--transition), background var(--transition), color var(--transition), box-shadow var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 0 0 rgba(255, 255, 255, 0.04);
}

nav a::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(94, 123, 255, 0.08), rgba(103, 136, 255, 0.08));
  opacity: 0;
  transition: opacity var(--transition);
  border-radius: inherit;
}

nav a:hover,
nav a:focus-visible {
  background: rgba(94, 123, 255, 0.12);
  color: var(--accent);
  transform: translateX(1px);
  box-shadow: 0 12px 30px rgba(17, 35, 78, 0.18);
  border-color: rgba(94, 123, 255, 0.22);
}

nav a:hover::before,
nav a.active::before,
nav a:focus-visible::before {
  opacity: 1;
}

nav i {
  width: 22px;
  text-align: center;
  color: inherit;
}

nav a.active {
  background: rgba(94, 123, 255, 0.2);
  color: var(--accent);
  border-color: rgba(94, 123, 255, 0.28);
  box-shadow: inset 0 0 0 1px rgba(94, 123, 255, 0.14), 0 12px 30px rgba(17, 35, 78, 0.22);
}

.link-group {
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.04);
  border-radius: 22px;
  overflow: hidden;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition), transform var(--transition);
  margin-top: 1rem;
}

.link-group:first-of-type {
  margin-top: 0;
}

.link-group:hover {
  background: rgba(255, 255, 255, 0.07);
  border-color: rgba(94, 123, 255, 0.18);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.1);
}

.link-group summary {
  list-style: none;
  padding: 1.1rem 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  cursor: pointer;
  font-weight: 700;
  color: var(--text);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02));
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.link-group summary::-webkit-details-marker,
.link-group summary::marker {
  display: none;
}

.link-group summary::after {
  content: '▾';
  font-size: 1.1rem;
  transition: transform var(--transition);
  color: var(--accent);
}

.link-group[open] summary::after {
  transform: rotate(180deg);
}

.link-group ul {
  list-style: none;
  margin: 0;
  padding: 0 1.5rem 1.25rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 260ms ease, padding 260ms ease;
}

.link-group[open] ul {
  max-height: 1000px;
  padding: 0 1.5rem 1.25rem;
}

.link-group li {
  margin-bottom: 0.9rem;
}

.link-group li:last-child {
  margin-bottom: 0;
}

.link-group a {
  display: inline-flex;
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition), transform var(--transition);
}

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

.group-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  padding: 0 1.5rem 1rem;
}

main {
  min-width: 0;
}

.page-section {
  display: none;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 260ms ease, transform 260ms ease;
}

.page-section.active {
  display: block;
  opacity: 1;
  transform: translateY(0);
}

.container {
  background: var(--surface-strong);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
  margin-bottom: 1.5rem;
}

.container h2 {
  margin-top: 0;
  margin-bottom: 1rem;
  font-size: clamp(1.8rem, 2.5vw, 2.2rem);
  color: var(--accent);
}

.container p,
.container li,
.container label,
.container b,
.container span {
  color: var(--muted);
  line-height: 1.75;
}

.container p + p {
  margin-top: 1rem;
}

.container ul {
  list-style: disc inside;
  margin: 1rem 0 0;
  padding: 0;
}

.container ul li {
  margin-bottom: 0.9rem;
}

.container a {
  color: var(--accent);
  text-decoration: none;
  position: relative;
  padding: 0.2rem 0.4rem;
  border-radius: 8px;
  transition: color var(--transition), background var(--transition);
}

.container a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

.container a:hover,
.container a:focus-visible {
  color: var(--accent-2);
  background: rgba(94, 123, 255, 0.1);
}

.container a:hover::after,
.container a:focus-visible::after {
  transform: scaleX(1);
}

.image-link-card {
  display: inline-flex;
  flex-direction: column;
  width: min(100%, 320px);
  overflow: hidden;
  border-radius: 32px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 28px 60px rgba(0, 0, 0, 0.22);
  text-decoration: none;
  color: var(--text);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.image-link-card:hover,
.image-link-card:focus-visible {
  transform: translateY(-3px);
  border-color: rgba(94, 123, 255, 0.24);
  box-shadow: 0 34px 72px rgba(0, 0, 0, 0.24);
}

.image-link-card__thumb {
  min-height: 220px;
  background: linear-gradient(180deg, rgba(94, 123, 255, 0.12), transparent 60%);
}

.image-link-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.image-link-card__bottom {
  position: relative;
  padding: 1.1rem 1rem 1.2rem;
  display: flex;
  justify-content: center;
  align-items: center;
  background: rgba(11, 18, 31, 0.98);
}

.image-link-card__bottom::before {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: calc(100% - 2rem);
  height: 28px;
  border-radius: 24px 24px 32px 32px;
  background: rgba(94, 123, 255, 0.14);
  z-index: 0;
}

.image-link-card__link {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.9rem 1.2rem;
  border-radius: 999px;
  background: rgba(94, 123, 255, 0.2);
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
  transition: transform var(--transition), background var(--transition), color var(--transition);
}

.image-link-card__link:hover,
.image-link-card__link:focus-visible {
  transform: translateY(-1px);
  background: rgba(94, 123, 255, 0.32);
  color: var(--accent-2);
}

iframe {
  width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 22px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.18);
  background: var(--surface);
}

.settings-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.theme-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.theme-card {
  all: unset;
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
  padding: 1rem;
  border-radius: 24px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.04);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition);
}

.theme-card:hover,
.theme-card:focus-visible {
  transform: translateY(-2px);
  border-color: rgba(94, 123, 255, 0.22);
  box-shadow: 0 20px 45px rgba(94, 123, 255, 0.14);
  background: rgba(255, 255, 255, 0.07);
}

.theme-card.selected {
  border-color: rgba(94, 123, 255, 0.28);
  box-shadow: 0 0 0 3px rgba(94, 123, 255, 0.12);
}

.theme-card__swatch {
  width: 56px;
  height: 56px;
  border-radius: 18px;
  flex-shrink: 0;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), rgba(255, 255, 255, 0.05));
}

.theme-card__swatch--ocean {
  background: linear-gradient(180deg, #5e7bff 0%, #2c4faf 100%);
}

.theme-card__swatch--forest {
  background: linear-gradient(180deg, #79d09a 0%, #2c4f34 100%);
}

.theme-card__swatch--beach {
  background: linear-gradient(180deg, #ffd58d 0%, #7bb6f5 100%);
}

.theme-card__swatch--sunset {
  background: linear-gradient(180deg, #ff7a5c 0%, #8b3f7d 100%);
}

.theme-card__swatch--sunrise {
  background: linear-gradient(180deg, #ffb37d 0%, #6a4b7b 100%);
}

.theme-card__swatch--moonlight {
  background: linear-gradient(180deg, #c0c7ff 0%, #7c8cff 100%);
}

.theme-card__swatch--raspberry {
  background: linear-gradient(180deg, #ff5c80 0%, #cc3a5c 100%);
}

.theme-card__swatch--simplelight {
  background: linear-gradient(180deg, #3182ce 0%, #63b3ed 100%);
}

.theme-card__swatch--custom {
  background: linear-gradient(135deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4);
}

.theme-card--custom {
  background: linear-gradient(135deg, rgba(255, 107, 107, 0.1), rgba(78, 205, 196, 0.1));
}

.custom-theme-editor {
  margin-top: 2rem;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.custom-theme-editor h3 {
  margin-bottom: 1rem;
  color: var(--accent);
}

.custom-inputs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.custom-inputs label {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.custom-inputs input {
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-strong);
  color: var(--text);
  font-size: 0.9rem;
}

.custom-inputs input[type="color"] {
  padding: 0.25rem;
  width: 60px;
  height: 40px;
  cursor: pointer;
}

.theme-card__body {
  display: flex;
  flex-direction: column;
  text-align: left;
}

.theme-card__title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
}

.theme-card__description {
  margin-top: 0.25rem;
  font-size: 0.94rem;
  color: var(--muted);
}

.setting-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 24px;
  padding: 1.5rem;
  transition: transform var(--transition), border-color var(--transition), background var(--transition);
}

.setting-item:hover,
.setting-item:focus-within {
  transform: translateY(-2px);
  border-color: rgba(94, 123, 255, 0.22);
  background: rgba(94, 123, 255, 0.04);
}

.setting-item h3 {
  margin: 0 0 0.75rem 0;
  font-size: 1.05rem;
  color: var(--text);
}

.setting-item p {
  margin: 0;
  color: var(--muted);
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 28px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  transition: background var(--transition);
}

.slider:before {
  content: '';
  position: absolute;
  left: 4px;
  top: 4px;
  width: 20px;
  height: 20px;
  background: #ffffff;
  border-radius: 50%;
  transition: transform var(--transition);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.16);
}

input:checked + .slider {
  background: var(--accent);
}

input:checked + .slider:before {
  transform: translateX(22px);
}

button,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  border: none;
  border-radius: 999px;
  padding: 0.95rem 1.5rem;
  cursor: pointer;
  font-weight: 700;
  transition: transform var(--transition), box-shadow var(--transition), filter var(--transition);
}

button:hover,
.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 40px rgba(94, 123, 255, 0.18);
}

button:active,
.button:active {
  transform: scale(0.98);
}

footer {
  text-align: center;
  color: var(--muted);
  padding: 2rem 1.5rem;
}

footer p {
  margin: 0;
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
    padding: 1.5rem;
  }

  .sidebar {
    position: static;
    top: auto;
  }

  nav {
    position: static;
    max-height: none;
  }
}

@media (max-width: 640px) {
  header {
    padding: 1.5rem 1rem;
  }

  nav a {
    padding: 0.9rem 1rem;
  }

  .container {
    padding: 1.5rem;
    border-radius: 20px;
  }

  .settings-grid {
    gap: 0.9rem;
  }
}