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

:root {
  --bg: #f9f9f9;
  --surface: #ffffff;
  --surface-soft: #f1f4f7;
  --text: #333333;
  --text-soft: #555555;
  --accent: #3498db;
  --accent-strong: #2980b9;
  --nav-bg: #2c3e50;
  --border: #d7dee5;
}

body.dark-theme {
  --bg: #0f1720;
  --surface: #1b2734;
  --surface-soft: #223243;
  --text: #e7edf3;
  --text-soft: #c8d5e2;
  --accent: #6bb3ff;
  --accent-strong: #91c5ff;
  --nav-bg: #121b25;
  --border: #324658;
}

body {
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu",
    "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
  line-height: 1.6;
  color: var(--text);
  background-color: var(--bg);
}

nav {
  background-color: var(--nav-bg);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  z-index: 100;
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

nav a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  transition: color 0.3s ease;
  padding: 0.5rem 1rem;
  border-radius: 4px;
}

nav a:hover {
  color: var(--accent);
  text-decoration: none;
  background-color: rgba(52, 152, 219, 0.1);
}

.theme-switcher {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: #fff;
  font-weight: 600;
}

.theme-switcher input {
  transform: scale(1.2);
  cursor: pointer;
}

section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 1rem;
  background-color: var(--surface);
  margin-bottom: 1rem;
  border-radius: 8px;
}

section:nth-child(odd) {
  background-color: var(--surface-soft);
}

section#about {
  margin-top: 20px;
}

section h1 {
  font-size: 2.5rem;
  color: var(--text);
  margin-bottom: 1.5rem;
  border-bottom: 3px solid var(--accent);
  padding-bottom: 0.5rem;
}

section p {
  font-size: 1.1rem;
  color: var(--text-soft);
  margin-bottom: 1rem;
  line-height: 1.8;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.3s ease;
  font-weight: 500;
}

a:hover {
  color: var(--accent-strong);
  text-decoration: underline;
}

ul {
  margin-left: 1.5rem;
  margin-top: 1rem;
}

li {
  margin-bottom: 1rem;
  color: var(--text-soft);
  line-height: 1.8;
}

li a {
  display: inline;
}

#comments-list {
  margin-top: 1rem;
  margin-left: 1.5rem;
}

#comments-list li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
}

.muted {
  opacity: 0.8;
}

footer {
  max-width: 1200px;
  margin: 0 auto 2rem;
  padding: 2rem 1rem;
  background: var(--surface);
  border-radius: 8px;
  border: 1px solid var(--border);
}

footer h2 {
  margin-bottom: 0.75rem;
}

#storage-content ul {
  margin-left: 1.5rem;
}

#storage-content li {
  margin-bottom: 0.4rem;
  word-break: break-word;
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 1rem;
  z-index: 300;
}

.hidden {
  display: none;
}

.modal-content {
  width: min(560px, 100%);
  background: var(--surface);
  color: var(--text);
  border-radius: 10px;
  border: 1px solid var(--border);
  padding: 1.25rem;
  position: relative;
}

.modal-close {
  position: absolute;
  top: 0.5rem;
  right: 0.8rem;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 1.8rem;
  cursor: pointer;
}

#feedback-form {
  display: grid;
  gap: 0.6rem;
}

#feedback-form input,
#feedback-form textarea,
#feedback-form button {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.65rem;
  font: inherit;
}

#feedback-form button {
  margin-top: 0.6rem;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
  border: none;
  font-weight: 600;
}

#feedback-form button:hover {
  background: var(--accent-strong);
}