/* === Base Theme === */
:root {
  --bg: #f4f5f2;
  --surface: #fbfbf7;
  --surface-soft: #fafaf8;
  --surface-muted: #ecefeb;
  --text: #1f2933;
  --text-muted: #5f6b76;
  --border: #d7ddd4;
  --accent: #2f6f73;
  --accent-dark: #24585b;
  --accent-soft: #e2f0ef;
  --shadow: 0 16px 40px rgba(31, 41, 51, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  font-family: Inter, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(47, 111, 115, 0.12), transparent 32rem),
    linear-gradient(180deg, #f9faf7 0%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.6;
  padding: 2rem clamp(1rem, 4vw, 3rem) 3rem;
}

body > h1,
.site-hero,
body > form,
body > .preview,
body > .output,
body > .divider {
  max-width: 1050px;
  margin-left: auto;
  margin-right: auto;
}

h1, h2 {
  color: var(--text);
  letter-spacing: -0.03em;
  margin: 0 0 0.65em;
}

h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.05;
}

h2 {
  font-size: 1.25rem;
}

.site-hero {
  text-align: center;
  margin-bottom: 2rem;
  padding: 2.4rem 1rem 1.2rem;
}

.site-hero p {
  max-width: 680px;
  margin: 0 auto;
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* === Form Container === */
form {
  background: rgba(251, 251, 247, 0.88);
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

label {
  display: block;
  margin-top: 1.1em;
  font-weight: 600;
  color: var(--text);
}

/* === Inputs & Textareas === */
input[type="text"],
input[type="number"],
textarea,
select {
  width: 100%;
  padding: 0.75em;
  margin-top: 0.4em;
  border: 1px solid var(--border);
  border-radius: 10px;
  background-color: var(--surface-soft);
  color: var(--text);
  font-size: 1em;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

input[type="text"]:focus,
input[type="number"]:focus,
textarea:focus,
select:focus {
  border-color: var(--accent);
  background-color: var(--surface);
  box-shadow: 0 0 0 4px rgba(47, 111, 115, 0.14);
  outline: none;
}

input[type="checkbox"] {
  margin-left: 0.6em;
  transform: scale(1.3);
  cursor: pointer;
}

/* === Buttons === */
button {
  margin-top: 1.5em;
  padding: 0.8em 1.6em;
  border: none;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: #fff;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 10px 20px rgba(47, 111, 115, 0.18);
  transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease;
}

button:hover {
  transform: translateY(-2px);
  filter: brightness(1.04);
  box-shadow: 0 14px 26px rgba(47, 111, 115, 0.24);
}

button:active {
  transform: translateY(0);
  box-shadow: 0 7px 16px rgba(47, 111, 115, 0.18);
}

/* === Output Section === */
.output {
  background: rgba(251, 251, 247, 0.9);
  margin-top: 2em;
  padding: 1.5em;
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

textarea[readonly] {
  background: #f7f8f5;
  border: 1px solid var(--border);
  resize: vertical;
  padding: 0.75em;
  border-radius: 10px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.95em;
  min-height: 150px;
}

/* === Divider === */
.divider {
  margin: 2em 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}

/* === Preview Section === */
.preview {
  margin-bottom: 20px;
  padding: 1.25rem;
  background: rgba(251, 251, 247, 0.78);
  border: 1px solid var(--border);
  border-radius: 18px;
  color: var(--text);
  box-shadow: 0 10px 28px rgba(31, 41, 51, 0.06);
}

.preview h2 {
  font-size: 1.3em;
  margin-bottom: 10px;
  color: var(--text);
  border-bottom: 1px solid var(--border);
  padding-bottom: 5px;
}

/* Cipher + Plaintext styling */
.cipher pre, .plain pre {
  font-family: monospace;
  font-size: 18px;
  margin: 0 0 10px 0;
  white-space: pre-wrap;
  display: block;
  letter-spacing: 2px;
}

/* Highlight plaintext row */
.plain pre {
  background: var(--accent-soft);
  color: var(--accent-dark);
  padding: 0.45rem;
  border-radius: 8px;
}

/* Frequency Table */
.freq table {
  border-collapse: collapse;
  margin-top: 10px;
  width: 100%;
  table-layout: fixed;
}

.freq th, .freq td {
  border: 1px solid var(--border);
  text-align: center;
  padding: 6px;
  color: var(--text);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

.freq th {
  background: var(--surface-muted);
  font-weight: bold;
}

/* Index page cipher cards */
.cipher-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 1rem;
  max-width: 1050px;
  margin: 1.5rem auto 0;
}

.cipher-card {
  background-color: rgba(251, 251, 247, 0.88);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 10px 26px rgba(31, 41, 51, 0.06);
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.cipher-card:hover {
  transform: translateY(-3px);
  border-color: rgba(47, 111, 115, 0.35);
  box-shadow: 0 18px 36px rgba(31, 41, 51, 0.1);
}

.cipher-card a {
  color: var(--text);
  text-decoration: none;
  font-weight: bold;
  display: block;
  font-size: 1.1em;
  padding: 1.2rem;
}

.cipher-card a::after {
  content: "Open encoder";
  display: block;
  margin-top: 0.35rem;
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

/* Preformatted for fractionated / aligned output */
#fracPreview pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  white-space: pre;
}

pre {
  color: var(--text);
}

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

  .cipher-list {
    grid-template-columns: 1fr;
  }
}