/* ── Variables ─────────────────────────────────────────────────────────────── */
:root {
  --bg:           #0a0a0a;
  --bg2:          #111111;
  --green:        #00cc44;
  --green-bright: #00ff66;
  --green-dim:    #005522;
  --green-border: #007733;
  --amber:        #ffaa00;
  --red:          #ff4444;
  --font:         'Courier New', Courier, monospace;
}

/* ── Reset ─────────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Base ──────────────────────────────────────────────────────────────────── */
body {
  background-color: var(--bg);
  color: var(--green);
  font-family: var(--font);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── Matrix rain canvas ────────────────────────────────────────────────────── */
#bg-canvas {
  position: fixed;
  inset: 0;
  z-index: 0;
  display: block;
}


.scanlines {
  position: fixed;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0,0,0,.04) 2px,
    rgba(0,0,0,.04) 4px
  );
  pointer-events: none;
  z-index: 999;
}

/* ── Layout ────────────────────────────────────────────────────────────────── */
.container {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
  padding: 2.25rem 1.5rem 2rem;
}

/* ── Header ────────────────────────────────────────────────────────────────── */
header {
  text-align: center;
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--green-border);
}

.logo {
  font-size: 2.4rem;
  font-weight: bold;
  letter-spacing: .18em;
  text-shadow: 0 0 10px var(--green), 0 0 22px rgba(0,204,68,.35);
}

.logo-hash {
  color: var(--green-bright);
  text-shadow: 0 0 14px var(--green-bright);
}

/* ── Tabs ──────────────────────────────────────────────────────────────────── */
.tabs {
  display: flex;
  gap: .4rem;
  margin-bottom: 0;
}

.tab {
  background: var(--bg);
  color: var(--green-border);
  border: 1px solid var(--green-border);
  border-bottom: none;
  padding: .5rem 1.4rem;
  font-family: var(--font);
  font-size: .88rem;
  cursor: pointer;
  letter-spacing: .1em;
  transition: color .1s, border-color .1s, background .1s;
}

.tab:hover {
  color: var(--green);
  border-color: var(--green);
}

.tab.active {
  color: var(--green-bright);
  border-color: var(--green);
  background: var(--bg2);
  text-shadow: 0 0 7px var(--green);
}

/* ── Panel ─────────────────────────────────────────────────────────────────── */
.panel {
  border: 1px solid var(--green-border);
  padding: 1.25rem;
  background: rgba(17,17,17,.82);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  margin-bottom: 1.2rem;
}

.panel.hidden { display: none; }

/* ── Label ─────────────────────────────────────────────────────────────────── */
.label {
  display: block;
  font-size: .78rem;
  color: var(--green-border);
  letter-spacing: .12em;
  margin-bottom: .45rem;
  text-transform: uppercase;
}

/* ── Textarea ──────────────────────────────────────────────────────────────── */
textarea {
  width: 100%;
  background: var(--bg);
  color: var(--green);
  border: 1px solid var(--green-border);
  font-family: var(--font);
  font-size: .92rem;
  line-height: 1.55;
  padding: .75rem;
  resize: none;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}

textarea:focus {
  border-color: var(--green);
  box-shadow: 0 0 8px rgba(0,204,68,.2);
}

textarea::placeholder { color: var(--green-dim); }

.text-meta {
  font-size: .73rem;
  color: var(--green-dim);
  margin-top: .35rem;
  text-align: right;
  letter-spacing: .06em;
}

/* ── Drop zone ─────────────────────────────────────────────────────────────── */
.drop-zone {
  border: 2px dashed var(--green-border);
  padding: 2.75rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
  user-select: none;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--green);
  background: rgba(0,204,68,.05);
}

.drop-zone:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 2px;
}

#file-input { display: none; }

.drop-icon {
  font-size: 1.4rem;
  color: var(--green-border);
  margin-bottom: .6rem;
  letter-spacing: .25em;
}

.drop-text {
  font-size: .95rem;
  letter-spacing: .2em;
  color: var(--green);
  margin-bottom: .3rem;
}

.drop-sub {
  font-size: .8rem;
  color: var(--green-border);
}

.link {
  color: var(--green);
  cursor: pointer;
  text-decoration: underline;
}

.link:hover { color: var(--green-bright); }

.file-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-top: .9rem;
  padding: .55rem .75rem;
  background: var(--bg);
  border: 1px solid var(--green-border);
  font-size: .83rem;
}

.file-info.hidden { display: none; }

#file-name {
  color: var(--green);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

#file-size {
  color: var(--green-border);
  white-space: nowrap;
  flex-shrink: 0;
}

/* ── Controls ──────────────────────────────────────────────────────────────── */
.controls {
  display: flex;
  align-items: flex-end;
  gap: 1rem;
  margin-bottom: 1.2rem;
  flex-wrap: wrap;
}

.algo-wrap { flex: 1; min-width: 180px; }

select {
  width: 100%;
  background: var(--bg);
  color: var(--green);
  border: 1px solid var(--green-border);
  font-family: var(--font);
  font-size: .92rem;
  padding: .6rem 2.2rem .6rem .75rem;
  outline: none;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%23007733'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .75rem center;
  transition: border-color .15s;
}

select:focus { border-color: var(--green); }

.compute-btn {
  background: var(--bg);
  color: var(--green-bright);
  border: 2px solid var(--green);
  font-family: var(--font);
  font-size: .98rem;
  font-weight: bold;
  padding: .6rem 1.6rem;
  cursor: pointer;
  letter-spacing: .15em;
  text-shadow: 0 0 8px var(--green);
  white-space: nowrap;
  transition: background .1s, box-shadow .1s;
}

.compute-btn:hover {
  background: rgba(0,204,68,.1);
  box-shadow: 0 0 14px rgba(0,204,68,.28);
}

.compute-btn:active { background: rgba(0,204,68,.2); }

.compute-btn.loading {
  color: var(--amber);
  border-color: var(--amber);
  text-shadow: 0 0 8px var(--amber);
}

/* ── Output ────────────────────────────────────────────────────────────────── */
.output-wrap {
  border: 1px solid var(--green-border);
  padding: 1.25rem;
  background: rgba(17,17,17,.82);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  margin-bottom: 1.2rem;
}

.output-box {
  background: var(--bg);
  border: 1px solid var(--green-border);
  padding: 1rem;
  margin: .7rem 0 1rem;
  min-height: 66px;
  word-break: break-all;
}

.output-meta {
  font-size: .7rem;
  color: var(--green-border);
  letter-spacing: .12em;
  margin-bottom: .45rem;
  min-height: 1em;
}

.output-hash {
  font-size: 1rem;
  color: var(--green-bright);
  letter-spacing: .06em;
  text-shadow: 0 0 6px rgba(0,255,102,.35);
  line-height: 1.65;
  min-height: 1.65em;
}

.output-hash.error {
  color: var(--red);
  text-shadow: 0 0 6px rgba(255,68,68,.4);
}

/* ── Output action buttons ─────────────────────────────────────────────────── */
.output-actions { display: flex; gap: .7rem; flex-wrap: wrap; }

.action-btn {
  background: var(--bg);
  color: var(--green-border);
  border: 1px solid var(--green-border);
  font-family: var(--font);
  font-size: .83rem;
  padding: .4rem 1rem;
  cursor: pointer;
  letter-spacing: .1em;
  transition: color .1s, border-color .1s;
}

.action-btn:hover:not(:disabled) {
  color: var(--green);
  border-color: var(--green);
}

.action-btn:disabled {
  opacity: .35;
  cursor: not-allowed;
}

.action-btn.copied {
  color: var(--green-bright);
  border-color: var(--green-bright);
  text-shadow: 0 0 6px var(--green);
}

/* ── Mobile ────────────────────────────────────────────────────────────────── */
@media (max-width: 580px) {
  .container       { padding: 1rem 1rem 1.5rem; }
  .logo            { font-size: 1.75rem; }
  .controls        { flex-direction: column; align-items: stretch; }
  .algo-wrap       { min-width: auto; }
  .compute-btn     { text-align: center; }
  .output-hash     { font-size: .88rem; }
}