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

:root {
  --bg:        #1c1917;
  --surface:   #28211e;
  --surface2:  #322b27;
  --border:    #3d342f;
  --text:      #fafaf9;
  --muted:     #a8a29e;
  --subtle:    #57534e;
  --accent:    #eab308;
  --accent-hi: #fde047;
  --accent-bg: #1c1400;
  --success:   #16a34a;
  --success-bg:#052e16;
  --warn-bg:   #1c1400;
  --warn-text: #fef08a;
}

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

/* ── Nav ──────────────────────────────────────────────────── */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.875rem 2rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

nav .wordmark {
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-hi);
  text-decoration: none;
  letter-spacing: -0.01em;
}

nav .nav-links { display: flex; gap: 1.25rem; align-items: center; }
nav .nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.15s;
}
nav .nav-links a:hover { color: var(--text); }

/* ── Layout ───────────────────────────────────────────────── */
main {
  max-width: 600px;
  margin: 2.5rem auto;
  padding: 0 1.25rem;
}

h1 {
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.4rem;
}

h2 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-hi);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 0.75rem;
}

p { color: var(--muted); font-size: 0.925rem; }

/* ── Card ─────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  margin-top: 1.25rem;
}

/* ── Forms ────────────────────────────────────────────────── */
label {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  margin-bottom: 0.35rem;
  letter-spacing: 0.02em;
}

input[type="text"],
input[type="password"],
input[type="file"] {
  width: 100%;
  padding: 0.6rem 0.9rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-size: 0.925rem;
  margin-bottom: 1rem;
  transition: border-color 0.15s;
  outline: none;
}

input[type="text"]:focus,
input[type="password"]:focus {
  border-color: var(--accent);
}

input[type="file"] { cursor: pointer; color: var(--muted); }

/* ── Buttons ──────────────────────────────────────────────── */
button, .btn {
  display: inline-block;
  padding: 0.55rem 1.1rem;
  border: none;
  border-radius: 10px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: filter 0.15s, transform 0.1s;
}

button:hover, .btn:hover { filter: brightness(1.1); }
button:active, .btn:active { transform: scale(0.98); }

.btn-primary   { background: var(--accent); color: #1c1000; }
.btn-secondary { background: var(--surface2); color: var(--text); border: 1px solid var(--border); }
.btn-success   { background: var(--success); color: #fff; }
.btn-sm        { padding: 0.3rem 0.65rem; font-size: 0.78rem; border-radius: 7px; }

/* ── Tabs ─────────────────────────────────────────────────── */
.tab-bar {
  display: flex;
  gap: 0.25rem;
  margin-bottom: 1.5rem;
  background: var(--bg);
  border-radius: 10px;
  padding: 0.25rem;
}

.tab-bar button {
  flex: 1;
  background: transparent;
  color: var(--muted);
  border-radius: 8px;
  padding: 0.45rem 0;
}

.tab-bar button.active {
  background: var(--accent);
  color: #1c1000;
}

/* ── Result box ───────────────────────────────────────────── */
.result-box {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem;
  margin-top: 0.85rem;
  word-break: break-all;
}

.result-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--border);
}
.result-row:last-child { border-bottom: none; padding-bottom: 0; }
.result-row:first-child { padding-top: 0; }

.result-label {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--subtle);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.2rem;
}
.result-value {
  font-family: ui-monospace, monospace;
  font-size: 0.82rem;
  color: var(--accent-hi);
  flex: 1;
}

/* ── Notices ──────────────────────────────────────────────── */
.notice {
  font-size: 0.85rem;
  padding: 0.65rem 1rem;
  border-radius: 10px;
  margin-top: 1rem;
  line-height: 1.5;
}
.notice-warn { background: var(--warn-bg);   color: var(--warn-text); border: 1px solid #854d0e; }
.notice-ok   { background: var(--success-bg); color: #86efac;          border: 1px solid #166534; }

/* ── Spinner ──────────────────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 0.9rem; height: 0.9rem;
  border: 2px solid var(--accent);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.65s linear infinite;
  vertical-align: middle;
  margin-right: 0.4rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Explain page ─────────────────────────────────────────── */
.card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.card p, .card li { font-size: 0.925rem; margin-bottom: 0.85rem; }
.card ul { padding-left: 1.4rem; }
.card li { line-height: 1.7; color: var(--muted); }
.card strong { color: var(--text); font-weight: 600; }

code {
  background: var(--surface2);
  border: 1px solid var(--border);
  padding: 0.15rem 0.45rem;
  border-radius: 5px;
  font-size: 0.82rem;
  font-family: ui-monospace, monospace;
  color: var(--accent-hi);
}

/* ── Section visibility ───────────────────────────────────── */
#auth-section, #app-section { display: none; }

#nav-user { font-size: 0.85rem; color: #64748b; }

/* ── Explain page sections ────────────────────────────────── */
.explain-section { margin-bottom: 0; }

/* ── Trash button ─────────────────────────────────────────── */
.trash-btn {
  background: none;
  border: none;
  color: var(--subtle);
  cursor: pointer;
  padding: 0.375rem;
  border-radius: 8px;
  transition: color 0.15s, background 0.15s;
  line-height: 0;
}
.trash-btn:hover { color: #f87171; background: rgba(248,113,113,0.1); filter: none; }

/* ── Mobile nav ───────────────────────────────────────────── */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.4rem;
  border-radius: 8px;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}
.nav-hamburger:hover { background: var(--surface2); filter: none; }

@media (max-width: 600px) {
  nav { flex-wrap: wrap; gap: 0; padding: 0.75rem 1.25rem; }

  .nav-hamburger { display: flex; margin-left: auto; }

  nav .nav-links {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    width: 100%;
    padding: 0.5rem 0 0.75rem;
    border-top: 1px solid var(--border);
    margin-top: 0.5rem;
  }
  nav .nav-links.open { display: flex; }

  nav .nav-links a, nav .nav-links span, nav .nav-links button {
    width: 100%;
    padding: 0.55rem 0.25rem;
    font-size: 0.95rem;
  }
  nav .nav-links .btn { text-align: left; margin-top: 0.25rem; }
}