@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@400;500&family=Instrument+Sans:wght@400;500;600&display=swap');

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

:root {
  --bg: #0c0d10;
  --surface: #16171c;
  --border: #26282f;
  --border-hover: #3a3c46;
  --text: #e6e6eb;
  --text-secondary: #9294a0;
  --text-muted: #55575f;
  --green: #4ade80;
  --green-bg: rgba(74, 222, 128, 0.08);
  --mono: 'DM Mono', ui-monospace, monospace;
  --sans: 'Instrument Sans', system-ui, sans-serif;
  --radius: 10px;
}

html {
  color-scheme: dark;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 3rem 1.25rem 2rem;
  max-width: 540px;
  margin: 0 auto;
  width: 100%;
  gap: 2rem;
}

header {
  text-align: center;
}

h1 {
  font-family: var(--sans);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.description {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.generator {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

#phone-number {
  width: 100%;
  font-family: var(--mono);
  font-size: clamp(1.6rem, 6vw, 2.2rem);
  font-weight: 500;
  text-align: center;
  letter-spacing: 0.04em;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.8rem 1rem;
  outline: none;
  cursor: text;
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

#phone-number:focus {
  border-color: var(--border-hover);
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.04);
}

#phone-number.copied {
  border-color: var(--green);
  color: var(--green);
}

.actions {
  display: flex;
  gap: 0.5rem;
}

.actions button {
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 500;
  padding: 0.5rem 1.2rem;
  border-radius: 8px;
  cursor: pointer;
  transition:
    background 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease;
}

#copy {
  color: var(--bg);
  background: var(--text);
  border: 1px solid var(--text);
}

#copy:hover {
  background: #fff;
  border-color: #fff;
}

#copy:active {
  background: #d0d0d5;
}

#regenerate {
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid var(--border);
}

#regenerate:hover {
  border-color: var(--border-hover);
  color: var(--text);
  background: var(--surface);
}

#regenerate:active {
  background: #1c1d24;
}

#copy-feedback {
  font-size: 0.75rem;
  color: var(--green);
  min-height: 1.2em;
  transition: opacity 0.2s ease;
}

.faq {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--border);
}

details {
  border-bottom: 1px solid var(--border);
}

summary {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.85rem 0;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color 0.15s ease;
}

summary:hover {
  color: var(--text);
}

summary::after {
  content: '+';
  font-family: var(--mono);
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: transform 0.2s ease;
}

details[open] summary::after {
  content: '-';
}

summary::-webkit-details-marker {
  display: none;
}

details p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  padding: 0 0 0.85rem;
  line-height: 1.7;
}

details a {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border);
  transition:
    text-decoration-color 0.15s ease;
}

details a:hover {
  text-decoration-color: var(--text-secondary);
}

footer {
  padding: 1.5rem 1.25rem;
  text-align: center;
  font-size: 0.7rem;
  color: var(--text-muted);
}

footer a {
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition:
    color 0.15s ease,
    border-color 0.15s ease;
}

footer a:hover {
  color: var(--text);
  border-color: var(--border-hover);
}