/**
 * Phone Word Converter — Styles
 * Minimal, responsive, system-font design.
 */

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

:root {
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --color-border: #e0e0e0;
  --color-text: #1a1a1a;
  --color-text-muted: #6b7280;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-accent: #f0f4ff;
  --color-tag-bg: #e8f0fe;
  --color-tag-text: #1a56db;
  --radius: 8px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', 'Courier New', monospace;
}

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

/* ── Layout ── */

.container {
  max-width: 560px;
  margin: 0 auto;
  padding: 0 20px;
  width: 100%;
}

header {
  text-align: center;
  padding: 48px 0 32px;
}

header h1 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 6px;
}

header p {
  color: var(--color-text-muted);
  font-size: 15px;
}

main {
  flex: 1;
  padding-bottom: 48px;
}

/* ── Tabs ── */

.tabs {
  display: flex;
  gap: 4px;
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 4px;
  margin-bottom: 24px;
}

.tab-btn {
  flex: 1;
  padding: 10px 16px;
  border: none;
  border-radius: 6px;
  background: transparent;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
}

.tab-btn:hover {
  color: var(--color-text);
}

.tab-btn.active {
  background: var(--color-bg);
  color: var(--color-text);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

/* ── Panels ── */

.panel {
  display: none;
}

.panel.active {
  display: block;
}

/* ── Input ── */

.input-group {
  margin-bottom: 20px;
}

.input-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

.input-wrap {
  position: relative;
}

.input-group input {
  width: 100%;
  padding: 12px 36px 12px 16px;
  font-family: var(--font-mono);
  font-size: 18px;
  letter-spacing: 1px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  outline: none;
  transition: border-color 0.15s ease;
}

.input-group input:focus {
  border-color: var(--color-primary);
}

/* ── Clear button ── */

.clear-btn {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 22px;
  height: 22px;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: var(--color-border);
  color: #fff;
  font-size: 14px;
  line-height: 22px;
  text-align: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
}

.input-wrap:hover .clear-btn,
.input-group input:focus ~ .clear-btn {
  opacity: 1;
  pointer-events: auto;
}

.clear-btn:hover {
  background: var(--color-text-muted);
}

.input-group input::placeholder {
  color: #c0c0c0;
  letter-spacing: 0;
  font-size: 15px;
}

/* ── Result ── */

.result {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 20px;
  min-height: 64px;
}

.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.result-label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--color-text-muted);
}

/* ── Share button ── */

.share-btn {
  padding: 4px 12px;
  font-family: var(--font);
  font-size: 12px;
  font-weight: 500;
  color: var(--color-primary);
  background: transparent;
  border: 1px solid var(--color-primary);
  border-radius: 14px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.share-btn:hover {
  background: var(--color-accent);
}

.share-btn.copied {
  color: #16a34a;
  border-color: #16a34a;
  background: #f0fdf4;
}

.result-value {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--color-primary);
  word-break: break-all;
}

.result-value:empty::after {
  content: '\2014';
  color: var(--color-border);
}

/* ── Word list (number-to-words) ── */

.word-count {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 12px;
}

.word-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
}

.word-list li {
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: 6px 14px;
  border-radius: 20px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.5px;
}

.empty-state {
  color: var(--color-text-muted);
  font-size: 14px;
  font-style: italic;
}

/* ── Keypad ── */

.keypad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-top: 24px;
  max-width: 300px;
  margin-left: auto;
  margin-right: auto;
}

.key {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 12px 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-bg);
  transition: all 0.15s ease;
  min-height: 56px;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
}

.key:hover {
  background: var(--color-surface);
  border-color: #c0c0c0;
}

.key:active,
.key.pressed {
  transform: scale(0.95);
  background: var(--color-accent);
  border-color: var(--color-primary);
}

.key.highlighted {
  background: var(--color-accent);
  border-color: var(--color-primary);
}

.key:not([data-digit]) {
  cursor: default;
  opacity: 0.4;
}

.key:not([data-digit]):hover {
  background: var(--color-bg);
  border-color: var(--color-border);
}

.key:not([data-digit]):active {
  transform: none;
  background: var(--color-bg);
  border-color: var(--color-border);
}

.key-digit {
  font-size: 18px;
  font-weight: 600;
  line-height: 1;
}

.key-letters {
  font-size: 10px;
  letter-spacing: 2px;
  color: var(--color-text-muted);
  margin-top: 2px;
}

/* ── Footer ── */

footer {
  text-align: center;
  padding: 24px 0;
  border-top: 1px solid var(--color-border);
  font-size: 13px;
  color: var(--color-text-muted);
}

footer a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
}

footer a:hover {
  text-decoration: underline;
}

/* ── Responsive ── */

@media (max-width: 480px) {
  header {
    padding: 32px 0 24px;
  }

  header h1 {
    font-size: 22px;
  }

  .result-value {
    font-size: 22px;
  }

  .keypad {
    max-width: 260px;
  }
}