/* ============================================================
   style.css -- Online Tip Calculator
   Material Design 3 inspired, orange accent, desktop-first
   ============================================================ */

/* ----- CSS Custom Properties (MD3 tokens) ----- */
:root {
  /* Brand colors */
  --color-primary:            #E65100;
  --color-on-primary:         #FFFFFF;
  --color-primary-container:  #FFDBCC;
  --color-on-primary-container: #380D00;
  --color-primary-hover:      #BF360C;

  /* Surface / background */
  --color-background:         #FFF8F6;
  --color-surface:            #FFFBFE;
  --color-surface-1:          #F8F1EF;
  --color-surface-variant:    #F5DDD5;

  /* Text */
  --color-on-surface:         #1C1B1F;
  --color-on-surface-variant: #53433E;

  /* Borders */
  --color-outline:            #85736E;
  --color-outline-variant:    #D8C2BC;

  /* Feedback */
  --color-error:              #B3261E;
  --color-success:            #2E7D32;

  /* Typography */
  --font:                     'Roboto', sans-serif;
  --fs-display:               2rem;
  --fs-headline:              1.5rem;
  --fs-title:                 1.125rem;
  --fs-body:                  1rem;
  --fs-label:                 0.875rem;
  --fs-caption:               0.75rem;

  /* Border radius */
  --r-xs:   4px;
  --r-sm:   8px;
  --r-md:   12px;
  --r-lg:   16px;
  --r-xl:   24px;
  --r-full: 50px;

  /* Elevation */
  --shadow-1: 0 1px 3px rgba(0,0,0,.12), 0 1px 2px rgba(0,0,0,.08);
  --shadow-2: 0 3px 6px rgba(0,0,0,.10), 0 2px 4px rgba(0,0,0,.08);
  --shadow-3: 0 8px 20px rgba(0,0,0,.10), 0 4px 8px rgba(0,0,0,.08);

  /* Spacing */
  --sp-xs:  4px;
  --sp-sm:  8px;
  --sp-md:  16px;
  --sp-lg:  24px;
  --sp-xl:  32px;
  --sp-2xl: 48px;

  /* Motion */
  --ease-fast: 120ms ease;
  --ease-std:  200ms ease;
  --ease-slow: 320ms ease;
}

/* ----- Self-hosted Roboto (files downloaded by download-fonts.py) ----- */
@font-face {
  font-family: 'Roboto';
  font-style: normal;
  font-weight: 300;
  font-display: block;
  src: url('fonts/roboto-light.woff2') format('woff2');
}

@font-face {
  font-family: 'Roboto';
  font-style: normal;
  font-weight: 400;
  font-display: block;
  src: url('fonts/roboto-regular.woff2') format('woff2');
}

@font-face {
  font-family: 'Roboto';
  font-style: normal;
  font-weight: 500;
  font-display: block;
  src: url('fonts/roboto-medium.woff2') format('woff2');
}

@font-face {
  font-family: 'Roboto';
  font-style: normal;
  font-weight: 700;
  font-display: block;
  src: url('fonts/roboto-bold.woff2') format('woff2');
}

@font-face {
  font-family: 'WindowsCommandPrompt';
  font-style: normal;
  font-weight: 400;
  font-display: block;
  src: url('fonts/windows_command_prompt.ttf') format('truetype');
}

/* ----- Reset -------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  font-size: var(--fs-body);
  color: var(--color-on-surface);
  background-color: var(--color-background);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
button { font-family: var(--font); cursor: pointer; }
input  { font-family: var(--font); }

/* ----- Site Header -------------------------------------------- */
.site-header {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  padding: var(--sp-md) var(--sp-xl);
  box-shadow: var(--shadow-2);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
}

.site-logo { font-size: 2.25rem; line-height: 1; }
.site-title { font-size: 2.25rem; font-weight: 700; letter-spacing: .01em; margin: 0; }

/* Make the header link behave like a block, not inline text */
a.header-inner {
  text-decoration: none;
  color: inherit;
}
a.header-inner:hover { opacity: .88; }

/* ----- Ad banners --------------------------------------------- */
.ad-banner {
  max-width: 1100px;
  margin: var(--sp-lg) auto;
  padding: 0 var(--sp-xl);
  text-align: center;
}

/* ----- Calculator layout (two-column desktop) ----------------- */
.calculator-layout {
  max-width: 1100px;
  margin: var(--sp-xl) auto;
  padding: 0 var(--sp-xl);
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: var(--sp-xl);
  align-items: start;
}

/* ----- Inputs panel ------------------------------------------- */
.inputs-panel {
  display: flex;
  flex-direction: column;
  gap: var(--sp-lg);
}

.field-group {
  display: flex;
  flex-direction: column;
  gap: var(--sp-xs);
}

.field-label {
  font-size: var(--fs-label);
  font-weight: 500;
  color: var(--color-on-surface-variant);
  letter-spacing: .04em;
  text-transform: uppercase;
}

.field-optional {
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
  font-size: var(--fs-caption);
  color: var(--color-outline);
}

/* ----- Text fields -------------------------------------------- */
.text-field {
  height: 56px;
  border: 1px solid var(--color-outline);
  border-radius: var(--r-sm);
  padding: 0 var(--sp-md);
  font-size: var(--fs-title);
  color: var(--color-on-surface);
  background-color: var(--color-surface);
  transition: border-color var(--ease-std), box-shadow var(--ease-std);
  outline: none;
  width: 100%;
}

.text-field:hover:not(:focus) { border-color: var(--color-on-surface); }

.text-field:focus {
  border-color: var(--color-primary);
  border-width: 2px;
  box-shadow: 0 0 0 3px rgba(230,81,0,.12);
}

/* Remove spinner arrows on number inputs */
.text-field[type="number"]::-webkit-inner-spin-button,
.text-field[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
.text-field[type="number"] { -moz-appearance: textfield; }

/* ----- Dollar prefix wrapper ---------------------------------- */
.input-prefix-wrapper { position: relative; display: flex; align-items: center; }

.input-prefix {
  position: absolute;
  left: var(--sp-md);
  font-size: var(--fs-title);
  color: var(--color-on-surface-variant);
  pointer-events: none;
  user-select: none;
}

.input-prefix-wrapper .text-field { padding-left: 28px; }

/* ----- People stepper ----------------------------------------- */
.stepper-wrapper { display: flex; align-items: center; gap: var(--sp-sm); }

.stepper-btn {
  width: 48px;
  height: 48px;
  border-radius: var(--r-full);
  border: 1px solid var(--color-primary);
  background-color: var(--color-primary-container);
  color: var(--color-primary);
  font-size: 1.5rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background-color var(--ease-fast), border-color var(--ease-fast), color var(--ease-fast);
}

.stepper-btn:hover {
  background-color: color-mix(in srgb, var(--color-primary-container) 75%, var(--color-primary) 25%);
  border-color: var(--color-primary);
}

.stepper-btn:active {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  transform: scale(.95);
}

.stepper-input { text-align: center; flex: 1; }

/* ----- Custom dropdown (desktop) ------------------------------ */

/* Hide the native select on desktop */
.native-select { display: none; }

.custom-select-wrapper { position: relative; width: 100%; }

.custom-select-trigger {
  width: 100%;
  height: 56px;
  border: 1px solid var(--color-outline);
  border-radius: var(--r-sm);
  padding: 0 var(--sp-md);
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
  background-color: var(--color-surface);
  color: var(--color-on-surface);
  font-size: var(--fs-body);
  transition: border-color var(--ease-std);
  outline: none;
  text-align: left;
}

.custom-select-trigger:hover { border-color: var(--color-on-surface); }

.custom-select-trigger[aria-expanded="true"] {
  border-color: var(--color-primary);
  border-width: 2px;
}

.trigger-icon  { font-size: 1.5rem; flex-shrink: 0; }
.trigger-text  { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--color-on-surface-variant); }
.trigger-text.selected { color: var(--color-on-surface); }
.trigger-arrow { font-size: .875rem; color: var(--color-on-surface-variant); flex-shrink: 0; transition: transform var(--ease-std); }
.custom-select-trigger[aria-expanded="true"] .trigger-arrow { transform: rotate(180deg); }

.custom-select-dropdown {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: 0; right: 0;
  background-color: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-3);
  z-index: 200;
  overflow: hidden;
  max-height: 320px;
}

.custom-select-dropdown.open { display: flex; flex-direction: column; }

.dropdown-search-wrapper {
  padding: var(--sp-sm) var(--sp-sm) var(--sp-xs);
  border-bottom: 1px solid var(--color-outline-variant);
  flex-shrink: 0;
}

.dropdown-search {
  width: 100%;
  height: 40px;
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--r-sm);
  padding: 0 var(--sp-sm);
  font-size: var(--fs-label);
  background-color: var(--color-surface-1);
  color: var(--color-on-surface);
  outline: none;
}

.dropdown-search:focus { border-color: var(--color-primary); }

.dropdown-list { list-style: none; overflow-y: auto; flex: 1; padding: var(--sp-xs) 0; }

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
  padding: var(--sp-sm) var(--sp-md);
  cursor: pointer;
  transition: background-color var(--ease-fast);
  font-size: var(--fs-body);
}

.dropdown-item:hover,
.dropdown-item.focused { background-color: var(--color-surface-variant); }

.dropdown-item.selected {
  background-color: var(--color-primary-container);
  color: var(--color-on-primary-container);
}

.dropdown-item-icon  { font-size: 1.5rem; flex-shrink: 0; width: 32px; text-align: center; }
.dropdown-item-name  { flex: 1; font-weight: 400; }
.dropdown-item-range { font-size: var(--fs-label); color: var(--color-on-surface-variant); font-weight: 500; }
.dropdown-item.selected .dropdown-item-range { color: var(--color-on-primary-container); }

.dropdown-item-clear {
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
  padding: var(--sp-sm) var(--sp-md);
  cursor: pointer;
  font-size: var(--fs-label);
  color: var(--color-on-surface-variant);
  border-top: 1px solid var(--color-outline-variant);
  transition: background-color var(--ease-fast);
}

.dropdown-item-clear:hover { background-color: var(--color-surface-variant); }

/* ----- Results panel ------------------------------------------ */
.results-panel {
  display: flex;
  flex-direction: column;
  gap: var(--sp-lg);
}

/* ----- Results card ------------------------------------------- */
.results-card {
  background-color: var(--color-surface);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-2);
  padding: var(--sp-lg);
  display: flex;
  flex-direction: column;
  gap: var(--sp-sm);
}

.result-row  { display: flex; justify-content: space-between; align-items: center; padding: var(--sp-xs) 0; }
.result-label { font-size: var(--fs-body); color: var(--color-on-surface-variant); }
.result-value { font-size: var(--fs-title); font-weight: 500; color: var(--color-on-surface); }

.result-divider { height: 1px; background-color: var(--color-outline-variant); margin: var(--sp-xs) 0; }

/* Your Tip % row */
.result-highlight .result-value { color: var(--color-primary); font-size: 1.25rem; font-weight: 700; }

/* Total Amount row */
.result-total .result-label,
.result-total .result-value { font-weight: 700; font-size: var(--fs-title); color: var(--color-on-surface); }

/* Amount / Person row */
.result-per-person {
  background-color: var(--color-primary-container);
  border-radius: var(--r-sm);
  padding: var(--sp-sm) var(--sp-md);
  margin-top: var(--sp-xs);
}

.result-per-person .result-label { color: var(--color-on-primary-container); font-weight: 500; }
.result-per-person .result-value { color: var(--color-on-primary-container); font-size: 1.375rem; font-weight: 700; }

/* ----- Flat tip display --------------------------------------- */
.flat-tip-card {
  background-color: var(--color-surface);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-2);
  padding: var(--sp-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--sp-md);
}

.flat-tip-icon   { font-size: 3rem; line-height: 1; }

.flat-tip-label  {
  font-size: var(--fs-label);
  font-weight: 500;
  color: var(--color-on-surface-variant);
  text-transform: uppercase;
  letter-spacing: .04em;
}

.flat-tip-amount {
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
}

.flat-tip-note {
  font-size: var(--fs-body);
  color: var(--color-on-surface-variant);
  line-height: 1.6;
  max-width: 300px;
  margin: 0;
}

/* ----- Slider section ----------------------------------------- */
.slider-section {
  background-color: var(--color-surface);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-2);
  padding: var(--sp-lg) var(--sp-xl);
  display: flex;
  flex-direction: column;
  gap: var(--sp-md);
}

/* Preset chips */
.preset-chips { display: flex; gap: var(--sp-sm); }

.chip {
  flex: 1;
  height: 64px;
  border: none;
  border-radius: var(--r-xs);
  background-color: #0066FF;
  color: #FFFFFF;
  font-size: 1.75rem;
  font-weight: 400;
  transition: background-color var(--ease-fast), transform var(--ease-fast);
  box-shadow: var(--shadow-2);
}

.chip:hover { background-color: #0052CC; }

.chip:active { transform: scale(.97); }

.chip.active {
  background-color: #003D99;
  box-shadow: var(--shadow-1);
}

/* Slider wrapper */
.slider-wrapper { position: relative; padding-top: 28px; }

.slider-floating-label {
  position: absolute;
  top: 0;
  left: 0;
  transform: translateX(-50%);
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  font-size: var(--fs-label);
  font-weight: 700;
  padding: 2px 8px;
  border-radius: var(--r-xs);
  pointer-events: none;
  white-space: nowrap;
  visibility: hidden;
}

.slider-floating-label::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 50%;
  transform: translateX(-50%);
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 5px solid var(--color-primary);
}

/* Range input */
.tip-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 10px;
  border-radius: var(--r-full);
  background: var(--color-outline-variant);
  outline: none;
  cursor: pointer;
}

.tip-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-primary);
  cursor: pointer;
  box-shadow: var(--shadow-2);
  transition: transform var(--ease-fast), box-shadow var(--ease-fast);
}

.tip-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 0 0 10px rgba(230,81,0,.15);
}

.tip-slider::-moz-range-thumb {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-primary);
  cursor: pointer;
  border: none;
  box-shadow: var(--shadow-2);
}

.slider-endpoints {
  display: flex;
  justify-content: space-between;
  margin-top: var(--sp-xs);
  font-size: var(--fs-label);
  font-weight: 500;
  color: var(--color-on-surface-variant);
}

/* ----- Action buttons ----------------------------------------- */
.action-buttons { display: flex; gap: var(--sp-sm); }

.btn-round-up,
.btn-share {
  flex: 1;
  height: 48px;
  border-radius: var(--r-full);
  border: none;
  font-size: var(--fs-body);
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-xs);
  transition: background-color var(--ease-std), box-shadow var(--ease-std), transform var(--ease-fast);
}

.btn-round-up {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  box-shadow: var(--shadow-1);
}

.btn-round-up:hover { background-color: var(--color-primary-hover); box-shadow: var(--shadow-2); }
.btn-round-up:active { transform: scale(.97); }
.btn-round-up.is-rounded { background-color: var(--color-surface); color: var(--color-primary); border: 4px solid var(--color-primary); box-shadow: none; font-weight: 700; } /* inverted "Undo" state */

.btn-share {
  background-color: var(--color-surface);
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}

.btn-share:hover { background-color: var(--color-primary-container); }
.btn-share:active { transform: scale(.97); }

.btn-icon { font-style: normal; font-size: 1.25rem; line-height: 1; }

/* ----- Toast -------------------------------------------------- */
.toast {
  position: fixed;
  bottom: var(--sp-xl);
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background-color: var(--color-on-surface);
  color: var(--color-surface);
  padding: var(--sp-sm) var(--sp-lg);
  border-radius: var(--r-full);
  font-size: var(--fs-label);
  font-weight: 500;
  box-shadow: var(--shadow-3);
  opacity: 0;
  transition: opacity var(--ease-std), transform var(--ease-std);
  pointer-events: none;
  z-index: 999;
  white-space: nowrap;
}

.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ----- SEO content -------------------------------------------- */
.seo-content {
  max-width: 1100px;
  margin: var(--sp-2xl) auto;
  padding: 0 var(--sp-xl);
}

.seo-section { margin-bottom: var(--sp-2xl); }

.seo-section h2 {
  font-size: var(--fs-headline);
  font-weight: 700;
  color: var(--color-on-surface);
  margin-bottom: var(--sp-md);
  padding-bottom: var(--sp-sm);
  border-bottom: 2px solid var(--color-primary-container);
}

.seo-section p {
  margin-bottom: var(--sp-md);
  color: var(--color-on-surface-variant);
  line-height: 1.7;
}

.seo-section p:last-child { margin-bottom: 0; }

/* Tip guide grid */
.tip-guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--sp-md);
  margin-top: var(--sp-md);
}

.tip-guide-card {
  background-color: var(--color-surface);
  border-radius: var(--r-md);
  padding: var(--sp-md);
  box-shadow: var(--shadow-1);
  display: flex;
  flex-direction: column;
  gap: var(--sp-xs);
}

.tip-guide-icon { font-size: 1.75rem; }
.tip-guide-card h3 { font-size: var(--fs-body); color: var(--color-on-surface); font-weight: 700; margin: 0; }

.tip-guide-range {
  display: inline-block;
  background-color: var(--color-primary-container);
  color: var(--color-on-primary-container);
  font-size: var(--fs-caption);
  font-weight: 700;
  padding: 2px 10px;
  border-radius: var(--r-full);
  margin-bottom: var(--sp-xs);
  width: fit-content;
}

.tip-guide-card p { font-size: var(--fs-body); color: var(--color-on-surface-variant); line-height: 1.6; margin: 0; }

/* FAQ */
.seo-faq .faq-item {
  margin-bottom: var(--sp-lg);
  padding: var(--sp-md);
  background-color: var(--color-surface);
  border-radius: var(--r-md);
  border-left: 4px solid var(--color-primary);
}

.seo-faq .faq-item:last-child { margin-bottom: 0; }

.seo-faq .faq-item h3 {
  font-size: var(--fs-body);
  font-weight: 700;
  color: var(--color-on-surface);
  margin-bottom: var(--sp-sm);
}

.seo-faq .faq-item p { font-size: var(--fs-body); color: var(--color-on-surface-variant); line-height: 1.7; margin: 0; }

/* ----- Site footer -------------------------------------------- */
.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-outline-variant);
  padding: var(--sp-lg) var(--sp-xl);
  text-align: center;
  font-size: 0.9375rem;
  color: var(--color-on-surface-variant);
}

.site-footer a { color: var(--color-primary); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }

/* Footer nav links — add <ul> items freely; | separators appear automatically */
.footer-links { list-style: none; display: flex; justify-content: center; flex-wrap: wrap; gap: var(--sp-xs); padding: 0; margin: 0; }
.footer-links li { display: flex; align-items: center; }
.footer-links li + li::before { content: '|'; margin-right: var(--sp-xs); color: var(--color-outline); }
.footer-copyright { font-family: 'WindowsCommandPrompt', monospace; }