/* ============================================================
   ROOT TOKENS
   ============================================================ */
:root {
  --color-bg:      #0f0f0f;
  --color-text:    #f5f0e8;
  --color-accent:  #c9a84c;
  --color-muted:   #5a5650;
  --color-subtle:  #2a2925;
  --color-error:   #c0392b;

  --font-display:  'Playfair Display', Georgia, serif;
  --font-body:     'Spectral', 'Times New Roman', serif;

  --size-hero:     clamp(4.5rem, 13vw, 9.5rem);
  --size-sub:      clamp(1.9rem, 4.8vw, 3.2rem);
  --size-heading:  clamp(1.4rem, 3vw, 2rem);
  --size-body:     1rem;
  --size-meta:     0.875rem;
  --size-label:    0.72rem;

  --space-xs:  0.5rem;
  --space-sm:  1rem;
  --space-md:  2rem;
  --space-lg:  4rem;
  --space-xl:  6rem;

  --content-width:   680px;
  --content-padding: clamp(1.5rem, 6vw, 3rem);

  --trans-fast:   150ms ease;
  --trans-medium: 300ms ease;
  --trans-slow:   600ms ease;
}

/* ============================================================
   RESET & BASE
   ============================================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

[hidden] { display: none !important; }

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================================
   LAYOUT
   ============================================================ */
#site-header,
#main-content,
#site-footer {
  max-width: var(--content-width);
  margin: 0 auto;
  padding-left: var(--content-padding);
  padding-right: var(--content-padding);
}

#site-header {
  padding-top: var(--space-xl);
  padding-bottom: 0;
}

#main-content {
  padding-top: var(--space-md);
  padding-bottom: var(--space-xl);
}

#site-footer {
  padding-bottom: var(--space-lg);
}

/* ============================================================
   TYPOGRAPHY UTILITIES
   ============================================================ */
.section-overline {
  font-family: var(--font-body);
  font-size: var(--size-label);
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: var(--space-xs);
}

.section-heading {
  font-family: var(--font-display);
  font-size: var(--size-heading);
  font-weight: 400;
  letter-spacing: 0.02em;
  line-height: 1.2;
  margin-bottom: var(--space-xs);
}

.hint-text {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  font-style: italic;
  color: var(--color-muted);
  line-height: 1.5;
}

.error-message {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  color: var(--color-error);
  margin-top: var(--space-xs);
}

/* ============================================================
   RULES
   ============================================================ */
.rule-heavy {
  border: none;
  border-top: 1px solid var(--color-text);
  opacity: 0.25;
  margin: var(--space-lg) 0;
}

.rule-light {
  border: none;
  border-top: 1px solid var(--color-subtle);
  margin: var(--space-md) 0;
}

/* ============================================================
   HEADER
   ============================================================ */
#site-title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 10vw, 6rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: 0;
}

/* ============================================================
   INPUT SECTION
   ============================================================ */
#section-input {
  padding-top: var(--space-sm);
}

#dob-label {
  display: block;
  font-family: var(--font-body);
  font-size: var(--size-label);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.75rem;
}

#input-wrapper {
  display: flex;
  align-items: flex-end;
  gap: var(--space-md);
  flex-wrap: wrap;
}

#input-hint {
  margin-top: var(--space-sm);
}

/* ============================================================
   INPUTS (shared)
   ============================================================ */
input[type="date"],
input[type="number"] {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--color-muted);
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 400;
  padding: 0.35rem 0;
  outline: none;
  color-scheme: dark;
  transition: border-color var(--trans-fast);
  min-width: 0;
}

input[type="date"] {
  flex: 1 1 200px;
}

input[type="number"] {
  width: 140px;
}

input[type="date"]:focus,
input[type="number"]:focus {
  border-bottom-color: var(--color-accent);
}

select {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--color-muted);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--size-meta);
  letter-spacing: 0.08em;
  padding: 0.5rem 0;
  outline: none;
  cursor: pointer;
  color-scheme: dark;
  transition: border-color var(--trans-fast);
  appearance: none;
  -webkit-appearance: none;
  padding-right: 1rem;
  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='%235a5650'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0 center;
}

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

/* ============================================================
   BUTTONS
   ============================================================ */
#btn-calculate {
  background: transparent;
  border: 1px solid var(--color-accent);
  color: var(--color-accent);
  font-family: var(--font-body);
  font-size: var(--size-label);
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 0.65rem 1.75rem;
  cursor: pointer;
  transition: background var(--trans-fast), color var(--trans-fast);
  white-space: nowrap;
  flex-shrink: 0;
}

#btn-calculate:hover,
#btn-calculate:focus-visible {
  background: var(--color-accent);
  color: var(--color-bg);
  outline: none;
}

.btn-secondary {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--color-muted);
  color: var(--color-muted);
  font-family: var(--font-body);
  font-size: var(--size-label);
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 0.5rem 0;
  cursor: pointer;
  transition: color var(--trans-fast), border-color var(--trans-fast);
  white-space: nowrap;
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  outline: none;
}

/* ============================================================
   HERO AGE DISPLAY
   ============================================================ */
#hero-age {
  padding-bottom: var(--space-sm);
}

#hero-primary {
  line-height: 1;
  margin-bottom: 0.4rem;
}

#hero-secondary {
  line-height: 1.1;
  margin-bottom: 0.25rem;
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0 0.4rem;
}

#hero-tertiary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0 0.4rem;
}

#hero-years {
  font-family: var(--font-display);
  font-size: var(--size-hero);
  font-weight: 900;
  color: var(--color-accent);
  line-height: 1;
  letter-spacing: -0.03em;
  display: inline-block;
}

#hero-primary em {
  font-family: var(--font-body);
  font-style: italic;
  font-weight: 300;
  font-size: clamp(1rem, 2.5vw, 1.5rem);
  color: var(--color-muted);
  letter-spacing: 0.04em;
  vertical-align: 0.15em;
}

#hero-months,
#hero-weeks,
#hero-days,
#hero-hours,
#hero-minutes {
  font-family: var(--font-display);
  font-size: var(--size-sub);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1;
  letter-spacing: -0.02em;
  display: inline-block;
}

#hero-hours,
#hero-minutes {
  opacity: 0.65;
}

#hero-secondary em,
#hero-tertiary em {
  font-family: var(--font-body);
  font-style: italic;
  font-weight: 300;
  font-size: clamp(0.65rem, 1.5vw, 0.9rem);
  color: var(--color-muted);
  letter-spacing: 0.04em;
  vertical-align: 0.12em;
}

.separator {
  color: var(--color-subtle);
  font-family: var(--font-body);
  font-size: 0.85em;
  opacity: 0.7;
}

/* ============================================================
   BIRTH META & ZODIAC
   ============================================================ */
#meta-weekday {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  font-weight: 400;
  color: var(--color-muted);
  letter-spacing: 0.03em;
  margin-bottom: var(--space-md);
}

#zodiac-display {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.zodiac-card {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.zodiac-emoji {
  font-size: 2.4rem;
  line-height: 1;
  flex-shrink: 0;
}

.zodiac-info {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.zodiac-name {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
  line-height: 1;
}

.zodiac-caption {
  font-family: var(--font-body);
  font-size: var(--size-label);
  font-weight: 400;
  color: var(--color-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  line-height: 1.4;
}

.zodiac-sep {
  width: 1px;
  height: 2.8rem;
  background: var(--color-subtle);
  flex-shrink: 0;
  align-self: center;
}

/* ============================================================
   BORN ON SECTION
   ============================================================ */
.born-on-today-text {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  font-style: italic;
  color: var(--color-muted);
  margin-bottom: var(--space-md);
}

.born-on-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-subtle);
}

.born-on-age-num {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  color: var(--color-accent);
  line-height: 1;
  letter-spacing: -0.03em;
  min-width: 3ch;
  flex-shrink: 0;
}

.born-on-item-info {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.born-on-item-label {
  font-family: var(--font-body);
  font-size: var(--size-label);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-muted);
}

.born-on-item-date {
  font-family: var(--font-display);
  font-size: clamp(1rem, 2.5vw, 1.35rem);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.born-on-item-weekday {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  color: var(--color-muted);
  font-style: italic;
}

#born-on-custom {
  margin-top: var(--space-md);
}

#born-on-custom-label {
  display: block;
  font-family: var(--font-body);
  font-size: var(--size-label);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.75rem;
}

/* ============================================================
   REVERSE CALCULATOR
   ============================================================ */
#reverse-header {
  margin-bottom: var(--space-md);
}

#reverse-tabs {
  display: flex;
  border-bottom: 1px solid var(--color-subtle);
  margin-bottom: var(--space-md);
}

.tab-btn {
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--color-muted);
  font-family: var(--font-body);
  font-size: var(--size-label);
  font-weight: 400;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: var(--space-xs) var(--space-md);
  padding-left: 0;
  margin-right: var(--space-md);
  margin-bottom: -1px;
  cursor: pointer;
  transition: color var(--trans-fast), border-color var(--trans-fast);
}

.tab-btn.tab-active {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

.tab-btn:hover:not(.tab-active) {
  color: var(--color-text);
}

[role="tabpanel"] > label {
  display: block;
  font-family: var(--font-body);
  font-size: var(--size-label);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.75rem;
}

.reverse-input-row {
  display: flex;
  align-items: flex-end;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.reverse-input-row input[type="date"] {
  flex: 1 1 180px;
}

#target-date-inputs {
  display: flex;
  align-items: flex-end;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.result-hero {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin-top: var(--space-md);
}

.result-sub {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  color: var(--color-muted);
  margin-top: var(--space-xs);
  font-style: italic;
}

/* ============================================================
   MILESTONE SECTION
   ============================================================ */
#birthday-countdown-block {
  margin-bottom: var(--space-md);
}

#countdown-date {
  margin-bottom: var(--space-sm);
}

#countdown-display {
  display: flex;
  align-items: baseline;
  gap: 0.15rem;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 7vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1;
}

.countdown-unit {
  display: inline-flex;
  align-items: baseline;
  gap: 0.1em;
}

.countdown-unit em {
  font-family: var(--font-body);
  font-style: normal;
  font-weight: 300;
  font-size: 0.35em;
  color: var(--color-muted);
  letter-spacing: 0.1em;
}

.countdown-sep {
  color: var(--color-subtle);
  font-size: 0.6em;
  padding: 0 0.05em;
}

#milestone-list {
  list-style: none;
  padding: 0;
}

#milestone-list li {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: var(--space-sm);
  align-items: baseline;
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--color-subtle);
}

.milestone-past {
  opacity: 0.32;
}

.milestone-label {
  font-family: var(--font-body);
  font-size: var(--size-body);
  font-weight: 500;
  color: var(--color-text);
}

.milestone-date {
  font-family: var(--font-display);
  font-size: var(--size-meta);
  color: var(--color-muted);
  white-space: nowrap;
}

.milestone-upcoming .milestone-date {
  color: var(--color-accent);
}

.milestone-delta {
  font-family: var(--font-body);
  font-size: var(--size-meta);
  color: var(--color-muted);
  font-style: italic;
  white-space: nowrap;
  text-align: right;
}

/* ============================================================
   FOOTER
   ============================================================ */
#footer-note {
  font-family: var(--font-body);
  font-size: var(--size-label);
  letter-spacing: 0.06em;
  color: var(--color-muted);
  text-align: center;
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes fadeSlideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.45; }
}

.animate-in {
  animation: fadeSlideUp var(--trans-slow) ease both;
}

.pulse-tick {
  animation: pulse 700ms ease;
}

/* ============================================================
   RESPONSIVE — 480px
   ============================================================ */
@media (max-width: 480px) {
  #hero-secondary,
  #hero-tertiary {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.15rem;
  }

  .separator {
    display: none;
  }

  #zodiac-display {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-sm);
  }

  .zodiac-sep {
    display: none;
  }

  #milestone-list li {
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    row-gap: 0.15rem;
  }

  .milestone-delta {
    grid-column: 2;
    grid-row: 2;
  }

  .milestone-date {
    grid-column: 2;
    grid-row: 1;
  }

  .milestone-label {
    grid-column: 1;
    grid-row: 1 / 3;
  }

  #target-date-inputs {
    flex-direction: column;
    align-items: flex-start;
  }

  #target-value,
  select {
    width: 100%;
  }

  .tab-btn {
    padding-left: 0;
    margin-right: var(--space-sm);
    font-size: 0.65rem;
  }
}