/* ===== CSS VARIABLES ===== */
:root {
  --bg: #071423;
  --card: #0c1624;
  --text: #e5eff7;
  --muted: #9fb0c1;
  --accent-start: #2dd4bf;
  --accent-end: #2aa3b2;
  --glass: rgba(255, 255, 255, 0.06);
  --shadow: 0 10px 36px rgba(2, 6, 12, 0.6);
  --btn-start: #1a2332;
  --btn-end: #0f1519;
  --input-bg: rgba(255, 255, 255, 0.04);
  --input-border: rgba(255, 255, 255, 0.1);
  --radius: 12px;
  --max-width: 1100px;
  --touch: 48px;
}

.light {
  --bg: #f8fafc;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --accent-start: #1e293b;
  --accent-end: #334155;
  --glass: rgba(15, 23, 42, 0.08);
  --shadow: 0 4px 20px rgba(15, 23, 42, 0.08);
  --btn-start: #1e293b;
  --btn-end: #0f172a;
  --input-bg: #f8fafc;
  --input-border: #e2e8f0;
}

/* ===== BASE STYLES ===== */
* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  font-family: Inter, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: linear-gradient(180deg, #071423 0%, #050b14 100%);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.light body,
body.light,
html.light body {
  background: linear-gradient(180deg, #f8fafc 0%, #e2e8f0 100%);
}

.wrap {
  max-width: var(--max-width);
  margin: 20px auto;
  padding: 18px;
}

/* ===== HEADER ===== */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}

.brand {
  display: flex;
  gap: 14px;
  align-items: center;
}

.brand svg {
  width: 48px;
  height: 48px;
}

.title {
  font-weight: 800;
  font-size: 20px;
  letter-spacing: 0.2px;
}

.subtitle {
  font-size: 12px;
  color: var(--muted);
}

.controls {
  display: flex;
  gap: 10px;
  align-items: center;
}

.theme-btn {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  border: 0;
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  color: white;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  position: relative;
  overflow: hidden;
}

.light .theme-btn {
  box-shadow: 0 4px 12px rgba(30, 41, 59, 0.25);
}

.theme-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.15), rgba(255, 255, 255, 0));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.theme-btn:hover {
  transform: translateY(-2px) scale(1.05);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.light .theme-btn:hover {
  box-shadow: 0 6px 20px rgba(30, 41, 59, 0.35);
}

.theme-btn:hover::before {
  opacity: 1;
}

.theme-btn:active {
  transform: translateY(0) scale(0.98);
}

.theme-btn svg {
  position: relative;
  z-index: 1;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.contact-open {
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  color: white;
  padding: 10px 16px;
  border-radius: 10px;
  border: 0;
  cursor: pointer;
  font-weight: 700;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.contact-open:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

/* ===== MAIN LAYOUT ===== */
main {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 1000px) {
  main {
    grid-template-columns: 1fr 340px;
  }
}

/* ===== CARD ===== */
.card {
  background: var(--card);
  border-radius: 12px;
  padding: 18px;
  box-shadow: var(--shadow);
  border: 1px solid var(--input-border);
}

h2 {
  margin: 0;
  font-size: 18px;
}

.muted {
  color: var(--muted);
  font-size: 13px;
}

/* ===== MODE SELECTOR ===== */
.mode-selector {
  margin-bottom: 20px;
}

.mode-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.mode-tab {
  flex: 1;
  min-width: 150px;
  padding: 12px 16px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: transparent;
  color: var(--muted);
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.2s ease;
}

.mode-tab:hover {
  background: var(--input-bg);
  border-color: var(--btn-start);
}

.mode-tab.active {
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  color: white;
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(30, 41, 59, 0.25);
}

.mode-tab svg {
  stroke-width: 2;
}

/* ===== CALCULATOR MODES ===== */
.calculator-mode {
  display: none;
  animation: fadeIn 0.3s ease;
}

.calculator-mode.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== FORM LAYOUT ===== */
.form-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 720px) {
  .form-grid.duration {
    grid-template-columns: repeat(2, 1fr);
  }
  .form-grid.blocks {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ===== INPUT WRAPPER ===== */
.input-wrap {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 56px;
  padding: 8px 56px 8px 46px;
  border-radius: 10px;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  box-sizing: border-box;
  overflow: visible;
  transition: all 0.2s ease;
}

.input-wrap:focus-within {
  border-color: var(--btn-start);
  box-shadow: 0 0 0 3px rgba(30, 41, 59, 0.1);
  background: var(--card);
}

.light .input-wrap:focus-within {
  box-shadow: 0 0 0 3px rgba(30, 41, 59, 0.08);
}

/* ===== INPUT ICON ===== */
.input-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  stroke-width: 2;
  color: var(--muted);
  pointer-events: none;
}

/* ===== INPUT FIELDS ===== */
.input-wrap input,
.input-wrap input[type="number"] {
  width: 100%;
  height: 100%;
  min-height: 42px;
  margin: 0;
  padding: 0;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
  box-sizing: border-box;
  font-family: inherit;
}

.input-wrap input::placeholder {
  color: var(--muted);
  opacity: 0.6;
  font-size: 13px;
}

input[type="date"],
input[type="time"] {
  width: 100%;
  padding: 14px 14px 14px 46px;
  min-height: 52px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text);
  font-size: 15px;
  transition: all 0.2s ease;
}

select {
  width: 100%;
  padding: 16px 44px 16px 16px;
  min-height: 52px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text);
  font-size: 15px;
  font-weight: 500;
  transition: all 0.2s ease;
  cursor: pointer;
  appearance: none;
}

select:hover {
  border-color: var(--btn-start);
  background: var(--card);
}

.light select:hover {
  background: #ffffff;
}

textarea {
  width: 100%;
  padding: 14px 16px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text);
  min-height: 120px;
  resize: vertical;
  line-height: 1.6;
  font-family: inherit;
  font-size: 15px;
  transition: all 0.2s ease;
}

input[type="text"] {
  padding: 14px 16px 14px 46px;
  min-height: 52px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text);
  font-size: 15px;
  transition: all 0.2s ease;
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--btn-start);
  box-shadow: 0 0 0 3px rgba(30, 41, 59, 0.1);
  background: var(--card);
}

.light input:focus,
.light textarea:focus,
.light select:focus {
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(30, 41, 59, 0.08);
}

.input-wrap input::placeholder {
  color: var(--muted);
  opacity: 0.7;
}

/* Remove default number input spinners */
.input-wrap input[type="number"]::-webkit-outer-spin-button,
.input-wrap input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
  display: none;
}

.input-wrap input[type="number"] {
  -moz-appearance: textfield;
}

/* ===== CUSTOM STEPPER ===== */
.stepper {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 5px;
  z-index: 2;
}

.stepper button {
  width: 32px;
  height: 20px;
  padding: 0;
  margin: 0;
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  border-radius: 6px;
  border: 1px solid var(--input-border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
  transition: all 0.15s ease;
}

.stepper button:hover {
  background: var(--btn-start);
  color: white;
  border-color: var(--btn-start);
  transform: scale(1.05);
}

.stepper button:active {
  transform: scale(0.98);
}

/* ===== SELECT ===== */
.light select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748b' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%239fb0c1' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
}

select option {
  background: var(--card);
  color: var(--text);
  padding: 10px;
}

/* ===== BUTTONS ===== */
.actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
  flex-wrap: wrap;
}

button.primary {
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  border: 0;
  color: white;
  padding: 12px 20px;
  border-radius: 10px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.25);
  transition: all 0.2s ease;
  font-family: inherit;
}

button.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(15, 23, 42, 0.35);
} 10px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(45, 212, 191, 0.3);
  transition: all 0.2s ease;
  font-family: inherit;
}

button.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(45, 212, 191, 0.4);
}

button.ghost {
  background: transparent;
  border: 1px solid var(--input-border);
  padding: 10px 16px;
  border-radius: 10px;
  cursor: pointer;
  color: var(--text);
  font-weight: 600;
  transition: all 0.2s ease;
  font-family: inherit;
}

button.ghost:hover {
  background: var(--input-bg);
  border-color: var(--btn-start);
  color: var(--btn-start);
}

/* ===== RESULTS ===== */
.result-card {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  padding: 24px;
  border-radius: 14px;
  border: 1px solid var(--input-border);
  background: linear-gradient(135deg, var(--input-bg), transparent);
  box-shadow: var(--shadow);
}

.result-header {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.big-number {
  font-weight: 800;
  font-size: 32px;
  color: var(--text);
  letter-spacing: -0.02em;
  line-height: 1.2;
  background: linear-gradient(135deg, #1e293b 0%, #ffffff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

.light .big-number {
  background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Fallback for browsers that don't support background-clip */
@supports not (background-clip: text) or not (-webkit-background-clip: text) {
  .big-number {
    color: var(--text);
    background: none;
    -webkit-text-fill-color: initial;
  }
}

.result-subtitle {
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.5;
}

.result-pills {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.pill {
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  color: white;
  padding: 8px 16px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 14px;
  box-shadow: 0 2px 8px rgba(15, 23, 42, 0.25);
  transition: transform 0.2s ease;
}

.pill:hover {
  transform: translateY(-2px);
}

.result-meta {
  font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
  background: var(--card);
  border-radius: 10px;
  padding: 16px;
  white-space: pre-wrap;
  font-size: 13px;
  line-height: 1.8;
  border: 1px solid var(--input-border);
  color: var(--muted);
  margin-top: 12px;
}

.result-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 12px;
}

.result-actions button {
  flex: 1;
  min-width: 120px;
}

@media (min-width: 640px) {
  .result-card {
    grid-template-columns: 1fr auto;
  }
  
  .result-actions {
    flex-direction: column;
  }
  
  .result-actions button {
    flex: none;
    width: 100%;
  }
}

/* ===== AD AREA ===== */
.ad-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 18px;
  border-radius: 12px;
  border: 1px dashed var(--input-border);
  background: var(--card);
  color: var(--muted);
  font-weight: 600;
}

/* ===== EXPLANATION AREA ===== */
.explanation-area {
  padding: 32px 28px;
  border-radius: 14px;
  border: 1px solid var(--input-border);
  background: var(--card);
  box-shadow: var(--shadow);
}

.explanation-area h1 {
  font-size: 28px;
  font-weight: 800;
  margin: 0 0 16px 0;
  color: var(--text);
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.explanation-area h2 {
  font-size: 22px;
  font-weight: 700;
  margin: 24px 0 12px 0;
  color: var(--text);
  line-height: 1.4;
}

.explanation-area h3 {
  font-size: 18px;
  font-weight: 600;
  margin: 20px 0 10px 0;
  color: var(--text);
  line-height: 1.4;
}

.explanation-area p {
  color: var(--muted);
  line-height: 1.8;
  margin: 0 0 16px 0;
  font-size: 15px;
}

.explanation-area ul,
.explanation-area ol {
  color: var(--muted);
  line-height: 1.8;
  margin: 0 0 16px 0;
  padding-left: 24px;
}

.explanation-area li {
  margin-bottom: 8px;
  font-size: 15px;
}

.explanation-area a {
  color: var(--btn-start);
  text-decoration: underline;
  transition: opacity 0.2s ease;
}

.explanation-area a:hover {
  opacity: 0.7;
}

.explanation-area strong {
  color: var(--text);
  font-weight: 600;
}

.explanation-area code {
  background: var(--input-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
  font-size: 14px;
  border: 1px solid var(--input-border);
}

/* ===== SIDEBAR ===== */
aside .card {
  position: sticky;
  top: 22px;
}

.sidebar-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 14px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  transition: all 0.2s ease;
  overflow: hidden;
}

.sidebar-item > div:last-child {
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

.sidebar-item input[type="number"] {
  width: 100%;
  min-width: 0;
}

.sidebar-item .action-row,
.sidebar-item > div > div:last-child {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.sidebar-item .action-row button {
  flex: 1;
  min-width: 0;
  font-size: 13px;
  padding: 8px 10px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-item:hover {
  border-color: var(--btn-start);
  box-shadow: 0 2px 8px rgba(30, 41, 59, 0.15);
}

.icon {
  width: 46px;
  height: 46px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
}

/* ===== MODAL ===== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(2, 6, 12, 0.8);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 18px;
  z-index: 120;
  animation: fadeIn 0.2s ease;
}

.modal {
  background: var(--card);
  padding: 24px;
  border-radius: 14px;
  width: 100%;
  max-width: 520px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  border: 1px solid var(--input-border);
  animation: slideUp 0.3s ease;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal .modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.modal .close-btn {
  background: transparent;
  border: 0;
  color: var(--muted);
  cursor: pointer;
  padding: 8px;
  border-radius: 8px;
  font-size: 20px;
  transition: all 0.2s ease;
}

.modal .close-btn:hover {
  background: var(--input-bg);
  color: var(--text);
}

/* ===== FOOTER ===== */
footer,
footer * {
  color: var(--muted);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 720px) {
  .result-card {
    grid-template-columns: 1fr;
  }

  .result-pills {
    justify-content: flex-start;
  }

  .result-actions {
    flex-direction: row;
  }
  
  .result-actions button {
    flex: 1;
  }
  
  .big-number {
    font-size: 26px;
  }
  
  .explanation-area {
    padding: 24px 20px;
  }
  
  .explanation-area h1 {
    font-size: 24px;
  }
}

@media (max-width: 520px) {
  .wrap {
    padding: 12px;
  }

  .theme-btn {
    width: 44px;
    height: 44px;
  }

  .brand .title {
    font-size: 18px;
  }

  .stepper {
    right: 8px;
    gap: 4px;
  }

  .stepper button {
    width: 28px;
    height: 18px;
    font-size: 13px;
  }

  .input-wrap {
    padding: 8px 50px 8px 42px;
    min-height: 54px;
  }

  .mode-tabs {
    flex-direction: column;
  }

  .mode-tab {
    min-width: 100%;
  }
  
  .big-number {
    font-size: 22px;
  }
  
  .explanation-area {
    padding: 20px 16px;
  }
  
  .explanation-area h1 {
    font-size: 22px;
  }
}

@media (max-width: 420px) {
  .input-wrap {
    padding: 8px 48px 8px 40px;
  }

  .big-number {
    font-size: 20px;
  }

  .contact-open {
    padding: 8px 12px;
    font-size: 14px;
  }
  
  .input-wrap input {
    font-size: 14px;
  }
  
  .input-wrap input::placeholder {
    font-size: 12px;
  }
  
  .stepper button {
    width: 26px;
    height: 17px;
  }
  
  .explanation-area h1 {
    font-size: 20px;
  }
  
  .explanation-area h2 {
    font-size: 18px;
  }
}