/* ======================================= */
/* REKENTOOL - MODERN GRADIENT STYLE       */
/* ======================================= */
.calculator-card {
  max-width: 1100px;
  margin: 0 auto;
  padding: 35px;
  background: linear-gradient(145deg, var(--card-bg) 0%, var(--secondary-bg) 100%);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  box-shadow: 
    0 20px 60px rgba(0, 0, 0, 0.5),
    0 0 0 1px rgba(255, 255, 255, 0.05) inset;
  color: var(--text-color);
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
}

.calculator-card .calculator-layout {
  display: grid;
  grid-template-columns: 500px 1fr;
  gap: 30px;
  align-items: start;
}

.calculator-card .calculator-main {
  display: flex;
  flex-direction: column;
}

.calculator-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-purple), var(--accent-blue), var(--accent-purple));
  background-size: 200% 100%;
  animation: calcGradientShift 3s ease infinite;
}

@keyframes calcGradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

.calculator-card h1 {
  color: var(--text-primary);
  font-size: 2rem;
  margin-bottom: 8px;
  text-align: center;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.calculator-card .intro {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 25px;
  font-weight: 400;
  line-height: 1.6;
}

/* Display */
.calculator-card .calc-display {
  margin-bottom: 20px;
}

.calculator-card .calc-display input {
  width: 100%;
  padding: 18px 20px;
  background: var(--overlay-dark);
  color: var(--text-primary);
  border: 2px solid var(--border-dark);
  border-radius: 12px;
  font-family: "Courier New", "Roboto Mono", monospace;
  font-size: 1.3rem;
  text-align: right;
  transition: all 0.3s ease;
  box-sizing: border-box;
  font-weight: 600;
  letter-spacing: 1px;
}

.calculator-card .calc-display input::placeholder {
  color: var(--text-secondary);
  opacity: 0.5;
  font-weight: 400;
}

.calculator-card .calc-display input:focus {
  outline: none;
  border-color: var(--accent-purple);
  box-shadow: 0 0 0 3px rgba(147, 51, 234, 0.2);
}

.calculator-card .calc-display input:hover {
  border-color: var(--accent-purple);
  box-shadow: 0 0 20px rgba(147, 51, 234, 0.1);
}

/* Buttons Grid */
.calculator-card .calc-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.calculator-card .calc-btn {
  padding: 20px 0;
  border: none;
  border-radius: 10px;
  background: var(--overlay-dark);
  color: var(--text-primary);
  font-size: 1.15rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 2px solid var(--border-dark);
  position: relative;
  overflow: hidden;
}

.calculator-card .calc-btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.calculator-card .calc-btn:hover::before {
  width: 300px;
  height: 300px;
}

.calculator-card .calc-btn:hover {
  background: var(--overlay-medium);
  border-color: var(--accent-purple);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(147, 51, 234, 0.3);
}

.calculator-card .calc-btn:active {
  transform: translateY(0);
  box-shadow: none;
}

/* Operator buttons */
.calculator-card .calc-btn.op {
  background: linear-gradient(135deg, var(--accent-blue) 0%, #2563eb 100%);
  border-color: var(--accent-blue);
  color: white;
  font-weight: 700;
}

.calculator-card .calc-btn.op:hover {
  background: linear-gradient(135deg, #3b82f6 0%, var(--accent-blue) 100%);
  box-shadow: 0 4px 15px rgba(59, 130, 246, 0.5);
}

/* Clear button */
.calculator-card .calc-btn.clear {
  background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  border-color: #f59e0b;
  color: white;
  font-weight: 700;
}

.calculator-card .calc-btn.clear:hover {
  background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
  box-shadow: 0 4px 15px rgba(245, 158, 11, 0.5);
}

/* Equals button */
.calculator-card .calc-btn.equals {
  background: linear-gradient(135deg, var(--button-primary-bg) 0%, var(--button-primary-hover) 100%);
  border-color: var(--button-primary-bg);
  color: white;
  font-size: 1.4rem;
  font-weight: 700;
}

.calculator-card .calc-btn.equals:hover {
  background: linear-gradient(135deg, var(--button-primary-hover) 0%, var(--button-primary-bg) 100%);
  box-shadow: 0 4px 15px rgba(35, 134, 54, 0.5);
}

/* Output Box */
.calculator-card .output-box {
  background: var(--overlay-dark);
  border: 2px solid var(--border-dark);
  border-radius: 12px;
  text-align: right;
  padding: 18px 20px;
  font-family: "Courier New", "Roboto Mono", monospace;
  font-size: 1.4rem;
  color: var(--text-primary);
  margin-bottom: 20px;
  min-height: 60px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  cursor: pointer;
  transition: all 0.3s ease;
  font-weight: 700;
  letter-spacing: 1px;
  backdrop-filter: blur(10px);
}

.calculator-card .output-box:hover {
  border-color: var(--accent-purple);
  box-shadow: 0 0 20px rgba(147, 51, 234, 0.2);
  transform: translateY(-2px);
}

.calculator-card .output-box.has-result {
  border-color: var(--button-primary-bg);
  box-shadow: 0 0 20px rgba(35, 134, 54, 0.3);
}

.calculator-card .output-box.has-result span {
  color: var(--strength-strong);
  font-weight: 700;
}

.calculator-card .output-box.has-error {
  border-color: #ef4444;
  box-shadow: 0 0 20px rgba(239, 68, 68, 0.3);
}

.calculator-card .output-box.has-error span {
  color: #ef4444;
  font-weight: 700;
}

/* Log Section */
.calculator-card .calc-log {
  background: var(--overlay-medium);
  border: 1px solid var(--border-dark);
  border-radius: 12px;
  padding: 20px;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.25);
  width: 100%;
  box-sizing: border-box;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.calculator-card .log-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border-dark);
}

.calculator-card .calc-log h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent-blue);
  margin: 0;
}

.calculator-card .clear-log-btn {
  background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
  color: white;
  border: none;
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(239, 68, 68, 0.3);
  position: relative;
  overflow: hidden;
}

.calculator-card .clear-log-btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.calculator-card .clear-log-btn:hover::before {
  width: 300px;
  height: 300px;
}

.calculator-card .clear-log-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.5);
}

.calculator-card .clear-log-btn:active {
  transform: translateY(0);
}

.calculator-card .log-list {
  width: 100%;
  box-sizing: border-box;
  max-height: 100%;
  flex: 1;
  overflow-y: auto;
  font-family: "Roboto Mono", monospace;
  background: var(--overlay-dark);
  border: 2px solid var(--border-dark);
  border-radius: 10px;
  padding: 10px;
}

.calculator-card .log-entry {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-dark);
  transition: all 0.2s ease;
  border-radius: 8px;
  cursor: pointer;
  margin-bottom: 6px;
}

.calculator-card .log-entry:last-child {
  border-bottom: none;
  margin-bottom: 0;
}

.calculator-card .log-entry:hover {
  background: var(--overlay-medium);
  border-color: var(--accent-purple);
  transform: translateX(6px);
  box-shadow: 0 2px 8px rgba(147, 51, 234, 0.2);
}

.calculator-card .log-entry .expr {
  flex: 1;
  color: var(--text-secondary);
  font-size: 0.95rem;
  word-break: break-word;
}

.calculator-card .log-entry .res {
  color: var(--accent-blue);
  font-weight: 700;
  font-size: 1rem;
}

.calculator-card .log-empty {
  color: var(--text-secondary);
  text-align: center;
  font-size: 0.9rem;
  padding: 30px 0;
  font-style: italic;
  opacity: 0.6;
}

/* Scrollbar styling */
.calculator-card .log-list::-webkit-scrollbar {
  width: 8px;
}

.calculator-card .log-list::-webkit-scrollbar-track {
  background: var(--overlay-dark);
  border-radius: 4px;
}

.calculator-card .log-list::-webkit-scrollbar-thumb {
  background: var(--accent-purple);
  border-radius: 4px;
}

.calculator-card .log-list::-webkit-scrollbar-thumb:hover {
  background: var(--accent-purple-dark);
}

/* Animations */
@keyframes calcSlideIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.calculator-card .log-entry {
  animation: calcSlideIn 0.3s ease;
}

/* Responsive */
@media (max-width: 1024px) {
  .calculator-card .calculator-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .calculator-card .calc-log {
    height: auto;
  }

  .calculator-card .log-list {
    max-height: 260px;
    flex: none;
  }
}

@media (max-width: 768px) {
  .calculator-card {
    padding: 20px 12px;
    border-radius: 16px;
    max-width: 100%;
  }

  .calculator-card h1 {
    font-size: 1.5rem;
    margin-bottom: 6px;
  }

  .calculator-card .intro {
    font-size: 0.85rem;
    margin-bottom: 20px;
  }

  .calculator-card .calc-display input {
    font-size: 1.15rem;
    padding: 14px 16px;
  }

  .calculator-card .calc-buttons {
    gap: 10px;
  }

  .calculator-card .calc-btn {
    padding: 16px 0;
    font-size: 1.05rem;
  }

  .calculator-card .calc-btn.equals {
    font-size: 1.25rem;
  }

  .calculator-card .output-box {
    font-size: 1.2rem;
    padding: 14px 16px;
    min-height: 54px;
  }

  .calculator-card .calc-log {
    padding: 16px;
    margin-top: 20px;
  }

  .calculator-card .log-list {
    max-height: 200px;
    padding: 8px;
  }

  .calculator-card .log-entry {
    padding: 10px 12px;
  }

  .calculator-card .log-entry .expr {
    font-size: 0.85rem;
  }

  .calculator-card .log-entry .res {
    font-size: 0.9rem;
  }

  .calculator-card .log-empty {
    padding: 24px 0;
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  .calculator-card {
    padding: 16px 10px;
  }

  .calculator-card h1 {
    font-size: 1.3rem;
  }

  .calculator-card .intro {
    font-size: 0.8rem;
  }

  .calculator-card .calc-buttons {
    gap: 8px;
  }

  .calculator-card .calc-btn {
    padding: 14px 0;
    font-size: 1rem;
  }

  .calculator-card .calc-btn.equals {
    font-size: 1.15rem;
  }

  .calculator-card .calc-display input {
    font-size: 1.05rem;
    padding: 12px 14px;
  }

  .calculator-card .output-box {
    font-size: 1.1rem;
    padding: 12px 14px;
  }

  .calculator-card .calc-log {
    padding: 14px;
  }

  .calculator-card .log-list {
    max-height: 180px;
  }
}

@media (max-width: 380px) {
  .calculator-card .calc-buttons {
    gap: 6px;
  }

  .calculator-card .calc-btn {
    padding: 12px 0;
    font-size: 0.95rem;
  }
}