style.css

:root {
  --bg-color-1: #e2e8f0;
  --bg-color-2: #cbd5e1;
  --bg-color-3: #94a3b8;
  
  --card-bg: rgba(255, 255, 255, 0.45);
  --card-border: rgba(255, 255, 255, 0.4);
  --card-shadow: 0 8px 32px 0 rgba(15, 23, 42, 0.08);
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --accent-color: #334155;
  --accent-glow: rgba(51, 65, 85, 0.15);
  
  --input-bg: rgba(255, 255, 255, 0.5);
  --input-border: rgba(15, 23, 42, 0.1);
  --input-focus-border: #334155;
  
  --error-color: #e11d48;
  --error-bg: rgba(225, 29, 72, 0.1);
  
  --row-hover-bg: rgba(255, 255, 255, 0.25);
  --border-sep: rgba(15, 23, 42, 0.06);
  --copy-btn-hover: rgba(15, 23, 42, 0.05);
}

[data-theme="dark"] {
  --bg-color-1: #0f172a;
  --bg-color-2: #1e293b;
  --bg-color-3: #0f172a;
  
  --card-bg: rgba(15, 23, 42, 0.45);
  --card-border: rgba(255, 255, 255, 0.08);
  --card-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent-color: #f1f5f9;
  --accent-glow: rgba(241, 245, 249, 0.15);
  
  --input-bg: rgba(15, 23, 42, 0.5);
  --input-border: rgba(255, 255, 255, 0.1);
  --input-focus-border: #f1f5f9;
  
  --error-color: #fb7185;
  --error-bg: rgba(251, 113, 133, 0.1);
  
  --row-hover-bg: rgba(255, 255, 255, 0.04);
  --border-sep: rgba(255, 255, 255, 0.05);
  --copy-btn-hover: rgba(255, 255, 255, 0.08);
}

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

html {
  overscroll-behavior-y: none;
}

body {
  font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
  color: var(--text-main);
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow-x: hidden;
  position: relative;
  transition: background-color 0.5s ease, color 0.3s ease;
  padding: 1.5rem;
  background-color: var(--bg-color-1);
  overscroll-behavior-y: none;
}

/* --- Animated Gradient Mesh Background --- */
.bg-mesh {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.6;
  mix-blend-mode: multiply;
  animation: float 25s infinite alternate ease-in-out;
  transition: background-color 0.8s ease;
}

[data-theme="dark"] .blob {
  mix-blend-mode: screen;
  opacity: 0.35;
}

.blob-1 {
  width: 450px;
  height: 450px;
  background: radial-gradient(circle, #cbd5e1 0%, rgba(203, 213, 225, 0) 70%);
  top: -10%;
  left: -10%;
}
[data-theme="dark"] .blob-1 {
  background: radial-gradient(circle, #334155 0%, rgba(51, 65, 85, 0) 70%);
}

.blob-2 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, #94a3b8 0%, rgba(148, 163, 184, 0) 70%);
  bottom: -15%;
  right: -5%;
  animation-duration: 30s;
  animation-delay: -5s;
}
[data-theme="dark"] .blob-2 {
  background: radial-gradient(circle, #475569 0%, rgba(71, 85, 105, 0) 70%);
}

.blob-3 {
  width: 350px;
  height: 350px;
  background: radial-gradient(circle, #e2e8f0 0%, rgba(226, 232, 240, 0) 70%);
  top: 40%;
  left: 50%;
  animation-duration: 20s;
  animation-delay: -10s;
}
[data-theme="dark"] .blob-3 {
  background: radial-gradient(circle, #1e293b 0%, rgba(30, 41, 59, 0) 70%);
}

@keyframes float {
  0% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(80px, 50px) scale(1.1);
  }
  100% {
    transform: translate(-40px, 120px) scale(0.95);
  }
}

/* --- Glassmorphism Card Container --- */
.glass-card {
  width: 100%;
  max-width: 540px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  box-shadow: var(--card-shadow);
  border-radius: 20px;
  padding: 2.5rem 2rem;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  z-index: 10;
  transition: background 0.3s ease, border 0.3s ease, box-shadow 0.3s ease;
}

header {
  margin-bottom: 2rem;
  text-align: center;
}

header h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 0.4rem;
  color: var(--text-main);
  background: linear-gradient(135deg, var(--text-main) 60%, var(--text-muted));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

header p {
  font-size: 0.925rem;
  color: var(--text-muted);
  font-weight: 450;
}

/* --- Input Area --- */
.input-section {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.input-group {
  display: flex;
  gap: 0.75rem;
  width: 100%;
}

.input-wrapper {
  flex-grow: 1;
  position: relative;
}

input[type="text"] {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  border-radius: 8px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text-main);
  transition: all 0.25s ease;
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

select {
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  border-radius: 8px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text-main);
  cursor: pointer;
  outline: none;
  min-width: 90px;
  transition: all 0.25s ease;
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

select option {
  background-color: var(--bg-color-2);
  color: var(--text-main);
}

input[type="text"]:focus, select:focus {
  outline: none;
  border-color: var(--input-focus-border);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

input.input-error {
  border-color: var(--error-color);
  background-color: var(--error-bg);
}

.error-message {
  font-size: 0.825rem;
  color: var(--error-color);
  display: none;
  padding-left: 0.25rem;
  animation: slideDown 0.2s forwards;
}

.error-message.visible {
  display: block;
}

/* --- Results Section --- */
.results-container {
  display: none;
  flex-direction: column;
  gap: 0.75rem;
  animation: fadeIn 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.results-container.visible {
  display: flex;
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 0.75rem;
  border-bottom: 1px solid var(--border-sep);
  border-radius: 6px;
  transition: background-color 0.2s ease;
}

.result-row:hover {
  background-color: var(--row-hover-bg);
}

.result-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 500;
}

.result-value-wrapper {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.result-value {
  font-family: "Cascadia Code", Consolas, "Courier New", monospace;
  font-size: 0.95rem;
  font-weight: 600;
  text-align: right;
  word-break: break-all;
}

/* --- Copy Button and Tooltip --- */
.copy-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 4px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: all 0.2s;
}

.copy-btn:hover {
  background-color: var(--copy-btn-hover);
  color: var(--text-main);
}

.copy-btn svg {
  width: 15px;
  height: 15px;
}

.copy-btn::after {
  content: "Copied!";
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(-4px);
  background: #0f172a;
  color: #f8fafc;
  font-size: 0.75rem;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  font-family: system-ui, sans-serif;
  white-space: nowrap;
}

[data-theme="dark"] .copy-btn::after {
  background: #f8fafc;
  color: #0f172a;
}

.copy-btn.copied::after {
  opacity: 1;
  transform: translateX(-50%) translateY(-8px);
}

/* --- Theme Toggle FAB --- */
.theme-fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--card-shadow);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 100;
  transition: transform 0.2s, background 0.3s, border 0.3s;
}

.theme-fab:hover {
  transform: scale(1.1);
}

.theme-fab:active {
  transform: scale(0.95);
}

.theme-fab svg {
  width: 20px;
  height: 20px;
}

/* --- Animations --- */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* --- Responsive Adjustments --- */
@media (max-width: 480px) {
  .glass-card {
    padding: 1.75rem 1.25rem;
  }
  
  header h1 {
    font-size: 1.75rem;
  }
  
  .input-group {
    flex-direction: column;
  }
  
  select {
    width: 100%;
  }

  .result-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
  }

  .result-value-wrapper {
    width: 100%;
    justify-content: space-between;
  }
}