:root {
  --primary: #e2e8f0;
  --primary-dark: #94a3b8;
  --accent-silver: #cbd5e1;
  --accent-gray: #475569;
  --background-light: #f8fafc;
  --background-dark: #0f172a;
  
  /* Tailwind Slate Palette */
  --slate-50: #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  
  --white: #ffffff;
  --black: #000000;
  
  --font-display: "Space Grotesk", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
    width: 100%;
    min-height: 100%;
}

body {
  background-color: var(--black); /* Dark mode default as per html class="dark" */
  font-family: var(--font-display);
  color: var(--slate-100);
    min-height: 100vh;
    min-height: 100svh;
    min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  /* justify-content: center; Removed to use margin: auto on main for safer overflow handling */
  position: relative;
  overflow-x: hidden;
  overflow-y: auto; /* Allow scrolling */
  margin: 0;
  padding: 1rem; /* Add padding to prevent content touching edges on small screens */
  
  /* Hide scrollbar for IE, Edge and Firefox */
  -ms-overflow-style: none;  /* IE and Edge */
  scrollbar-width: none;  /* Firefox */
}

/* Hide scrollbar for Chrome, Safari and Opera */
body::-webkit-scrollbar {
  display: none;
}

body::selection {
    background-color: var(--white);
    color: var(--black);
}

/* Background Effects */
.bg-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none;
    z-index: 0;
}

.blob-1 {
    position: absolute;
    top: -10%;
    left: -10%;
    width: 31.25rem; /* 500px */
    height: 31.25rem;
    border-radius: 9999px;
    background-color: rgba(100, 116, 139, 0.1); /* slate-500/10 */
    filter: blur(6.25rem); /* 100px */
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

.blob-2 {
    position: absolute;
    bottom: -10%;
    right: -10%;
    width: 37.5rem; /* 600px */
    height: 37.5rem;
    border-radius: 9999px;
    background-color: rgba(255, 255, 255, 0.05); /* white/5 */
    filter: blur(7.5rem); /* 120px */
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
    animation-delay: 2s;
}

.blob-3 {
    position: absolute;
    top: 40%;
    left: 60%;
    width: 18.75rem; /* 300px */
    height: 18.75rem;
    border-radius: 9999px;
    background-color: rgba(148, 163, 184, 0.05); /* slate-400/5 */
    filter: blur(5rem); /* 80px */
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .5; }
}

/* Layout */
main {
    position: relative;
    z-index: 10;
    width: 100%;
    max-width: 32rem; /* max-w-lg */
    margin-top: auto;
    margin-bottom: auto;
    /* max-height removed to let content flow */
    /* overflow-y removed */
    /* Removed padding: 1rem; as it's handled by body or media query */
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 2rem;
}

.header-flex{
    display: flex;
    gap: 1rem;
    justify-content: center;
    align-items: center;
}

.icon-container {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem;
    border-radius: 1rem;
    background-color: rgba(255, 255, 255, 0.05);
    margin-bottom: 1rem;
    border: 0.0625rem solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(0.25rem);
    box-shadow: 0 0 0.9375rem rgba(255, 255, 255, 0.05);
}

.header-title {
    font-size: 2.25rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    background-image: linear-gradient(to right, var(--slate-200), var(--white), var(--slate-400));
    margin: 0;
}

.header-subtitle {
    color: var(--slate-400);
    margin-top: 0.5rem;
    font-size: 1.125rem;
}

/* Card */
.glass-card {
    background: rgba(20, 20, 23, 0.6);
    backdrop-filter: blur(1.25rem);
    -webkit-backdrop-filter: blur(1.25rem);
    border: 0.0625rem solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 1.5625rem 3.125rem -0.75rem rgba(0, 0, 0, 0.8);
    border-radius: 1rem;
    padding: 1.5rem;
}

.card-content-spacing > * + * {
    margin-top: 2rem;
}

/* Generated Password Display */
.password-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--slate-400);
    font-weight: 600;
    margin-bottom: 0.5rem;
    margin-left: 0.25rem;
}

.password-input-wrapper {
    position: relative;
}

.glass-input {
    background: rgba(255, 255, 255, 0.05);
    border: 0.0625rem solid rgba(255, 255, 255, 0.1);
    width: 100%;
    padding-left: 1.5rem;
    padding-right: 3.5rem;
    padding-top: 1rem;
    padding-bottom: 1rem;
    border-radius: 0.75rem;
    font-size: 1.5rem;
    font-family: var(--font-mono);
    color: var(--white);
    letter-spacing: 0.1em;
    text-align: center;
    box-shadow: inset 0 0.125rem 0.25rem rgba(0,0,0,0.5);
    transition: all 0.2s;
}

.glass-input:focus {
    outline: none;
    box-shadow: 0 0 0 0.125rem rgba(255, 255, 255, 0.3), inset 0 0.125rem 0.25rem rgba(0,0,0,0.5);
}

.copy-btn {
    position: absolute;
    right: 0.5rem;
    top: 50%;
    transform: translateY(-50%);
    padding: 0.5rem;
    border-radius: 0.5rem;
    color: var(--slate-500);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: color 0.15s, background-color 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.copy-btn:hover {
    color: var(--white);
    background-color: rgba(255, 255, 255, 0.1);
}

.copied-msg {
    position: absolute;
    right: 3.5rem;
    top: 50%;
    transform: translateY(-50%) translateX(10px);
    background-color: var(--slate-800);
    color: var(--accent-silver);
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.875rem;
    font-weight: 500;
    opacity: 0;
    pointer-events: none;
    transition: all 0.2s ease;
    border: 1px solid var(--slate-600);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.copied-msg.visible {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
}

.copy-btn:focus-visible,
.generate-btn:focus-visible,
.range-slider:focus-visible {
    outline: 0.125rem solid rgba(255, 255, 255, 0.7);
    outline-offset: 0.125rem;
}

/* Strength Bar */
.strength-container {
    margin-top: 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
}

.strength-bar-bg {
    height: 0.375rem;
    flex: 1;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 9999px;
    overflow: hidden;
}

.strength-bar-fill {
    height: 100%;
    width: 100%;
    background-image: linear-gradient(to right, var(--slate-600), var(--slate-400), var(--white));
    border-radius: 9999px;
    box-shadow: 0 0 0.625rem rgba(255, 255, 255, 0.3);
    transition: width 0.2s ease, background-image 0.2s ease;
}

.mono-text-glow {
    text-shadow: 0 0 0.5rem rgba(255, 255, 255, 0.3);
}

.strength-text {
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

/* Settings */
.settings-space > * + * {
    margin-top: 1.5rem;
}

/* Length Slider */
.length-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.length-label {
    color: var(--slate-400);
    font-weight: 500;
    font-size: 0.875rem;
}

.length-value {
    color: var(--white);
    font-weight: 700;
    font-size: 1.25rem;
    background-color: rgba(255, 255, 255, 0.05);
    padding: 0.25rem 0.75rem;
    border-radius: 0.5rem;
    border: 0.0625rem solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 0.625rem rgba(255, 255, 255, 0.05);
}

.slider-container {
    position: relative;
    width: 100%;
    height: 1.5rem;
    display: flex;
    align-items: center;
}

.range-slider {
    width: 100%;
    z-index: 20;
    margin: 0;
}

/* Input Range Styles from original */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    background: transparent;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 1.5rem;
    width: 1.5rem;
    border-radius: 50%;
    background: #ffffff;
    background: linear-gradient(135deg, #f8fafc, #e2e8f0);
    cursor: pointer;
    margin-top: -0.625rem;
    box-shadow: 0 0 0.625rem rgba(255, 255, 255, 0.4);
    border: 0.125rem solid #ffffff;
}
input[type="range"]::-webkit-slider-runnable-track {
    width: 100%;
    height: 0.25rem;
    cursor: pointer;
    background: transparent;
    border-radius: 0.125rem;
}

.range-track-filled {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 0.25rem;
    background-image: linear-gradient(to right, var(--slate-400), var(--white));
    width: 50%; /* Should be dynamic via JS */
    border-top-left-radius: 9999px;
    border-bottom-left-radius: 9999px;
    z-index: 10;
    box-shadow: 0 0 0.5rem rgba(255, 255, 255, 0.3);
    transition: width 0.15s ease;
}

.range-track-empty {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 0.25rem;
    background-color: rgba(255, 255, 255, 0.05);
    width: 50%;
    border-top-right-radius: 9999px;
    border-bottom-right-radius: 9999px;
    z-index: 0;
    transition: width 0.15s ease;
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--slate-500);
    margin-top: 0.5rem;
    font-family: var(--font-mono);
}

/* Options Grid */
.options-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

.option-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem;
    border-radius: 0.75rem;
    background-color: rgba(255, 255, 255, 0.05);
    border: 0.0625rem solid rgba(255, 255, 255, 0.05);
    transition: border-color 0.2s;
    cursor: pointer;
}

.option-card:hover {
    border-color: rgba(255, 255, 255, 0.2);
}

.option-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.option-icon {
    color: var(--slate-500);
    transition: color 0.2s;
    font-size: 1.125rem;
}

.option-card:hover .option-icon {
    color: var(--white);
}

.option-label {
    color: var(--slate-300);
    font-size: 0.875rem;
    font-weight: 500;
}

/* Toggle Switch */
.toggle-label-wrapper {
    position: relative;
    display: inline-flex;
    align-items: center;
    cursor: pointer;
}

.sr-only {
    position: absolute;
    width: 0.0625rem;
    height: 0.0625rem;
    padding: 0;
    margin: -0.0625rem;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.toggle-bg {
    width: 2.75rem;
    height: 1.5rem;
    background-color: var(--slate-800);
    border-radius: 9999px;
    position: relative;
    transition: background 0.2s;
}

.toggle-bg::after {
    content: '';
    position: absolute;
    top: 0.125rem;
    left: 0.125rem;
    background-color: var(--slate-300);
    border: 0.0625rem solid #d1d5db;
    border-radius: 9999px;
    height: 1.25rem;
    width: 1.25rem;
    transition: all 0.2s;
}

input:focus ~ .toggle-bg {
    outline: none;
    box-shadow: 0 0 0 0.125rem rgba(255, 255, 255, 0.3);
}

input:checked ~ .toggle-bg {
    background-image: linear-gradient(to right, #94a3b8, #f8fafc);
}

input:checked ~ .toggle-bg::after {
    transform: translateX(100%);
    background-color: var(--white);
    border-color: var(--white);
}

/* Generate Button */
.generate-btn {
    width: 100%;
    background-image: linear-gradient(to right, var(--slate-200), var(--white));
    color: var(--black);
    font-weight: 700;
    padding: 1rem 1.5rem;
    border-radius: 0.75rem;
    border: none;
    transition: all 0.2s;
    transform: scale(1);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    cursor: pointer;
    margin-top: 2rem;
}

.mono-glow {
    box-shadow: 0 0 1.25rem rgba(255, 255, 255, 0.25);
}

.generate-btn:hover {
    background-image: linear-gradient(to right, var(--white), var(--slate-200));
    transform: scale(1.02);
}

.btn-icon {
    transition: transform 0.5s;
}

.generate-btn:hover .btn-icon {
    transform: rotate(180deg);
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Footer */
.footer {
    text-align: center;
    padding-top: 0.5rem;
}

.footer-text {
    font-size: 0.75rem;
    color: var(--slate-500);
}

/* Material Icons size utilities if needed */
.text-3xl { font-size: 1.875rem; }
.text-xl { font-size: 1.25rem; }
.text-lg { font-size: 1.125rem; }

.header-icon {
    color: var(--slate-200);
    font-size: 1.2rem;
}

/* Responsive Media Queries */

/* Tablet & Up */
@media (min-width: 48rem) { /* 768px */
    .header-title {
        font-size: 3rem;
    }
    
    .glass-card {
        padding: 2rem;
    }
    
    .glass-input {
        font-size: 1.875rem;
    }
}

/* Desktop Grid for Options */
@media (min-width: 40rem) { /* 640px */
    .options-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Short screens / Landscape mobile - compact view */
@media (max-height: 50rem) { /* 800px */
    .header {
        margin-bottom: 1rem;
    }
    
    .glass-card {
        padding: 1rem;
    }
    
    .card-content-spacing > * + * {
        margin-top: 1rem;
    }
    
    .generate-btn {
        margin-top: 1.25rem;
        padding: 0.75rem 1rem;
    }
    
    .settings-space > * + * {
        margin-top: 1rem;
    }
    
    .icon-container {
        margin-bottom: 0.5rem;
        padding: 0.5rem;
    }
    
    .header-title {
        font-size: 1.75rem;
    }
    
    @media (min-width: 48rem) {
        .header-title {
            font-size: 2.25rem;
        }
    }
}