/* --- DESIGN SYSTEM & CSS VARIABLES --- */
:root {
    --bg-primary: hsl(222, 47%, 8%);
    --bg-secondary: hsl(222, 47%, 12%);
    --card-bg: hsla(223, 47%, 15%, 0.55);
    --border-color: hsla(217, 30%, 60%, 0.12);
    --border-hover: hsla(255, 85%, 65%, 0.3);
    
    /* Brand Colors */
    --primary: hsl(255, 85%, 65%);
    --primary-hover: hsl(255, 85%, 70%);
    --primary-glow: hsla(255, 85%, 65%, 0.35);
    --accent-cyan: hsl(190, 90%, 50%);
    
    /* Text Colors */
    --text-main: hsl(210, 40%, 96%);
    --text-muted: hsl(215, 20%, 65%);
    --text-dark: hsl(222, 47%, 11%);
    
    /* Strength Colors */
    --strength-0: hsl(0, 85%, 60%);       /* Very Weak */
    --strength-1: hsl(24, 95%, 60%);      /* Weak */
    --strength-2: hsl(45, 95%, 50%);      /* Medium */
    --strength-3: hsl(142, 70%, 45%);     /* Strong */
    --strength-4: hsl(175, 90%, 43%);     /* Very Strong / Excellent */

    --font-sans: 'Inter', sans-serif;
    --font-heading: 'Outfit', sans-serif;
    --font-mono: 'Fira Code', monospace;
    
    --radius-lg: 24px;
    --radius-md: 16px;
    --radius-sm: 8px;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* --- RESET & BASE STYLES --- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-main);
    font-family: var(--font-sans);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow-x: hidden;
    padding: 2rem 1rem;
}

/* --- DECORATIVE BACKGROUND --- */
.background-decor {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    pointer-events: none;
}

.glow-sphere {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.25;
}

.sphere-1 {
    top: -10%;
    left: -10%;
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
    animation: pulse-slow 15s infinite alternate;
}

.sphere-2 {
    bottom: -10%;
    right: -10%;
    width: 45vw;
    height: 45vw;
    background: radial-gradient(circle, var(--accent-cyan) 0%, transparent 70%);
    animation: pulse-slow 20s infinite alternate-reverse;
}

@keyframes pulse-slow {
    0% { transform: scale(1) translate(0, 0); opacity: 0.2; }
    50% { transform: scale(1.15) translate(3%, 5%); opacity: 0.3; }
    100% { transform: scale(0.9) translate(-2%, -3%); opacity: 0.15; }
}

/* --- APP LAYOUT --- */
.app-container {
    width: 100%;
    max-width: 540px;
    z-index: 10;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* --- HEADER --- */
.app-header {
    text-align: center;
    margin-bottom: 0.5rem;
}

.logo-area {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.shield-logo {
    width: 32px;
    height: 32px;
    color: var(--accent-cyan);
    filter: drop-shadow(0 0 8px hsla(190, 90%, 50%, 0.4));
}

.app-header h1 {
    font-family: var(--font-heading);
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, var(--text-main) 30%, var(--text-muted) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.app-header .subtitle {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 400;
}

/* --- CARD GLASSMORPHISM --- */
.glass {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: 0 16px 36px hsla(222, 47%, 2%, 0.4);
}

.card {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

/* --- PASSWORD DISPLAY & OUTPUT --- */
.output-container {
    display: flex;
    background: hsla(222, 47%, 8%, 0.65);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.5rem;
    align-items: center;
    justify-content: space-between;
    transition: var(--transition);
}

.output-container:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.password-wrapper {
    flex-grow: 1;
    position: relative;
    display: flex;
    align-items: center;
    padding-left: 0.75rem;
    overflow: hidden;
}

#password-display {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-main);
    font-family: var(--font-mono);
    font-size: 1.35rem;
    letter-spacing: 0.5px;
    text-overflow: ellipsis;
    white-space: nowrap;
    overflow: hidden;
}

#password-display::placeholder {
    color: var(--text-muted);
    font-family: var(--font-sans);
    font-size: 1.1rem;
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
}

.icon-btn svg {
    width: 20px;
    height: 20px;
    transition: var(--transition);
}

.icon-btn:hover {
    color: var(--text-main);
    background: hsla(223, 20%, 40%, 0.15);
}

.icon-btn.primary {
    background: var(--primary);
    color: white;
}

.icon-btn.primary:hover {
    background: var(--primary-hover);
    box-shadow: 0 0 12px var(--primary-glow);
}

.icon-btn.primary:active svg {
    transform: rotate(180deg);
}

.icon-btn.copied {
    color: var(--strength-3) !important;
}

/* Tooltip for Copy Feedback */
.tooltip {
    position: absolute;
    bottom: calc(100% + 12px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    background: hsl(222, 47%, 95%);
    color: var(--text-dark);
    font-size: 0.8rem;
    font-weight: 600;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275), transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 100;
}

.tooltip::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border-width: 6px;
    border-style: solid;
    border-color: hsl(222, 47%, 95%) transparent transparent transparent;
}

.tooltip.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* --- STRENGTH METER --- */
.strength-meter-container {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.strength-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.strength-label {
    font-weight: 600;
    transition: var(--transition);
}

.strength-track {
    height: 6px;
    width: 100%;
    background: hsla(222, 47%, 8%, 0.5);
    border-radius: 10px;
    overflow: hidden;
}

.strength-bar {
    height: 100%;
    width: 0%;
    border-radius: 10px;
    transition: width 0.4s cubic-bezier(0.25, 0.8, 0.25, 1), background-color 0.3s ease;
}

/* Strength States */
.strength-bar.level-0 { width: 5%; background-color: var(--strength-0); }
.strength-bar.level-1 { width: 25%; background-color: var(--strength-1); }
.strength-bar.level-2 { width: 50%; background-color: var(--strength-2); }
.strength-bar.level-3 { width: 75%; background-color: var(--strength-3); }
.strength-bar.level-4 { width: 100%; background-color: var(--strength-4); }

.strength-label.level-0 { color: var(--strength-0); }
.strength-label.level-1 { color: var(--strength-1); }
.strength-label.level-2 { color: var(--strength-2); }
.strength-label.level-3 { color: var(--strength-3); }
.strength-label.level-4 { color: var(--strength-4); }

/* --- SETTINGS AREA --- */
.settings-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.range-setting {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.setting-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-main);
    font-weight: 500;
    font-size: 0.95rem;
}

#length-input {
    width: 60px;
    background: hsla(222, 47%, 8%, 0.6);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 600;
    text-align: center;
    padding: 6px 4px;
    outline: none;
    transition: var(--transition);
}

#length-input:focus {
    border-color: var(--primary);
}

/* Chrome, Safari, Edge, Opera: Remove spin buttons */
#length-input::-webkit-outer-spin-button,
#length-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
/* Firefox: Remove spin buttons */
#length-input[type=number] {
    -moz-appearance: textfield;
}

.slider-wrapper {
    width: 100%;
}

/* Custom Slider Styling */
input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: hsla(222, 47%, 8%, 0.7);
    outline: none;
}

/* Chrome/Safari Thumb */
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 0 10px var(--primary-glow);
    transition: var(--transition);
    border: 2px solid var(--text-main);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    background: var(--primary-hover);
}

/* Firefox Thumb */
input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border: 2px solid var(--text-main);
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 0 10px var(--primary-glow);
    transition: var(--transition);
}

input[type="range"]::-moz-range-thumb:hover {
    transform: scale(1.15);
    background: var(--primary-hover);
}

.divider {
    border: none;
    border-bottom: 1px solid var(--border-color);
}

/* --- OPTIONS GRID --- */
.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}

.option-item {
    display: flex;
    align-items: center;
}

/* Toggle Switch Styles */
.switch-container {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    user-select: none;
    width: 100%;
    padding: 4px 0;
}

.switch-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.switch-slider {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
    background-color: hsla(222, 47%, 8%, 0.8);
    border: 1px solid var(--border-color);
    border-radius: 34px;
    transition: var(--transition);
    flex-shrink: 0;
}

.switch-slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 3px;
    bottom: 3px;
    background-color: var(--text-muted);
    border-radius: 50%;
    transition: var(--transition);
}

.switch-container input:checked + .switch-slider {
    background-color: var(--primary);
    border-color: var(--primary);
}

.switch-container input:checked + .switch-slider:before {
    transform: translateX(20px);
    background-color: white;
}

.switch-container:hover .switch-slider:before {
    box-shadow: 0 0 5px hsla(0, 0%, 100%, 0.3);
}

.switch-container.highlight input:checked + .switch-slider {
    background-color: var(--accent-cyan);
    border-color: var(--accent-cyan);
}

.option-text {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-main);
}

.char-preview {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    margin-left: 2px;
}

/* --- PRIVACY BADGE --- */
.privacy-badge {
    padding: 1.25rem 1.5rem;
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.info-icon {
    width: 24px;
    height: 24px;
    color: var(--accent-cyan);
    flex-shrink: 0;
    margin-top: 2px;
}

.privacy-badge h3 {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-main);
}

.privacy-badge p {
    font-size: 0.825rem;
    color: var(--text-muted);
    line-height: 1.4;
}

/* --- FOOTER --- */
.main-footer {
    margin-top: 1.5rem;
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* --- RESPONSIVE ADJUSTMENTS --- */
@media (max-width: 480px) {
    .card {
        padding: 1.5rem;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .full-width-mobile {
        grid-column: 1 / -1;
    }
    
    body {
        padding: 1rem 0.5rem;
    }
    
    .app-header h1 {
        font-size: 1.85rem;
    }
}