/* ====================================
   CSS CUSTOM PROPERTIES - PREMIUM THEME
   ==================================== */
:root {
    /* Primary Colors - Soft, modern palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-color: #667eea;
    --primary-light: #8fa4f3;
    --primary-dark: #5a6fd8;
    
    /* Secondary Colors - Complementary pastels */
    --secondary-color: #f093fb;
    --secondary-light: #f5b3fc;
    --secondary-dark: #e777f8;
    
    /* Accent Colors - Bold highlights */
    --accent-color: #4ecdc4;
    --accent-secondary: #45b7b8;
    --success-color: #6c5ce7;
    --warning-color: #fdcb6e;
    
    /* Background & Surface - Clean, minimal */
    --background-color: #fafbff;
    --background-gradient: linear-gradient(135deg, #fafbff 0%, #f4f7ff 100%);
    --surface-color: #ffffff;
    --surface-elevated: #ffffff;
    --glass-effect: rgba(255, 255, 255, 0.95);
    
    /* Text Colors - High contrast, readable */
    --text-primary: #2d3748;
    --text-secondary: #718096;
    --text-muted: #a0aec0;
    --text-accent: var(--primary-color);
    
    /* Border & Dividers */
    --border-color: rgba(203, 213, 225, 0.6);
    --border-focus: var(--primary-color);
    --divider-color: rgba(203, 213, 225, 0.4);
    
    /* Shadows - Soft, modern elevation */
    --shadow-sm: 0 2px 4px rgba(16, 24, 40, 0.04);
    --shadow-md: 0 4px 12px rgba(16, 24, 40, 0.08);
    --shadow-lg: 0 8px 24px rgba(16, 24, 40, 0.12);
    --shadow-xl: 0 16px 48px rgba(16, 24, 40, 0.16);
    --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.3);
    
    /* Spacing & Layout */
    --border-radius-sm: 8px;
    --border-radius: 12px;
    --border-radius-lg: 16px;
    --border-radius-xl: 24px;
    
    /* Animations & Transitions */
    --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    --spring: cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* ====================================
   DARK THEME - PREMIUM PALETTE
   ==================================== */
[data-theme="dark"] {
    /* Background & Surface - Rich, deep tones */
    --background-color: #0f0f23;
    --background-gradient: linear-gradient(135deg, #0f0f23 0%, #1a1a2e 100%);
    --surface-color: #16213e;
    --surface-elevated: #1e2749;
    --glass-effect: rgba(22, 33, 62, 0.95);
    
    /* Text Colors - High contrast for readability */
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --text-accent: #8fa4f3;
    
    /* Accent Colors - Vibrant but not harsh */
    --accent-color: #56d1c7;
    --accent-secondary: #4dd4d6;
    
    /* Border & Dividers */
    --border-color: rgba(71, 85, 105, 0.4);
    --border-focus: var(--primary-light);
    --divider-color: rgba(71, 85, 105, 0.3);
    
    /* Shadows - Enhanced for dark theme */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(143, 164, 243, 0.4);
}

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

*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-weight: 400;
    background: var(--background-gradient);
    color: var(--text-primary);
    line-height: 1.7;
    letter-spacing: 0.01em;
    transition: var(--transition-normal);
    min-height: 100vh;
    overflow-x: hidden;
    padding-top: 80px; /* Space for fixed navbar */
}

/* ====================================
   NAVIGATION - PREMIUM MENU BAR
   ==================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--glass-effect);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition-normal);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-logo i {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 1.75rem;
}

.nav-logo span {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 2rem;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.nav-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    opacity: 0;
    transition: var(--transition-normal);
    z-index: -1;
}

.nav-link:hover {
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.nav-link:hover::before {
    left: 0;
    opacity: 1;
}

.nav-link i {
    font-size: 1rem;
    transition: var(--transition-fast);
}

.nav-link:hover i {
    transform: scale(1.1);
}

/* Theme toggle in navbar */
.navbar .theme-toggle {
    position: static;
    margin: 0;
}

/* ====================================
   LAYOUT - PREMIUM CONTAINER SYSTEM
   ==================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    display: block;
    position: relative;
}

/* ====================================
   HEADER - PREMIUM BRANDING
   ==================================== */
header {
    text-align: center;
    margin-bottom: 4rem;
    margin-top: 2rem;
    position: relative;
    z-index: 10;
}

header h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

header h1 i {
    margin-right: 0.75rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: float 3s ease-in-out infinite;
    display: inline-block;
}

header p {
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

/* ====================================
   THEME TOGGLE - PREMIUM FLOATING BUTTON
   ==================================== */
.theme-toggle {
    background: var(--glass-effect);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 56px;
    height: 56px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-normal);
    box-shadow: var(--shadow-md);
    z-index: 100;
}

.theme-toggle:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-focus);
}

.theme-toggle:active {
    transform: translateY(-1px) scale(1.02);
}

.theme-toggle i {
    font-size: 1.25rem;
    color: var(--text-accent);
    transition: var(--transition-fast);
}

.theme-toggle:hover i {
    transform: rotate(180deg);
    color: var(--primary-color);
}

/* ====================================
   CALCULATOR CONTAINER - PREMIUM CARD
   ==================================== */
.calculator-container {
    background: var(--glass-effect);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-xl);
    padding: 3rem;
    box-shadow: var(--shadow-xl);
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

.calculator-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--primary-color), transparent);
    opacity: 0.5;
}

/* ====================================
   INPUT SECTION - PREMIUM FORM ELEMENTS
   ==================================== */
.input-section {
    margin-bottom: 3rem;
}

.pet-selection {
    margin-bottom: 2rem;
}

.pet-selection label {
    display: block;
    margin-bottom: 0.75rem;
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-primary);
    letter-spacing: 0.01em;
}

.pet-dropdown {
    width: 100%;
    padding: 1.25rem 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    background: var(--surface-color);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    font-weight: 500;
    transition: var(--transition-normal);
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

.pet-dropdown:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: var(--shadow-md), 0 0 0 4px rgba(102, 126, 234, 0.1);
    transform: translateY(-1px);
}

.pet-dropdown:hover {
    border-color: var(--primary-light);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.pet-dropdown option {
    padding: 0.75rem;
    font-weight: 500;
}

.pet-dropdown optgroup {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 0.95rem;
    padding: 0.5rem;
}

/* Disabled state for pet dropdown */
.pet-dropdown.disabled {
    opacity: 0.6;
    cursor: not-allowed;
    background-color: var(--surface-color);
    color: var(--text-muted);
}

.pet-dropdown.disabled:hover {
    border-color: var(--border-color);
    transform: none;
    box-shadow: var(--shadow-sm);
}

/* Breed selection spacing */
.breed-selection-wrapper {
    display: none;
    margin-bottom: 2rem;
}

.breed-selection-wrapper > label {
    display: block;
    margin-bottom: 0.75rem;
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-primary);
    letter-spacing: 0.01em;
}

.breed-selection {
    margin-top: 0;
}

.breed-selection label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
    font-size: 1.1rem;
    letter-spacing: 0.01em;
}

#noBreedMessage {
    padding: 0.95rem 1.1rem;
    border: 1px dashed var(--border-color);
    border-radius: var(--border-radius);
    background: rgba(102, 126, 234, 0.04);
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ====================================
   AGE INPUT SECTION - PREMIUM CONTROLS
   ==================================== */
.age-input-section {
    margin-bottom: 1.5rem;
}

.age-input {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.age-input label {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-primary);
    letter-spacing: 0.01em;
}

.age-input input {
    width: 100%;
    padding: 1.25rem 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    background: var(--surface-color);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    font-weight: 500;
    transition: var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.age-input input:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: var(--shadow-md), 0 0 0 4px rgba(102, 126, 234, 0.1);
    transform: translateY(-1px);
}

.age-input input:hover {
    border-color: var(--primary-light);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.age-input input::placeholder {
    color: var(--text-muted);
    font-style: normal;
}

/* ====================================
   BUTTON GROUP - PREMIUM INTERACTIVE ELEMENTS
   ==================================== */
.button-group {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.calculate-btn,
.random-btn {
    flex: 1;
    padding: 1.25rem 2rem;
    border: none;
    border-radius: var(--border-radius-lg);
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    letter-spacing: 0.01em;
    box-shadow: var(--shadow-md);
}

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

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.calculate-btn:active {
    transform: translateY(-1px);
}

.random-btn {
    background: var(--surface-color);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.random-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.random-btn:active {
    transform: translateY(-1px);
}

.calculate-btn i,
.random-btn i {
    font-size: 1.1rem;
    transition: var(--transition-fast);
}

.calculate-btn:hover i,
.random-btn:hover i {
    transform: scale(1.1);
}

/* ====================================
   RESULT SECTION - PREMIUM DISPLAY
   ==================================== */
.result-section {
    display: none;
    text-align: center;
    padding: 1.25rem 0 0;
    border-top: 1px solid var(--divider-color);
    margin-top: 1.5rem;
}

.pet-image-container {
    display: none;
}

.pet-image {
    display: none;
}

.pet-image::before {
    display: none;
}

.pet-image i {
    color: white;
    transition: var(--transition-normal);
}

.pet-image:hover {
    transform: none;
    box-shadow: none;
}

.result-display {
    margin-bottom: 0;
}

.result-display h2 {
    font-size: clamp(1.55rem, 3.6vw, 2.5rem);
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.65rem;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.result-display p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    font-weight: 500;
    max-width: 720px;
    margin: 0 auto;
}

.fun-fact {
    background: var(--surface-elevated);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 1.25rem 1.25rem 1.1rem;
    margin-top: 1.5rem;
    font-style: italic;
    color: var(--text-secondary);
    line-height: 1.6;
    box-shadow: var(--shadow-sm);
    position: relative;
    text-align: left;
}

.fun-fact::before {
    content: '💡';
    font-size: 1.5rem;
    position: absolute;
    top: -0.75rem;
    left: 1.5rem;
    background: var(--surface-elevated);
    padding: 0 0.5rem;
}

/* ====================================
   FOOTER - PREMIUM CREDITS
   ==================================== */
footer {
    text-align: center;
    padding: 2rem 0;
    border-top: 1px solid var(--divider-color);
    margin-top: auto;
}

footer p {
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 400;
}

footer i {
    color: #e74c3c;
    margin: 0 0.25rem;
    animation: heartbeat 2s ease-in-out infinite;
}

/* ====================================
   ANIMATIONS - PREMIUM MOTION DESIGN
   ==================================== */
@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

@keyframes heartbeat {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

/* ====================================
   RESPONSIVE DESIGN - PREMIUM MOBILE FIRST
   ==================================== */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 1rem;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .nav-link {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
    
    .nav-link span {
        display: none;
    }
    
    .container {
        padding: 1rem;
    }
    
    header {
        margin-bottom: 2rem;
        margin-top: 1rem;
    }
    
    .calculator-container {
        padding: 2rem;
        border-radius: var(--border-radius-lg);
    }
    
    .button-group {
        flex-direction: column;
        gap: 0.75rem;
    }
    
    .result-display h2 {
        font-size: 2rem;
    }
    
    .fun-fact {
        padding: 1.1rem;
        font-size: 0.95rem;
    }
}

@media (max-width: 480px) {
    body {
        padding-top: 70px;
    }
    
    .nav-container {
        height: 70px;
        padding: 0 0.75rem;
    }
    
    .nav-logo {
        font-size: 1.25rem;
    }
    
    .nav-logo i {
        font-size: 1.5rem;
    }
    
    .theme-toggle {
        width: 48px;
        height: 48px;
    }
    
    .theme-toggle i {
        font-size: 1.1rem;
    }
    
    .calculator-container {
        padding: 1.5rem;
        margin-bottom: 2rem;
    }
    
    .pet-dropdown,
    .age-input input {
        padding: 1rem 1.25rem;
        font-size: 0.95rem;
    }
    
    .calculate-btn,
    .random-btn {
        padding: 1rem 1.5rem;
        font-size: 0.95rem;
    }
    
    .result-display h2 {
        font-size: 1.75rem;
    }
    
    .result-display p {
        font-size: 1.1rem;
    }
}

/* ====================================
   ACCESSIBILITY ENHANCEMENTS
   ==================================== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus indicators for accessibility */
.calculate-btn:focus-visible,
.random-btn:focus-visible,
.mode-btn:focus-visible,
.theme-toggle:focus-visible {
    outline: 2px solid var(--border-focus);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --text-secondary: #000000;
        --text-muted: #333333;
    }
    
    [data-theme="dark"] {
        --border-color: #ffffff;
        --text-secondary: #ffffff;
        --text-muted: #cccccc;
    }
}

/* ====================================
   BREED-SPECIFIC PAGE ADDITIONS
   ==================================== */
.breed-selection-wrapper--fixed {
    display: block;
}

.breed-fixed-card {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    padding: 1.25rem 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    background: var(--surface-color);
    box-shadow: var(--shadow-sm);
}

.fixed-value {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
}

.fixed-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    white-space: nowrap;
    padding: 0.55rem 0.8rem;
    border-radius: 999px;
    background: rgba(102, 126, 234, 0.12);
    color: var(--primary-color);
    font-size: 0.9rem;
    font-weight: 600;
}

.breed-note {
    margin-top: 0.45rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.55;
}

.button-group--single {
    justify-content: flex-start;
}

.content-card {
    margin-top: 2rem;
    padding: 2rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-xl);
    background: var(--glass-effect);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.content-card h2 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.content-card p + p {
    margin-top: 1rem;
}

@media (max-width: 768px) {
    .breed-fixed-card {
        flex-direction: column;
        align-items: flex-start;
    }
}