/* ===== CSS Variables for Design System ===== */
:root {
    /* Primary colors */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-color: #667eea;
    --primary-dark: #5a67d8;
    --primary-light: #9f7aea;
    
    /* Accent colors */
    --accent-success: #48bb78;
    --accent-success-light: #68d391;
    --accent-warning: #ecc94b;
    --accent-danger: #f56565;
    --accent-info: #4299e1;
    
    /* Background colors */
    --bg-gradient: linear-gradient(135deg, #1a1c2e 0%, #2d1b4e 50%, #1a1c2e 100%);
    --bg-card: rgba(255, 255, 255, 0.08);
    --bg-card-hover: rgba(255, 255, 255, 0.12);
    --bg-input: rgba(255, 255, 255, 0.06);
    --bg-input-focus: rgba(255, 255, 255, 0.1);
    
    /* Text colors */
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);
    
    /* Border colors */
    --border-color: rgba(255, 255, 255, 0.1);
    --border-focus: rgba(102, 126, 234, 0.5);
    
    /* Shadow */
    --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-button: 0 4px 15px rgba(102, 126, 234, 0.4);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.3);
    
    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Border radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===== Global Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;600;700&display=swap');

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-gradient);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-primary);
    padding: var(--spacing-lg);
    overflow-x: hidden;
}

/* Animated background effect */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(118, 75, 162, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(72, 187, 120, 0.08) 0%, transparent 40%);
    pointer-events: none;
    z-index: -1;
    animation: backgroundPulse 15s ease-in-out infinite;
}

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

/* ===== Header Styles ===== */
h1 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    background: linear-gradient(135deg, #ffffff 0%, #a5b4fc 50%, #c4b5fd 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 0.5px;
    position: relative;
    padding-bottom: var(--spacing-md);
    animation: titleGlow 3s ease-in-out infinite;
}

h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--primary-gradient);
    border-radius: 2px;
}

h1 i {
    -webkit-text-fill-color: #48bb78;
    margin-right: var(--spacing-sm);
    animation: houseFloat 3s ease-in-out infinite;
}

@keyframes titleGlow {
    0%, 100% { filter: drop-shadow(0 0 10px rgba(102, 126, 234, 0.3)); }
    50% { filter: drop-shadow(0 0 20px rgba(102, 126, 234, 0.5)); }
}

@keyframes houseFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

/* ===== Container Styles ===== */
.container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    width: 100%;
    max-width: 1400px;
    animation: containerFadeIn 0.8s ease-out;
}

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

/* ===== Section Cards ===== */
.form-section,
.result-section,
.info-section {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-card);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.form-section::before,
.result-section::before,
.info-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary-gradient);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.form-section:hover,
.result-section:hover,
.info-section:hover {
    background: var(--bg-card-hover);
    transform: translateY(-5px);
    box-shadow: var(--shadow-card), var(--shadow-glow);
}

.form-section:hover::before,
.result-section:hover::before,
.info-section:hover::before {
    opacity: 1;
}

/* ===== Section Headers ===== */
.form-section h2,
.result-section h2,
.info-section h2 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.form-section h2 i,
.result-section h2 i,
.info-section h2 i {
    font-size: 1.1rem;
    color: var(--primary-light);
}

/* ===== Input Group Styles ===== */
.input-group {
    margin-bottom: var(--spacing-lg);
    animation: inputSlideIn 0.5s ease-out backwards;
}

.input-group:nth-child(1) { animation-delay: 0.1s; }
.input-group:nth-child(2) { animation-delay: 0.15s; }
.input-group:nth-child(3) { animation-delay: 0.2s; }
.input-group:nth-child(4) { animation-delay: 0.25s; }
.input-group:nth-child(5) { animation-delay: 0.3s; }
.input-group:nth-child(6) { animation-delay: 0.35s; }

@keyframes inputSlideIn {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

.input-group label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    transition: color var(--transition-fast);
}

.input-group label i {
    color: var(--primary-light);
    font-size: 0.9rem;
    width: 20px;
    text-align: center;
}

.input-group:focus-within label {
    color: var(--text-primary);
}

.input-group:focus-within label i {
    color: var(--primary-color);
}

.input-group input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1rem;
    font-family: inherit;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    transition: all var(--transition-normal);
    outline: none;
}

.input-group input::placeholder {
    color: var(--text-muted);
}

.input-group input:hover {
    background: var(--bg-input-focus);
    border-color: rgba(255, 255, 255, 0.2);
}

.input-group input:focus {
    background: var(--bg-input-focus);
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2), 0 0 20px rgba(102, 126, 234, 0.15);
}

/* ===== Button Styles ===== */
.button {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.1rem;
    font-weight: 600;
    font-family: inherit;
    color: var(--text-primary);
    background: var(--primary-gradient);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-button);
    position: relative;
    overflow: hidden;
    margin-top: var(--spacing-md);
}

.button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.button:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-button), 0 8px 25px rgba(102, 126, 234, 0.5);
}

.button:hover::before {
    left: 100%;
}

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

.button i {
    font-size: 1rem;
    transition: transform var(--transition-normal);
}

.button:hover i {
    transform: rotate(15deg) scale(1.1);
}

/* ===== Result & Advice Styles ===== */
.result,
.advice {
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    font-size: 0.95rem;
    line-height: 1.8;
    color: var(--text-secondary);
    transition: all var(--transition-normal);
    min-height: 120px;
}

.result {
    border-left: 4px solid var(--accent-info);
    margin-bottom: var(--spacing-xl);
}

.advice {
    border-left: 4px solid var(--accent-warning);
}

.result span,
.advice span {
    display: inline-block;
}

/* ===== Status Colors ===== */
.red {
    color: var(--accent-danger) !important;
    font-weight: 600;
    text-shadow: 0 0 10px rgba(245, 101, 101, 0.3);
}

.green {
    color: var(--accent-success) !important;
    font-weight: 600;
    text-shadow: 0 0 10px rgba(72, 187, 120, 0.3);
}

/* ===== Info Section Styles ===== */
.info-section p {
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
    color: var(--text-secondary);
    padding-left: var(--spacing-md);
    border-left: 2px solid transparent;
    transition: all var(--transition-normal);
}

.info-section p:hover {
    border-left-color: var(--primary-light);
    padding-left: var(--spacing-lg);
    color: var(--text-primary);
}

.info-section p strong {
    color: var(--primary-light);
    font-weight: 600;
    display: inline-block;
    margin-bottom: var(--spacing-xs);
}

.info-section p span {
    color: var(--text-muted);
    font-style: italic;
    font-size: 0.9rem;
}

/* ===== Appreciation Section ===== */
.v50 {
    text-align: center;
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    margin-top: var(--spacing-xl);
    transition: all var(--transition-normal);
}

.v50:hover {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.15) 100%);
    transform: scale(1.02);
}

.appreciate-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.appreciate-img {
    width: 180px;
    height: 180px;
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    transition: all var(--transition-normal);
    border: 3px solid rgba(255, 255, 255, 0.1);
}

.appreciate-img:hover {
    transform: scale(1.05) rotate(2deg);
    box-shadow: 0 12px 32px rgba(102, 126, 234, 0.4);
    border-color: var(--primary-light);
}

.appreciate-section p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.appreciate-section p::before {
    content: '❤️';
    animation: heartBeat 1.5s ease-in-out infinite;
}

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

/* ===== Loading Animation ===== */
.fa-spinner {
    animation: spin 1s linear infinite;
}

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

#loading {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--primary-light);
    font-weight: 500;
}

/* ===== Responsive Design ===== */
@media (max-width: 1200px) {
    .container {
        grid-template-columns: 1fr 1fr;
    }
    
    .info-section {
        grid-column: span 2;
    }
}

@media (max-width: 768px) {
    body {
        padding: var(--spacing-md);
    }
    
    .container {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .info-section {
        grid-column: span 1;
    }
    
    h1 {
        font-size: 1.5rem;
        margin-bottom: var(--spacing-lg);
    }
    
    .form-section,
    .result-section,
    .info-section {
        padding: var(--spacing-lg);
    }
    
    .appreciate-img {
        width: 150px;
        height: 150px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.3rem;
    }
    
    .button {
        font-size: 1rem;
        padding: var(--spacing-sm) var(--spacing-lg);
    }
    
    .input-group input {
        padding: var(--spacing-sm) var(--spacing-md);
    }
}

/* ===== Scrollbar Styles ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: rgba(102, 126, 234, 0.5);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(102, 126, 234, 0.7);
}

/* ===== Selection Styles ===== */
::selection {
    background: rgba(102, 126, 234, 0.4);
    color: var(--text-primary);
}

/* ===== Number Input Arrows ===== */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    opacity: 0.5;
    height: 30px;
}

input[type=number]:hover::-webkit-inner-spin-button,
input[type=number]:hover::-webkit-outer-spin-button {
    opacity: 1;
}