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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #10b981;
    --light-bg: #f9fafb;
    --dark-bg: #111827;
    --card-light: #ffffff;
    --card-dark: #1f2937;
    --text-light: #374151;
    --text-dark: #f3f4f6;
    --border-light: #e5e7eb;
    --border-dark: #374151;
    --shadow-light: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-dark: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--light-bg);
    color: var(--text-light);
    transition: var(--transition);
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
}

/* Floating Math Elements Background */
.math-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}

.math-element {
    position: absolute;
    opacity: 0.15;
    font-size: 1.5rem;
    color: rgba(0, 0, 0, 0.8);
    text-shadow: 0 0 2px rgba(16, 185, 129, 0.5); /* Green tint */
    animation: float 30s linear infinite;
    transform-origin: center;
}

@keyframes float {
    0% {
        transform: translateY(100vh) rotate(0deg) translateX(0);
    }
    25% {
        transform: translateY(50vh) rotate(90deg) translateX(20px);
    }
    50% {
        transform: translateY(0) rotate(180deg) translateX(0);
    }
    75% {
        transform: translateY(-50vh) rotate(270deg) translateX(-20px);
    }
    100% {
        transform: translateY(-100vh) rotate(360deg) translateX(0);
    }
}

.container {
    max-width: 1100px;
    padding: 0 20px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

header {
    padding: 3rem 0 2rem;
    text-align: center;
}

h1 {
    font-weight: 700;
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    display: inline-block;
}

.lead {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
    color: var(--text-light);
    opacity: 0.9;
}

.card {
    background-color: var(--card-light);
    border-radius: 16px;
    border: 1px solid var(--border-light);
    overflow: hidden;
    margin-bottom: 25px;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    transform: translateY(0);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.card-body {
    padding: 2rem;
}

.form-label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    display: block;
    color: var(--text-light);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 8px;
    border: 1px solid var(--border-light);
    background-color: var(--light-bg);
    transition: var(--transition);
}

textarea.form-control {
    font-family: 'JetBrains Mono', monospace;
    resize: vertical;
    min-height: 100px;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.btn {
    display: inline-block;
    font-weight: 500;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    user-select: none;
    border: 1px solid transparent;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 8px;
    transition: var(--transition);
    cursor: pointer;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-2px);
}

.btn-outline-secondary {
    background-color: transparent;
    border-color: var(--border-light);
    color: var(--text-light);
}

.btn-outline-secondary:hover {
    background-color: var(--light-bg);
    color: var(--primary-color);
}

.d-grid {
    display: grid;
    grid-gap: 0.75rem;
}

#equation-preview {
    min-height: 60px;
    background-color: var(--light-bg);
    border-radius: 8px;
    padding: 1rem;
    margin-top: 0.75rem;
    border: 1px solid var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
}

.equation-display,
#explanation-display,
#breakdown-display {
    position: relative;
    background-color: var(--light-bg);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    overflow-x: auto;
    transition: var(--transition);
}

.equation-display {
    font-size: 1.2rem;
    text-align: center;
}

#explanation-display,
#breakdown-display {
    line-height: 1.7;
}

/* Loading spinner */
.spinner-border {
    display: inline-block;
    width: 2rem;
    height: 2rem;
    vertical-align: text-bottom;
    border: 0.25em solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: spinner 0.75s linear infinite;
}

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

/* Dark Mode Styles */
body.dark-mode {
    background-color: var(--dark-bg);
    color: var(--text-dark);
}

.dark-mode .card {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}

.dark-mode .form-label {
    color: var(--text-dark);
}

.dark-mode .form-control {
    background-color: #2d3748;
    border-color: var(--border-dark);
    color: var(--text-dark);
}

.dark-mode .form-control::placeholder {
    color: #9ca3af;
}

.dark-mode .equation-display,
.dark-mode #explanation-display,
.dark-mode #breakdown-display,
.dark-mode #equation-preview {
    background-color: #2d3748;
    border-color: var(--border-dark);
    color: var(--text-dark);
}

.dark-mode .btn-outline-secondary {
    border-color: var(--border-dark);
    color: var(--text-dark);
}

.dark-mode .btn-outline-secondary:hover {
    background-color: #2d3748;
}

.dark-mode .lead {
    color: #d1d5db;
}

.dark-mode .math-element {
    opacity: 0.2;
    color: rgba(255, 255, 255, 0.8);
    text-shadow: 0 0 2px rgba(99, 102, 241, 0.5); /* Blue tint */
}

/* Dark Mode Toggle */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    cursor: pointer;
    background-color: var(--card-light);
    border: 1px solid var(--border-light);
    font-size: 1.25rem;
    color: var(--text-light);
    padding: 0.5rem;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.theme-toggle:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.dark-mode .theme-toggle {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
    color: var(--text-dark);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
}

/* Copy button styles */
.copy-button-container {
    position: absolute;
    top: 10px;
    right: 10px;
    z-index: 10;
}

.copy-button {
    background-color: rgba(255, 255, 255, 0.8);
    border: none;
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 5px;
    color: var(--text-light);
}

.copy-button:hover {
    background-color: rgba(255, 255, 255, 0.95);
    transform: translateY(-2px);
}

.dark-mode .copy-button {
    background-color: rgba(45, 55, 72, 0.8);
    color: var(--text-dark);
}

.dark-mode .copy-button:hover {
    background-color: rgba(45, 55, 72, 0.95);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }

    h1 {
        font-size: 2rem;
    }
    
    .card-body {
        padding: 1.5rem;
    }
    
    .theme-toggle {
        top: 15px;
        right: 15px;
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
}

/* Footer styles */
footer {
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
    color: var(--text-light);
    opacity: 0.8;
    font-size: 0.9rem;
}

.dark-mode footer {
    color: var(--text-dark);
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

footer a:hover {
    text-decoration: underline;
}

/* Image upload button */
#image-upload-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Loading indicator */
#loading-container {
    text-align: center;
    padding: 2rem 0;
}

/* Result container */
#result-container h4 {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.card, #result-container, #loading-container {
    animation: fadeIn 0.5s ease-out;
}