/* ========================================
   Ohm's Law Calculator - Custom Styles
   ======================================== */

/* ========================================
   CSS Custom Properties (Theme Variables)
   ======================================== */
:root {
    /* Light Theme Colors */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Accent Colors */
    --accent-primary: #3b82f6;
    --accent-primary-hover: #2563eb;
    --accent-success: #10b981;
    --accent-error: #ef4444;
    --accent-warning: #f59e0b;

    /* Input States */
    --input-bg: #f8fafc;
    --input-border: #cbd5e1;
    --input-focus: #3b82f6;
    --input-calculated: #dbeafe;
    --input-calculated-border: #93c5fd;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;
}

[data-theme="dark"] {
    /* Dark Theme Colors */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.4);

    /* Accent Colors (slightly adjusted for dark mode) */
    --accent-primary: #60a5fa;
    --accent-primary-hover: #3b82f6;
    --accent-success: #34d399;
    --accent-error: #f87171;
    --accent-warning: #fbbf24;

    /* Input States */
    --input-bg: #0f172a;
    --input-border: #475569;
    --input-focus: #60a5fa;
    --input-calculated: #1e3a5f;
    --input-calculated-border: #3b82f6;
}

/* ========================================
   Main Wrapper
   ======================================== */
.ohms-calculator-wrapper {
    max-width: 900px;
    margin: 2rem auto;
    padding: 1.5rem;
    background: var(--bg-primary);
    transition: background var(--transition-normal);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* ========================================
   Theme Toggle
   ======================================== */
.theme-toggle-container {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 1rem;
}

.theme-toggle-btn {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

.theme-toggle-btn:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
    border-color: var(--accent-primary);
}

.theme-toggle-btn:active {
    transform: scale(0.95);
}

.theme-toggle-btn svg {
    transition: opacity var(--transition-fast);
}

.theme-toggle-btn .hidden {
    display: none;
}

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

.calculator-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0 0 0.5rem 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.title-icon {
    color: var(--accent-primary);
    animation: rotate 20s linear infinite;
}

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

    to {
        transform: rotate(360deg);
    }
}

.calculator-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    margin: 0;
    line-height: 1.5;
}

/* ========================================
   Sample Values Section
   ======================================== */
.sample-values-section {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.sample-values-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin: 0 0 0.75rem 0;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

.sample-btn {
    background: var(--accent-primary);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.sample-btn:hover {
    background: var(--accent-primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.sample-btn:active {
    transform: translateY(0);
}

/* ========================================
   Calculator Card
   ======================================== */
.calculator-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
}

/* ========================================
   Input Fields Grid
   ======================================== */
.inputs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-label {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.25rem;
}

.label-icon {
    color: var(--accent-primary);
}

.input-wrapper {
    position: relative;
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.calc-input {
    flex: 1;
    padding: 1rem 1.25rem;
    font-size: 1.25rem;
    font-weight: 600;
    border: 3px solid var(--input-border);
    border-radius: 10px;
    background: var(--input-bg);
    color: var(--text-primary);
    transition: all var(--transition-fast);
    font-family: 'Courier New', monospace;
    min-height: 56px;
    box-shadow: var(--shadow-sm);
}

.calc-input:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-md);
}

.calc-input:focus {
    outline: none;
    border-color: var(--input-focus);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.2);
    transform: scale(1.02);
}

.calc-input.calculated {
    background: var(--input-calculated);
    border-color: var(--input-calculated-border);
    font-weight: 700;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.calc-input.error {
    border-color: var(--accent-error);
    animation: shake 0.3s ease;
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-5px);
    }

    75% {
        transform: translateX(5px);
    }
}

.unit-select {
    padding: 1rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    border: 2px solid var(--input-border);
    border-radius: 8px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
    min-width: 60px;
    max-width: 60px;
    text-align: center;
}

.unit-select:hover {
    border-color: var(--accent-primary);
    background: var(--input-bg);
}

.unit-select:focus {
    outline: none;
    border-color: var(--input-focus);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.copy-btn {
    padding: 1rem;
    background: transparent;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 56px;
    min-width: 56px;
}

.copy-btn:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.copy-btn:active {
    transform: scale(0.95);
}

.error-message {
    font-size: 0.75rem;
    color: var(--accent-error);
    min-height: 1rem;
    display: block;
}

/* ========================================
   Action Buttons
   ======================================== */
.action-buttons {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.reset-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.reset-btn:active {
    transform: translateY(0);
}

/* ========================================
   Formula Display
   ======================================== */
.formula-display {
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-primary-hover) 100%);
    border-radius: 12px;
    padding: 1.25rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-md);
}

.formula-text {
    margin: 0;
    color: white;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    font-family: 'Courier New', monospace;
}

/* ========================================
   Calculation History
   ======================================== */
.calculation-history {
    border-top: 2px solid var(--border-color);
    padding-top: 1.5rem;
}

.history-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0 0 1rem 0;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.history-empty {
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-align: center;
    padding: 1rem;
    margin: 0;
}

.history-item {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    color: var(--text-primary);
    font-family: 'Courier New', monospace;
    transition: all var(--transition-fast);
}

.history-item:hover {
    border-color: var(--accent-primary);
    transform: translateX(4px);
}

/* ========================================
   Toast Notification
   ======================================== */
.toast-notification {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--accent-success);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 500;
    opacity: 0;
    transform: translateY(100px);
    transition: all var(--transition-normal);
    pointer-events: none;
    z-index: 1000;
}

.toast-notification.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 768px) {
    .ohms-calculator-wrapper {
        padding: 1rem;
        margin: 1rem auto;
    }

    .calculator-card {
        padding: 1.5rem;
    }

    .calculator-title {
        font-size: 1.5rem;
    }

    .inputs-grid {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }

    .sample-buttons {
        flex-direction: column;
    }

    .sample-btn {
        width: 100%;
    }

    .toast-notification {
        bottom: 1rem;
        right: 1rem;
        left: 1rem;
    }
}

/* ========================================
   Print Styles
   ======================================== */
@media print {

    .theme-toggle-container,
    .sample-values-section,
    .action-buttons,
    .copy-btn,
    .toast-notification {
        display: none !important;
    }

    .calculator-card {
        box-shadow: none;
        border: 2px solid #000;
    }

    .calc-input {
        border: 1px solid #000;
    }
}

/* ========================================
   Accessibility Enhancements
   ======================================== */
.calc-input:focus-visible,
.unit-select:focus-visible,
.copy-btn:focus-visible,
.reset-btn:focus-visible,
.sample-btn:focus-visible,
.theme-toggle-btn:focus-visible {
    outline: 3px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}