/* CalcSolver - Main Styles */

/* CSS Variables */
:root {
    /* Colors - Light Theme */
    --bg-primary: #f5f5f7;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e8e8ed;
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --text-placeholder: #c7c7cc;
    --border-color: #d2d2d7;
    --shadow-color: rgba(0, 0, 0, 0.1);

    /* Button Colors */
    --btn-number-bg: #ffffff;
    --btn-number-hover: #f0f0f5;
    --btn-operator-bg: #ff9500;
    --btn-operator-hover: #e88900;
    --btn-function-bg: #a5a5a5;
    --btn-function-hover: #949494;
    --btn-equals-bg: #4cd964;
    --btn-equals-hover: #44c85c;
    --btn-clear-bg: #ff3b30;
    --btn-clear-hover: #e6352b;
    --btn-constant-bg: #5ac8fa;
    --btn-constant-hover: #4bb8e8;

    /* Display Colors */
    --display-bg: #1c1c1e;
    --display-text: #ffffff;
    --result-text: #30d158;
    --error-text: #ff453a;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 8px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #000000;
    --bg-secondary: #1c1c1e;
    --bg-tertiary: #2c2c2e;
    --text-primary: #ffffff;
    --text-secondary: #98989d;
    --text-placeholder: #48484a;
    --border-color: #3a3a3c;
    --shadow-color: rgba(0, 0, 0, 0.3);

    --btn-number-bg: #333336;
    --btn-number-hover: #444447;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navbar Styles */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 10px var(--shadow-color);
}

.navbar-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    height: 60px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -1px;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0;
}

.navbar-brand:hover {
    transform: scale(1.02);
}

.navbar-brand .brand-solver {
    background: linear-gradient(135deg, #ff9500, #ff6b00);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-xl) var(--spacing-lg);
}

/* Hero Section - Description Area */
.hero-section {
    width: 100%;
    max-width: 1200px;
    padding: var(--spacing-xl) var(--spacing-xl);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.hero-title {
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    letter-spacing: -1px;
}

.hero-description {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: var(--spacing-lg);
}

.hero-description .highlight {
    color: var(--btn-operator-bg);
    font-weight: 700;
}

.feature-tags {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.tag {
    font-size: 0.95rem;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.15) 100%);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    white-space: nowrap;
    font-weight: 500;
}

/* Calculator Container */
.calculator-container {
    width: 100%;
    max-width: 420px;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-xl);
    box-shadow: 0 10px 40px var(--shadow-color);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

/* Header - Removed (now using navbar) */

.icon-btn {
    background: var(--bg-tertiary);
    border: none;
    border-radius: var(--radius-md);
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    font-size: 1.1rem;
}

.icon-btn:hover {
    background: var(--btn-operator-bg);
    transform: scale(1.05);
}

.icon-btn .icon-moon {
    display: none;
}

[data-theme="dark"] .icon-btn .icon-sun {
    display: none;
}

[data-theme="dark"] .icon-btn .icon-moon {
    display: inline;
}

/* Display Area */
.display-area {
    background-color: var(--display-bg);
    padding: var(--spacing-lg);
    min-height: 140px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.expression-wrapper {
    margin-bottom: var(--spacing-sm);
}

.expression-display {
    font-size: 1.75rem;
    color: var(--display-text);
    min-height: 40px;
    word-wrap: break-word;
    word-break: break-all;
    outline: none;
    line-height: 1.4;
}

.expression-display .placeholder {
    color: var(--text-placeholder);
    font-style: italic;
}

.expression-display:focus {
    outline: none;
}

/* Syntax Highlighting Classes */
.expression-display .number {
    color: #ffffff;
}

.expression-display .operator {
    color: #ff9f43;
}

.expression-display .function {
    color: #5ac8fa;
}

.expression-display .constant {
    color: #a29bfe;
}

.expression-display .parenthesis {
    color: #dfe6e9;
}

.result-wrapper {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.equals-sign {
    font-size: 1.5rem;
    color: var(--text-secondary);
    font-weight: 300;
}

.result-display {
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--result-text);
    word-wrap: break-word;
    word-break: break-all;
    transition: color var(--transition-fast);
}

.result-display.error {
    color: var(--error-text);
    font-size: 1rem;
    font-weight: 400;
}

.error-message {
    color: var(--error-text);
    font-size: 0.875rem;
    margin-top: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: rgba(255, 59, 48, 0.1);
    border-radius: var(--radius-sm);
}

.error-message.hidden {
    display: none;
}

/* Mode Toggle */
.mode-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
}

.mode-btn {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.mode-btn:hover {
    background: var(--bg-secondary);
}

.mode-btn.active {
    background: var(--bg-secondary);
    color: var(--text-primary);
    box-shadow: 0 2px 8px var(--shadow-color);
}

.angle-toggle {
    display: flex;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 2px;
}

.angle-btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.angle-btn.active {
    background: var(--btn-operator-bg);
    color: white;
}

/* Button Panel */
.button-panel {
    padding: var(--spacing-md);
}

.button-panel.hidden {
    display: none;
}

.button-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-sm);
}

.scientific-grid {
    grid-template-columns: repeat(4, 1fr);
}

/* History Panel */
.history-panel {
    display: none;
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-tertiary);
    position: sticky;
    top: 0;
}

.history-header h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.text-btn {
    background: none;
    border: none;
    color: var(--btn-operator-bg);
    font-size: 0.75rem;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.text-btn:hover {
    text-decoration: underline;
}

.history-list {
    padding: var(--spacing-sm);
}

.empty-history {
    text-align: center;
    color: var(--text-placeholder);
    font-size: 0.875rem;
    padding: var(--spacing-lg);
}

.history-item {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.history-item:hover {
    background-color: var(--bg-tertiary);
}

.history-expression {
    font-size: 0.9rem;
    color: var(--text-primary);
    word-break: break-all;
}

.history-result {
    font-size: 1rem;
    font-weight: 600;
    color: var(--btn-operator-bg);
}

.history-time {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 2px;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--text-secondary);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-primary);
}

/* Calculator Info Section */
.calculator-info-section {
    width: 80%;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
}

.info-block {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.info-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--btn-operator-bg);
    display: inline-block;
}

.info-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.feature-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.feature-item {
    font-size: 0.8rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: linear-gradient(135deg, rgba(255, 149, 0, 0.15) 0%, rgba(255, 107, 0, 0.15) 100%);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-weight: 500;
}

.audience-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.audience-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.audience-icon {
    font-size: 1.2rem;
}

/* Usage Guide Section */
.usage-guide-section {
    width: 80%;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
}

.usage-guide-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.usage-guide-list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
}

.usage-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    text-decoration: none;
    transition: all var(--transition-normal);
    cursor: pointer;
}

.usage-item:hover {
    border-color: var(--btn-operator-bg);
    box-shadow: 0 4px 12px var(--shadow-color);
    transform: translateY(-2px);
}

.usage-icon {
    font-size: 1.5rem;
    min-width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(255, 149, 0, 0.15) 0%, rgba(255, 107, 0, 0.15) 100%);
    border-radius: var(--radius-md);
}

.usage-content {
    flex: 1;
    min-width: 0;
}

.usage-name {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.usage-desc {
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.usage-arrow {
    font-size: 1.2rem;
    color: var(--btn-operator-bg);
    opacity: 0;
    transform: translateX(-8px);
    transition: all var(--transition-fast);
}

.usage-item:hover .usage-arrow {
    opacity: 1;
    transform: translateX(0);
}