/* Global box-sizing */
.speed-calc-container,
.speed-calc-container *,
.speed-calc-container *::before,
.speed-calc-container *::after {
    box-sizing: border-box;
}

/* 🌞 라이트 모드 CSS 변수 (기본) */
.speed-calc-container {
    /* Background colors */
    --bg-primary: #f5f5f0;
    --bg-secondary: #fff;
    --bg-section: #fff;
    
    /* Borders */
    --border-color: #333;
    
    /* Text colors */
    --text-primary: #222;
    --text-secondary: #555;
    --text-light: #666;
    
    /* Brand colors */
    --color-accent: #3498db;
    --color-success: #27ae60;
    --color-warning: #f39c12;
    --color-danger: #e74c3c;
    --color-purple: #9b59b6;
    --color-teal: #1abc9c;
    
    /* Shadows (neobrutalism) */
    --shadow-sm: 2px 2px 0 rgba(0,0,0,0.1);
    --shadow-md: 4px 4px 0 rgba(0,0,0,0.15);
    --shadow-lg: 8px 8px 0 rgba(0,0,0,0.15);
    
    /* Input focus */
    --input-focus-bg: #fffacd;
    
    /* Header title */
    --title-color: #2c3e50;
    --title-shadow: 2px 2px 0 rgba(255,255,255,0.5);
    
    /* Button hover background */
    --btn-hover-overlay: rgba(0,0,0,0.1);
    
    /* Result box backgrounds */
    --result-speed-bg: #ebf5fb;
    --result-distance-bg: #eafaf1;
    --result-time-bg: #fef5e7;
    
    /* Info box background */
    --info-bg: #f9f9f9;
    --footer-bg: #f0f0f0;
    --footer-border: #999;
}

/* 🌙 수동 다크 모드 */
.speed-calc-container.dark {
    /* Background colors */
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-section: #2d2d2d;
    
    /* Borders */
    --border-color: #e0e0e0;
    
    /* Text colors */
    --text-primary: #e8e8e8;
    --text-secondary: #b0b0b0;
    --text-light: #909090;
    
    /* Brand colors */
    --color-accent: #5dade2;
    --color-success: #52c77a;
    --color-warning: #f5b041;
    --color-danger: #ec7063;
    --color-purple: #af7ac5;
    --color-teal: #48d1cc;
    
    /* Shadows */
    --shadow-sm: 2px 2px 0 rgba(255,255,255,0.08);
    --shadow-md: 4px 4px 0 rgba(255,255,255,0.12);
    --shadow-lg: 8px 8px 0 rgba(255,255,255,0.12);
    
    /* Input focus */
    --input-focus-bg: #3a3a3a;
    
    /* Header title */
    --title-color: #7fb3d5;
    --title-shadow: 2px 2px 0 rgba(0,0,0,0.5);
    
    /* Button hover background */
    --btn-hover-overlay: rgba(255,255,255,0.1);
    
    /* Result box backgrounds */
    --result-speed-bg: #1e3a5f;
    --result-distance-bg: #1e4d2f;
    --result-time-bg: #5f3e1e;
    
    /* Info box background */
    --info-bg: #242424;
    --footer-bg: #242424;
    --footer-border: #555;
}

/* 🌙 시스템 다크모드 자동 감지 */
@media (prefers-color-scheme: dark) {
    .speed-calc-container:not(.dark):not(.light) {
        /* Background colors */
        --bg-primary: #1a1a1a;
        --bg-secondary: #2d2d2d;
        --bg-section: #2d2d2d;
        
        /* Borders */
        --border-color: #e0e0e0;
        
        /* Text colors */
        --text-primary: #e8e8e8;
        --text-secondary: #b0b0b0;
        --text-light: #909090;
        
        /* Brand colors */
        --color-accent: #5dade2;
        --color-success: #52c77a;
        --color-warning: #f5b041;
        --color-danger: #ec7063;
        --color-purple: #af7ac5;
        --color-teal: #48d1cc;
        
        /* Shadows */
        --shadow-sm: 2px 2px 0 rgba(255,255,255,0.08);
        --shadow-md: 4px 4px 0 rgba(255,255,255,0.12);
        --shadow-lg: 8px 8px 0 rgba(255,255,255,0.12);
        
        /* Input focus */
        --input-focus-bg: #3a3a3a;
        
        /* Header title */
        --title-color: #7fb3d5;
        --title-shadow: 2px 2px 0 rgba(0,0,0,0.5);
        
        /* Button hover background */
        --btn-hover-overlay: rgba(255,255,255,0.1);
        
        /* Result box backgrounds */
        --result-speed-bg: #1e3a5f;
        --result-distance-bg: #1e4d2f;
        --result-time-bg: #5f3e1e;
        
        /* Info box background */
        --info-bg: #242424;
        --footer-bg: #242424;
        --footer-border: #555;
    }
}

/* Dark mode toggle button */
.dark-mode-toggle {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 6px 10px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow-sm);
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    z-index: 10;
    border-radius: 4px;
}

.dark-mode-toggle:hover {
    transform: translate(0.5px, 0.5px);
    box-shadow: 1px 1px 0 rgba(0,0,0,0.15);
}

.dark-mode-toggle:active {
    transform: translate(2px, 2px);
    box-shadow: none;
}

.theme-icon {
    display: inline-block;
    line-height: 1;
}

/* Main container */
.speed-calc-container {
    position: relative;
    all: initial;
    display: block;
    max-width: 1180px;
    margin: 20px auto;
    padding: 20px;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    color: var(--text-primary);
    box-shadow: var(--shadow-lg);
    box-sizing: border-box;
    border-radius: 8px;
}

.speed-calc-container * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* Header */
.speed-calc-header {
    text-align: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 3px double var(--border-color);
}

.speed-calc-title {
    display: block;
    margin: 0 0 8px 0;
    padding: 0;
    font-size: 28px;
    font-weight: 700;
    color: var(--title-color);
    line-height: 1.3;
    text-shadow: var(--title-shadow);
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

.speed-calc-subtitle {
    display: block;
    margin: 0;
    padding: 0;
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.4;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

/* Grid layout */
.speed-calc-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    margin-bottom: 20px;
}

/* Cards */
.speed-calc-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 15px;
    box-shadow: var(--shadow-md);
    border-radius: 6px;
}

.speed-calc-card-title {
    display: block;
    margin: 0 0 15px 0;
    padding: 0 0 8px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

.speed-card .speed-calc-card-title {
    color: var(--color-accent);
}

.distance-card .speed-calc-card-title {
    color: var(--color-success);
}

.time-card .speed-calc-card-title {
    color: var(--color-warning);
}

/* Input fields */
.speed-calc-field {
    margin-bottom: 12px;
}

.speed-calc-label {
    display: block;
    margin-bottom: 5px;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    line-height: 1.3;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

/* Input & Select base styles */
.speed-calc-input,
.speed-calc-select {
    display: block;
    width: 100%;
    height: 36px;
    padding: 8px 10px;
    margin: 0;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--bg-secondary);
    background-color: var(--bg-secondary);
    font-size: 14px;
    font-weight: 600;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    color: var(--text-primary);
    line-height: 1.3;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    outline: none;
    box-shadow: none;
    transition: all 0.2s;
}

.speed-calc-input:focus,
.speed-calc-select:focus {
    background: var(--input-focus-bg);
    background-color: var(--input-focus-bg);
    border-color: var(--color-warning);
    outline: none;
    box-shadow: none;
}

.speed-calc-input::placeholder {
    color: var(--text-light);
    opacity: 0.6;
}

/* Select arrow - dark mode compatible */
.speed-calc-select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23666' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 8px center;
    background-size: 12px;
    padding-right: 30px;
    cursor: pointer;
}

.speed-calc-container.dark .speed-calc-select,
@media (prefers-color-scheme: dark) {
    .speed-calc-container:not(.light) .speed-calc-select {
        background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23b0b0b0' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    }
}

.speed-calc-select-full {
    width: 100%;
}

/* Input Row */
.speed-calc-input-row {
    display: flex;
    gap: 8px;
}

.speed-calc-input-row .speed-calc-input {
    flex: 1;
    min-width: 0;
}

.speed-calc-input-row .speed-calc-select {
    flex: 0 0 90px;
    width: 90px;
}

/* Time Row */
.speed-calc-time-row {
    display: flex;
    gap: 6px;
}

.speed-calc-time-item {
    flex: 1;
    min-width: 0;
}

.speed-calc-time-item .speed-calc-input {
    text-align: center;
    margin-bottom: 3px;
}

.speed-calc-unit-text {
    display: block;
    text-align: center;
    font-size: 11px;
    color: var(--color-warning);
    font-weight: 600;
    line-height: 1.2;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

/* Result boxes */
.speed-calc-result {
    margin-top: 15px;
    padding: 12px;
    border: 2px solid var(--border-color);
    background: var(--bg-section);
    text-align: center;
    border-radius: 4px;
}

.speed-result-box {
    background: var(--result-speed-bg);
    border-color: var(--color-accent);
}

.distance-result-box {
    background: var(--result-distance-bg);
    border-color: var(--color-success);
}

.time-result-box {
    background: var(--result-time-bg);
    border-color: var(--color-warning);
}

.speed-calc-result-label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
    line-height: 1.3;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

.speed-calc-result-value {
    display: block;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

.speed-result-box .speed-calc-result-value {
    color: var(--color-accent);
}

.distance-result-box .speed-calc-result-value {
    color: var(--color-success);
}

.time-result-box .speed-calc-result-value {
    color: var(--color-warning);
}

/* Info grid */
.speed-calc-info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 20px;
}

.speed-calc-info-box {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 15px;
    box-shadow: var(--shadow-md);
    border-radius: 6px;
}

.speed-calc-info-title {
    display: block;
    margin: 0 0 12px 0;
    padding: 0;
    font-size: 15px;
    font-weight: 700;
    color: var(--title-color);
    line-height: 1.3;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

.speed-calc-list {
    margin: 0;
    padding: 0 0 0 20px;
    list-style: disc;
}

.speed-calc-list li {
    margin-bottom: 6px;
    font-size: 13px;
    line-height: 1.5;
    color: var(--text-secondary);
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

.speed-calc-example {
    margin-bottom: 10px;
    padding: 10px;
    background: var(--info-bg);
    border-left: 3px solid var(--color-warning);
    font-size: 13px;
    line-height: 1.5;
    color: var(--text-secondary);
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    border-radius: 2px;
}

.speed-calc-example:last-child {
    margin-bottom: 0;
}

.speed-calc-example strong {
    color: var(--color-warning);
    font-weight: 700;
}

/* Footer */
.speed-calc-footer {
    padding: 12px;
    background: var(--footer-bg);
    border: 2px dashed var(--footer-border);
    text-align: center;
    border-radius: 4px;
}

.speed-calc-footer p {
    display: block;
    margin: 0;
    padding: 0;
    font-size: 12px;
    color: var(--text-light);
    line-height: 1.4;
    font-family: 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

/* Responsive */
@media (max-width: 1024px) {
    .speed-calc-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .time-card {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    .speed-calc-container {
        padding: 15px;
        margin: 10px;
    }
    
    .speed-calc-title {
        font-size: 24px;
    }
    
    .speed-calc-grid {
        grid-template-columns: 1fr;
    }
    
    .speed-calc-info-grid {
        grid-template-columns: 1fr;
    }
    
    .dark-mode-toggle {
        top: 8px;
        right: 8px;
        padding: 5px 8px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .speed-calc-container {
        padding: 12px;
        margin: 8px;
    }
    
    .speed-calc-time-row {
        gap: 4px;
    }
    
    .speed-calc-input,
    .speed-calc-select {
        font-size: 13px;
        padding: 6px 8px;
        height: 32px;
    }
    
    .speed-calc-result-value {
        font-size: 18px;
    }
    
    .dark-mode-toggle {
        padding: 4px 7px;
        font-size: 15px;
    }
}