/* ============================================================
   Advanced Electronics Calculator - Styles
   ============================================================ */

/* ---------- CSS Variables / Theming ---------- */
:root {
    --bg-primary: #0d0d1a;
    --bg-secondary: #1a1a2e;
    --bg-card: rgba(30, 30, 60, 0.7);
    --text-primary: #e0e0ff;
    --text-secondary: #8888aa;
    --accent: #00e5ff;
    --accent-glow: rgba(0, 229, 255, 0.4);
    --accent2: #ff4081;
    --accent2-glow: rgba(255, 64, 129, 0.4);
    --btn-bg: rgba(255, 255, 255, 0.06);
    --btn-hover: rgba(255, 255, 255, 0.12);
    --btn-active: rgba(0, 229, 255, 0.15);
    --border: rgba(255, 255, 255, 0.08);
    --glass: rgba(255, 255, 255, 0.04);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --radius: 16px;
    --radius-sm: 10px;
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light theme overrides */
body.light-theme {
    --bg-primary: #f0f2f5;
    --bg-secondary: #ffffff;
    --bg-card: rgba(255, 255, 255, 0.85);
    --text-primary: #1a1a2e;
    --text-secondary: #666688;
    --accent: #0077cc;
    --accent-glow: rgba(0, 119, 204, 0.3);
    --accent2: #d81b60;
    --accent2-glow: rgba(216, 27, 96, 0.3);
    --btn-bg: rgba(0, 0, 0, 0.05);
    --btn-hover: rgba(0, 0, 0, 0.1);
    --btn-active: rgba(0, 119, 204, 0.12);
    --border: rgba(0, 0, 0, 0.1);
    --glass: rgba(255, 255, 255, 0.6);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    padding-bottom: 80px;
    transition: background var(--transition), color var(--transition);
    overflow-x: hidden;
}

/* ---------- Theme Toggle ---------- */
.theme-toggle {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 1000;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--border);
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    transition: all var(--transition);
    box-shadow: var(--shadow);
}

.theme-toggle:hover {
    transform: rotate(30deg) scale(1.1);
    border-color: var(--accent);
}

.dark-theme .icon-sun { display: inline; }
.dark-theme .icon-moon { display: none; }
.light-theme .icon-sun { display: none; }
.light-theme .icon-moon { display: inline; }

/* ---------- Calculator Container ---------- */
.calculator-container {
    width: 100%;
    max-width: 440px;
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px;
    animation: fadeSlideIn 0.6s ease-out;
}

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

.title {
    text-align: center;
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ---------- Mode Tabs ---------- */
.mode-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 14px;
    background: var(--btn-bg);
    border-radius: var(--radius-sm);
    padding: 4px;
}

.tab {
    flex: 1;
    padding: 10px 6px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.tab:hover {
    color: var(--text-primary);
    background: var(--btn-hover);
}

.tab.active {
    color: var(--accent);
    background: var(--btn-active);
    box-shadow: 0 0 12px var(--accent-glow);
}

/* ---------- Display ---------- */
.display-wrapper {
    margin-bottom: 14px;
}

.display {
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 16px 18px;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: flex-end;
    overflow: hidden;
}

.light-theme .display {
    background: rgba(0, 0, 0, 0.04);
}

.expression {
    font-size: 0.9rem;
    color: var(--text-secondary);
    min-height: 1.2em;
    word-break: break-all;
    text-align: right;
    transition: all var(--transition);
}

.result {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--text-primary);
    word-break: break-all;
    text-align: right;
    transition: all 0.3s ease;
}

.result.animate {
    animation: resultPop 0.3s ease;
}

@keyframes resultPop {
    0% { transform: scale(0.95); opacity: 0.6; }
    50% { transform: scale(1.03); }
    100% { transform: scale(1); opacity: 1; }
}

/* ---------- Error Alert ---------- */
.error-alert {
    background: rgba(255, 64, 129, 0.15);
    border: 1px solid var(--accent2);
    color: var(--accent2);
    border-radius: 8px;
    padding: 10px 14px;
    margin-bottom: 10px;
    font-size: 0.85rem;
    font-weight: 500;
    display: none;
    animation: shakeIn 0.4s ease;
}

.error-alert.show {
    display: block;
}

@keyframes shakeIn {
    0% { transform: translateX(-10px); opacity: 0; }
    25% { transform: translateX(8px); }
    50% { transform: translateX(-5px); }
    75% { transform: translateX(3px); }
    100% { transform: translateX(0); opacity: 1; }
}

/* ---------- Mode Panels ---------- */
.mode-panel {
    display: none;
    animation: panelFade 0.35s ease;
}

.mode-panel.active {
    display: block;
}

@keyframes panelFade {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ---------- Button Grid (Standard) ---------- */
.btn-grid {
    display: grid;
    gap: 8px;
}

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

.standard-grid .zero {
    grid-column: span 2;
}

.standard-grid .equals {
    grid-column: span 1;
}

/* ---------- Button Grid (Scientific) ---------- */
.scientific-grid {
    grid-template-columns: repeat(5, 1fr);
}

.sci-eq {
    grid-column: span 2;
}

/* ---------- Buttons ---------- */
.btn {
    padding: 16px 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--btn-bg);
    color: var(--text-primary);
    font-size: 1.05rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.btn:hover {
    background: var(--btn-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.btn:active {
    transform: translateY(0) scale(0.97);
}

.btn.op {
    color: var(--accent);
    font-size: 1.2rem;
}

.btn.func {
    color: var(--accent2);
}

.btn.equals {
    background: linear-gradient(135deg, var(--accent), #00b8d4);
    color: #fff;
    font-size: 1.3rem;
    border: none;
}

.btn.equals:hover {
    box-shadow: 0 4px 20px var(--accent-glow);
}

.btn.sci {
    font-size: 0.82rem;
    padding: 12px 6px;
    color: var(--accent);
}

/* Ripple effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: scale(0);
    animation: rippleAnim 0.6s ease-out;
    pointer-events: none;
}

@keyframes rippleAnim {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

/* ---------- Electronics Sub-tabs ---------- */
.sub-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    margin-bottom: 14px;
}

.sub-tab {
    flex: 1 1 auto;
    min-width: 70px;
    padding: 8px 10px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--btn-bg);
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
}

.sub-tab:hover {
    color: var(--text-primary);
    background: var(--btn-hover);
}

.sub-tab.active {
    color: var(--accent);
    background: var(--btn-active);
    border-color: var(--accent);
}

/* ---------- Electronics Panels ---------- */
.elec-panel {
    display: none;
    animation: panelFade 0.3s ease;
}

.elec-panel.active {
    display: block;
}

.elec-panel h3 {
    font-size: 0.95rem;
    margin-bottom: 14px;
    color: var(--accent);
}

.input-group {
    margin-bottom: 10px;
}

.input-group label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
    font-weight: 500;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--btn-bg);
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: all var(--transition);
    outline: none;
}

.input-group input:focus,
.input-group select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-group input::placeholder {
    color: var(--text-secondary);
    opacity: 0.6;
}

.calc-btn {
    width: 100%;
    margin-top: 10px;
    padding: 12px;
    background: linear-gradient(135deg, var(--accent), #00b8d4) !important;
    color: #fff !important;
    font-size: 1rem;
    border: none !important;
}

.calc-btn:hover {
    box-shadow: 0 4px 20px var(--accent-glow);
}

.elec-result {
    margin-top: 12px;
    padding: 12px 14px;
    background: rgba(0, 229, 255, 0.06);
    border: 1px solid rgba(0, 229, 255, 0.15);
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-primary);
    min-height: 20px;
    line-height: 1.6;
    transition: all var(--transition);
}

.elec-result.animate {
    animation: resultPop 0.3s ease;
}

/* ---------- Resistor Visual (Realistic) ---------- */
.resistor-visual {
    display: flex;
    justify-content: center;
    margin: 16px 0;
}

.resistor-body {
    display: flex;
    align-items: center;
    background: linear-gradient(180deg, #d4b896 0%, #c4a882 40%, #a68b6a 100%);
    border-radius: 25px;
    padding: 10px 8px;
    position: relative;
    height: 45px;
    min-width: 200px;
    box-shadow: 
        inset 0 2px 4px rgba(255,255,255,0.3),
        inset 0 -2px 4px rgba(0,0,0,0.2),
        0 4px 8px rgba(0,0,0,0.3);
}

.resistor-body::before,
.resistor-body::after {
    content: '';
    position: absolute;
    width: 8px;
    height: 20px;
    background: linear-gradient(180deg, #999 0%, #666 50%, #999 100%);
    top: 50%;
    transform: translateY(-50%);
}

.resistor-body::before {
    left: -10px;
    border-radius: 3px 0 0 3px;
}

.resistor-body::after {
    right: -10px;
    border-radius: 0 3px 3px 0;
}

.resistor-body .band {
    width: 14px;
    height: 100%;
    border-radius: 3px;
    margin: 0 5px;
    transition: background var(--transition);
    box-shadow: 
        inset 0 2px 3px rgba(255,255,255,0.3),
        inset 0 -2px 3px rgba(0,0,0,0.2);
}

.resistor-body .band-gap {
    width: 22px;
}

/* 5-band resistor */
.resistor-5band {
    min-width: 230px;
}

.resistor-5band .band {
    width: 12px;
}

/* 6-band resistor */
.resistor-6band {
    min-width: 260px;
}

.resistor-6band .band {
    width: 10px;
}

.resistor-body .wire {
    width: 30px;
    height: 3px;
    background: #888;
}

.left-wire { margin-right: 4px; }
.right-wire { margin-left: 4px; }

/* ---------- Responsive ---------- */
@media (max-width: 480px) {
    body {
        padding: 10px;
        padding-bottom: 90px;
    }

    .calculator-container {
        padding: 12px;
        border-radius: 12px;
    }

    .title {
        font-size: 1.1rem;
    }

    .result {
        font-size: 1.6rem;
        min-height: 45px;
    }

    .expression {
        font-size: 0.8rem;
    }

    .sub-tabs {
        gap: 3px;
    }

    .sub-tab {
        font-size: 0.65rem;
        padding: 6px 4px;
        min-width: 50px;
    }

    .input-group {
        margin-bottom: 8px;
    }

    .input-group label {
        font-size: 0.75rem;
    }

    .input-group input,
    .input-group select {
        padding: 8px 10px;
        font-size: 0.85rem;
    }

    .resistor-body {
        height: 35px;
        min-width: 160px;
    }

    .resistor-body .band {
        width: 10px;
        margin: 0 3px;
    }

    .resistor-body .band-gap {
        width: 14px;
    }

    .resistor-5band {
        min-width: 180px;
    }

    .resistor-5band .band {
        width: 9px;
    }

    .resistor-6band {
        min-width: 200px;
    }

    .resistor-6band .band {
        width: 8px;
    }

    .footer {
        padding: 10px;
        font-size: 0.7rem;
    }

    .footer .fb-icon {
        width: 12px;
        height: 12px;
    }
}

/* Extra small devices */
@media (max-width: 360px) {
    body {
        padding: 8px;
        padding-bottom: 85px;
    }

    .calculator-container {
        padding: 10px;
    }

    .title {
        font-size: 1rem;
    }

    .result {
        font-size: 1.4rem;
    }

    .sub-tab {
        font-size: 0.6rem;
        padding: 5px 3px;
        min-width: 42px;
    }

    .resistor-body {
        height: 30px;
        min-width: 140px;
    }

    .resistor-body .band {
        width: 8px;
        margin: 0 2px;
    }

    .footer {
        font-size: 0.65rem;
    }
}

/* Large screens */
@media (min-width: 768px) {
    .calculator-container {
        max-width: 500px;
    }

    .title {
        font-size: 1.4rem;
    }
}

/* Ultra large screens */
@media (min-width: 1200px) {
    .calculator-container {
        max-width: 550px;
    }

    .title {
        font-size: 1.5rem;
    }

    .result {
        font-size: 2rem;
    }
}

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

::-webkit-scrollbar-track {
    background: transparent;
}

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

/* ---------- Footer ---------- */
.footer {
    text-align: center;
    margin-top: auto;
    padding: 14px;
    color: var(--text-secondary);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    width: 100%;
    max-width: 440px;
    border-radius: var(--radius);
    margin-bottom: 10px;
}

.footer a {
    color: var(--accent);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: all var(--transition);
}

.footer a:hover {
    color: var(--accent2);
    text-decoration: underline;
}

.footer .fb-icon {
    width: 14px;
    height: 14px;
}