body {
    font-family: 'Poppins', sans-serif;
    display: flex;
    justify-content: center;
    align-items: flex-start; 
    width: 100vw;
    min-height: 100vh;
    padding: 30px 0; 
    margin: 0;
    background-color: #0a0a0a;
    color: #f0f0f0;
    line-height: 1.6;
}

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

.timer-container {
    background: rgba(18, 18, 18, 0.95);
    padding: 2rem; 
    border-radius: 1.5rem; 
    box-shadow: 0 0 20px rgba(255, 215, 0, 0.2), 
                0 0 5px rgba(255, 215, 0, 0.1),  
                inset 0 0 10px rgba(255, 215, 0, 0.05); 
    border: none;
    text-align: center;
    width: 90%;
    max-width: 420px; 
    transition: transform 0.3s ease-in-out; 
    box-sizing: border-box; 
}

h1 {
    color: #ffd700;
    margin-top: 0;
    font-size: 1.8rem; 
    font-weight: 700; 
    text-shadow: 0 0 7px rgba(255, 215, 0, 0.6); 
}

#time-display {
    font-family: 'Roboto Mono', monospace;
    font-size: 4.5rem; 
    margin-bottom: 1.5rem; 
    font-weight: 700; 
    letter-spacing: 2px;
    color: #ffd700; 
    background-color: #0d0d0d; 
    padding: 0.5rem 1rem;
    border-radius: 0.5rem; 
    text-shadow: 0 0 5px rgba(255, 215, 0, 0.4); 
    display: inline-block; 
}

.note-container {
    margin-bottom: 1rem; 
    text-align: left;
}

.note-container label {
    font-weight: 500;
    margin-bottom: 0.3rem; 
    color: #bdbdbd; 
    font-size: 0.9rem;
}

#session-note {
    width: calc(100% - 18px); 
    padding: 0.6rem 0.8rem; 
    border: 1px solid #424242; 
    border-radius: 0.4rem;
    font-size: 0.9rem;
    background-color: #212121; 
    color: #f0f0f0;
    box-shadow: inset 0 0 5px rgba(255, 215, 0, 0.1); 
}

#session-note:focus {
    outline: none;
    border-color: #ffd700;
    box-shadow: 0 0 0 3px rgba(255, 215, 0, 0.5), inset 0 0 5px rgba(255, 215, 0, 0.2); 
}

.controls {
    display: flex;
    justify-content: center; 
    gap: 0.5rem; 
    margin-bottom: 0.8rem; 
}

.control-btn {
    padding: 0.7rem 1.2rem; 
    font-size: 0.9rem; 
    font-weight: 600; 
    border-radius: 0.5rem; 
    text-transform: none; 
    letter-spacing: 0;
    flex-grow: 1; 
    max-width: 120px; 
    color: #212121; 
}

#start-btn { background-color: #2ecc71; }
#stop-btn { background-color: #ffd700; }
#reset-btn { background-color: #9e9e9e; }

.control-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.4);
    opacity: 0.9;
}

.control-btn:disabled {
    background-color: #424242;
    color: #757575;
}

.logged-sessions-container {
    margin-top: 1rem; 
    padding-top: 1.5rem; 
    border-top: 1px solid #424242; 
    text-align: center; 
}

.logged-sessions-container h2 {
    font-size: 1.4rem; 
    color: #f0f0f0; 
    margin-bottom: 1rem; 
    padding-bottom: 0.2rem;
    border-bottom: 2px solid #ffd700;
    display: inline-block; 
}

#daily-summary-container {
    padding: 1rem; 
    margin-bottom: 1rem; 
    background-color: #1a1a1a; 
    border-radius: 0.75rem;
    border: 1px solid rgba(255, 215, 0, 0.1); 
    box-shadow: inset 0 0 8px rgba(255, 215, 0, 0.15), 0 5px 10px rgba(0, 0, 0, 0.6); 
    text-align: center;
}

#daily-summary-container h3 {
    color: #f0f0f0;
    margin: 0 0 0.5rem;
    font-size: 1.1rem; 
}

#daily-total-time {
    color: #ffd700;
    font-size: 1.3rem; 
    margin-bottom: 0.5rem;
    text-shadow: 0 0 3px rgba(255, 215, 0, 0.3);
}

#daily-qr-code {
    width: 110px; 
    height: 110px;
    padding: 10px; 
    margin: 0.5rem auto; 
    border: 1px solid #ffd700; 
    background-color: #ffffff; 
    border-radius: 5px; 
    display: flex;
    justify-content: center;
    align-items: center;
}

.daily-scan-text {
    font-size: 0.8rem; 
    color: #bdbdbd;
    margin-top: 0.5rem;
    margin-bottom: 0.8rem;
}

.download-btn { 
    background-color: #ffd700 !important;
    color: #212121; 
    font-weight: 700;
    max-width: none; 
}

.download-btn:hover:not(:disabled) {
    background-color: #ffc107 !important;
}

#sessions-list {
    margin-top: 1rem; 
}

.session-item {
    border: 1px solid #333333; 
    border-radius: 0.5rem;
    padding: 0.8rem; 
    margin-bottom: 0.7rem; 
    background-color: #212121; 
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.6); 
}

.session-header {
    display: flex; 
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.3rem; 
}

.delete-btn {
    background-color: #e74c3c; 
    padding: 0.4rem 0.7rem; 
    font-size: 0.75rem;
    border-radius: 0.3rem;
    font-weight: 500;
}

.session-duration {
    margin: 0;
}

.session-duration strong {
    color: #ffd700;
    font-size: 1.1em;
    text-shadow: 0 0 3px rgba(255, 215, 0, 0.3);
}

.session-note {
    border-left: 3px solid #ffd700;
    background-color: #2a2a2a;
    color: #f0f0f0;
    padding: 0.5rem 0.8rem;
    font-size: 0.85rem;
    margin-top: 0.5rem;
    border-radius: 0 0.4rem 0.4rem 0; 
}

.session-divider {
    border-top: 1px dashed #424242; 
    margin: 1rem 0 0;
}

@media (max-width: 600px) {
    .timer-container {
        padding: 1.2rem;
        max-width: 95%;
    }
    #time-display {
        font-size: 3rem;
    }
    .controls {
        flex-direction: column; 
        gap: 0.4rem;
    }
    .control-btn {
        width: 100%;
        max-width: none;
    }
}

#toggle-log-btn {
    background-color: #212121;
    color: #ffd700;
    border: 1px solid rgba(255, 215, 0, 0.3);
    margin: 0.5rem auto 1.5rem;
    width: 100%;
    max-width: none;
    display: block;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.5);
    font-weight: 600;
}

#toggle-log-btn:hover {
    background-color: #333333;
    color: #ffc107;
}

#sessions-list {
    display: none;
}

.sessions-list-visible {
    display: block !important;
}